Recovery Plan 

for 

Southern Resident Killer Whales (Orcinus orca) 

Prepared by 

National Marine Fisheries Service 

Northwest Regional Office 

 

_____________________________________________________________________________________

January i NMFS 

DISCLAIMER 

Recovery plans delineate such reasonable actions as may be necessary, based upon the best 

scientific and commercial data available, for the conservation and survival of listed species. 

Plans are published by the National Marine Fisheries Service (NMFS), sometimes prepared with 

the assistance of recovery teams, contractors, State agencies and others. Recovery plans do not 

necessarily represent the views, official positions or approval of any individuals or agencies 

involved in the plan formulation, other than NMFS. They represent the official position of 

NMFS only after they have been signed by the Assistant Administrator. Recovery plans are 

guidance and planning documents only; identification of an action to be implemented by any 

public or private party does not create a legal obligation beyond existing legal requirements. 

Nothing in this plan should be construed as a commitment or requirement that any Federal 

agency obligate or pay funds in any one fiscal year in excess of appropriations made by Congress 

for that fiscal year in contravention of the Anti-Deficiency Act, 31 U.S.C. 1341, or any other law 

or regulation. Approved recovery plans are subject to modification as dictated by new findings, 

changes in species status, and the completion of recovery actions. 

The literature citation should read as follows: 

National Marine Fisheries Service. 2008. Recovery Plan for Southern Resident Killer Whales 

(Orcinus orca). National Marine Fisheries Service, Northwest Region, Seattle, 

Washington. 

Additional copies of this recovery plan may be obtained from: 

 National Marine Fisheries Service 

 Northwest Region 

 Protected Resources Division 

 7600 Sand Point Way NE 

 Seattle, WA 98115 

 

Or on the web at: http://www.nwr.noaa.gov 

or http://www.nmfs.noaa.gov/pr/recovery/plans.htm 
January 2008 ii NMFS 

ACKNOWLEDGEMENTS 

The principal author of this document was Lynne M. Barre (National Marine Fisheries Service) 

with significant contributions from Gary J. Wiles (Washington Department of Fish and Wildlife) 

as well as input from J. Brent Norberg (National Marine Fisheries Service) and J. Pete Schroeder 

(Marine Mammal Research Associates). The Background section is largely based on 

information appearing in the Washington State Status Report for the Killer Whale (Wiles 2004), 

with extensive material drawn from the status reviews prepared by the NMFS Biological Review 

Team (Krahn et al. 2002, 2004a). 

This final plan is the result of wide public participation in conservation planning meetings and 

technical workshops. We would like to thank all of the presenters and participants in the series 

of workshops held in 2003 and 2004 to identify management actions for consideration in the 

conservation plan. In addition valuable comments were provided during three comment periods 

on a draft and proposed conservation plan and the proposed recovery plan. NMFS appreciates 

the support of the Washington Congressional Delegation and thanks Senator Maria Cantwell for 

her assistance in bringing the community together to conserve killer whales. 

NMFS gratefully acknowledges the following people who provided updated information or 

reviewed sections of the plan: Ken Balcomb, Dave Ellifrit, Linda Jones, John Ford, Kari Koski, 

Craig Matkin, Sandie O’Neill, Marilyn Dahlheim, Rich Osborne, John Kerwin, Steve Jeffries, 

Pam Meacham, Joe Gaydos, John Dohrmann, David Bain, Christine Garrett, Brad Hanson, 

Jonathon Mintz, Kathy Heise, Mary Sternfeld, Stephanie Norman, Bruce Sanford, Andy 

Thomson, Patty Glick, Candice Emmons and Harriet Allen. Additional thanks go to all of the 

organizations and individuals who kindly offered thorough and thoughtful comments on the 

proposed plan and previous drafts. NMFS reviewers of the plan were: Joe Scordino, Donna 

Darm, Garth Griffin, Lisa VanAtta, Melanie Rowland, Tom Eagle, Laurie Allen, Roger Gentry, 

Brandon Southall, Donna Wieting, Susan Pultz, Naomi Lundberg, Doug DeMaster, Brad Hanson 

and Dawn Noren. The cover illustration and some figures appearing in this report were taken 

from Wiles (2004) and were prepared by Darrell Pruett of the Washington Department of 

Printing. 
January 2008 iii NMFS 

TABLE OF CONTENTS 

DISCLAIMER......................................................................................................................... i 

ACKNOWLEDGEMENTS.............................................................................................. ...........ii 

EXECUTIVE SUMMARY.........................................................................................................iv 

I. INTRODUCTION............................................................................................................................................... I-1 

II. BACKGROUND................................................................................................................................................II-1 

 A. TAXONOMY .............................................................................................................................................II-1 

 B. DESCRIPTION ..........................................................................................................................................II-2 

 C. DISTRIBUTION ........................................................................................................................................II-4 

 D. CLASSIFICATION OF KILLER WHALES IN THE NORTHEASTERN PACIFIC ..............................II-5 

 E. NATURAL HISTORY .............................................................................................................................II-10 

 Social Organization ..................................................................................................................................II-10 

 Vocalizations.............................................................................................................................................II-13 

 Hearing and Other Senses ........................................................................................................................II-15 

 Swimming and Diving Behaviour ............................................................................................................II-15 

 Diet and Foraging......................................................................................................................................II-16 

 Other Behavior ..........................................................................................................................................II-22 

 Movements and Dispersal .........................................................................................................................II-25 

 Habitat Use................................................................................................................................................II-34 

 Reproduction and Growth .........................................................................................................................II-39 

 Survival, Longevity, and Natural Mortality ..............................................................................................II-42 

 Human-Related Sources of Mortality and Live-Captures .........................................................................II-47 

 F. POPULATION STATUS .........................................................................................................................II-52 

 G. EXISTING PROTECTIVE MEASURES ................................................................................................II-67 

 H. POTENTIAL THREATS TO SOUTHERN RESIDENT KILLER WHALES ........................................II-71 

 Prey Availability .......................................................................................................................................II-75 

 Environmental Contaminants ...................................................................................................................II-87 

 Vessel Effects and Sound........................................................................................................................II-103 

 Oil Spills .................................................................................................................................................II-116 

 Alternative Energy Projects.....................................................................................................................II-119 

 Disease ....................................................................................................................................................II-120 

 Research .................................................................................................................................................II-121 

 Cumulative Effects..................................................................................................................................II-122 

III. RECOVERY STRATEGY.........................................................................................................................III-1 

IV. RECOVERY GOALS, OBJECTIVES AND CRITERIA ........................................................................ IV-1 

 Delisting Criteria....................................................................................................................................... IV-4 

 Downlisting Criteria.................................................................................................................................. IV-8 

V. RECOVERY PROGRAM...........................................................................................................................V-1 

 Recovery Action Outline.............................................................................................................................V-1 

 Recovery Action Narrative..........................................................................................................................V-7 

VI. IMPLEMENTATION SCHEDULE AND COSTS .................................................................................. VI-1 

VII. LITERATURE CITED.............................................................................................................................VII-1 

Appendix A. The current “Be Whale Wise” guidelines.................................................................A-1 

Appendix B. List of major sewage treatments plans and pulp and paper mills in the Puget Sound and Georgia 

Basin region...........................................................................................................B-1 

Appendix C. Past and present Superfund sites located in the greater Puget Sound region................................C-1 
January 2008 iv NMFS 

EXECUTIVE SUMMARY 

Current Species Status: The distinct population segment (DPS) of Southern Resident killer 

whales (Orcinus orca) was listed as endangered under the Endangered Species Act (ESA) on 

November 18, 2005 (70 FR 69903). Prior to the ESA listing the National Marine Fisheries 

Service (NMFS) determined that the Southern Resident stock was below its optimum sustainable 

population (OSP) and designated it as depleted under the Marine Mammal Protection Act 

(MMPA) in May 2003 (68 FR 31980). Southern Resident killer whales occur primarily in 

Washington State and British Columbia in the summer and fall and in coastal waters in the 

winter. Southern Residents use echolocation during foraging and feed primarily on salmonids. 

The whales exhibit advanced vocal communication and live in highly stable social groupings, or 

pods, led by matriarchal females. The Southern Resident distinct population segment (DPS) 

experienced an almost 20 percent decline from 1996 to 2001 and was petitioned for listing under 

the ESA in 2001, and was listed as endangered in 2005. Since 2001 the population has 

increased, with 87 whales in the Southern Resident DPS in 2007. The major threats identified in 

the listing were prey availability, pollution and contaminants, and effects from vessels and 

sound. In addition demographics, small population size, vulnerability to oil spills and other 

factors were considered. 

The Recovery Plan: The ESA requires the Secretary of Commerce to develop and implement 

recovery plans for the conservation and survival of endangered and threatened species. NMFS 

developed a proposed conservation plan under the MMPA which served as the foundation for the 

recovery plan. NMFS held a series of workshops in 2003-2004 to receive input from a variety of 

stakeholders on ideas for management actions to include in a conservation plan. A preliminary 

draft document was posted for public review in March 2005. Comments on the draft plan were 

incorporated into a proposed conservation plan which was released for further public comment in 

October 2005. NMFS incorporated comments, added ESA elements, and released a proposed 

recovery plan for public review in November 2006. We received comments and prepared a 

summary of the comments and provided information on our responses, including descriptions of 

the edits made to this Final Recovery Plan to incorporate suggestions. We also included new 

information, research results and references that have become available since the proposed 

recovery plan was released. The Final Recovery Plan reviews and assesses the potential factors 

affecting the Southern Residents and lays out a recovery program to address each of the threats. 

Recovery Strategy: There is considerable uncertainty regarding which threats may be 

responsible for the decline in the population or which is the most important to address for 

recovery. The plan lays out an adaptive management approach and a recovery strategy that 

addresses each of the potential threats based on the best available science. The recovery program 

outline links the management actions to an active research program to fill data gaps and a 

monitoring program to assess effectiveness. Feedback from research and monitoring will 

provide the information necessary to refine ongoing actions and develop and prioritize new 

actions. The recovery program in the plan includes actions to address the following topics: 

Prey Availability: Support salmon restoration efforts in the region including habitat, 

harvest and hatchery management considerations and continued use of existing NMFS 
January 2008 v NMFS 

authorities under the ESA and Magnuson-Stevens Fishery Conservation and Management 

Act to ensure an adequate prey base. 

Pollution/Contamination: Clean up existing contaminated sites, minimize continuing 

inputs of contaminants harmful to killer whales, and monitor emerging contaminants. 

Vessel Effects: Continue with evaluation and improvement of guidelines for vessel 

activity near Southern Resident killer whales and evaluate the need for regulations or 

protected areas. 

Oil Spills: Prevent oil spills and improve response preparation to minimize effects on 

Southern Residents and their habitat in the event of a spill. 

Acoustic Effects: Continue agency coordination and use of existing ESA and MMPA 

mechanisms to minimize potential impacts from anthropogenic sound. 

Education and Outreach: Enhance public awareness, educate the public on actions they 

can participate in to conserve killer whales and improve reporting of Southern Resident 

killer whale sightings and strandings. 

Response to Sick, Stranded, Injured Killer Whales: Improve responses to live and 

dead killer whales to implement rescues, conduct health assessments, and determine 

causes of death to learn more about threats and guide overall conservation efforts. 

Transboundary and Interagency Coordination: Coordinate monitoring, research, 

enforcement, and complementary recovery planning with Canadian agencies, and Federal 

and State partners. 

Research and Monitoring: Conduct research to facilitate and enhance conservation 

efforts. Continue the annual census to monitor trends in the population, identify 

individual animals, and track demographic parameters. 

Recovery Goals, Objectives, and Criteria: The goal of the plan is to restore the endangered 

Southern Residents to the point where they no longer require the protections of the ESA. 

Delisting: When the Southern Resident killer whales have sustained an average growth of 2.3 

percent per year for 28 years, population parameters are consistent with a healthy growing 

population, and threats have been addressed, they will no longer be in danger of extinction or 

likely to become endangered in the foreseeable future (for more specifics, see section IV, Goals, 

Objectives and Criteria). 

Downlisting: Interim downlisting criteria of average growth of 2.3 percent per year for 14 years 

and progress toward addressing threats represent sustained growth to indicate that the population 

could be downlisted to threatened, i.e., likely to become endangered in the foreseeable future. 

(for more specifics, see section IV, Goals, Objectives and Criteria). 
January 2008 vi NMFS 

Monitoring population trends over time will be necessary to confirm that the population has 

recovered. 

Estimated Cost of Recovery: Many efforts are currently underway in Puget Sound to address 

recovery of depleted salmon stocks, improve the condition of Puget Sound, and assist in 

prevention and response to oil spills. In addition to these ongoing efforts, the Recovery Program 

identifies the cost and time to carry out actions to address the threats specific to Southern 

Resident killer whales although we cannot estimate when the most important threats will be 

identified or when recovery criteria will be met. The Southern Resident DPS could meet the 

biological criteria under a variety of scenarios and time frames. Funding for research and 

conservation efforts has been available for fiscal years 2003- 2007 and continued recovery and 

research efforts over the next five years are estimated to cost $15,040,000. If the first five years 

of actions occurred, the annual cost would likely be reduced for subsequent years 

(~$1,500,000/year). Assuming a time frame of 28 years for delisting, the total estimated cost of 

recovery would be $49,540,000. 

Recovery of the Southern Resident killer whale DPS is a long-term effort that requires 

cooperation and coordination of West Coast communities from California to British Columbia. 

The plan was developed with input from a variety of stakeholders, including Federal and State 

agencies, Tribes, non-profit groups, industries, the academic community, and concerned citizens. 

Development of this plan was closely coordinated with the State of Washington and the 

Canadian Department of Fisheries and Oceans. 
_____________________________________________________________________________________

January 2008 I-1 NMFS 

I. INTRODUCTION 

Killer whales are an icon of the Pacific Northwest and the Southern Residents have been the 

focus of tremendous public interest, scientific curiosity and awe. Many people feel a kinship or 

connection to these family-oriented mammals. Indian Tribes in the Pacific Northwest hold killer 

whales in high regard both culturally and spiritually. Some consider them relatives or other 

tribes roaming the waters and many tribes have featured killer whales in their stories and art. 

The Tulalip Tribes tell stories of killer whales, called blackfish, assisting the Tulalip people in 

times of famine and have chosen the whale for their logo. While the cultural and spiritual 

importance of the whales to the people of the Pacific Northwest may not be the focus of an ESA 

listing or recovery plan, it is important to acknowledge the role they serve in the environment 

and in people’s lives. This Recovery Plan for Southern Resident killer whales represents an 

important step toward preserving these amazing animals for future generations. 

The overall goal of a recovery plan is to meet the recovery criteria and address threats to allow 

removal from the List of Endangered and Threatened Wildlife (List). It is challenging to identify 

the most immediate needs for conservation and recovery of Southern Resident killer whales. For 

many listed species of marine mammals, there is a primary cause of direct mortality that can be 

attributed to a particular source (e.g., ship strikes, fishery interactions, or harvest), but this is not 

the case for Southern Residents. It is unknown which of the threats has caused the decline or 

may have the most significant impact on recovery of the population. It may be a combination of 

threats or the cumulative effects that are the problem. In addition, there are inherent risks for 

small populations. This plan addresses each of the potential threats based on current knowledge. 

 

To address the data gaps and uncertainties, there is an active research program underway. While 

researchers have been studying the Southern Residents for over 30 years, there has been 

increased interest and funding support in the last several years because of the status of the 

population. The research program administered by NOAA’s Northwest Fisheries Science Center 

has targeted specific questions that will assist in management and conservation. The research 

program is a long-term effort by many institutions and individuals and it will take time to 

discover answers, particularly in light of the long-lived nature of this species. The management 

actions in this plan are based on the best available science and the current understanding of the 

threats. Because it is not possible at this time to identify exactly which actions will be required 

for recovery of the species, the plan represents an initial approach to begin addressing each of the 

threats. 

Research and monitoring are key components of the plan and they will make an adaptive 

management approach possible. Conservation of killer whales is a long-term cooperative effort 

that will evolve as more is learned from research and monitoring. Continued monitoring of the 

status of the population will assist in evaluating the effectiveness of management actions. 

Research will help refine actions that have been implemented and identify new actions to fill 

data gaps about the threats. An adaptive management approach will also provide information to 

adjust priorities as conservation progresses and to modify and periodically update the plan. 

This plan identifies a range of actions that will contribute to recovery of Southern Resident killer 

whales. Many of these actions will have a direct effect on killer whale habitat, but they will also 
January 2008 I-2 NMFS 

help restore and improve a range of habitats, species and ecosystem processes. Although the 

recovery plan is focused on Southern Residents, the proposed actions will benefit many native 

species and natural communities. The plan refers to significant efforts on local, state and 

regional levels to address recovery of other species (particularly salmon), clean up of Puget 

Sound and management of local resources. Salmon recovery programs throughout Washington, 

Oregon and California as well as in Canada identify goals that will benefit the entire ecosystem. 

The Puget Sound Partnership provides a comprehensive approach to cleaning up inland waters of 

Puget Sound. There are numerous local efforts that are also focused on improving the health of 

the ecosystem such as the Marine Stewardship Area established in San Juan County. Over time, 

each of these programs should improve the overall health and biodiversity of the ecosystem. 

This plan provides background information on Southern Resident killer whale life history and 

status, and existing protective measures. Recovery goals and criteria are provided along with 

recovery actions, research and monitoring tasks in a narrative outline. Priorities and costs for 

the measures are provided in an implementation table. 

Public Input and Comments 

The Final Recovery Plan for Southern Resident Killer Whales is the product of an open public 

process, including a series of draft documents with opportunities for public review and comment. 

This plan began as a conservation plan under the MMPA and following the listing of Southern 

Residents under the ESA, the plan was updated to meet the requirements under the ESA. 

Conservation Plan. When the Southern Resident killer whales were designated as a depleted 

stock under the MMPA in 2003, NMFS began developing a conservation plan, as required under 

the MMPA. We held a series of public workshops on each of the major threats – prey 

availability, contaminants and vessel interactions, to gather input on potential management 

actions to include in the plan (http://www.nwr.noaa.gov/Marine-Mammals/Whales-DolphinsPorpoise/Killer-Whales/Conservation-Planning/Index.cfm). The format of the workshops 

included presentations by researchers and agency representatives to identify the current condition 

of the Southern Residents. The presentations were followed by breakout groups to brainstorm 

and discuss management actions. The results of the workshops were posted on our web page and 

used to create a draft conservation plan. The plan was posted for public comment and we 

received a variety of additional suggestions for management actions. This first round of 

comments were reviewed and incorporated as appropriate into the proposed conservation plan. 

In October 2005 we published a Notice of Availability of a Proposed Conservation Plan for 

Southern Resident Killer Whales for further public comment. In addition to notifying the large 

list of interested parties that had signed up for our e-mail list, we contacted several agencies that 

were identified as responsible parties in the draft plan to gather information on their programs 

and develop cost estimates based on multiple agency efforts. During the public comment period 

posted in the Federal Register, we received over 40 comments from government agencies, 

conservation groups, industry representatives, researchers, and interested citizens. 

Not surprisingly, commenters with different interests provided strikingly different perspectives 

that were often in opposition to each other. There were comments that we incorporated to clarify 

concepts, strengthen language and ensure that all of the background information was accurate 
January 2008 I-3 NMFS 

and up-to-date. Other comments suggested that emphasis should be placed on particular threats. 

Each of the major threats was suggested as the most important problem for Southern Residents 

by at least one commenter, and several of the threats were dismissed as unimportant. Our 

approach to recovery addresses the uncertainty regarding which threat may have caused the 

decline or may limit recovery and includes actions for each of the threats. The adaptive 

approach incorporating research to refine management actions will provide feedback to establish 

which threats should take priority. While many comments were constructive, some were too 

broad to address, unrealistic or not consistent with the requirements or goals of the ESA and, 

therefore, were not addressed. 

Proposed Recovery Plan. When the Southern Residents were listed under the ESA, several 

commenters suggested that we convene a recovery team to develop an ESA recovery plan. 

Fortunately, we had already made significant progress on a conservation plan that could be 

amended to meet the needs of a recovery plan as well. Under the ESA, “The Secretary, in 

developing and implementing recovery plans, may procure the services of appropriate public and 

private agencies and institutions, and other qualified persons” which often form a recovery team. 

While this is often a valuable approach to include various stakeholders in the recovery planning 

process, we determined that the open public process used to develop the conservation plan 

already included interested stakeholder groups and actually allowed for even broader 

participation than a recovery team would have allowed. The various parties that are key players 

with important information from the research community, industry, conservation groups and 

government agencies were already involved and actively participated in the process. 

Several examples of comments that we incorporated into the proposed recovery plan include the 

addition of responsible parties for some actions, inclusion of beneficial programs currently 

underway that were brought to our attention, clarification of the descriptions of levels of social 

structure, and identification of new research results and scientific papers to update the plan. 

Government agencies provided valuable information on current programs already in place to 

address threats such as contamination in Puget Sound, including the newly formed Puget Sound 

Partnership. Other community efforts currently underway and highlighted in the comments are 

the Shared Strategy for Puget Sound and the draft recovery plan for Puget Sound Chinook, both 

of which became available after the proposed conservation plan was released. These initiatives 

were added into the plan. In addition, NOAA’s Northwest Fisheries Science Center hosted a 

“Research Workshop on Southern Resident Killer Whales” in April of 2006 and many of the 

presentations and abstracts prepared for that conference provided valuable new information that 

was incorporated into the plan. 

The broad participation in reviewing the plan contributed to conflicting comments about our 

approach to recovery. Industry groups reacted to inclusion of management actions that could 

affect their activities and have economic impacts. They suggested that management actions with 

economic impacts should not be implemented until sufficient scientific evidence was obtained to 

prove effects to the whales and assure that the actions are necessary for their recovery. 

Conservation groups on the other hand, suggested that a precautionary approach was necessary 

and that we cannot wait to obtain additional research results before implementing actions. In the 

proposed recovery plan, we attempted to address the uncertainty that exists, as well as address 

varying views. 
January 2008 I-4 NMFS 

For example, we received opposing comments regarding how we should address the threat of oil 

spills. Industry groups provided detailed information on the various state, federal, and 

international regulations and programs currently in place and argued that these are sufficient to 

address the uncertain threat of an oil spill. They suggested that emphasis be placed on 

addressing issues such as prey that they consider to be a more serious threat. Conservation 

groups, however, specifically suggested that additional actions be taken to prevent and respond 

to oils spills because spills are perhaps the biggest single threat to killer whales. In this proposed 

recovery plan we have attempted to reconcile these disparate views. We have included 

references to additional safety measures that were provided by industry groups, yet we have also 

maintained language regarding potential improvements that can be made to specifically address 

risks of oil spills to killer whales. 

There were similar comments regarding salmon recovery efforts and how they were addressed in 

the plan. While some commenters felt that salmon recovery should be separate from the goals of 

the killer whale recovery plan and that the current salmon recovery efforts were sufficient, other 

commenters felt that the killer whale conservation plan should include salmon recovery efforts 

and should set more expedited goals for salmon recovery than what is currently proposed in 

salmon plans. Some commenters raised the issue of hatcheries, supporting them as a source for 

sufficiently large numbers of fish for the whales, while others were cautious about the effects 

hatchery fish have on wild populations. Another criticism of the plan was that prey other than 

salmon were not adequately addressed. 

There were also opposing comments regarding vessels. Several commenters were critical of the 

whale watching industry and its impact on Southern Residents, while other commenters disputed 

that vessels have any substantial effects on the whales and were critical of the emphasis on whale 

watching as a primary threat. Some commented on the beneficial aspects of whale watching to 

educate people and inspire protection of killer whales and the environment. Both potential 

adverse effects and benefits are currently included in the recovery plan. In addition, one 

contingent suggested that the Be Whale Wise guidelines are insufficient to protect Southern 

Residents and that NMFS should implement and enforce formal regulations. Other commenters 

supported the efforts of the whale watching industry to educate the public and to follow the 

voluntary guidelines, which they felt were sufficient to address any perceived concerns. To 

address this issue, the proposed recovery plan included management actions linked to research to 

evaluate the impacts of vessels of all types and determine if regulations or protected areas are 

warranted. NMFS will engage the community and industry groups in the evaluation and go 

through a public process that would allow for input from all of the stakeholders if any restrictions 

or regulations are considered. 

Final Recovery Plan. In November 2006 NMFS published a Notice of Availability of a 

Proposed Recovery Plan for Southern Resident Killer Whales and opened a public comment 

period. We received 50 comments on the proposed recovery plan from a variety of sources 

including local, state, and Federal government entities, Tribes, nonprofit organizations and 

interest groups, researchers and concerned citizens. NMFS participated in several informal 

public meetings on the proposed recovery plan in Friday Harbor and Seattle upon request from 

interested parties. NMFS staff also met with several commenters who requested an opportunity 

to review and clarify their comments. 
January 2008 I-5 NMFS 

As a proposed recovery plan under the ESA, several elements of the plan had been updated to 

reflect requirements under the ESA. The biggest changes were the recovery criteria and the 

addition of information on ESA elements such as critical habitat and requirements such as 

section 7 consultations. Some of the comments we received were similar with respect to the 

contradictory elements described above. We took the same approach to resolve opposing 

comments. Wherever possible, comments and suggestions were incorporated directly into the 

Final Recovery Plan. We also drafted a comment/response document separate from the Final 

Recovery Plan to provide explanations regarding some of the comments received and how they 

were addressed. The comment/response document is posted on our web page along with the 

Final Recovery Plan. 

The Southern Residents killer whales are important to the people of the Pacific Northwest and 

we are grateful for the high level of public participation in developing a Final Recovery Plan. 

We appreciate the high quality of the comments and the great care with which so many 

individuals and organizations responded to the proposed conservation plan and proposed 

recovery plan. Many commenters provided positive feedback on elements of the plan and the 

timeliness of its development along with thoughtful critiques and suggestions for improvement. 

The Final Recovery Plan is the product of an open process over several years with input from 

hundreds of individuals and organizations and we intend to continue the long-term collaboration 

that will be necessary to implement the actions in the plan and update the plan in the future.
_____________________________________________________________________________________

January 2008 II-1 NMFS 

 II. BACKGROUND 

A. TAXONOMY 

Killer whales (Orcinus orca) are members of the family Delphinidae, which includes 17-19 genera of 

marine dolphins (Rice 1998, LeDuc et al. 1999). Systematic classifications based on morphology have 

variously placed the genus Orcinus in the subfamilies Globicephalinae or Orcininae with other genera 

such as Feresa, Globicephala, Orcaella, Peponocephala, and Pseudorca (Slijper 1936, Fraser and Purves 

1960, Kasuya 1973, Mead 1975, Perrin 1989, Fordyce and Barnes 1994). However, molecular work 

suggests that Orcinus is most closely related to the Irawaddy dolphin (Orcaella brevirostris), with both 

forming the subfamily Orcininae (LeDuc et al. 1999). 

Orcinus has traditionally been considered monotypic, despite some variation in color patterns, 

morphology, and ecology across its distribution. No subspecies are formally recognized. In the 

early 1980s, Soviet scientists proposed two new species (O. nanus and O. glacialis) in 

Antarctica, based on their smaller sizes and other traits (Mikhalev et al. 1981, Berzin and 

Vladimirov 1983, Pitman and Ensor 2003). Similarly, Baird (1994, 2002) argued that resident 

and transient forms in the northeastern Pacific should be treated as separate species due to 

differences in behavior, ecology, and vocalizations. However, these proposals did not receive 

wide acceptance (Hoelzel et al. 1998, Rice 1998, Barrett-Lennard 2000). Additional 

investigation documented genetic distinctions among populations in the northeastern Pacific, but 

these were considered insufficient to warrant designation of discrete taxa (Hoelzel and Dover 

1991, Hoelzel et al. 1998, Barrett-Lennard 2000, Barrett-Lennard and Ellis 2001). Hoelzel et al. 

(2002) reported low diversity and inconsistent geographic patterns in mitochondrial DNA 

(mtDNA) among worldwide populations, which supported the lack of taxonomic differentiation 

within the species. Despite these findings, a number of authorities believed that the classification 

of killer whales as a single species without subspecies was inaccurate (Krahn et al. 2002, Waples 

and Clapham 2004), as suggested by the recent recognition of three distinct forms in Antarctica 

(Pitman and Ensor 2003). Preliminary evidence suggests that multiple ecotypes may also occur 

in Norway and New Zealand (Waples and Clapham 2004). Furthermore, the low genetic 

diversity of killer whales may be more reflective of their matrilineal social structure (Whitehead 

1998) than an absence of taxonomic separation. 

Ongoing genetic studies are providing further understanding of the relationships among killer 

whale populations (Waples and Clapham 2004). However, many of the results are open to 

multiple interpretations, thus precluding firm taxonomic conclusions. Analyses of mitochondrial 

DNA diversity reveal greater genetic variation in the species than previously recognized, based 

on the discovery of a much larger number of haplotypes. Two major groups of haplotypes exist 

(LeDuc and Taylor 2004), as illustrated in a preliminary phylogenetic tree prepared by R. LeDuc 

(Krahn et al. 2004a). The largest clade appears to be distributed worldwide and includes resident 

and offshore whales from the northeastern Pacific, other fish-eating populations, and some 

mammal-eating populations from the eastern tropical Pacific, Argentina, and the Gulf of Mexico. 

The second clade is known thus far only from the North Pacific and Antarctica, and includes the 

mammal-feeding transient whales from the west coast of North America. Hoelzel (2004), using 

mitochondrial DNA sequence data, similarly found that transient haplotypes were divergent from 

those of other populations in the North Pacific and Iceland. Total genetic variation in Antarctic 

killer whales is comparable to that in combined populations from the rest of the world (LeDuc 
January 2008 II-2 NMFS 

and Pitman 2004). Based on mitochondrial DNA, Hoelzel et al. (2002) postulated that killer 

whales as a species experienced a population bottleneck perhaps 145,000 to 210,000 years ago. 

This information, together with tentative morphological evidence (C. W. Fung and L. G. BarrettLennard, unpubl. data), has caused most cetacean taxonomists to now believe that multiple 

species or subspecies of killer whales exist worldwide (Krahn et al. 2004a, Reeves et al. 2004, 

Waples and Clapham 2004). Most participants at a taxonomy workshop held in April-May 2004 

concluded that sufficient information currently exists to formally recognize resident and transient 

whales in the northeastern Pacific and two or three forms from Antarctica as subspecies, with 

further study needed to determine whether classification as full species is appropriate (Reeves et 

al. 2004). If subspecies designations proceed, a lengthy review of museum material and 

published species descriptions is necessary before assignment of nomenclature can occur (Krahn 

et al. 2004a, Perrin 2004). Based on this evidence, Krahn et al. (2004a) concluded that all North 

Pacific resident killer whales should be treated as a single unnamed subspecies distinct from 

offshore and transient whales. The Biological Review Team also concluded that the Southern 

Residents were discrete from other North Pacific residents and significant with respect to the 

North Pacific resident taxon, and therefore should be considered a distinct population segment 

(Krahn et al. 2004a.) 

Common Names 

The name “killer whale” originates from early whalers and is appropriately based on the species’ 

predatory habits, as well as its large size, which distinguishes it from other dolphins. Other 

common names currently or formerly used in North America include “orca,” “blackfish,” 

“killer,” “grampus,” and “swordfish.” The name “orca” has become increasingly popular in 

recent decades as a less sinister alternative to “killer whale” (Spalding 1998). A variety of 

Native American names also exist, including klasqo’kapix (Makah, Olympic Peninsula), ka-kowwud (Quileute, Olympic Peninsula), max’inux (Kwakiutl, northern Vancouver Island), qaqawun

(Nootka, western Vancouver Island), and ska-ana (Haida, Queen Charlotte Islands) (Hoyt 1990, 

Matkin et al. 1999a, Ford et al. 2000). 

B. DESCRIPTION 

Killer whales are the world’s largest dolphin. The sexes show considerable size dimorphism, 

with males attaining maximum lengths and weights of 9.0 m and 5,568 kg, respectively, 

compared to 7.7 m and 3,810 kg for females (Dahlheim and Heyning 1999). Adult males 

develop larger pectoral flippers, dorsal fins, tail flukes, and girths than females (Clark and Odell 

1999). The dorsal fin reaches heights of 1.8 m and is pointed in males, but grows to only 0.7 m 

and is more curved in females (Figure 1). Killer whales have large paddle-shaped pectoral fins 

and broad rounded heads with only the hint of a facial beak. The flukes have pointed tips and 

form a notch at their midpoint on the trailing edge. Ten to 14 teeth occur on each side of both 

jaws and measure up to 13 cm in length (Eschricht 1866, Scammon 1874, Nishiwaki 1972). 

Skull morphology and other anatomical features are described by Tomilin (1957) and Dahlheim 

and Heyning (1999). 
January 2008 II-3 NMFS 

Figure 1. Lateral and ventral views of an adult male killer whale. Small insets show the dorsal fin and 

genital pigmentation of a female. Adapted from Dahlheim and Heyning (1999) and Ford et al. (2000). 

Reprinted from Wiles (2004). 

Killer whales are easily identifiable by their distinctive black-and-white color pattern, which is 

among the most striking of all cetaceans. Animals are black dorsally and have a white ventral 

region extending from the chin and lower face to the belly and anal region (Figure 1). The 

underside of the tail fluke is white or pale gray, and may be thinly edged in black. Several 

additional white or gray markings occur on the flanks and back. These include a small white 

oval patch behind and above the eye, a larger area of white connected to the main belly marking 

and sweeping upward onto the lower rear flank, and a gray or white “saddle” patch usually 

present behind the dorsal fin. These color patterns exhibit regional and age variation (Carl 1946, 

Evans et al. 1982, Baird and Stacey 1988, Ford et al. 2000, Pitman and Ensor 2003). Infants 

feature yellowish, rather than white, markings. Each whale has a uniquely shaped and scarred 

dorsal fin and saddle patch, which permits animals to be recognized on an individual basis, as 

depicted in photo-identification catalogs, such as those compiled for the northeastern Pacific 

region (e.g., Black et al. 1997, Dahlheim 1997, Dahlheim et al. 1997, van Ginneken et al. 1998, 
January 2008 II-4 NMFS 

2000, Matkin et al. 1999a, Ford and Ellis 1999, Ford et al. 2000, Ellifrit et al. 2006). Shape and 

coloration of the saddle often differs on the left and right sides of an animal (Ford et al. 2000, 

van Ginneken et al. 2000). Eye-patch shape is also unique among individuals (Carl 1946, Visser 

and Mäkeläinen 2000). In the Antarctic, several populations of killer whales display grayish 

dorsal “capes” extending over large portions of the back and flanks (Evans et al. 1982, Visser 

1999a, Pitman and Ensor 2003). 

In addition to the characters mentioned above, male and female killer whales are distinguishable 

by pigmentation differences in the genital area (Figure 1; Ford et al. 2000). Females have a 

roughly circular or oval white patch surrounding the genital area. Within this patch, the two 

mammary slits are marked with gray or black and are located on either side of the genital slit, 

which also usually has a dark marking. Males have a more elongated white patch surrounding 

the genital area, a larger darker spot at the genital slit, and lack the darkly shaded mammary slits. 

When viewed at long distances, false killer whales (Pseudorca crassidens) and Risso’s dolphins 

(Grampus griseus) can be mistaken for female and immature killer whales (Leatherwood et al. 

1988). Blows of killer whales are low and bushy-shaped, reaching a height of about 1-3 m 

(Scammon 1874, Scheffer and Slipp 1948, Eder 2001). Scheffer and Slipp (1948) described the 

sound of blowing as “a quick breathy puff, louder and sharper and lacking the double gasp of the 

harbor porpoise” (Phocoena phocoena). 

C. DISTRIBUTION 

Killer whales have a cosmopolitan distribution considered the largest of any cetacean (Figure 2). 

The species occurs in all oceans, but is generally most common in coastal waters and at higher 

latitudes, with fewer sightings from tropical regions (Dahlheim and Heyning 1999; Forney and 

Wade, 2007). In the North Pacific, killer whales occur in waters off Alaska, including the 

Aleutian Islands and Bering Sea (Murie 1959, Braham and Dahlheim 1982, Dahlheim 1994, 

Matkin and Saulitis 1994, Miyashita et al. 1995, Dahlheim 1997, Waite et al. 2002), and range 

southward along the North American coast and continental slope (Norris and Prescott 1961, 

Fiscus and Niggol 1965, Gilmore 1976, Dahlheim et al. 1982, Black et al. 1997, Guerrero-Ruiz 

et al. 1998). Populations are also present along the northeastern coast of Asia from eastern 

Russia to southern China (Zenkovich 1938, Tomilin 1957, Nishiwaki and Handa 1958, Kasuya 

1971, Wang 1985, Miyashita et al. 1995). Northward occurrence in this region extends into the 

Chukchi and Beaufort Seas (Ivashin and Votrogov 1981, Lowry et al. 1987, Matkin and Saulitis 

1994, Melnikov and Zagrebin 2005). Sightings are generally infrequent to rare across the 

tropical Pacific, extending from Central and South America (Dahlheim et al. 1982, Wade and 

Gerrodette 1993, García-Godos 2004) westward to much of the Indo-Pacific region (Tomich 

1986, Eldredge 1991, Miyashita et al. 1995, Reeves et al. 1999, Visser and Bonoccorso 2003; 

Baird et al. 2006; Forney and Wade, 2007). Killer whales occur broadly in the world’s other 

oceans, with the exception of the Arctic Ocean (Figure 2; Miyashita et al. 1995, Dahlheim and 

Heyning 1999; Forney and Wade, 2007). 
January 2008 II-5 NMFS 

Figure 2. Worldwide range of killer whales. Dark areas depict the distribution of known records. White 

areas are probably also inhabited, but documented sightings are lacking. Adapted from Miyashita et al. 

(1995) and Dahlheim and Heyning (1999), with additional information from Reeves and Mitchell 

(1988b), Wade and Gerrodette (1993), Andersen and Kinze (1999), and Reeves et al. (1999). 

Reprinted from Wiles (2004). 

D. CLASSIFICATION OF KILLER WHALES IN THE NORTHEASTERN PACIFIC 

Three distinct forms of killer whales, termed as residents, transients, and offshores, are 

recognized in the northeastern Pacific Ocean. Although there is considerable overlap in their 

ranges, these populations display significant genetic differences due to a lack of interchange of

member animals (Stevens et al. 1989, Hoelzel and Dover 1991, Hoelzel et al. 1998, BarrettLennard 2000, Barrett-Lennard and Ellis 2001, Hoelzel 2004, Krahn et al. 2004a). Important 

differences in ecology, behavior, morphology, and acoustics also exist (Baird 2000, Ford et 

al.2000). The names “resident” and “transient” were coined during early studies of killer whale 

communities in the northeastern Pacific (Bigg 1982), but continued research has shown that 

neither term is particularly descriptive of actual movement patterns (Dahlheim and Heyning 

1999, Baird and Whitehead 2000, Baird 2001). Both names, plus “offshore,” are currently 

applied only to killer whales occurring in this region, but may also be appropriate for some 

populations off eastern Asia (Krahn et al. 2002). Similar differences among overlapping 

populations of killer whales have been found in Antarctica (Berzin and Vladimirov 1983, Pitman 

and Ensor 2003) and may eventually be recognized in the populations of many localities 

(Hoelzel and Dover 1991, Ford et al. 1998). 
January 2008 II-6 NMFS 

Resident Killer Whales 

Resident killer whales in the Northeast Pacific are distributed from Alaska to California, with 

four distinct communities recognized: southern, northern, southern Alaska, and western Alaska 

(Krahn et al. 2002, 2004a). Resident animals differ from transient and offshore killer whales by 

having a dorsal fin that is more curved and rounded at the tip (Ford et al. 2000). Residents 

exhibit five patterns of saddle patch pigmentation, two of which are shared with transients (Baird 

and Stacey 1988). Residents also differ in vocalization patterns and skull traits, feed primarily 

on fish, and occur in large stable pods typically comprised of 10 to about 60 individuals (Ford 

1989, Felleman et al. 1991, Ford et al. 1998, 2000, Saulitis et al. 2000; C. W. Fung and L. G. 

Barrett-Lennard, unpubl. data). An additional resident community, known as the western North 

Pacific residents, occurs off eastern Russia and perhaps Japan (Hoelzel 2004, Krahn et al. 

2004a). 

Southern Residents. This population consists of three pods, designated J, K, and L pods, that 

reside for part of the year in the inland waterways of Washington State and British Columbia 

(Strait of Georgia, Strait of Juan de Fuca, and Puget Sound), principally during the late spring, 

summer, and fall (Bigg 1982, Ford et al. 2000, Krahn et al. 2002). Pods have visited coastal sites 

off Washington and Vancouver Island (Ford et al. 2000), and are known to travel as far south as 

central California and as far north as the Queen Charlotte Islands (Figure 3). Winter and early 

spring movements and distribution are largely unknown for the population. Although there is 

considerable overlap in the geographic ranges of Southern and Northern Residents, pods from 

the two populations have not been observed to intermix (Ford et al. 2000). Genetic analyses 

using nuclear (microsatellite) and mitochondrial DNA indicate that the two populations are most 

likely reproductively isolated from each other (Hoelzel et al. 1998, Barrett-Lennard 2000, 

Barrett-Lennard and Ellis 2001). 

Northern Residents. This community contains 16 pods (A1, A4, A5, B1, C1, D1, H1, I1, I2, I18, 

G1, G12, I11, I31, R1, and W1) that reside primarily from central Vancouver Island (including 

the northern Strait of Georgia) to Frederick Sound in southeastern Alaska (Figure 3; Dahlheim et 

al. 1997, Ford et al. 2000), although animals occasionally venture as far south as the Strait of 

Juan de Fuca, San Juan Islands, and the west coast of Washington (Barrett-Lennard and Ellis 

2001, Calambokidis et al. 2004, Wiles 2004; J. K. B. Ford, unpubl. data, NWFSC unpubl. data). 

From June to October, many Northern Resident pods congregate in the vicinity of Johnstone 

Strait and Queen Charlotte Strait off northeastern Vancouver Island, but movements and 

distribution during other times of the year are less well known (Ford et al. 2000). In southeastern 

Alaska, Northern Residents have been seen within 500 m of pods from the Southern Alaska 

Resident community (Krahn et al. 2004a) and limited gene flow may occur between these two 

populations (Hoelzel et al. 1998, Barrett-Lennard 2000, Barrett-Lennard and Ellis 2001). 

Southern Alaska Residents. Southern Alaska Resident killer whales inhabit the waters of 

southeastern Alaska and the Gulf of Alaska, including Prince William Sound, Kenai Fjords, and 

Kodiak Island (see Figure 1 in Krahn et al. 2004a) (Dahlheim et al. 1997, Matkin and Saulitis 

1997, Matkin et al. 1997, 1999a). At least 25 pods have been identified (Matkin et al. 2003, 

Angliss and Outlaw 2005). However, some groups remain poorly known and a full inventory of
_____________________________________________________________________________________

January 2008 II-7 NMFS 

Figure 3. Geographic ranges (light shading) of the Southern Resident (left) and Northern Resident (right) 

killer whale populations in the northeastern Pacific. The western pelagic boundary of the ranges is illdefined. Reprinted from Wiles (2004). 

the community has not yet been accomplished (C. O. Matkin, pers. comm.). Genetic analyses 

indicate that this population is most closely related to the Northern Residents and that occasional 

intermatings may occur between the two (Hoelzel et al. 1998, Barrett-Lennard 2000, BarrettLennard and Ellis 2001). Southern Alaska Residents are also closely related to the Western 

Alaska Resident community (Hoelzel 2004) and have been observed once off Kodiak Island in 

association with whales from this population (M. E. Dahlheim, unpubl. data). 

Western Alaska Residents. The distribution and abundance of this community is less understood, 

but its range includes coastal and offshore waters west of Kodiak Island to the Aleutian Islands 

and the Bering Sea (see Figure 1 in Krahn et al. 2004a) (Dahlheim 1997, Krahn et al. 2004a, 

Zerbinin et al. 2006). It is also thought to be the largest resident community in the region (Krahn 

et al. 2004a). An unknown number of pods is present and pod names have not yet been assigned. 

Recent genetic studies by Hoelzel (2004) suggest that the population is more closely related to 

the Southern Alaska Residents than to the western North Pacific residents. 
January 2008 II-8 NMFS 

Transient Killer Whales 

Transients do not associate with resident and offshore whales despite having a geographic range 

that is largely sympatric with both forms (Figure 4). Compared to residents, transients occur in 

smaller groups of usually fewer than 10 individuals (Ford and Ellis 1999, Baird 2000, Baird and 

Whitehead 2000, Zerbinin et al. 2006), display a more fluid social organization, and have diets 

consisting largely of other marine mammals (Baird and Dill 1996, Ford et al. 1998, Saulitis et al. 

2000). They also move greater distances and tend to have larger home ranges than residents 

(Goley and Straley 1994, Dahlheim and Heyning 1999, Baird 2000). Morphologically, the 

dorsal fins of transients are straighter at the tip than in residents and offshores (Ford and Ellis 

1999, Ford et al. 2000). Two patterns of saddle pigmentation are recognized (Baird and Stacey 

1988). Genetic investigations using both nuclear DNA and mtDNA have found significant 

genetic differences between transients and other killer whale forms, confirming the lack of 

interbreeding (Stevens 1989, Hoelzel and Dover 1991, Hoelzel et al. 1998, Barrett-Lennard 

2000, Barrett-Lennard and Ellis 2001, Hoelzel 2004, Leduc and Taylor 2004). These studies 

also indicate that three genetically distinct assemblages of transient killer whales exist in the 

northeastern Pacific. These are identified as 1) west coast transients, which occur from southern 

California to southeastern Alaska (Figure 4); 2) Gulf of Alaska transients, which inhabit the Gulf 

of Alaska, Aleutians, and Bering Sea (although significant genetic differences may exist within 

the population [Angliss and Outlaw 2005]); and 3) the AT1 pod, which occurs in Prince William 

Sound and the Kenai Fjords in the northern Gulf of Alaska and has been designated as a depleted 

stock with no more than seven whales remaining (Ford and Ellis 1999, Barrett-Lennard 2000, 

Barrett-Lennard and Ellis 2001, NMFS 2003a; C. O. Matkin, unpubl. data). Genetic and 

acoustic evidence suggests there is little or no interchange of members among these populations 

(Barrett-Lennard and Ellis 2001, Saulitis et al. 2005). 

Offshore Killer Whales 

Due to a scarcity of sightings, much less information is available for the offshore killer whale 

population, which was first identified in the late 1980s (Ford et al. 1992, 1994, Walters et al. 

1992). Offshores have the largest geographic range of any killer whale community in the 

northeastern Pacific. Records are distributed from southern California to Alaska (Figure 4), 

including many from western Vancouver Island and the Queen Charlotte Islands (Ford and Ellis 

1999, Krahn et al. 2002). Recent data from Alaska has extended the population’s range to the 

western Gulf of Alaska and eastern Aleutians (M. E. Dahlheim, pers. comm.). Offshore killer 

whales usually occur 15 km or more offshore, but also visit coastal waters and occasionally enter 

protected inshore waters. Sightings have been made up to 500 km off the Washington coast 

(Krahn et al. 2002). Animals typically congregate in groups of 20-75 animals and are presumed 

to feed primarily on fish. Intermixing with residents and transients has not been observed. 

Genetic analyses indicate that offshore killer whales are reproductively isolated from other 

forms, but are most closely related to the Southern Residents (Hoelzel et al. 1998, BarrettLennard and Ellis 2001). Offshores are thought to be slightly smaller in body size than residents 

and transients, and have dorsal fins and saddle patches resembling those of residents (Walters et 

al. 1992, Ford et al. 2000). 
January 2008 II-9 NMFS 

Figure 4. Geographic ranges (light shading) of the west coast transient (left) and offshore (right) 

killer whale populations in the northeastern Pacific. The western pelagic boundary of the ranges 

is ill-defined. The northern range of the offshore population extends westward to the eastern 

Aleutian Islands. Reprinted from Wiles (2004). 
January 2008 II-10 NMFS 

Naming Systems of Killer Whales in the Northeastern Pacific 

As previously noted, killer whales are individually recognizable by the unique markings and 

shapes of their dorsal fin, saddle patch, and eye patches. In the northeastern Pacific, researchers 

use a variety of alphanumeric naming systems to maintain sighting records and other data for 

individual whales in each community. For Southern Resident whales, animals are assigned their 

own alphanumeric names, based on their pod and the sequence in which they were identified 

(Ford et al. 2000). Thus, the Southern Resident known as “L7” was the seventh member to be 

documented in L pod. Similar naming systems have been applied to each of the region’s other 

killer whale communities (e.g., Dahlheim 1997, Dahlheim et al. 1997, Matkin et al. 1999a), but 

these may or may not be standardized among researchers. Thus, individual whales sighted in 

multiple areas may have more than one name (e.g., Ford and Ellis 1999). 

E. NATURAL HISTORY 

Social Organization 

Killer whales are highly social animals that occur primarily in groups or pods of up to 40-50 

animals (Dahlheim and Heyning 1999, Baird 2000). Mean pod size varies among populations, 

but often ranges from 2 to 15 animals (Kasuya 1971, Condy et al. 1978, Mikhalev et al. 1981, 

Braham and Dahlheim 1982, Dahlheim et al. 1982, Baird and Dill 1996). Larger aggregations of 

up to several hundred individuals occasionally form, but are usually considered temporary 

groupings of smaller social units that probably congregate near seasonal concentrations of prey, 

for social interaction, or breeding (Dahlheim and Heyning 1999, Baird 2000, Ford et al. 2000). 

Single whales, usually adult males, also occur in many populations (Norris and Prescott 1961, 

Hoelzel 1993, Baird 1994). Differences in spatial distribution, abundance, and behavior of food 

resources probably account for much of the variation in group size among killer whale 

populations. For example, sympatric populations of resident and transient whales in the 

northeastern Pacific vary substantially in average pod size. The larger groups of residents may 

be better suited for detecting schools of fish, enabling individual members to increase food 

consumption (Ford et al. 2000). In contrast, transients forage in small groups on wary and 

patchily distributed marine mammals and are presumably able to maximize their per capita 

energy intake through reduced competition over food (Baird and Dill 1996, Ford and Ellis 1999, 

Baird and Whitehead 2000). 

The age and sex structure of killer whale social groups has been reported for populations at 

several locations. The Southern and Northern Resident communities combined were comprised 

of 19 percent adult males, 31 percent adult females, and 50 percent immature whales of either 

sex in 1987 (Olesiuk et al. 1990a). Nearly identical age and sex cohorts were present among the 

Southern Alaska Residents in 2001, with 19 percent of the animals being adult males, 24 percent 

reproductive females, 7 percent post-reproductive females, and 51 percent juveniles (Matkin et 

al. 2003). For southern oceans, Miyazaki (1989) found that 16 percent of populations were adult 

males, 8 percent were adult females with calves, and 76 percent were immatures and adult 

females without calves. At Marion Island in the southern Indian Ocean, 29 percent of the 

population were adult males, 21 percent were adult females, 8 percent were calves, 25 percent 

were subadults, and 17 percent were unidentified (Condy et al. 1978). 
January 2008 II-11 NMFS 

Some of the most detailed studies of social structure in killer whales have been made in British 

Columbia, Washington, and Alaska during the past few decades, with much information 

available on group size, structure, and stability, and vocal traits (Ford 1989, 1991, Bigg et al. 

1990, Baird and Dill 1996, Matkin et al. 1999b, Baird 2000, Baird and Whitehead 2000, Ford et 

al. 2000, Miller and Bain 2000, Yurk et al. 2002). Social organization in this region is based on 

maternal kinship and may be characteristic of killer whale populations throughout the world 

(Ford 2002). 

Residents. Four levels of social structure have been identified among resident killer whales. The 

basic and most important social unit is the matriline, which is a highly stable hierarchical group 

of individuals linked by maternal descent (Baird 2000, Ford et al. 2000, Ford 2002, Ford and 

Ellis 2002). A matriline is usually composed of a female, her sons and daughters, and offspring 

of her daughters, and contains one to 17 (mean = 5.5) individuals spanning one to five (mean = 

3) generations. Members maintain extremely strong bonds and individuals seldom separate from 

the group for more than a few hours. Permanent dispersal of individuals from resident matrilines 

has never been recorded (Bigg et al. 1990, Baird 2000, Ford et al. 2000, Barrett-Lennard and 

Ellis 2001) and the two recent separations of calves (A73 and L98) from their natal pods are 

considered anomalous. Matriarchal females likely hold important social knowledge that guides 

the behavior of individual matrilines (Boran and Heimlich 1999, McComb et al. 2001). 

Groups of related matrilines are known as pods. Matrilines within pods share a common 

maternal ancestor from the recent past, making them more closely related to one another than to 

those of other pods (Baird 2000, Ford et al. 2000). Pods are less cohesive than matrilines and 

member matrilines may travel apart for periods of weeks or months. Nonetheless, matrilines 

associate more often with others from their pod than with matrilines from other pods. Most pods 

are comprised of one to four matrilines, but one Southern Resident pod (L pod) holds 12 

matrilines (Table 1). Resident pods have contained two to 59 whales (Bigg et al. 1987, Ford et 

al. 2000, Ford 2002, Matkin et al. 2003; Center for Whale Research, unpubl. data). Gradual 

changes in pod structure and cohesion occur through time with the deaths and births of members, 

as seen after the death of one matriarchal female, which appeared to prompt the fragmentation of 

her matriline (Ford et al. 2000). Such changes in association patterns caused some observers to 

believe that L pod was comprised of three smaller pods during the 1980s (Hoelzel 1993). Within 

pods, some researchers recognize the existence of an intermediate type of association known as 

the subpod, which is defined as a grouping of matrilines that spends more than 95 percent of 

their time together (Baird 2000). While pods have been traditionally used as a social structure 

grouping, recent studies indicate that killer whale pods may be more ephemeral than previously 

believed, due to matrilineal splitting over time (Ford et al. 2003). 

Clans are the next level of social structure and are composed of pods with similar vocal dialects 

and a common but older maternal heritage (Ford 1991, Ford et al. 2000, Yurk et al. 2002). 

Those pods with similar dialects are presumably more closely related to one another than those 

with greater differences in their dialects (Ford 1991). However, vocalizations known as pulsed 

calls are not shared between different clans, indicating a lack of recent common ancestry 

between clans. Clans overlap in their geographic ranges and pods from different clans frequently 

intermingle. 
January 2008 II-12 NMFS 

Pods (and clans) that regularly associate with one another are known as communities, which 

represent the highest level of social organization in resident killer whale societies (Ford et al. 

2000, Ford 2002). Four communities (southern, northern, southern Alaska, and western Alaska) 

of resident whales exist in the northeastern Pacific. Communities are based solely on association 

patterns rather than maternal relatedness or acoustic similarity. Ranges of neighboring 

communities partially overlap and member pods may or may not associate on an occasional basis 

with those from other communities (Baird 2000). The Southern Resident community is 

comprised of three pods belonging to one clan (J), whereas the Northern Resident community 

has 16 pods in three clans (A, G, and R) (Table 1, Ford et al. 2000). 

Table 1. Social hierarchy and pod sizes of Southern and Northern Resident killer whales in Washington 

and British Columbia (Ford et al. 2000; Center for Whale Research, unpubl. data). 

Community Clan Poda Matrilines 

No. of members 

per podb

 

Southern Residents J J J2, J8, J9, J16 25 

 J K K3, K4, K7, K18 19 

 J L L2, L4, L9, L12, L21, L25, L26, 

L28, L32, L35, L37, L45 

 43 

 Total 87 

 

Northern Residents A A1 A12, A30, A36 16 

 A A4 A11, A24 11 

 A A5 A8, A9, A23, A25 13 

 A B1 B7 7 

 A C1 C6, C10 14 

 A D1 D7, D11 12 

 A H1 H6 9 

 A I1 I1 8 

 A I2 I22 2 

 A I18 I17, I18 16 

 G G1 G3, G4, G17, G18, G29 29 

 G G12 G2, G12 13 

 G I11 I11, I15 22 

 G I31 I31 12 

 R R1 R2, R5, R9, R17 29 

 R W1 W3 3 

 Total 216 

a Southern Resident pods are also known as J1, K1, and L1 pods (Ford et al. 2000). b Pod sizes are based on population monitoring results through October 2007 for Southern Residents (Center for Whale 

Research, unpubl. data) and from 1998 for Northern Residents (Ford et al. 2000).

Transients. The social organization of transients is less understood than for resident whales. 

Transients also occur in fairly stable maternal groups, with some associations between individual 

animals exceeding 15 years (Baird 2000, Baird and Whitehead 2000). Groups are thought to 

usually comprise an adult female and one or two of her offspring (Ford and Ellis 1999, Baird and 

Whitehead 2000). Male offspring typically maintain stronger relationships with their mother 
January 2008 II-13 NMFS 

than female offspring, and such bonds can extend well into adulthood. Unlike residents, 

extended or permanent dispersal of transient offspring away from natal matrilines is common, 

with juveniles and adults of both sexes participating (Ford and Ellis 1999, Baird 2000, Baird and 

Whitehead 2000). Some males depart to become “roving” males. These individuals do not form 

long-term associations with other whales, but live solitarily much of the time and occasionally 

join groups that contain potentially reproductive females (Baird 2000, Baird and Whitehead 

2000). Roving males do not associate together in all-male groups. Females that disperse from 

their maternal matriline appear to be more gregarious than males, but remain socially mobile 

(Baird and Whitehead 2000). 

Transient pods are smaller than those of residents, numbering just one to four individuals (mean 

= 2.4) (Baird and Dill 1996, Ford and Ellis 1999, Baird and Whitehead 2000). Ford and Ellis 

(1999) reported that about 70 percent of all transient groups contained two to six animals 

(median = four), 17 percent had 7-11 animals, 10 percent were lone animals (these are mostly 

males; Baird 1994), and 3 percent had 12-22 individuals. Larger groups result from matrilines 

temporarily joining each other to forage and socialize (Baird and Dill 1995, 1996, Ford and Ellis 

1999, Baird and Whitehead 2000). In comparison with resident killer whales, transient 

matrilines generally maintain more flexible association patterns with one another (Baird and Dill 

1995, Baird 2000). However, some matrilines associate preferentially with certain other 

matrilines, perhaps for reasons of enhanced foraging success (Baird and Dill 1995). As in 

resident clans, all members of the transient community share a related acoustic repertoire, 

although regional differences in vocalizations have been noted (Ford 2002). 

Offshores. The social structure of offshore killer whales has not been studied in detail. These 

whales usually occur in large groups of 20-75 animals, but aggregations of up to 200 whales 

have been recorded (Walters et al. 1992, Ford et al. 2000, Krahn et al. 2002, 2004a). 

Membership patterns within groups appear to be dynamic, with considerable interchange of 

animals noted between sightings (K. C. Balcomb, unpubl. data). 

Vocalizations 

Vocal communication is particularly advanced in killer whales and is an essential element of the 

species’ complex social structure. Like all dolphins, killer whales produce numerous types of 

vocalizations that are useful in navigation, communication, and foraging (Dahlheim and Awbrey 

1982, Ford 1989, Barrett-Lennard et al. 1996, Ford et al. 2000, Miller 2002, Miller et al. 2004, 

Saulitis et al. 2005). Sounds are made by air forced through structures in the nasal passage and 

are enhanced and directed forward by a fatty enlargement near the top of the head, known as the 

melon. Most calls consist of both low- and high-frequency components (Bain and Dahlheim 

1994). The low-frequency component is relatively omnidirectional, with most energy directed 

forward and to the sides (Schevill and Watkins 1966). A fundamental tone between 250-1,500 

Hz and harmonics ranging to about 10 kHz are present in this component. Most of the energy in 

the high-frequency component is beamed directly ahead of the animal. This component has a 

fundamental tone between 5-12 kHz and harmonics ranging to over 100 kHz (Bain and 

Dahlheim 1994). 
January 2008 II-14 NMFS 

Newborn calves produce calls similar to adults, but have a more limited repertoire (Dahlheim 

and Awbrey 1982). As young animals mature, complete call repertoires are most likely 

developed through vocal imitation and learning from association with closely related animals 

rather than being genetically inherited (Bowles et al. 1988, Bain 1989, Ford 1989, 1991, Miller 

and Bain 2000, Yurk et al. 2002, Riesch et al. 2006). Regional differences in call structure and 

vocalization patterns have been recorded from the North Pacific, North Atlantic, and Antarctic 

(Jehl et al. 1980, Thomas et al. 1981, Awbrey et al. 1982, Strager 1995). 

Killer whales produce three categories of sounds: echolocation clicks, tonal whistles, and pulsed 

calls (Ford 1989). Clicks are brief pulses of ultrasonic sound given singly or more often in series 

known as click trains. They are used primarily for navigation and discriminating prey and other 

objects in the surrounding environment, but are also commonly heard during social interactions 

and may have a communicative function (Barrett-Lennard et al. 1996). Barrett-Lennard et al. 

(1996) suggested that killer whales share information obtained from echolocation, but further 

clarification of this possible function is needed (Baird 2000). Individual clicks are highly 

variable in structure, lasting from 0.1 to 25 milliseconds and containing a narrow to broad range 

of frequencies that usually range from 4-18 kHz, but extend up to 50-85 kHz (Diercks et al. 

1973, Awbrey et al. 1982, Ford 1989, Barrett-Lennard et al. 1996, Au et al. 2004). Most click 

trains last 2-8 seconds and have repetition rates of 2-50 clicks per second, but some exceed 10 

seconds or hold as many as 300 clicks per second (Jehl et al. 1980, Ford 1989, Barrett-Lennard et 

al. 1996, Ford et al. 2000). Slower click trains are probably used for navigation and orientation 

on more distant objects, such as other whales and features on the seafloor, whereas rapid click 

rates appear to be used for investigating objects within 10 m (Ford 1989). 

Most whistles are tonal sounds of a fundamental frequency with the addition of several 

harmonics (Thomsen et al. 2001). Whistles have an average dominant frequency of 8.3 kHz 

(range = 2-18.5 kHz), an average bandwidth of 4.5 kHz (range = 0.5-10.2 kHz), and an average 

of 5.0 frequency modulations per whistle (range = 0-71 frequency modulations) (Thomsen et al. 

2001, Riesch et al. 2006). Mean duration is 1.8 seconds (range = 0.06-18.3 seconds). Whistle 

structure is stable over time, although gradual minor changes in some whistle types have been 

detected (Riesch et al. 2006). Whistle repertoires are essentially the same among the three 

Northern Resident clans, but differ substantially from that of the Southern Residents (Riesch et 

al. 2006). Southern Residents produce whistles for both long-range communication (e.g., during 

foraging and slow traveling) and social interactions, whereas the Northern Residents use whistles 

as their primary type of vocalization during close-range social communication (Thomsen et al. 

2002, Riesch et al. 2006). 

Pulsed calls are the most common type of vocalization in killer whales and resemble squeaks, 

screams, and squawks to the human ear. Most calls are highly stereotyped and distinctive in 

structure, being characterized by rapid changes in tone and pulse repetition rate, with some 

reaching up to 4,000 or more pulses per second (Jehl et al. 1980, Ford 1989). Duration is usually 

less than two seconds. Call frequencies often fall between 1-6 kHz, but may reach more than 30 

kHz. Three categories of pulsed calls are distinguishable: discrete, variable, and aberrant (Ford 

1989). Discrete calls have received considerable study and are especially noteworthy because 

they are used repetitively and have stable group-specific structural traits. Discrete calls are the 

predominant sound type during foraging and traveling, and are used for maintaining acoustic 
January 2008 II-15 NMFS 

contact with other group members, especially those out of visual range (Ford 1989, Ford et al. 

2000, Miller 2002). Variable and aberrant calls are given more frequently after animals join 

together and interact socially. Representative sound spectrograms of discrete calls are presented 

in Ford (1989, 1991). 

The vocal repertoires of killer whale pods are comprised of specific numbers and types of 

repetitive discrete calls, which together are known as a dialect (Ford 1991). Dialects are 

complex and stable over time, and are unique to single pods. Call patterns and structure are also 

distinctive within matrilines (Miller and Bain 2000). Individuals likely learn their dialect 

through contact with their mother and other pod members (Ford 1989, 1991, Miller and Bain 

2000). Dialects are probably an important means of maintaining group identity and 

cohesiveness. Similarity in dialects likely reflects the degree of relatedness between pods, with 

variation building through time as matrilines and pods grow and split (Ford 1989, 1991, Bigg et 

al. 1990, Miller and Bain 2000). Researchers have thus far been unable to determine whether 

specific calls have particular meanings or are associated with certain activities. Deecke et al. 

(2000) reported that some calls undergo gradual modification in structure over time, probably 

due to cultural drift, maturational effects, or some combination thereof. 

Dialects of resident killer whale pods contain seven to 17 (mean = 11) distinctive call types (Ford 

1991). Pods with similar vocal dialects make up social groups, known as clans. Transient 

dialects are much different, having only four to six discrete calls, none of which are shared with 

residents (Ford and Ellis 1999, Deecke et al. 2005). All members of the west coast transient 

community possess the same basic dialect, as would be expected due to this population’s fluid 

social system, although some minor regional variation in call types is evident (Ford and Ellis 

1999). Preliminary research indicates that offshore killer whales have group-specific dialects 

unlike those of residents and transients (Ford et al. 2000). 

Hearing and Other Senses 

As with other delphinids, killer whales hear sounds through the lower jaw and other portions of 

the head, which transmit the sound signals to receptor cells in the middle and inner ears (Møhl et 

al. 1999, Au 2002). Killer whale hearing is the most sensitive of any odontocete tested thus far. 

Hearing ability extends from 1 to at least 120 kHz, but is most sensitive in the range of 18-42 

kHz (Szymanski et al. 1999). The most sensitive frequency is 20 kHz, which corresponds with 

the approximate peak energy of the species’ echolocation clicks (Szymanski et al. 1999). This 

frequency is lower than in many other toothed whales. Hearing sensitivity declines below 4 kHz 

and above 60 kHz. Killer whale vision is also considered well developed (White et al. 1971). 

Swimming and Diving Behavior 

The typical swimming pattern of foraging and traveling killer whales is a sequence of three to 

five shallow dives lasting 10-35 seconds each followed by a long dive, with surface blows of 3-4 

seconds occurring after each dive (Erickson 1978, Morton 1990, Ford and Ellis 1999). This 

pattern is typically synchronized among pod members. Dive cycles in resident whales average 

about 3-5 minutes in total length and have a long dive usually lasting 2-4 minutes (Morton 1990; 

Ford and Ellis 1999; Baird et al. 2005). Transients have longer dive cycles, with long dives 
January 2008 II-16 NMFS 

averaging 4-7 minutes (range = 1-17 minutes) (Erickson 1978, Morton 1990, Ford and Ellis 

1999). Cycle lengths and respiration rates vary with activity level (Erickson 1978, Ford 1989, 

Kriete 1995). 

While in the inshore waters of southern British Columbia and Washington, the Southern 

Residents spend 95 percent of their time underwater, nearly all of which is between the surface 

and a depth of 30 m (Baird 2000; Baird et al. 2003, 2005). During a study of 28 whales tagged 

with time-depth recorders from 1993-2002, Baird et al. (2003, 2005) reported an average of 

about 0.7 to two dives per hour made below 30 m, with such dives occurring more often during 

daytime. These represented 5 percent of all dives and occupied less than 2.5 percent of an 

animal’s total dive time. During the day, dives greater than 150 m deep were made on average 

about once every five hours. Overall dive rates were greater during the day than at night, but did 

not differ among pods or with age (Baird et al. 2005). Dive rates below 30 m were also greater 

in adult males than adult females, with adult males diving deeper than 100 m more than twice as 

often as adult females. Maximum dive depths for all ages averaged 141 m, with 10 study 

animals exceeding depths of 190 m. Three-year-old whales reached mean maximum depths of 

134 m, indicating that diving skills are developed fairly early in life (Baird et al. 2005). Much 

less is known about the diving behavior of transients, but one similarly tagged individual spent 

more than 66 percent of its time at depths between 20 and 60 m (Baird 1994). The deepest dives 

reported for killer whales are 264 m by a Southern Resident (Baird et al. 2005) and 260 m by a 

trained animal (Bowers and Henderson 1972). However, Baird et al. (2003) speculated that the 

Southern Residents are probably capable of diving to the deepest portions of the core inland 

waters of their summer range, which reach approximately 330 m. 

Killer whales normally swim at speeds of 5-10 km per hour, but can attain maximum speeds of 

40 km per hour (Lang 1966, Erickson 1978, Kruse 1991, Kriete 1995, Williams et al. 2002a). 

Descent and ascent rates of diving animals typically average 4-6.5 km per hour, or 1.1-1.8 m per 

second, but can sometimes reach velocities of 22-29 km per hour, or 6-8 m per second (Baird 

1994). Bursts of speed during dives commonly occur when prey are chased (Baird et al. 2003). 

Swimming speeds are greater during the day than at night for the Southern Residents (Baird et al. 

2005). 

Diet and Foraging 

As top-level predators, killer whales feed on a variety of marine organisms ranging from fish to 

squid to other marine mammal species. Some populations have specialized diets throughout the 

year and employ specific foraging strategies that reflect the behavior of their prey. Such dietary 

specialization has probably evolved in regions where abundant prey resources occur year-round 

(Ford 2002). Cooperative hunting, food sharing, and innovative learning are other notable 

foraging traits in killer whales (Smith et al. 1981, Lopez and Lopez 1985, Felleman et al. 1991, 

Hoelzel 1991, Jefferson et al. 1991, Hoelzel 1993, Similä and Ugarte 1993, Baird and Dill 1995, 

Boran and Heimlich 1999, Guinet et al. 2000, Pitman et al. 2003, Ford and Ellis 2006). 

Cooperative hunting presumably increases hunting efficiency and prey capture success of group 

members, and may also enhance group bonds. Additionally, group living facilitates knowledge 

of specialized hunting skills and productive foraging areas to be passed traditionally from 
January 2008 II-17 NMFS 

generation to generation (Lopez and Lopez 1985, Guinet 1991, Guinet and Bouvier 1995, Ford et 

al. 1998). Some foraging styles require extensive practice and learning (e.g., Guinet 1991). 

Dietary information was formerly derived primarily through examination of stomach contents 

from stranded whales or those killed during commercial whaling operations, but in recent years, 

direct observations of feeding behavior have added new data on the species’ food habits. Killer 

whales are the only cetacean to routinely prey on marine mammals, with attacks documented on 

more than 35 mammal species, including species as large as blue whales (Balaenoptera 

musculus), fin whales (B. physalus), and sperm whales (Physeter macrocephalus) (Tomilin 1957, 

Tarpy 1979, Hoyt 1990, Jefferson et al. 1991, Dahlheim and Heyning 1999, Pitman et al. 2001). 

Pinnipeds and cetaceans are major prey items for some populations (Zenkovich 1938, Tomilin 

1957, Rice 1968, Hoelzel 1991, Jefferson et al. 1991, Baird and Dill 1996, Ford et al. 1998, 

Dahlheim and Heyning 1999, Melnikov and Zagrebin 2005). Because killer whales probably 

represent the principal predators of many marine mammals, their predation has presumably been 

a major evolutionary influence on the life history of these prey species (Jefferson et al. 1991, 

Corkeron and Conner 1999, Pitman et al. 2001, Deecke et al. 2002). Fish (including tuna, rays, 

and sharks) and squid are other major foods, with penguins, other seabirds, and sea turtles also 

taken (Tomilin 1957, Nishiwaki and Handa 1958, Caldwell and Caldwell 1969, Condy et al. 

1978, Ivashin 1982, Hoyt 1990, Fertl et al. 1996, Similä et al. 1996, Ford et al. 1998, Dahlheim 

and Heyning 1999, Ford and Ellis 1999, Visser 1999b, 2005, Aguiar dos Santos and Haimovici 

2001, Ainley 2002, Visser and Bonoccorso 2003, Pitman and Dutton 2004, Reyes and GarcíaBorboroglu 2004). Killer whales also may remove fish from fishing gear of longlining vessels 

(Dahlheim 1988, Yano and Dahlheim 1995a, 1995b, Secchi and Vaske 1998, Visser 2000a), 

scavenge the discarded bycatch of fisheries operations (Sergeant and Fisher 1957, Dahlheim and 

Heyning 1999), and feed on harpooned whales under tow by whaling ships (Scammon 1874, 

Heptner et al. 1976, Hoyt 1990, Whitehead and Reeves 2005). There are no verified records of 

killer whales killing humans. In general, populations specializing on either fish or marine 

mammals occur at higher latitudes, whereas populations at lower latitudes tend to have generalist 

diets (Forney and Wade in press). 

Residents. Fish are the major dietary component of resident killer whales in the northeastern 

Pacific, with 22 species of fish and one species of squid (Gonatopsis borealis) known to be eaten 

(Scheffer and Slipp 1948, Ford et al. 1998, 2000, Saulitis et al. 2000, Ford and Ellis 2006). 

Observations from this region indicate that salmon are preferred as prey. Most published dietary 

data originate from a single long-term study using focal animal observations and scale and tissue 

sampling that was focused primarily on the Northern Residents during the late spring, summer, 

and fall (Ford et al. 1998, Ford and Ellis 2005, 2006). These techniques are susceptible to bias, 

especially when conducted opportunistically, and may underestimate the extent of feeding on 

bottom fish (Baird 2000). Salmon were found to represent at least 97 percent of Northern 

Resident prey (n = 463), with Chinook salmon (Oncorhynchus tshawytscha) comprising 69 

percent of identified prey. The preference for Chinook was noted among all age and sex classes 

of Northern Residents. This selectivity also occurred despite the much lower numerical 

abundance of Chinook in the study area in comparison to other salmonids and is probably related 

to the species’ large size, high fat and energy content (see Salmon Body Composition), and yearround occurrence in the area (Ford and Ellis 2006). Whales also captured older (i.e., larger) than 

average Chinook. Chum salmon (O. keta), the second largest salmonid in the region, comprised 
January 2008 II-18 NMFS 

25 percent of identified prey and were mostly taken in the fall. Other salmonids were eaten in 

much smaller amounts and included pink (O. gorbuscha, 3 percent of the diet) and coho (O. 

kisutch, 2 percent) salmon. Other species such as Pacific halibut (Hippoglossus stenolepis), a 

number of smaller flatfish, yelloweye rockfish (Sebastes ruberrimus), lingcod (Ophiodon 

elongatus), greenling (Hexagrammos spp.), and Pacific herring (Clupea pallasi) also contributed 

to the diet, but appeared to be eaten in only small amounts during the summer and fall (Ford et 

al. 1998, Ford and Ellis 2006). Similar dietary preferences extended across all three of the 

Northern Resident clans. 

Less dietary information exists for Southern Resident killer whales. Nevertheless, known 

feeding records (n = 115) suggest that diet resembles that of the Northern Residents, with a 

strong preference for Chinook salmon (78 percent of identified prey) during late spring to fall 

(Hanson et al. 2005, Ford and Ellis 2006). Chum salmon (11 percent) are also taken in 

significant amounts, especially in autumn. Other species eaten include coho (5 percent), 

steelhead (O. mykiss, 2 percent), sockeye (O. nerka, 1 percent), and non-salmonids (e.g., Pacific 

herring and quillback rockfish [Sebastes maliger] 3 percent combined). Researchers are 

expanding the sample size for Southern Residents and collecting additional fecal samples for 

analysis to address the potential biases of scale sampling (NWFSC unpublished data.) Chemical 

analyses are another line of evidence supporting the salmon diet results. The toxicology analyses 

of Krahn et al. (2002), who examined the ratios of DDT (and its metabolites) to various PCB 

compounds in the whales, also suggest that the whales feed on salmon rather than other fish 

species. 

Little is known about the winter and early spring foods of Southern and Northern Residents or 

whether individual pods have specific dietary preferences or have shifted preference for different 

prey species over time. New chemical analyses are beginning to provide information on pod diet 

differences and patterns over time. 

Research update 

Future research on the food habits of both populations in more varied locations and throughout 

the year may provide new insights into the patterns described above. 

Krahn et al. (2007) analyzed stable isotopes from tissue samples collected in 1996 and 

2004/2006. Carbon and nitrogen stable isotopes indicated that J and L pods consumed 

prey from similar trophic levels in 2004/2006 and showed no evidence of a large shift 

in the trophic level of prey consumed by L pod between 1996 and 2004/2006. Ratios 

of contaminants in the different pods support observations that J and L pods may be 

occupying different ranges in the winter. L pod had higher DDT ratios, reflecting a 

“California signature,” while J pod had higher relative PCB content, consistent with 

high PCB concentrations in Puget Sound. 
January 2008 II-19 NMFS 

Data gathered thus far for the Southern Alaska Residents also indicate that salmon are heavily 

preferred as prey, with extensive use of coho salmon recorded in Prince William Sound (Saulitis 

et al. 2000) and regular consumption of Chinook salmon in Kenai Fjords (Matkin et al. 2003). 

However, these observations suffer from the limitations reported by Ford et al. (1998) and small 

sample sizes. Western North Pacific resident killer whales also appear to target salmon as prey 

(V. Burkanov, pers. comm. in Krahn et al. 2004a). 

Resident whales have been seen to harass porpoises and harbor seals (Phoca vitulina), but never 

kill to eat them (Ford et al. 1998). Several observations of Southern Residents killing harbor 

porpoises were observed in 2005, but, the porpoises were not consumed (R. W. Baird, 

unpublished data.) 

Resident whales spend about 50-67 percent of their time foraging (Heimlich-Boran 1988, Ford 

1989, Morton 1990, Felleman et al. 1991). Groups of animals often disperse over several square 

kilometers while searching for salmon, with members moving at roughly the same speed (range 

of 3-10 km/hr, mean = 6 km/hr) and direction (Ford 1989, 2002, Ford et al. 1998). Foraging 

episodes usually cover areas of 3-10 km2

 and last 2-3 hours, but may extend up to 7 hours. 

Individual salmon are pursued, captured, and eaten by single animals or small subgroups, usually 

a mother and her young offspring (Scheffer and Slipp 1948, Jacobsen 1986, Osborne 1986, 

Felleman et al. 1991, Ford 1989, Ford et al. 1998). Foraging whales commonly make two or 

three brief shallow dives, followed by a longer dive of 1-3 minutes (Ford et al. 2000). Pursuit of 

prey often involves subtle changes in swimming direction, speed, and dive length, or less 

frequently may be vigorous with rapid chasing or turning (Hanson et al. 2005, Ford and Ellis 

2006). Several whales may occasionally work together to corral fish near the shore, but 

coordinated encirclement of prey has not been observed in Washington or British Columbia 

(Ford 1989, Ford et al. 1998). The large sizes of resident pods may benefit members by 

improving the success rate of locating scattered salmon (Heimlich-Boran 1988, Bigg et al. 1990, 

Hoelzel 1993). Prey are detected through a combination of echolocation and passive listening 

(Barrett-Lennard et al. 1996), whereas vision and echolocation are probably used during prey 

capture. Foraging animals produce rapid series of evenly spaced echolocation clicks, but 

whistles and pulsed calls are also emitted during this activity (Ford 1989). Echolocation signals 

allow salmon to be detected out to distances of about 100 m (Au et al. 2004). More foraging 

may occur during the day than at night (Baird et al. 2005), although inshore feeding possibly 

increases at night (Scheffer and Slipp 1948). There is some evidence that adult resident males 

forage differently than females and immatures, possibly because their larger size makes them 

less maneuverable in shallow waters (Baird 2000, Ford and Ellis 2006). Adult males have been 

noted to hunt in deeper waters than females, dive more deeply than females, and spend more 

time foraging independently on the edges of pods (Ford et al. 1998; Baird et al. 2005, Ford and 

Ellis 2006). Females and subadults occasionally attempt to capture salmon hiding in rock 

crevices near shore, a behavior not seen in adult males. Baird et al. (2005) reported no 

significant differences in the diving behavior of the three Southern Resident pods, suggesting 

that each hunts for prey in a similar manner. 

Recent studies have identified prey sharing as an important aspect of Northern Resident killer 

whale foraging and social behavior (Ford and Ellis 2005). Foraging by resident killer whales 

often involves cooperation among kin-related group members, and prey items are frequently 
January 2008 II-20 NMFS 

shared at the surface by two or more whales after a capture. Ford and Ellis (2006) observed or 

strongly suspected sharing in 76 percent of 235 feeding events. Adult males shared prey much 

less often than females and juveniles. Prey sharing was unrelated to prey size (Ford and Ellis 

2005). The occurrence of prey sharing in Southern Residents has been strongly suspected 

(NWFSC unpubl. data, Cascadia Research unpubl. data) 

Transients. The dietary habits of transients and other mammal-eating killer whale populations 

are summarized in Jefferson et al. (1991), Ford and Ellis (1999), and Wiles (2004). Unlike 

resident whales, transients feed almost entirely on marine mammals. Harbor seals are the most 

important prey item in much of the northeastern Pacific, but other species are regularly taken as 

well, including Dall’s porpoises (Phocenoides dalli), harbor porpoises, Steller’s sea lions 

(Eumetopias jubatus), and California sea lions (Zalophus californianus) (Matkin and Saulitis 

1994, Baird and Dill 1996, Ford et al. 1998, Saulitis et al. 2000, Heise et al. 2003). Predation on 

a variety of other marine mammals, including large whales, is generally less frequent (Jefferson 

et al. 1991, Baird and Dill 1996, Ford et al. 1998, 2005a, Mizroch and Rice 2006, Voes et al. 

2006), although migrating gray whales (Eschrichtius robustus) with calves are apparently 

routinely attacked (Andrews 1914, Morejohn 1968, Rice and Wolman 1971, Jefferson et al. 

1991, Goley and Straley 1994, Ford et al. 1998, Ford 2002). Seabirds are also occasionally 

eaten, but fish are not consumed. 

Transients usually forage in smaller groups than residents, with mean group size numbering from 

three to five whales depending on the prey species (Baird and Dill 1996, Ford et al. 1998, 

2005a). Transients are stealthy hunters and often rely on surprise to capture unsuspecting prey. 

Unlike residents, they are much quieter while foraging, which probably allows them to avoid 

acoustical detection by their wary mammalian prey (Morton 1990, Felleman et al. 1991, BarrettLennard et al. 1996, Ford and Ellis 1999). Transients may instead rely heavily on passive 

listening to detect the sounds of swimming prey (Barrett-Lennard et al. 1996). Vision may also 

be useful (Baird 2000). Transients spend 60-90 percent of daylight hours foraging and 

commonly hunt in both nearshore and open-water habitats (Heimlich-Boran 1988, Morton 1990, 

Baird and Dill 1995, Ford and Ellis 1999). 

A recent theory proposes that predation by mammal-eating killer whales, possibly transients, 

may have been responsible for a series of precipitous population declines in harbor seals, 

northern fur seals (Callorhinus ursinus), Steller’s sea lions, and sea otters (Enhydra lutris) in 

southwestern Alaska between the 1960s and 1990s (Estes et al. 1998, Hatfield et al. 1998, Doroff 

et al. 2003, Springer et al. 2003, Williams et al. 2004). Such predation may have resulted after 

heavy commercial whaling decimated baleen and sperm whale numbers in the North Pacific after 

World War II, perhaps causing at least some killer whales to shift to other prey species (Springer 

et al. 2003). A recent increase in predation on belugas (Delphinapterus leucas) by probable 

transients in Cook Inlet, Alaska, may be due to similar reasons (Shelden et al. 2003). The 

“sequential meagafaunal collapse” theory remains highly controversial and some scientists have 

pointed out the lack of empirical evidence to support the theory. Several authors have recently 

refuted the assumptions that North Pacific mammal-eating killer whales depended on large 

whales as prey either prior to or concurrent with the whaling era, or that a shift toward pinnipeds 

and otters occurred in their diets (DeMaster et al. 2006, Mizroch and Rice 2006). 
January 2008 II-21 NMFS 

Offshores. Little is known about the diets of offshore killer whales. They are suspected to feed 

primarily on fish and squid, based on their frequent use of echolocation, large group sizes, the 

stomach contents of a few animals, a single feeding observation and very limited testing of fatty 

acid concentrations (Ford et al. 2000, Heise et al. 2003, Herman et al. 2005, Jones 2006). Prey 

may include sharks, halibut, and migratory fish (Krahn et al. 2004a, Jones 2006). However, 

preliminary analyses of stable isotopes and organochlorine contaminants in offshores suggest the 

possibility that marine mammals are also eaten (Herman et al. 2005). 

Food requirements. Captive killer whales consume about 3.6-4 percent of their body weight 

daily (Sergeant 1969, Kastelein et al. 2000). Food intake in captive animals gradually increases 

from birth until about 20 years of age (Kriete 1995, Kastelein et al. 2003). For example, a 

captive female ate about 22 kg of fish per day at one year of age, 45 kg per day at 10 years of 

age, and about 56 kg per day at 18 years of age (Kastelein and Vaughan 1989, Kastelein et al. 

2000). Food consumption has also been noted to increase among captive females late in 

pregnancy or while lactating (Kriete 1995, Kastelein et al. 2003). Due to their greater activity 

levels, wild killer whales presumably have greater food demands than captive individuals 

(Kastelein et al. 2003). Osborne (1999) estimated that the energy requirements of killer whales 

are about 85,000 kcal per day for juveniles, 100,000 kcal per day for immatures, 160,000 kcal 

per day for adult females, and 200,000 kcal per day for adult males (Osborne 1999). Baird and 

Dill (1996) reported a somewhat higher mean energy intake of 62 kcal/kg/day among transient 

whales. Williams et al. (2004) estimated about 193,000 and 287,000 kcal per day for adult freeranging females and males, respectively, consuming whole prey. Additional information on 

metabolic rates of wild killer whales is needed to determine whether captive studies 

underestimate requirements of more active wild animals or overestimate requirements because 

captive animals are on a generous weight maintenance diet. 

Based on the average size values for five salmon species combined, Osborne (1999) estimated 

that adult Southern Residents must consume about 28-34 adult salmon daily and that younger 

whales (<13 years of age) need 15-17 salmon daily to maintain their energy requirements. These 

data provided a “rule of thumb” of about 25 salmon per day per whale, estimated over all age 

classes. Extrapolation of this estimate indicates that a Southern Resident population of 90 

whales would eat about 820,000 adult salmon annually (Osborne 1999). This does not, however, 

account for any other prey species and is therefore likely an overestimate of potential salmon 

consumption. The average fish size was based on a combination of five species, so the estimate 

does not account for consumption of varying amounts of different species (and size) of salmon. 

Additional studies have refined the estimates of metabolic needs for killer whales based on new 

information. In an analysis of transient killer whales eating marine mammals, Williams et al. 

(2004) estimated higher metabolic needs for adult free-ranging female and male killer whales 

ranging from 193,000 to 287,000 kcal per day based on field metabolic rates for smaller marine 

mammals and accounting for efficiency in digestion. 
January 2008 II-22 NMFS 

Research update 

Other Behavior 

In addition to foraging, killer whales spend significant amounts of time traveling, resting, and 

socializing (Baird and Dill 1995, Ford 2002, Saulitis et al. 2000). Limited evidence from radiotracking and acoustic monitoring indicates that most behavior patterns are similar during day and 

night (Erickson 1978, Osborne 1986). By comparison, examination of diving behavior and swim 

speeds suggests killer whales are more active in the daytime (Baird et al. 2005). 

Traveling. Whales swimming in a constant direction at a slow, moderate, or rapid pace without 

feeding are considered to be traveling (Jacobsen 1986, Baird and Dill 1995, Ford 1989, Ford and 

Ellis 1999, Ford et al. 2000). This behavior is usually seen among animals moving between 

locations, such as desirable feeding areas. Speeds of about 10 km/hr (range = 4-20 km/hr) are 

maintained, which is usually significantly faster than during foraging. Traveling whales often 

line up abreast in fairly tight formations and commonly surface and dive in synchrony, with 

individuals occasionally jumping entirely out of the water. Resident animals are usually much 

more vocal while traveling than transients (Barrett-Lennard et al. 1996), but may at times be 

silent. In Washington and British Columbia, traveling occupies about 15-31 percent of the total 

activity budget of transients, but only about 4-8 percent of the time of Northern Residents (Ford 

1989, Morton 1990, Baird and Dill 1995). Southern Residents reportedly spend more time 

traveling than Northern Residents (Heimlich-Boran 1988), perhaps because of longer distances 

between their feeding sites (Ford et al. 2000). 

NMFS is continuing to refine the estimates of the prey needs of the Southern Resident 

killer whale DPS. As described above, Osborne’s estimates used broad age groups to 

estimate energy needs of the population and did not distinguish between energy needs 

of males and females. New analyses have refined the energy needs of the population 

by estimating the needs of each individual based on that individual’s age and sex 

(Noren, in review, 2007). Noren estimated the potential range of daily energy 

expenditure for the Southern Resident killer whales of all ages, taking into account 

metabolic needs for growth and lactation. 

Also as described above, Osborne calculated a salmon size by averaging across all 

five salmon species. More recent information demonstrates a strong preference for 

Chinook salmon (Hanson et al. 2005, NWFSC unpubl. data). Using the refined 

estimate of metabolic needs, the new information on Chinook preference, and data on 

fish weights, NMFS estimated that for the summer months (May-September), the 

Southern Residents would need up to 143,000 Chinook and 53,000 other salmon to 

meet their metabolic needs (NMFS 2007a). These numbers are lower than Osborne’s 

because Chinook are larger and provide more calories than Osborne’s generic salmon. 
January 2008 II-23 NMFS 

Resting. This behavior often follows periods of foraging. In resident groups, whales usually 

gather together abreast in a tight formation, with animals diving and surfacing in subdued unison 

(Jacobsen 1986, Osborne 1986, Ford 1989, Baird and Dill 1995, Ford et al. 2000). Individuals 

often arrange themselves according to matriline or pod, and offspring usually swim near or 

touching their mother. Forward motion is slow (mean = 3 km/hr) or stops entirely. Dives and 

surfacings become characteristically regular, with a series of several short shallow surfacings 

lasting 2-3 minutes followed by a longer dive of 2-5 minutes. Resting whales are usually silent, 

except for occasional vocalizations. Resting periods average about 2 hours, but may last from 30 

minutes to 7 hours (Osborne 1986, Ford 1989). Transient whales display similar resting 

behavior, but spend only 2-7 percent of their time resting, compared to 10-21 percent for 

residents (Heimlich-Boran 1988, Ford 1989, Morton 1990, Baird and Dill 1995, Ford and Ellis 

1999, Saulitis et al. 2000). 

Socializing. Killer whales perform numerous displays and interactions that are categorized as 

socializing behaviors (Ford 1989, Ford and Ellis 1999, Ford et al. 2000). During socializing, all 

members of a pod may participate or just a few individuals may do so while others rest quietly at 

the surface or feed. Socializing behaviors are seen most frequently among juveniles and may 

represent a type of play (Jacobsen 1986, Osborne 1986, Ford 1989, Rose 1992). They include 

chasing, splashing at the surface, spyhopping, breaching, fin slapping, tail lobbing, head 

standing, rolling over other animals, and playing with objects such as kelp or jellyfish. 

Descriptions and photographs of these behaviors are presented in Jacobsen (1986) and Osborne 

(1986). Wave riding occasionally takes place in the wakes of vessels and on naturally generated 

waves (Jacobsen 1986, Ford et al. 2000), as does bow-riding in the bow waves of boats 

(Dahlheim 1980). Socializing behavior may involve considerable physical contact among 

animals. All-male subgroups commonly engage in sexual behavior, such as penile erections and 

nosing of genital areas (Haenel 1986, Osborne 1986, Jacobsen 1986, Ford 1989, Rose 1992). 

Play and sexual behavior may help adolescents, especially males, gain courtship skills (Rose 

1992). Whales become especially vocal while socializing and emit a wide range of whistles and 

calls heard infrequently during other activities, such as foraging and resting (Ford 1989, BarrettLennard et al. 1996, Thomsen et al. 2002). Residents spend about 12-15 percent of their time 

engaged in socializing (Heimlich-Boran 1988, Ford 1989, Saulitis et al. 2000). Transient whales 

socialize less than residents and do so most often after successful hunts (Heimlich-Boran 1988, 

Baird and Dill 1995, Ford and Ellis 1999, Saulitis et al. 2000). 

Several differences in socializing behavior have been documented among resident killer whale 

communities in the northeastern Pacific (Ford 1989, Ford et al. 2000). Southern Residents 

perform aerial displays more frequently and with greater vigor than Northern Residents. They 

also engage in a greeting ceremony that occurs when pods meet after being separated for a day or 

more (Osborne 1986, Ford et al. 2000). During this interaction, pods approach each other in two 

tight lines, stop for 10-30 seconds at the surface when 10-50 m apart, then merge underwater 

with considerable excitement, vocalizing, and physical contact. Beach rubbing, which involves 

whales visiting particular beaches to rub their bodies on smooth pebbles in shallow water 

(Jacobsen 1986), is common among Northern Residents, but has never been observed in 

Southern Residents or transients (Ford 1989, Ford et al. 2000). Beach rubbing also occasionally 

occurs among some Southern Alaska Residents inhabiting Prince William Sound (Matkin and 
January 2008 II-24 NMFS 

Saulitis 1994, 1997). These examples are particularly illustrative of the cultural variation that 

can occur among these communities (Whitehead et al. 2004). 

Courtship and mating. Courtship and mating behavior remains poorly documented among wild 

killer whales. Jacobsen (1986) reported some preliminary observations. In captive situations, 

males may court a particular estrous female for 5-10 days and have been noted to copulate with 

anestrous and pregnant females as well (Duffield et al. 1995). It is unknown whether similar 

behavior occurs in the wild. 

Parturition. Stacey and Baird (1997) described various behaviors associated with the birth of a 

resident killer whale, which took place within a pod of 11-13 animals. An individual presumed 

to be the mother was seen making several rapid rotations at the surface during a 30-second 

period. Birth then apparently took place underwater and was immediately followed by three pod 

members lifting the newborn entirely out of the water for several seconds. Unusual swimming 

behavior by the group, bouts of high-speed swimming and percussive activity, and additional 

lifting of the calf was seen during the next two hours. Bouts of nursing take place both 

underwater and at the surface (Jacobsen 1986). Newborn calves in captivity have been observed 

to nurse an average of 32-34 times per day totaling 3.2-3.6 hours per day, with suckling bouts 

lasting a mean of 6.8-7.2 min (Kastelein et al. 2003). 

Alloparental care. Non-reproductive female and male killer whales sometimes tend and give 

parent-like care to young animals that are not their own, a behavior known as alloparental care 

(Haenel 1986, Waite 1988). Older immatures are commonly the recipients of such care after 

their mothers give birth to new calves. Adult males have occasionally been seen to “baby-sit” 

groups of calves and juveniles (Haenel 1986, Jacobsen 1986). 

Care-giving behavior. This behavior is directed at stricken individuals by other members of a 

group (Zenkovich 1938, Tomilin 1957, Caldwell and Caldwell 1966). Ford et al. (2000) 

published an account of one such incident involving a pod comprised of a male, female, and two 

calves in the Strait of Georgia in 1973. One of the calves was struck and severely injured by the 

propeller of a ferryboat. The male and female swam in closely and cradled the injured calf 

between them to prevent it from turning upside-down. The male regularly repositioned itself to 

maintain its location next to the calf. 

Aggressive behavior. Aggressive interactions between killer whales are rarely witnessed. 

Bisther (2002) reported occasional antagonistic encounters involving the displacement of one 

killer whale pod by another at herring feeding sites in Norway, but such behavior has never been 

seen in the northeastern Pacific. The parallel scarring patterns seen on the backs and dorsal fins 

of some killer whales are suggestive of intraspecific aggression (Scheffer 1968, Greenwood et al. 

1974, Jacobsen 1986, Visser 1998). However, some of these markings possibly result instead 

from social interactions or the defensive responses of pinnipeds (Jacobsen 1986, Ford 1989, 

Dahlheim and Heyning 1999). 

Interactions between transients and residents. Resident killer whales are not known to interact 

socially with transient whales. Baird (2000) summarized evidence that members of the two 

communities deliberately avoid one another when traveling on intersecting routes. In 11 
January 2008 II-25 NMFS 

observations where a resident and transient group approached within several kilometers of each 

other, the transients responded by changing their travel direction eight times, while the residents 

did so in three instances. However, on eight other occasions when non-intersecting courses were 

involved, the groups passed within several kilometers of one another without altering their paths. 

Reasons for avoidance are speculative, but may be related to the usually smaller group sizes of 

transients or to perceived threats to vulnerable calves. Residents perhaps show less evasive 

behavior simply because they are unaware of the presence of transient groups, which usually 

forage quietly. A single aggressive interaction between the two forms has been witnessed and 

involved about 13 residents chasing and attacking three transients (Ford and Ellis 1999). 

Alaskan residents and transients similarly avoid contact with each other (Matkin and Saulitis 

1997). 

Movements and Dispersal 

Killer whale movements are generally thought to be far ranging, but detailed information on 

year-round travel patterns is lacking for virtually all populations. Significant time gaps with few 

or no location data exist for all populations, including the well-studied Southern and Northern 

Resident communities. Researchers have relied on non-intrusive observational methods, 

especially photo-documentation and focal group following, to study population distribution and 

movements of individual whales. However, these techniques suffer from seasonal biases in 

viewing effort due to limitations in the distances that observers can travel, inclement weather, 

and seasonal availability of daylight (Baird 2001, Hooker and Baird 2001). A lack of photoidentification work in offshore areas is problematic for many populations (Baird 2000). Radio 

and satellite telemetry technology have been employed on a limited basis and techniques for 

long-term deployments on killer whales are still being developed and refined. 

Many killer whale populations appear to inhabit relatively well-defined seasonal home ranges 

linked to locations of favored prey, especially during periods of high prey abundance or 

vulnerability, such as fish spawning and seal pupping seasons (Jefferson et al. 1991, Reeves et al. 

2002). Killer whale occurrence has been tied to returning salmon in the North Pacific 

(Zenkovich 1938, Balcomb et al. 1980, Heimlich-Boran 1986a, 1988, Felleman et al. 1991, 

Nichol and Shackleton 1996), migrating herring (Clupea harengus) and other fish in the 

northeastern Atlantic (Jonsgård and Lyshoel 1970, Bloch and Lockyer 1988, Christensen 1988, 

Evans 1988, Similä et al. 1996), migrating rorqual whales off eastern Canada (Sergeant and 

Fisher 1957), minke whale presence in southern oceans (Mikhalev et al. 1981, Pitman and Ensor 

2003), seal, sea lion, and elephant seal pupping sites in the southwest Indian Ocean, Argentina, 

and North Pacific (Zenkovich 1938, Tomilin 1957, Norris and Prescott 1961, Condy et al. 1978, 

Lopez and Lopez 1985, Hoelzel 1991, Baird and Dill 1995), and migrating pinnipeds in the 

North Pacific (Zenkovich 1938). Defended territories have not been observed around these or 

other food resources (Dahlheim and Heyning 1999, Baird 2000). 

Clear evidence of annual north-south migrations has not been documented for any killer whale 

population (Baird 2001), although such movements are suspected among some animals visiting 

the Antarctic (Mikhalev et al. 1981, Visser 1999a, Pitman and Ensor 2003). Regional movement 

patterns are probably best known for populations in the northeastern Pacific and may be 

illustrative of movements occurring in other parts of the world. Both resident and transient killer 
January 2008 II-26 NMFS 

whales have been recorded year-round in Washington, British Columbia, and Alaska (HeimlichBoran 1988, Baird and Dill 1995, Olson 1998, Baird 2001). Many pods inhabit relatively small 

core areas for periods of a few weeks or months, but travel extensively at other times. Known 

ranges of some individual whales or pods extend from central California to the Queen Charlotte 

Islands off northern British Columbia (a distance of about 2,200 km) for Southern Residents, 

from southern Vancouver Island to southeastern Alaska (about 1,200 km) for Northern 

Residents, from southeastern Alaska to Kodiak Island (about 1,450 km) for Southern Alaska 

Residents, and from central California to southeastern Alaska (about 2,660 km) for west coast 

transients (Goley and Straley 1994; Dahlheim and Heyning 1999; Krahn et al. 2002; J. K. B. 

Ford and G. M. Ellis, unpubl. data). Both types of whales can swim up to 160 km per day 

(Erickson 1978, Baird 2000), allowing rapid movement between areas. For example, members 

of K and L pods once traveled a straight-line distance of about 940 km from the northern Queen 

Charlotte Islands to Victoria, Vancouver Island, in seven days (J. K. B. Ford and G. M. Ellis, 

unpubl. data). In Alaska, one resident pod journeyed 740 km in six days and another made a 

1,900-km round trip during a 53-day period (Matkin et al. 1997). Transients are believed to 

travel greater distances and have larger ranges than residents (Goley and Straley 1994, Dahlheim 

and Heyning 1999, Baird 2000), as reflected by maximum home range estimates of 140,000 km2

for transients and 90,000 km2

 for residents suggested by Baird (2000). A linear distance of 2,660 

km covered by three transients from Glacier Bay, Alaska, to Monterey Bay, California (Goley 

and Straley 1994), is one of the longest recorded movements by the species (see Guerrero-Ruiz 

et al. 2005). 

Southern Residents. Little information is available on the movements of this community prior to 

the early 1970s, when observers were unaware of the distinction between resident, transient, and 

offshore whales. Scheffer and Slipp’s (1948) report suggests that killer whales in general 

frequented many of the same areas in Washington during the 1930s and 1940s that are currently 

occupied by Southern Residents and transients. They noted that whales, presumably Southern 

Residents, commonly moved into Tulalip Bay and the waters surrounding Camano Island during 

salmon and herring runs. Palo (1972) remarked that killer whales visited southern Puget Sound 

most often during the fall and winter. He added that the whales’ preferred access route to this 

portion of the sound was through Colvos Passage along the west side of Vashon Island and that 

McNeil Island and Carr Inlet were visited annually. These sites were productive areas for 

salmon and herring in the 1960s (Palo 1972). 

Photo-identification work and tracking by boats have provided considerable information on the 

ranges and movements of Southern Resident killer whales since the early 1970s. In addition, 

The Whale Museum in Friday Harbor, Washington has maintained a database since the 1970s 

that includes sightings from researchers as well as opportunistic observations from a variety of 

sources, such as the public, the commercial whale watching industry pager system, the 

Soundwatch Boater Education Program, and land-based sighting from Lime Kiln Point State 

Park (The Whale Museum 2003, 2005). The Whale Museum data set is the most comprehensive 

long-term data set available on broad-scale whale distribution in inland waters. We have used 

this data to create a GIS database and maps (Figure 5). 
January 2008 II-27 NMFS 

Figure 5. Distribution of Southern Resident killer whale sightings from 1990-2005 (The Whale 

Museum 2005). Multiple sightings of whales in the same location on the same day were 

eliminated to reduce bias and resulted in 15,540 unique sightings. 
January 2008 II-28 NMFS 

Figure 6. Monthly occurrence of the three Southern Resident killer whale pods (J, K, and L) in the 

inland waters of Washington and British Columbia, 1976-2005. This geographic area is defined as 

the region east of Race Rocks at the southern end of Vancouver Island and Port Angeles on the 

Olympic Peninsula. Pods were recorded as present during a month if they were sighted on at least 

one day. Data come from a historical sighting archive held at The Whale Museum (2005). 

Southern Resident ranges are best known from late spring to early autumn, when survey effort is 

greatest. During this period, all three Southern Resident pods are regularly present in the 

Georgia Basin (defined as the Georgia Strait, San Juan Islands, and Strait of Juan de Fuca) 

(Heimlich-Boran 1988, Felleman et al. 1991, Olson 1998, Osborne 1999, Hauser 2006), with K 

and L pods typically arriving in May or June and spending most of their time there until 

departing in October or November (Figure 6). However, during this season, both pods make 

frequent trips lasting a few days to the outer coasts of Washington and southern Vancouver 

Island (Ford et al. 2000). 

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 

1976 J,K 

1977 

1978 J,K 

1979 J,K 

1980 

1981 J,K 

1982 J,K J,K 

1983 J,K J,K 

1984 J,K 

1985 J,K 

1986 J,K 

1987 J,K J,K J,K 

1988 J,K 

1989 J,K J,K J,K J,K 

1990 

1991 J,K J,K 

1992 

1993 J,K 

1994 J,L 

1995 

1996 J,K J,K 

1997 J,L J,L J,K 

1998 J,K 

1999 

2000 

2001 

2002 J,K,L? 

2003 J,K 

2004 J,L J,L J,K 

2005 J? J,L 

Only J Pod 

present 

Two pods present, as 

indicated 

J, K, and L pods 

present 

Data not 

available 
January 2008 II-29 NMFS 

While in inland waters during warmer months, all of the pods concentrate their activity from the 

south side of the San Juan Islands through Haro Strait northward to North and South Pender 

Islands and Boundary Passage (Figure 5; Hauser 2006). Less time is generally spent elsewhere, 

including other sections of the Georgia Strait, Strait of Juan de Fuca, and San Juan Islands and 

the Southern Gulf Islands, Rosario Strait, Admiralty Inlet west of Whidbey Island, and Puget 

Sound. Individual pods are generally similar in their preferred areas of use (Olson 1998), 

although some seasonal and temporal differences exist in areas visited (Hauser 2006). For 

example, Swanson Channel and Active Pass are used most often by J pod, but not used by L pod. 

J pod also visits Rosario Strait more frequently than K or L pods. L pod is the only group that 

regularly visits an area in Strait of Juan de Fuca off southern Vancouver Island. Pods probably 

seek out and forage in areas that salmon most commonly occur, especially those associated with 

migrating salmon (Heimlich-Boran 1986a, 1988, but see McCluskey 2006). Many of the most 

important sites reported by Hauser (2006) are major corridors of migrating salmon (Felleman et 

al. 1991; Ford et al. 2000; K. C. Balcomb, unpubl. data). 

During early autumn, Southern Resident pods, especially J pod, expand their routine movements 

into Puget Sound to likely take advantage of chum and Chinook salmon runs (Osborne 1999). In 

recent years, this has become the only time of year that K and L pods regularly occur in the 

Sound. Movements into seldom-visited bodies of water may occur at this time. One noteworthy 

example of such use occurred in Dyes Inlet near Bremerton in 1997. Nineteen members of L 

pod entered the 19-km2

-sized inlet, which is surrounded by urban and residential development, 

on 21 October during a strong run of chum salmon into Chico Creek and remained there until 19 

November, when salmon abundance finally tapered off. The reasons for this long length of 

residence are unclear, but may have been related to food abundance (K. C. Balcomb, pers. 

comm.; D. K. Ellifrit, pers. comm.) or a reluctance by the whales to depart the inlet because of 

the physical presence of a bridge crossing the Port Washington Narrows and associated road 

noise (J. Smith, pers. comm.). Southern Residents (J pod) have also been documented in Hood 

Canal, by sound recordings in 1995 and 1958, a photograph from 1973 and there are also 

anecdotal accounts of historical use, but these may be transient whales. 

Recent analyses by McCluskey (2006) found no clear relationships between the summer and 

early autumn movement patterns of Southern Resident pods and salmon distribution from 1991-

2001. In most years while in inland waters, the total areas covered by each pod and the shape of 

their travel patterns were not linked to areas of high abundance of Chinook, chum, or all salmon 

species combined, as measured through human harvests and catch per unit effort. All three pods 

showed reduced movements during the early 1990s, when overall salmon abundance was higher 

and the Southern Resident population was increasing, than in the late 1990s, when salmon were 

less abundant and the whale population was decreasing. McCluskey (2006) also reported that L 

pod generally traveled over larger areas and showed greater movement complexity than J and K 

pods in all but one year from 1991-2001, which was perhaps related to L pod’s larger size. The 

variable results of this study are indicative of the complexity in the marine ecosystem in the 

Georgia Basin and Puget Sound, as well as the limitations in existing whale and salmon data. 

Late spring to early fall movements of Southern Residents in the Georgia Basin have remained 

fairly consistent since the early 1970s, with strong site fidelity shown to the region as a whole. 
January 2008 II-30 NMFS 

However, some areas of use have changed over time. Visitation of Puget Sound has diminished 

since the mid-1980s, whereas Swanson Channel receives noticeably more use now than in the 

past (K. C. Balcomb, unpubl. data). Long-term differences in the availability of salmon at 

particular sites are one possible explanation for these alterations. Another theory is that certain 

older experienced whales that were knowledgeable of good feeding sites are no longer present to 

direct the movements of their pods to these sites or along favored travel routes. 

During the late fall, winter, and early spring, the ranges and movements of the Southern 

Residents are less well known. J pod continues to occur intermittently in the Georgia Basin and 

Puget Sound throughout this time (Figure 6), but its location during apparent absences is 

uncertain (Osborne 1999). One sighting of this pod was made off Cape Flattery, Washington, in 

March 2004 (Krahn et al. 2004a). Prior to 1999, K and L pods followed a general pattern in 

which they spent progressively smaller amounts of time in inland waters during October and 

November and departed them entirely by December of most years (Figure 6; Osborne 1999). 

Sightings of both groups passing through the Strait of Juan de Fuca in late fall suggested that 

activity shifted to the outer coasts of Vancouver Island and Washington, although it was unclear 

if the whales spent a substantial portion of their time in this area or were simply in transit to 

other locations (Krahn et al. 2002). Since the winter of 1999-2000, K and L pods have extended 

their use of inland waters until January or February each year (Figure 6). The causes behind this 

change are unknown, but may relate to altered food availability, for example, increased 

abundance of chum or hatchery Chinook in these waters or reduced food resources along the 

outer coast (R. W. Osborne, pers. comm.). Thus, since 1999, both pods are completely absent 

from the Georgia Basin and Puget Sound only from about early or mid-February to May or June. 

In recent years, regular use of the waters around Vashon Island in south-central Puget Sound has 

also been documented for all three pods from October to early January (M. Sears, pers. comm.) 

Areas of activity by K and L pods are poorly known during their absences. Only 38 verified 

sightings or strandings of J, K or L pods have occurred along the outer coast from 1975-2007, 

with most made from January to May (Table 2). These include 16 records off Vancouver Island 

and the Queen Charlottes, 11 off Washington, four off Oregon, and seven off central California. 

Most records have occurred since 1996, but this is perhaps more likely due to increased viewing 

effort along the coast rather than a recent change in the pattern of occurrence for this time of 

year. The Southern Residents were formerly thought to range southward along the coast only to 

about Grays Harbor (Bigg et al. 1990) or the mouth of the Columbia River (Ford et al. 2000). 

However, recent sightings of members of K and L pods in Oregon (L pod at Depoe Bay in April 

1999 and Yaquina Bay in March 2000, unidentified Southern Residents at Depoe Bay in April 

2000, and members of K and L pods off of the Columbia River) and California (17 members of 

L pod and four members of K pod at Monterey Bay on 29 January 2000, L71 and probably other 

L pod members at Monterey Bay on 13 March 2003, and members of L pod near the Farallon 

Islands on 16 February 2005 and again off Pt. Reyes on 26 January 2006) have considerably 

extended the southern limit of their known range (Table 2). Both Monterey sightings coincided 
January 2008 II-31 NMFS 

Table 2. Summary of known sightings of Southern Resident killer whales along the outer Pacific 

Ocean coast from California to British Columbia. Adapted and updated from Krahn et al (2004a). 

Date Location Identificationa Comments Sourceb

British Columbia 

31 Jan 1982 Off Barkley Sound, sw Vancouver Island L pod - 1, 2 

21 Oct 1987 Coal Harbour, northern Vancouver Island Part of L pod Whales were far up an inlet 2 

3 May 1989 Tofino, west-central Vancouver Island K pod - 3 

4 Jul 1995 Hippa Island, s Queen Charlotte Islands Southern Resident Strandedc

 2 

May 1996 Cape Scott, northern Vancouver Island Southern Resident Strandedc

 2 

4 Sep 1997 Carmanah Point, sw Vancouver Island L pod - 4, 5 

14 Apr 2001 Tofino, west-central Vancouver Island L pod - 2 

27 Apr 2002 Tofino, west-central Vancouver Island L pod - 2 

12 May 2002 Tofino, west-central Vancouver Island L pod - 2 

30 May 2003 Langara Island, n Queen Charlotte Islands L pod - 6 

17 May 2004 Tofino, west-central Vancouver Island K and L pods - 6 

9 Jun 2005 West of Cape Flattery, Washington, in 

Canadian waters 

L pod - 7 

7 Sep 2005 West of Cape Flattery, Washington, in 

Canadian waters 

L pod - 8 

18 Mar 2006 North of Neah Bay, Washington, in Canadian 

waters 

J pod Whales were exiting the 

Strait of Juan de Fuca 

8 

8 May 2006 Off Brooks Peninsula, nw Vancouver Island L pod - 2 

1 Dec 2007 Johnstone Strait L pod - 2 

Washington 

4 Apr 1986 Off Westport/Grays Harbor L pod - 2, 9 

13 Sep 1989 West of Cape Flattery L pod - 10 

17 Mar 1996 3 km offshore Grays Harbor L pod - 10 

20 Sep 1996 Off Sand Point (29 km so. of Cape Flattery) L pod - 4, 5 

15 Apr 2002 Long Beach L60 Stranded 11, 12 

11 Mar 2004 Off Grays Harbor L pod - 8 

13 Mar 2004 Off Cape Flattery J pod Whales were exiting the 

Strait of Juan de Fuca 

8 

22 Mar 2005 Fort Canby-North Head L pod - 8 

23 Oct 2005 Off Columbia River K pod - 7 

29 Oct 2005 Off Columbia River K and L pods - 7 

6 Apr 2006 Westport K and L pods - 13 

Oregon 

Apr 1999 Off Depoe Bay L pod - 2 

21 Mar 2000 Off Yaquina Bay L pod Seen week of March 20 2 

14 Apr 2000 Off Depoe Bay Southern Resident - 12 

30 Mar 2006 Off Columbia River K and L pods - 8 

California 

29 Jan 2000 Monterey Bay K and L pods Feeding on fish (Chinook?) 14, 15 

13 Mar 2003 Monterey Bay L pod - 14, 16 

16 Feb 2005 Farallon Islands L pod - 12 

26 Jan 2006 Pt. Reyes L pod - 17 

24 Jan 2007 San Francisco K pod - 12, 14 

18 Mar 2007 Fort Bragg L pod - 12 

24 Mar 2007 Monterey Bay K and L pods - 14 

a

 Pod listings do not imply that the entire pod was present.b Sources: 1, Ford et al. (2000); 2, J. K. B. Ford, Pacific Biological Station, 

Department of Fisheries and Oceans Canada, Nanaimo, British Columbia; 3, The Whale Museum sighting archives (1978–2006), 

Friday Harbor, Washington; 4, P. Gearin, National Marine Mammal Laboratory, Alaska Fisheries Science Center, Seattle, 

Washington; 5, D. Ellifrit, Center for Whale Research, Friday Harbor, Washington; 6, M. Joyce, Fisheries and Oceans Canada, 

Vancouver, British Columbia; 7, Southwest Fisheries Science Center, La Jolla, California; 8, Northwest Fisheries Science Center, 

Seattle, Washington; 9, Bigg et al. (1990); 10, Calambokidis et al. (2004); 11, D. Duffield, Portland State University, Portland, 

Oregon; 12, K. C. Balcomb, Center for Whale Research, Friday Harbor, Washington; 13 Cascadia Research Collective, Olympia, 

Washington; 14, N. A. Black, Monterey Bay Whale Watch, Pacific Grove, California; 15, Black et al. (2001); 16, Monterey Bay 

Whale Watch (2003); 17, S. Allen, National Park Service, Pt. Reyes, California. c Carcass identified by genetic testing. 
January 2008 II-32 NMFS 

with large runs of salmon, with feeding witnessed in 2000 (Black et al. 2001). L pod was also 

seen feeding on unidentified salmon off Westport, Washington, in March 2004 during the spring 

Chinook run in the Columbia River (M. B. Hanson, pers. obs., in Krahn et al. 2004a). 

Research update 

Available information suggests that K and L pods travel to northern Vancouver Island and 

occasionally to the Queen Charlotte Islands during May and June. Multiple sightings have been 

made during this period near Tofino on the west-central coast of Vancouver Island (Krahn et al. 

2004a). Both pods sometimes make their initial spring entry into the Strait of Georgia via 

Johnstone Strait (Ford et al. 2000), implying regular movement around the northern end of 

Vancouver Island. On 28 May 2003, members of both pods were identified for the first time in 

the Queen Charlotte Islands, when a group of 30 or more whales was viewed off Langara Island 

(54°15'N, 133°02'W) at the north end of the island group about 46 km south of Alaska (J. K. B. 

Ford and G. M. Ellis, unpubl. data). Other records from this region include the carcass of an 

unidentified Southern Resident (recognized through genetic testing) that was found on the west 

coast of the Queen Charlottes in June 1995 (Ford et al. 2000) and another dead individual found 

off Cape Scott at the northwestern tip of Vancouver Island in May 1996 (J. K. B. Ford, pers. 

comm.). To date, there is no evidence that the Southern Residents travel more than 50 km 

offshore (Ford et al. 2005b). 

Due to extensive changes in distribution and abundance in many salmon stocks along the North 

American west coast during the past 150 years, it is possible that the current movement patterns 

of the Southern Residents are somewhat different from those of several centuries ago. In 

particular, there is speculation that the whales may have once been regularly attracted to the 

Columbia River mouth or Central Valley, where immense numbers of salmon previously 

returned during their spawning migrations. Morin et al. (2006) has recently attempted to assess 

the extent of past movements of these whales to California by examining mitochondrial DNA 

from specimens collected there from the mid-1800s to 1979. No Southern Residents were found 

in the sample (i.e., only transient and offshore haplotypes were detected). Although this outcome 

is not conclusive proof that Southern Residents did not historically visit Californian waters, it 

does suggest that such movements may have been infrequent or highly seasonal during the past 

150 years. 

Northern Residents. Despite considerable overlap in their full geographic distributions (Figure 

3), Southern and Northern Residents maintain separate ranges during most of the year. Some 

Northern Resident pods are seen most predictably from June to October in western Johnstone 

Strait and Queen Charlotte Strait, where occurrence is closely associated with salmon 

In addition to the sighting information, killer whale vocalizations were recorded by 

hydrophones in coastal waters (NWFSC unpubl. data) off Westport, Cape Flattery and 

British Columbia. Successive recordings, in combination with sightings, will provide 

insight into the direction the whales were traveling and how far they may be moving in 

short periods of time giving us a better understanding of coastal habitat use.
January 2008 II-33 NMFS 

congregating to enter spawning rivers (Morton 1990, Nichol and Shackleton 1996, Ford et al. 

2000). However, the majority of animals occur farther north during this season in passages and 

inlets of the central and northern British Columbia coast, in Hecate Strait and Queen Charlotte 

Islands, and reaching Frederick Sound in southeastern Alaska (Nichol and Shackleton 1996, 

Dahlheim et al. 1997, Ford et al. 2000). Less information is available on the winter distribution 

of Northern Residents, but use of Johnstone Strait and neighboring areas declines markedly 

during this time (Morton 1990, Nichol and Shackleton 1996). The two communities occur 

sympatrically at times during the spring, when some Southern Residents visit northern 

Vancouver Island and the Queen Charlotte Islands (Osborne 1999, Ford et al. 2000). Northern 

Resident pods have been rarely documented in Washington State at locations as far south as 

Willipa Bay (Calambokidis et al. 2004, Wiles 2004; D. K. Ellifrit, unpubl. data; J. K. B. Ford, 

unpubl. data, NWFSC, unpubl. data). 

West coast transients. This is the only transient community that overlaps in range with the 

Southern Residents, being distributed from the Los Angeles area of southern California to the Icy 

Strait and Glacier Bay region of southeastern Alaska (Figure 4; Ford and Ellis 1999, Baird 2001, 

Barrett-Lennard and Ellis 2001; N. A. Black, pers. comm.). Transient whales are considered 

farther ranging and more unpredictable in their daily movements than residents. Detailed 

information on seasonal movements is not available because of the relatively few identifications 

made of nearly all individuals. In contrast to the Southern Residents, transient patterns of 

occurrence show less seasonal change in abundance and distribution, which probably relates to 

the year-round presence of their marine mammal prey (Ford and Ellis 1999). Based on photoidentification records, some transients are regularly seen in particular sub-regions (e.g., 

moderately sized areas of British Columbia and southeastern Alaska), whereas other individuals 

travel across much of the community’s geographic range (Ford and Ellis 1999). Regional-scale 

movements are evident in many of the transients identified in British Columbia or Washington, 

with slightly more than half (111 of 206 animals) having been sighted in southeastern Alaska 

(Dahlheim et al. 1997, Ford and Ellis 1999). About 13 percent of the individuals photographed 

off California have been observed in Washington, British Columbia, or Alaska (Black et al. 

1997). Most transient sightings in Washington and around Vancouver Island occur in the 

summer and early fall, when viewing effort is greatest and harbor seals pup (Morton 1990, Baird 

and Dill 1995, Olson 1998, Ford and Ellis 1999). Observations in the Georgia Basin and Puget 

Sound are concentrated around southeastern Vancouver Island, the San Juan Islands, and the 

southern edge of the Gulf Islands (Olson 1998; K. C. Balcomb, unpubl. data). Several unusual 

cases of transients remaining for extended periods of time in relatively small areas have been 

documented, including two different groups that spent 59 days in 2003 and 172 days in 2005 in 

Hood Canal in Puget Sound (London 2006). Additional information on the movements of this 

community is summarized in Ford and Ellis (1999) and Wiles (2004). 

Offshores. The offshore community is distributed from the area north of Los Angeles in 

southern California to the eastern Aleutian Islands (Ford and Ellis 1999; M. E. Dahlheim, 

unpubl. data; N. A. Black, pers. comm.), giving it the largest geographic range of any killer 

whale community in the northeastern Pacific. However, movements of individual animals are 

poorly understood due to the small numbers of verified observations. At least 20 of the 

approximately 200 individuals photographed in Washington, British Columbia, and Alaska have 

been sighted in California (Black et al. 1997; M. E. Dahlheim, unpubl. data), indicating that 
January 2008 II-34 NMFS 

some members of the population travel long distances. Such travel patterns may be related to the 

movements of migratory fish that are possibly eaten (Krahn et al. 2004a). Offshore killer whales 

primarily inhabit offshore locations, but are also seen in nearshore coastal waters and 

occasionally in inland waters (see summary in Wiles 2004). 

Dispersal among residents and transients. Social dispersal, in which an animal more-or-less 

permanently departs its natal group to live alone or in association with unrelated individuals 

while remaining part of the breeding population, has never been recorded in resident killer 

whales, which maintain highly stable social bonds throughout their lives (Bigg et al. 1990, Baird 

2000, Ford et al. 2000). By comparison, such dispersal is believed to occur commonly in 

transient whales, with juveniles and adults of both sexes participating (Ford and Ellis 1999, Baird 

2000, Baird and Whitehead 2000). In doing so, dispersing transients continue to occupy their 

large natal geographic ranges throughout their lives. 

Several instances of young solitary resident killer whales found away from their natal pods have 

been recorded in Washington and British Columbia (Balcomb 2002), but likely represent 

orphaned or poorly nurtured individuals that became separated from their pods rather than true 

examples of dispersal. Animals such as these are believed to usually die rather than reestablish 

permanent bonds with other resident whales. A73, a one-year old Northern Resident female calf, 

appeared in Puget Sound in late 2001 or early 2002 far from her expected range and eventually 

took up residence near Seattle. She remained there until being captured in June 2002, after 

which she was translocated back to Canadian waters and was successfully reunited with her natal 

pod in Johnstone Strait (Norberg et al. 2003). A73 has subsequently been seen with her pod in 

the summers of 2003 through 2007. This individual suffered from declining health prior to its 

capture and would have likely died without human intervention. L98, a Southern Resident male, 

was discovered in Nootka Sound on western Vancouver Island in July 2001 after apparently 

becoming separated from L pod at about 2 years of age and resided alone there until 2006. L98 

engaged in frequent interactions with vessels and float planes, resulting in minor injuries to 

himself and property damage. One unsuccessful capture attempt was conducted in 2004. DFO 

and the local Mowachaht /Muchalaht first nations band conducted monitoring programs to 

educate boaters to stay away from L98. L98 was killed by a tugboat in March 2006. 

Habitat Use 

Killer whales frequent a variety of marine habitats that are likely sources of adequate prey 

resources and do not appear to be constrained by water depth, temperature, or salinity (Baird 

2000). Although the species occurs widely as a pelagic inhabitant of open ocean, many 

populations spend large amounts of time in shallower coastal and inland marine waters, foraging 

even in inter-tidal areas in just a few meters of water. Killer whales tolerate a range of water 

temperatures, occurring from warm tropical seas to polar regions with ice floes and near-freezing 

waters. Brackish waters and rivers are also occasionally entered (Scheffer and Slipp 1948, 

Tomilin 1957). Individual knowledge of productive feeding areas and other special habitats 

(e.g., beach rubbing sites) is probably an important determinant in the selection of locations 

visited and is likely a learned tradition passed from one generation to the next (Ford et al. 1998). 
January 2008 II-35 NMFS 

Residents. Resident and transient killer whales exhibit somewhat different patterns of habitat use 

while in protected inland waters, where most observations are made (Heimlich-Boran 1988, 

Morton 1990, Felleman et al. 1991, Baird and Dill 1995, Matkin and Saulitis 1997, Scheel et al. 

2001). Residents generally spend more time in deeper water and only occasionally enter water 

less than 5 m deep (Heimlich-Boran 1988, Baird 2000, 2001, Hauser 2006). Distribution is 

strongly associated with areas of greater salmon abundance (Heimlich-Boran 1986a, 1988, 

Felleman et al. 1991, Nichol and Shackleton 1996), but research to date has yielded conflicting 

information on preferred foraging habitats. Several studies have reported that Southern 

Residents feed heavily in areas characterized by high-relief underwater topography, such as 

subsurface canyons, seamounts, ridges, and steep slopes (Heimlich-Boran 1988, Felleman et al. 

1991). Such features may concentrate prey, thereby resulting in greater prey availability, and be 

used by the whales as underwater barriers to assist in herding fish (Heimlich-Boran 1988). The 

primary prey at greater depths may be Chinook salmon, which swim at depths averaging 25-80 

m and extending down to 300-400 m (Candy and Quinn 1999). Other salmonids mostly inhabit 

the upper 30 m of the water column (Quinn and terHart 1987, Quinn et al. 1989, Ruggerone et al. 

1990, Ishida et al. 2001). Hauser (2006) also reported an overall tendency for the Southern 

Residents to occur in areas of steeper topography. 

In contrast, Hoelzel (1993) reported no correlation between the feeding behavior of residents and 

bottom topography, and found that most foraging took place over deep open water (41 percent of 

sightings), shallow slopes (32 percent), and deep slopes (19 percent). Ford et al. (1998) 

described residents as frequently foraging within 50-100 m of shore and using steep nearshore 

topography to corral fish. Both of these studies, plus those of Baird et al. (2003, 2005), have 

reported that most feeding and diving activity occurs in the upper 30 m of the water column, 

where most salmon are distributed (Stasko et al. 1976, Quinn and terHart 1987, Quinn et al. 

1989, Ruggerone et al. 1990, Olson and Quinn 1993, Nichol and Shackleton 1996, Candy and 

Quinn 1999, Baird 2000). Additionally, Chinook salmon occupy nearshore habitats more so than 

other salmonids (Stasko et al. 1976, Quinn et al. 1989). Reasons for the discrepancies between 

studies are unclear, but may result from interpod variation and differences in study methodology 

(Nichol and Shackleton 1996, Baird 2001). Baird et al. (2005) have recently reported a shift to 

shallower daytime depths among Southern Residents between 1993 and 2002, which possibly 

reflects long-term changes in prey behavior or selection of prey. Other behaviors, such as resting 

and socializing, are performed in open water with varied bathymetry (Heimlich-Boran 1988, 

Felleman et al. 1991). 

Habitat use patterns for Southern Resident pods visiting the outer coast are virtually unknown. 

Sightings of Southern Residents off the coast of Washington, Oregon, and California indicate 

that they are utilizing resources in the California Current ecosystem in contrast to other North 

Pacific resident pods that exclusively use resources in the Alaskan Gyre system. 

Habitat use may be affected by anthropogenic factors such as sound. A study in British 

Columbia documented a change in habitat use of killer whales in response to installation of 

acoustic harassment devices (AHDs) at fish farms (Morton and Symonds 2002). Both residents 

and transients were sighted less frequently in one area while AHDs were in use, while in a 

similar area in the region where AHDs were absent, killer whale presence remained relatively 

stable during the same time period. Morton and Symonds (2002) noted that long-term 
January 2008 II-36 NMFS 

displacement of whales by sound sources is difficult to document and the exact mechanism by 

which sound can displace marine mammals is poorly understood. 

Transients. Transient whales also occupy a wide range of water depths, including deep areas 

exceeding 300 m. However, transients show greater variability in habitat use than residents, with 

some groups spending most of their time foraging in shallow waters close to shore and others 

hunting almost entirely in open water (Heimlich-Boran 1988, Felleman et al. 1991, Baird and 

Dill 1995, Matkin and Saulitis 1997). Small bays and narrow passages are entered, in contrast to 

residents (Morton 1990, Scheel et al. 2001). Groups using nearshore habitats often concentrate 

their activity in shallow waters near pinniped haul-out sites. While foraging, these whales often 

closely follow the shoreline, entering small bays and narrow passages, circling small islets and 

rocks, and exploring inter-tidal areas at high tides. Transients that spend more time in open 

water probably prey more frequently on porpoises as well as pinnipeds. 

Occurrence along outer coastlines. Abundance patterns of killer whales are poorly known for 

many outer coastal areas of western North America. Several studies off Washington and Oregon 

have reported relatively low encounter rates during shipborne and aerial surveys, with most 

sightings made along the continental shelf within about 50 km of land (Green et al. 1992, 1993, 

Shelden et al. 2000). Very few observations during these studies were identifiable to community 

type. Killer whales were encountered somewhat more often during another study by 

Calambokidis et al. (2004), who conducted summer ship surveys off the Olympic Peninsula from 

1995-2002. These researchers detected transient whales most frequently, but members of the 

Southern and Northern Resident and offshore communities were also observed. Sightings were 

made predominantly at mid-shelf depths averaging 100-200 m and at distances of 40-80 km from 

land. Killer whales were also occasionally observed during another series of shipboard transects 

conducted off California, Oregon, and Washington from 1991-2001, although community type 

was again not determined (Barlow 2003, Carretta et al. 2004). 

Use of rivers. Killer whales in the northeastern Pacific occasionally enter the lower reaches of 

rivers while foraging. Use of the lower Fraser River by resident killer whales has been reported 

(Baird 2001, pers. comm.) and may have involved animals in pursuit of salmon. Transients have 

been recently recorded in several rivers or river mouths in Oregon (K. C. Balcomb, unpubl. 

data). Several instances of whales ascending up to 180 km up the Columbia River are known 

from the 1930s and 1940s (Shepard 1932, Scheffer and Slipp 1948), but it is not known whether 

these animals were resident or transient whales. 

Critical habitat under the ESA. The ESA requires that NOAA and the U.S. Fish and Wildlife 

Service designate critical habitat for species that have been listed as threatened or endangered. 

In so doing, the agencies must use the best scientific information available, in an open public 

process, within specific timeframes. The ESA defines critical habitat as specific areas: 1) within 

the geographical area occupied by the species at the time of listing, if they contain physical or 

biological features essential to conservation, and those features may require special management 

considerations or protection; and 2) outside the geographical area occupied by the species if the 

agency determines that the area itself is essential for conservation. Before designating critical 

habitat, careful consideration must be given to the economic impacts, impacts on national 

security, and other relevant impacts of specifying any particular area as critical habitat. The 
January 2008 II-37 NMFS 

Secretary of Commerce may exclude an area from critical habitat if the benefits of exclusion 

outweigh the benefits of designation, unless excluding the area will result in the extinction of the 

species concerned. 

In November 2006, NMFS designated critical habitat for Southern Resident killer whales. The 

designated area – just over 2,500 square miles -- encompasses parts of Haro Strait and the U.S. 

waters around the San Juan Islands, the Strait of Juan de Fuca and all of Puget Sound (Figure 7). 

We proposed critical habitat in June 2006, held public meetings, reviewed all comments and new 

information provided by the public and other reviewers, and incorporated minor revisions into 

the final designation (NMFS 2006a, 71 FR 69054). 

Based on the natural history of the Southern Residents and their habitat needs, we identified the 

following physical or biological features essential to conservation: (1) water quality to support 

growth and development; (2) prey species of sufficient quantity, quality and availability to 

support individual growth, reproduction and development, as well as overall population growth; 

and (3) passage conditions to allow for migration, resting, and foraging. From the sightings and 

other data, we identified three "specific areas," within the geographical area occupied by the 

species, containing these features. We considered presence and movements of the whales, 

behavioral observations and studies, and other information to verify that one or more of the 

physical or biological features can be found in these three areas. We designated three specific 

areas, (1) the Summer Core Area in Haro Strait and waters around the San Juan Islands; (2) 

Puget Sound; and (3) the Strait of Juan de Fuca, which comprise approximately 2,560 square 

miles of marine habitat within the area occupied by Southern Resident killer whales in 

Washington (Figure 7). We did not have sufficient information to consider Hood Canal as 

occupied at the time of listing. Critical habitat includes all waters relative to a contiguous 

shoreline delimited by the line at a depth of 20 feet relative to extreme high water. Some of 

these areas overlap with military sites, which are not designated as critical habitat because they 

were determined to have national security impacts that outweigh the benefit of designation and 

were therefore excluded under ESA section 4(b)(2). We concluded that exclusion of these areas 

would not result in extinction of the Southern Residents. We determined that the economic 

benefits of exclusion of any of the areas did not outweigh the benefits of designation, and we 

therefore did not exclude any areas based on economic impacts. We did not designate coastal or 

offshore areas, though we do recognize that they are important for the Southern Resident killer 

whales and anticipate additional information on coastal habitat use from research projects in the 

coming years. 
January 2008 II-38 NMFS 

Figure 7. Designated critical habitat for Southern Resident killer whales.
January 2008 II-39 NMFS 

Reproduction and Growth 

Much of the information on reproduction and growth in killer whales comes either from 

observations of animals held in captivity or from long-term photo-identification studies of the 

resident whale communities in Washington, British Columbia, and Alaska (Olesiuk et al. 1990a, 

2005, Matkin et al. 2003). Variation in these parameters can be expected in other populations 

(Ford 2002). 

Mating system. Killer whales are polygamous (Dahlheim and Heyning 1999). Paternity 

analyses using microsatellite DNA indicate that resident males nearly always mate with females 

outside of their own pods, thereby reducing the risks of inbreeding (Barrett-Lennard 2000, 

Barrett-Lennard and Ellis 2001). Differences in dialects very likely assist animals in determining 

the degree of relatedness among prospective mating partners, with female choice probably being 

the major factor in the mating success of males (Ford 1989, 1991, Ford et al. 2000, Yurk et al. 

2002). Only physically mature males are known to sire calves (Olesiuk et al. 2005). 

Mating season and estrous activity. Most mating in the North Pacific is believed to occur from 

April to October (Nishiwaki 1972, Olesiuk et al. 1990a, 2005, Matkin et al. 1997). However, 

small numbers of conceptions apparently happen year-round, as evidenced by births of calves in 

all months. 

Captive adult females experience periods of multiple estrous cycling interspersed with intervals 

of non-cycling (Walker et al. 1988, Robeck et al. 1993, 2005, Duffield et al. 1995). The lengths 

of these periods are highly variable, both within an individual and a population. Estrous cycle 

lengths average 41-44 days (range = 18-91 days), with a mean of four cycles (range = 1-12 

cycles) during polyestrous. Non-cycling intervals last an average of 7-8 months (range = 3-16 

months) (Robeck et al. 1993, Duffield et al. 1995). Profiles of reproductive hormones during 

ovarian cycles and pregnancy in captive females are presented by Walker et al. (1988), Duffield 

et al. (1995), and Robeck et al. (2005). 

Calving interval. Estimates of calving intervals, defined as the length of time between the births 

of surviving calves, average from 4.9 to 7.7 years (range = 2-14 years) in resident killer whales 

(Olesiuk et al. 1990a, 2005, Krahn et al. 2002, 2004a, Matkin et al. 2003) and range from 3.0-8.3 

years for other populations in the North Atlantic and Antarctica (Christensen 1984, Perrin and 

Reilly 1984). Females in captivity have produced calves 2.7-4.8 years apart (Duffield et al. 

1995). Some females may become pregnant again relatively soon after the loss of a calf. Hoyt 

(1990) cited a captive female that gave birth 19 months after the death of her previous newborn 

calf and Olesiuk et al. (2005) noted three Northern Resident females that lost calves and were 

seen with new calves two summers later. Jacobsen (1986) observed copulation in a wild female 

that had given birth to and then lost a calf the previous year. Calving interval does not appear to 

be affected by a female’s age (Olesiuk et al. 2005). Several authors have suggested that birth 

rates in some populations may be density dependent (Fowler 1984, Kasuya and Marsh 1984, 

Brault and Caswell 1993, Dahlheim and Heyning 1999). However, no study has confirmed this 

trait among resident whales in the northeastern Pacific (Taylor and Plater 2001 Olesiuk et al. 

2005). Olesiuk et al. (1990a) reported mean annual pregnancy rates of 52.8 percent for resident 
January 2008 II-40 NMFS 

females of reproductive age and 35.4 percent for all mature resident females in Washington and 

British Columbia. 

Gestation period. Gestation periods in captive killer whales average about 17 months (mean ±

SD = 521 ± 20 days, range = 468-554 days) (Asper et al. 1988, Walker et al. 1988, Duffield et al. 

1995, Robeck et al. 2005). Fetal development and morphology have been described in several 

studies (Turner 1872, Guldberg and Nansen 1894, Benirschke and Cornell 1987). 

Calving season and characteristics of newborns. In resident killer whales, births occur largely 

from September to December (and probably extending through the winter), but can take place 

during any month (Olesiuk et al. 2005). Parturition dates are thought to be mainly from 

November to February in the North Atlantic (Jonsgård and Lyshoel 1970, Evans 1988) and from 

January to April in the Antarctic, which corresponds there to the late austral summer (Anderson 

1982). Only single calves are born. Several previous reports of twins (e.g., Olesiuk et al. 1990a, 

Baird 2000) have proven erroneous (Ford and Ellis 1999). Nearly all calves are born tail-first 

(Duffield et al. 1995). Newborns measure 2.2-2.7 m long and weigh about 200 kg (Nishiwaki 

and Handa 1958, Olesiuk et al. 1990a, Clark et al. 2000, Ford 2002). Heyning (1988) reported a 

mean length of 2.36 m in northeastern Pacific calves. Sex ratios at birth are probably 1:1 

(Dahlheim and Heyning 1999). Taylor and Plater (2001) reported a sex ratio of 57 percent males 

among 65 Southern Resident calves born after 1973, but this did not differ significantly from a 

1:1 sex ratio. 

Development and growth of young. Calves remain close to their mothers during their first year 

of life, often swimming slightly behind and to the side of the mother’s dorsal fin. Weaning age 

remains unknown, but nursing probably ends at 1-2 years of age (Haenel 1986, Asper et al. 1988, 

Kastelein et al. 2003). Tooth eruption begins from several to 11 weeks of age, which is about the 

time that calves begin taking solid food from their mothers (Haenel 1986, Asper et al. 1988, 

Heyning 1988, Kastelein et al. 2003). Asper et al. (1988) reported a captive calf that consumed 

6.6 kg of fish per day at 5 months of age and 22 kg per day of fish and squid at 15 months of age. 

Another captive animal increased its food consumption from about 22 kg per day at one year of 

age to about 45 kg at 10 years of age (Kastelein and Vaughan 1989). As young killer whales 

grow older, they spend increasing amounts of time with siblings and other pod members (Haenel 

1986). Juveniles are especially active and curious. They regularly join subgroups of several 

other youngsters and participate in chasing, leaping, and high-speed porpoising. Young males of 

2-6 years of age also engage in displays of sexual behavior. Among resident whales, maternal 

associations slowly weaken as juveniles reach adolescence (Haenel 1986), but typically continue 

well into adulthood. 

Studies to date have yielded somewhat contradictory information on growth patterns of killer 

whales, which may partially reflect population differences and whether or not the animals were 

wild or captive. Christensen (1984) indicated that males and females displayed similar growth 

rates up to about 15 years of age, but Clark et al. (2000) found that males had lower growth rates 

than females during the ages of one to six. Several studies have reported linear growth rates 

during the first nine to 12 years for females and first 12 to 16 years in males, after which growth 

slows in both sexes (Bigg 1982, Duffield and Miller 1988). Annual growth rates for captive 

juveniles originating from the northeastern Pacific averaged 38 cm per year (range = 26-52 cm 
January 2008 II-41 NMFS 

per year), but fell into two categories for animals from the North Atlantic, averaging 21 cm per 

year (range = 17-25 cm per year) in one group and 39 cm per year (range = 31-48 cm per year) in 

a second group (Duffield and Miller 1988). For youngsters one to six years of age, Clark et al. 

(2000) reported mean growth rates of 28 cm and 182 kg per year for males and 36 cm and 248 kg 

per year for females. Based on whaling data, Christensen (1984) suggested that male killer 

whales enter a period of sudden growth during adolescence. The validity of this finding has been 

questioned (Duffield and Miller 1988, Baird 2000), but measurements taken by Clark and Odell 

(1999) support Christensen’s (1984) hypothesis. Both sexes continue to grow until physical 

maturity is reached at about 16-25 years of age (Christensen 1984, Kastelein et al. 2000 Olesiuk 

et al. 2005). Bigg and Wolman (1975) calculated the relationship between body length and 

weight in both sexes of killer whale as being: weight = 0.000208 length2.577 (weight in kg, length 

in cm). Kastelein et al. (2003) noted a similar growth pattern among captive animals. New 

research techniques, such as laser-metrics, have been used to measure dorsal fin size, which may 

assist with assessing physical maturity (Durban and Parsons 2006). This technique may also be 

used in the future to make additional body size estimates and assess growth of free-swimming 

killer whales. 

 

Characteristics of reproductive adults. Females achieve sexual maturity at lengths of 4.6-5.4 m, 

depending on geographical region (Perrin and Reilly 1984). Sexual maturity, when reproduction 

is physiologically possible, generally occurs two to three years before reproductive maturity, 

when reproduction occurs with the greatest chance of conception and birth of healthy calves. 

Most wild females from the northeastern Pacific give birth to their first surviving calf between 

the ages of 12 and 17 years (mean = about 14.9 years, range = 10-22 years) (Olesiuk et al. 1990a, 

2005, Matkin et al. 2003), but when adjusted for the high mortality rate among newborns, the 

probable mean age at first birth of either a viable or non-viable calf is reduced to about 13 years 

(Olesiuk et al. 1990a). This latter age corresponds to a probable mean age at first conception of 

11.6 years. Pubescent females may ovulate several times before conceiving, thus average age at 

first ovulation is probably even younger (Olesiuk et al. 1990a). Duffield et al. (1995) reported 

similar ages for initial births among captive females from this region, but noted a captive-born 

female that gave birth when 8 years old. Somewhat younger ages of 7-14 years have been 

reported for North Atlantic females becoming sexually mature or bearing their first calf 

(Christensen 1984, Duffield et al. 1995, Kastelein et al. 2003). Resident females have a mean 

reproductive potential of about 4.5-5.7 calves during a reproductive life span lasting about 20-24 

years and produce an average of 2.2-4.1 surviving calves (Olesiuk et al. 1990a, 2005, Matkin et 

al. 2003). Breeding in resident females typically lasts until about 38-45 years of age, but can end 

anywhere from about 22-53 years of age (Olesiuk et al. 1990a, 2005, Matkin et al. 2003). 

Females then enter a post-reproductive period that continues until their death. This averages 

about 10 years in length, but extends more than 30 years in a few individuals. 

Males become sexually mature at body lengths ranging from 5.2-6.4 m (Christensen 1984, Perrin 

and Reilly 1984, Duffield and Miller 1988, Olesiuk et al. 1990a). Male Northern Residents 

usually begin to show enlarged or “sprouting” dorsal fins, which are a sign of the onset of sexual 

maturity, at 11-15 years of age (mean = 12.9, range = 9-18 years; Olesiuk et al. 2005). The 

sprouting phase typically lasts 5-6 years (mean = 5.5 years; range = 3-7 years). Males are 

presumed to remain sexually active throughout their adult lives (see Olesiuk et al. 1990a). 
January 2008 II-42 NMFS 

Survival, Longevity, and Natural Mortality 

Survival. Population demography in the species is best understood for resident killer whales 

(Olesiuk et al. 1990a, 2005, Krahn et al. 2002, 2004a, Matkin et al. 2003). Mortality curves are 

U-shaped for both sexes, although the curve is narrower for males (Olesiuk et al. 1990a, 2005, 

Matkin et al. 2003). Mortality is quite high during the first six months of life, when 37-50 

percent of all calves die (Bain 1990, Olesiuk et al. 1990a) although this may be an overestimate 

(Olesiuk et al. 2005). Annual death rates among Northern Resident juveniles usually decline 

steadily thereafter, falling to 0.6-2.3 percent for both sexes from 10.5 to 14.5 years of age 

(Olesiuk et al. 2005). However, during a period of no population growth, Olesiuk et al. (2005) 

noted a spike in mortality occurring among juveniles in the 3.5-5.5 year age class, which 

corresponded to the period when their mothers gave birth to their next calf. An estimated 61-82 

percent of viable calves reach maturity, depending on prevailing environmental conditions. 

Death rates remain low among females of reproductive age, averaging just 0-2.5 percent per year 

for various age classes between 15.5 and 44.5 years (Olesiuk et al. 1990a, 2005). Overall, 41-75 

percent of females survive to the end of their reproductive lifespan at about 40 years of age. 

Mortality increases dramatically to 4.7-6.8 percent annually among older females, especially 

those beyond 50 years of age. After reaching sexual maturity, death rates for males increase 

throughout life, up to 18.3 percent annually among Northern Resident individuals older than 30 

years (Olesiuk et al. 2005). Life history tables for Northern and Southern Resident populations 

are presented in Olesiuk et al. (1990a, 2005). Fairly similar survival patterns have been reported 

among the Southern Alaska Residents (Matkin et al. 2003). 

Seasonal mortality rates among Southern and Northern Resident whales have not been analyzed, 

but are believed to be highest during the winter and early spring, based on the numbers of 

animals missing from pods returning to inland waters each spring (J. K. B. Ford, pers. comm.; K. 

C. Balcomb, pers. comm.). This contention is supported by the higher winter and spring 

stranding rates reported for all killer whale forms in Washington and Oregon (Table 3; Norman 

et al. 2004). Olesiuk et al. (2005) also identified high neonate mortality that occurred outside of 

the summer field research seasons. They reported that at least 12 newborn calves (9 in southern 

community and 3 in northern community) were seen outside the summer field season and 

disappeared by the next field season. 

Comparable data for transients and offshores are not available because of the difficulty in closely 

monitoring their populations, but death rates in transients are perhaps similar to those of 

residents (Ford and Ellis 1999). Rates of mortality for killer whales held in captivity are 6.2-8.9 

percent per year (DeMaster and Drevenak 1988, Duffield and Miller 1988, Small and DeMaster 

1995). 

Longevity. At birth, the average life expectancy of Southern and Northern Resident killer whales 

is about 29 years for females and 17 years for males (Olesiuk et al. 1990a). However, for 

Northern Residents that survive their first six months, mean life expectancy increases to about 

30-46 years for females and 19-31 years for males (Olesiuk et al. 2005). Life expectancy at 

sexual maturity (about 15 years of age in both sexes) averages about 31-41 years for females and 

13-22 years for males. Maximum life span in both communities is estimated to be 80-90 years 

for females and 60-70 years for males (Olesiuk et al. 1990a, 2005). Reasons for the shorter 
January 2008 II-43 NMFS 

longevity of males are unknown, but are probably linked to sexual selection (Baird 2000). 

Among Southern Alaska Residents, females reaching 6 months of age have a shorter life 

expectancy of 39 years and a maximum life span of 60-70 years (Matkin et al. 2003). 

Natural mortality. Natural causes of death in killer whales remain largely unidentified, even in 

the well-investigated Southern and Northern Resident populations. Animals usually sink after 

dying, giving researchers little opportunity to conduct post-mortem examinations of carcasses. 

Thus, reasons for the high mortality rates among calves are not known (Baird 2000). Killer 

whales have no predators other than humans (Baird 2000, Ford 2002). Field observations and 

the lack of shark-induced scars, such as those seen on some dolphin species (Corkeron et al. 

1987, Heithaus 2001), suggest that shark predation is insignificant even on young animals (Baird 

2000). Visible signs of emaciation are rarely seen among resident and transient whales in 

Washington and British Columbia (K. C. Balcomb, pers. comm.; J. K. B. Ford, pers. comm.; R. 

W. Baird, pers. comm.), thus it is unknown whether these populations experience annual periods 

of food scarcity that might contribute to increased mortality. 

Individual and mass live strandings and entrapments of killer whales are considered rare 

(Dahlheim and Heyning 1999) and often end in the deaths of some or most animals. These 

events sometimes result when whales foraging in shallow waters become accidentally trapped by 

a receding tide, but fast-forming ice can also be a cause (Taylor 1957, Mitchell and Reeves 1988, 

Reeves et al. 2002). Disease, parasitism, and intense human-generated sound may also drive 

animals ashore in some cases (Walsh et al. 2001, Perrin and Geraci 2002). Fewer than 20 

records of mass strandings are known worldwide, but four of these occurred in British Columbia 

during the 1940s (Pike and MacAskie 1969, Mitchell and Reeves 1988; M. Sternfeld, unpubl. 

data). These included 11 whales stranded near Masset in the Queen Charlotte Islands in January 

1941 (Cameron 1941), “a number” of whales temporarily stranded at Cherry Point near 

Cowichan Bay, Vancouver Island, in September 1944 (Carl 1946), and 20 whales stranded near 

Estevan Point on western Vancouver Island in June 1945 (Carl 1946). Pike and MacAskie 

(1969) described five entrapped whales that eventually stranded and died in Von Donnop 

Lagoon on Cortez Island near Campbell River, Vancouver Island, in March 1949. Seven 

strandings or entrapments involving three or more whales have occurred in Alaska since 1982 

(Lowry et al. 1987, Heise et al. 2003, Shelden et al. 2003; M. B. Hanson, unpubl. data; M. 

Sternfeld, unpubl. data) and are the only other records reported from western North America 

(Mitchell and Reeves 1988, Norman et al. 2004; J. Gaydos, unpubl. data; N. A. Black, pers. 

comm.). These involved a mean of 5.6 animals, with the largest event comprised of nine 

offshore whales trapped in Barnes Lake on Prince of Wales Island for about two months in 1994 

(D. E. Bain, unpubl. data). Two of the animals died before the remainder were driven back to 

the ocean by rescuers. 

The NMFS National Marine Mammal Stranding Database contains records of 20 individual 

stranded killer whales in Washington and Oregon since 1930 (Table 3; Norman et al. 2004). 

Fifteen (75 percent) strandings occurred in the winter or spring, and eleven (55 percent) were 

newborns or young calves. The number of calf strandings may indicate that this age class is 

especially vulnerable to disease and separation from the pod. Seven of the 20 (35 percent) were 

confirmed as or suspected to be Southern Residents. Additional stranded Southern Residents 
January 2008 II-44 NMFS 

Table 3. List of known killer whale strandings in Washington and Oregon recorded since 1930. 

Data originate from the National Marine Mammal Stranding Database, National Marine 

Fisheries Service, and from Bigg and Wolman (1975), Calambokidis et al. (1984), Stevens et al. 

1989, Hoyt (1990), Olesiuk et al. (1990a), Jarman et al. (1996), Osborne (1999), and Hayteas 

and Duffield (2000)a

. 

Date Location Sexb Populationc

Length 

(cm) Comments 

 

Aug 1970 Port Madison, WA F SRd 280 Live, captured for aquaria display 

Mar 1973 Ocean City, WA F SRd

 488 Live, captured for aquaria display 

28 Sep 1977 San Juan Island, WA M SR (L pod) 621 Dead, contaminant levels reported in 

Calambokidis et al. (1984) 

15 Nov 1983 Seattle, WA F SR (J or K pod) 218 Newborn 

7 Mar 1987 Fort Stevens, OR M WCT 249 - 

8 Feb 1988 Pacific City, OR M WCTd

 385 Contaminant levels reported in 

Hayteas and Duffield (2000) 

5 Jan 1989 Stuart Island, WA M SR (J pod) 230 Dead, newborn, contaminant levels 

reported in Jarman et al. (1996) 

8 Apr 1989 Cape Flattery, WA - U - Dead 

24 Jul 1993 Seal Rock, OR M U 235 Dead, contaminant levels reported in 

Hayteas and Duffield (2000) 

13 May 1995 Newport, OR F U 212 Dead, newborn, contaminant levels reported in Hayteas and Duffield (2000) 

12 Apr 1996 Netarts, OR F U 622 Dead, contaminant levels reported in 

Hayteas and Duffield (2000) 

21 Apr 1997 Tillamook, OR M U 256 Dead, contaminant levels reported in 

Hayteas and Duffield (2000) 

20 Nov 1997 Gearhart, OR - U 180 Dead, length may be incorrect 

9 Jan 1998 Pacific City, OR - U 120 Dead, length may be incorrect 

8 Feb 1999 Greenbank, WA M SR (J pod) 220 Dead, newborn 

1 May 2000 Winchester Bay, OR M WCT 270 Dead 

2 Jan 2002 Dungeness Bay, WA M WCT (CA188) 700 Live, successfully rescued and 

returned to water 

2 Jan 2002 Dungeness River, WA F WCT (CA189) 671 Dead 

14 Apr 2002 Long Beach, WA F SR (L60) 606 Dead, held high contaminant levels 

3 May 2004 Bandon, OR F WCT 650 Alive, but died soon after 

22 May 2007 Westport, WA F WCT (T086) - Dead, dorsal fin and part of back only 

a Osborne (1999) reported two additional strandings of individual whales from Lummi Island, Washington (14 Aug 1981, 580 cm 

long), and Clallam Bay, Washington (26 May 1991, newborn). The National Marine Fisheries Service was listed as the 

source of these records, but neither appears in the database of the Northwest Marine Mammal Stranding Network. Osborne 

(1999) did not list the population or sex of either animal. 

b M, male; and F, female. 

c SR, Southern Resident; NR, Northern Resident, WCT, west coast transient; and U, not identified. Identity of pod or individual 

whale is listed in parentheses when known. 

d Identified as a West Coast Transient by Stevens et al. (1989).

have been identified in Canada (Osborne 1999). Three stranded whales in Oregon were 

confirmed as transients (Stevens et al. 1989, Northwest Marine Mammal Stranding Network) as 

well as two adults (CA188 and CA189) stranded near Dungeness Bay and by the mouth of the 

Dungeness River in Washington in January 2002 were also transients. Members of the 

Northwest Marine Mammal Stranding Network with the assistance of other killer whale experts 

were able to rescue the live-stranded whale at Dungeness Bay, moving the animal out of the bay 
January 2008 II-45 NMFS 

to the north of Dungeness Spit allowing it swim into open water. Several older stranding records 

are also known from Washington. Scheffer and Slipp (1948) described two entrapments 

involving single whales in Puget Sound, including one animal caught behind a dock. Both 

escaped on the next incoming tide. 

Research update 

Diseases. Cause of death has been reported for some killer whales held in captivity, but may not 

be representative of mortality in the wild. Deaths of 32 captive individuals were attributed to 

pneumonia (25 percent), systemic mycosis (22 percent), other bacterial infections (16 percent), 

mediastinal abscesses (9 percent), and undiagnosed causes (28 percent) (Greenwood and Taylor 

1985). Little is known about infectious diseases of wild killer whales or the threat that they pose 

to populations. Sixteen pathogens have been identified from captive and free-ranging animals, 

including nine types of bacteria, four viruses, and three fungi (Gaydos et al. 2004). Three of 

these, marine Brucella, Edwardsiella tarda, and cetacean poxvirus, were detected in wild 

individuals. Marine Brucella and cetacean poxvirus have the potential to cause mortality in 

calves and marine Brucella may cause abortion (Miller et al. 1999, Van Bressem et al. 1999). 

Cetacean poxvirus also produces skin lesions, but probably does not cause many deaths in 

cetaceans (Van Bressem et al. 1999). Antibodies to Brucella spp. were detected in a female 

transient that stranded near the Dungeness River mouth in January 2002 (Gaydos et al. 2004). In 

2000, a male Southern Resident died from a severe infection caused by E. tarda (Ford et al. 

2000). An additional 28 pathogens (12 fungi, 12 bacteria, and four viruses) have been identified 

from other species of toothed whales that are sympatric with the Southern Residents and are 

considered potentially transmittable to killer whales (Palmer et al. 1991, Gaydos et al. 2004). 

Several, including porpoise morbillivirus, dolphin morbillivirus, and herpes viruses, are highly 

virulent and are capable of causing large-scale disease outbreaks in some related species. 

Disease epidemics have never been reported in killer whales in the northeastern Pacific (Gaydos 

et al. 2004). 

Killer whales are susceptible to other forms of disease, including Hodgkin’s disease and severe 

atherosclerosis of the coronary arteries (Roberts et al. 1965, Yonezawa et al. 1989). Tumors and 

bone fusion have also been recorded (Tomilin 1957). Jaw abscesses and dental disease are 

common problems caused by heavy tooth wear down to the gum line, resulting in exposure and 

infection of the pulp cavity and surrounding tissue (Carl 1946, Tomilin 1957, Caldwell and 

Brown 1964). Noticeable tooth wear can occur even in some younger animals (Carl 1946). 

Captive animals commonly suffer from abscessed vestigial hair follicles on the rostrum, a 

Gaydos and Raverty (2007) compiled recent killer whale stranding information to 

learn more about diseases in free-ranging killer whales as well as add to information 

on mortality factors, genetics and natural history. Since the summer of 2005, 11 killer 

whales stranded along the west coast from California to Alaska including transients, 

offshores, Northern Residents and one Southern Resident (L98 killed by tug boat 

propeller in March 2006). The causes of death that could be determined included 

ingested fish hook with trailing line, trauma from ship strikes, and Salmonellla 

septicemia. Additional results are still pending. 
January 2008 II-46 NMFS 

condition that can eventually spread over the entire skin surface (Simpson and Gardner 1972). A 

genetic disorder known as Chediak-Higashi syndrome was diagnosed in a young transient killer 

whale from southern Vancouver Island in the early 1970s (Haley 1973, Taylor and Farrell 1973, 

Hoyt 1990, Ford and Ellis 1999). The syndrome causes partial albinism, susceptibility to 

infections, and a reduction in life span. 

The collapsed dorsal fins commonly seen in captive killer whales (Hoyt 1992) do not result from 

a pathogenic condition, but are instead thought to most likely originate from an irreversible 

structural change in the fin’s collagen over time (B. Hanson, pers. comm.). Possible 

explanations for this include (1) alterations in water balance caused by the stresses of captivity or 

dietary changes, (2) lowered blood pressure due to reduced activity patterns, or (3) overheating 

of the collagen brought on by greater exposure of the fin to the ambient air. Collapsed or 

collapsing dorsal fins are rare in most wild populations (Hoyt 1992, Ford et al. 1994, Visser 

1998, Ford and Ellis 1999) and usually result from a serious injury to the fin, such as from being 

shot or colliding with a vessel. Matkin and Saulitis (1997) reported that the dorsal fins of two 

male resident whales in Alaska began to fold soon after their pod’s exposure to oil during the 

Exxon Valdez spill in 1989 and were completely flattened within two years. Both animals were 

suspected to be in poor health and subsequently died. The dorsal fin of a male transient stranded 

at Dungeness Bay, Washington, in 2002 showed signs of collapse after three days, but regained 

its natural upright appearance as soon as the whale resumed strong normal swimming upon 

release (J. P. Schroeder, pers. obs.). 

Parasites. Relatively little information is available on the parasites of killer whales. Known 

endoparasites include Campula sp., Fasciola skrjabini, Leucasiella subtilla, and Oschmarinella 

albamarina (Trematoda), Diphyllobothrium polyrugosum, Phyllobothrium sp., and 

Trigonocotyle spasskyi (Cestoda), Anisakis pacificus and A. simplex (Nematoda), Bolbosoma 

nipponicum and B. physeteris (Acanthocephala), Kyaroikeus cetarius (Ciliata), and Toxoplasma 

gondii (Apicomplexa) (Dailey and Brownell 1972, Heptner et al. 1976, Heyning 1988, Sniezek 

et al. 1995, Gibson and Bray 1997, Gibson et al. 1998, Murata et al. 2004). These are 

transmitted primarily through the ingestion of infected prey (Baird 2000). An estimated 5,000 

unidentified nematodes were reported in the stomach of a resident whale from Washington 

(Scheffer and Slipp 1948). The forestomach of a calf estimated at 1-2 months of age in 

California contained numerous Anisakis simplex worms, indicating that infections can begin at 

an early age (Heyning 1988). Increased vigor and appetite were observed in the orphaned 

Northern Resident killer whale calf A73 following treatment for intestinal parasites during 

rehabilitation. Ectoparasites are infrequently found and include the whale lice Cyamus orcini, C. 

antarcticensis, and Isocyamus delphinii (Amphipoda) (Leung 1970, Berzin and Vlasova 1982, 

Wardle et al. 2000). Most external parasites are probably transmitted through body contact with 

other individuals, such as during social encounters and mother-young interactions (Baird 2000). 

No severe parasitic infestations have been reported in killer whales in the northeastern Pacific. 

Commensal organisms associating with killer whales include barnacles, remoras, and diatoms 

(Hart 1935, Nemoto et al. 1980, Fertl and Landry 1999, Guerrero-Ruiz and Urbán 2000). 

Barnacles are rare in most populations (Samaras 1989, Dahlheim and Heyning 1999), but are 

present on many Mexican killer whales (Guerrero-Ruiz 1997, Black et al. 1997). 
January 2008 II-47 NMFS 

Human-Related Sources of Mortality and Live-Captures 

Commercial exploitation. The first records of commercial hunting of killer whales date back to 

the 1700s in Japan (Ohsumi 1975). During the 19th and early 20th centuries, the global whaling 

industry harvested immense numbers of baleen and sperm whales, but largely ignored killer 

whales because of their limited amounts of recoverable oil, their smaller populations, and the 

difficulty that whalers had in capturing them (Scammon 1874, Scheffer and Slipp 1948, Budker 

1958, Reeves and Mitchell 1988a). No killer whales were reported among the nearly 25,000 

whales processed by coastal whaling stations in British Columbia from 1908-1967 (Gregr et al. 

2000). Similarly, none were among the 2,698 whales handled at the Bay City whaling plant in 

Grays Harbor, Washington, during its 14 years of operation from 1911-1925 (Scheffer and Slipp 

1948, Crowell 1983). 

 

From the 1920s to 1940s, small whaling fisheries were developed or became more sophisticated 

in several countries, primarily Norway, the Soviet Union, and Japan, resulting in greater hunting 

pressure on smaller whales, dolphins, and killer whales (Jonsgård and Lyshoel 1970, Mitchell 

1975, Ohsumi 1975, Øien 1988). Available harvest statistics indicate that each of these countries 

killed an average of about 43-56 killer whales annually from the 1940s to 1981, with most 

animals taken from the North Atlantic (total = 2,435 whales), Antarctic and southern oceans 

(1,681 whales), Japanese coastal waters (1,534 whales), and Soviet far east (301 whales) 

(Ohsumi 1975, Øien 1988, Hoyt 1990). It should be noted that some of the official harvest data 

from this era are erroneous, with both under-reporting and over-reporting known or suspected to 

have occurred (Brownell and Yablokov 2002). Furthermore, catch data would likely exclude 

any wounded animals that escaped and eventually died. These harvests ended by the early 

1990s. The only killer whales reported as commercially taken in the northeastern Pacific from 

the 1940s to early 1980s were a single animal in British Columbia in 1955 (Pike and MacAskie 

1969) and five whales in California between 1959 and 1970 (Rice 1974). Although the 

commercial harvests of this period likely reduced killer whale abundance in some regions of the 

world, they probably had no impact on most populations in the northeastern Pacific. The current 

numbers of killer whales hunted for profit in the world are probably quite small (Baird 2001, 

Reeves et al. 2003), but documentation is lacking. Very small amounts of killer whale meat 

continued to be present in retail markets in Japan and South Korea during the 1990s, but may 

have come from animals incidentally caught in coastal fisheries (Baker et al. 2000). 

Mortality associated with killer whale depredation. As with other large and highly visible 

predators, killer whales historically generated a variety of negative emotions among people, 

ranging from general dislike to fear and outright hatred. Such feelings were most prevalent 

among fishermen, whalers, sealers, and sportsmen, and largely stemmed from perceived 

competition over prey resources, damage caused to fishing gear and captured baleen whales, and 

the belief that killer whales scared off other marine mammals that were potentially harvestable. 

As a result, killer whales were widely persecuted to varying extents. Shooting was probably the 

most popular method of responding to nuisance animals (Bennett 1932, Budker 1958, Heptner et 

al. 1976) and likely resulted in the loss of substantial numbers of whales in some localities so 

that significant population declines may have occurred (Lien et al. 1988, Olesiuk et al. 1990a). 

Governments sometimes supported the use of lethal control measures on killer whales, as seen in 

the opportunistic shooting of animals by fisheries department personnel in British Columbia 
January 2008 II-48 NMFS 

(Ford et al. 2000, Baird 2001), the establishment of a bounty in Greenland from 1960-1975 

(Heide-Jørgensen 1988), the recommendations of Russian scientists to conduct large-scale 

culling programs to protect seal populations for human harvest (Zenkovich 1938, Tomilin 1957), 

and the killing of possibly hundreds of whales by the U.S. military in Icelandic waters during the 

mid-1950s (Anonymous 1954, 1956, Vangstein 1956, Dahlheim 1981, Hoyt 1990) and in the 

North Atlantic in 1964 (Hoyt 1990). 

Animosity toward killer whales has abated in recent decades, but often persists where 

interference with fishing activities occurs (Klinowska 1991, Matkin and Saulitis 1997). 

Conflicts with longline fishing operations are common in a number of regions, including Alaska 

(Rice and Saayman 1987, Matkin 1994, Matkin and Saulitis 1994, Yano and Dahlheim 1995a, 

1995b, Ashford et al. 1996, Secchi and Vaske 1998, Visser 2000a, Whale and Dolphin 

Conservation Society 2002). Longline losses to whales can be extensive and reach 50-100 

percent of the catch in extreme cases. Net fisheries are also affected, including gillnetting and 

purse seining (Young et al. 1993). As a result, fishermen frequently resort to shooting at killer 

whales or harassing them with small underwater explosives (“seal bombs”) in an effort to drive 

off the whales (Matkin 1986, 1994, Hoyt 1990, Dahlheim and Matkin 1994, Yano and Dahlheim 

1995a, Visser 2000a). Many bullet wounds are probably non-fatal, but accurate information on 

wounding and killing rates is difficult to obtain. 

Deaths from deliberate shooting were probably once relatively common in Washington and 

British Columbia (Scheffer and Slipp 1948, Pike and MacAskie 1969, Haley 1970, Olesiuk et al. 

1990a, Baird 2001). As an indication of the intensity of shooting that occurred until fairly 

recently, about 25 percent of the killer whales captured in Puget Sound for aquaria through 1970 

bore bullet scars (Hoyt 1990). Shootings have tapered off since then (Hoyt 1990, Olesiuk et al. 

1990a, Baird 2001) and only several resident animals currently show evidence of bullet wounds 

to their dorsal fins (Bigg et al. 1987, Ford et al. 2000). One Northern Resident, a matriarchal 

female, died from being shot in 1983 (Ford et al. 2000). Deliberate killings associated with 

fishery interactions are currently considered insignificant at a population level throughout the 

northeastern Pacific (Young et al. 1993, Carretta et al. 2001), but may be more prevalent than 

reported. 

Aboriginal harvest. The extent to which North Pacific indigenous peoples hunted or utilized 

killer whales in the past is uncertain based on limited documentation. There is no tradition of 

hunting killer whales in the Canadian Arctic (Reeves and Mitchell 1988b) or along the Pacific 

coast (Ivashin and Votrogov 1981, Olesiuk et al. 1990a, Matkin et al. 1999a). Hoyt (1990) stated 

that a general taboo against killing the species was widespread among coastal North American 

tribes, often based on the fear that surviving whales would avenge the deaths of pod members. 

Native Alaskans commonly viewed killer whales with respect and considered them as totem 

(Matkin et al. 1999a). In Washington, the Makah are known to have occasionally caught killer 

whales and regarded their meat and fat superior to that of baleen whales (Scammon 1874). The 

species was not hunted by the neighboring Quillayute (Scheffer and Slipp 1948). Carl (1946) 

reported that the Nootka on Vancouver Island ate the meat and oil from killer whales, but it was 

unclear whether these were obtained through active hunting or only from beached animals. 

Small-scale subsistence harvesting of killer whales continues to the present at several locations 

in the world (Reeves et al. 2003). 
January 2008 II-49 NMFS 

Incidental human-related mortality. Drowning from accidental entanglement in nets and 

longlines is an additional minor source of fishing-related mortality in killer whales. Scheffer and 

Slipp (1948) documented several deaths of animals caught in gillnets and salmon traps in 

Washington between 1929 and 1943. Whales are occasionally observed near fishing gear in 

Washington and British Columbia, and more frequently in much of Alaska, but current evidence 

indicates that entanglements and deaths are rare except in the Bering Sea (Bigg and Wolman 

1975, Barlow et al. 1994, Matkin 1994, Matkin and Saulitis 1994, Pierce et al. 1996, Carretta et 

al. 2001, 2004, Angliss and Outlaw 2005). One individual is known to have contacted a salmon 

gillnet in British Columbia in 1994, but did not entangle (Guenther et al. 1995). Typically, killer 

whales are able to avoid nets by swimming around or underneath them (Jacobsen 1986, Matkin 

1994). Not all entanglements result in death. 

In rare instances, killer whales are injured or killed by collisions with passing ships and 

powerboats, primarily from being struck by the propeller blades (Visser 1999c, Ford et al. 2000, 

Visser and Fertl 2000, Baird 2001, Carretta et al. 2001, 2004). Some animals with severe 

injuries eventually make full recoveries, such as a female described by Ford et al. (2000) that 

showed healed wounds extending almost to her backbone. One mortality from a vessel collision 

was reported for Washington and British Columbia between the 1960s and 1990s (Baird 2002). 

However, two additional mortalities have occurred since then. In March of 2006 the lone killer 

whale, L98, residing in Nootka Sound for several years, was killed by the engine of a tug boat. 

While L98 exhibited unusual behavior and often interacted with vessels, his death demonstrates 

the risk of vessel accidents and is the second fatal interaction reported. In July 2006, the death of 

a stranded Northern Resident female was attributed to blunt trauma, probably from a vessel 

strike (Gaydos and Raverty 2007) Five additional accidents between vessels and killer whales 

have been documented in the region since the 1990s (Baird 2001; DFO, unpubl. data, NMFS, 

unpubl. data). One took place on the Washington side of Haro Strait in 1998 and involved a 

slow moving boat that apparently did not injure the whale. In 1995, a Northern Resident was 

struck by a speedboat, causing a wound to the dorsal fin that quickly healed. Another Northern 

Resident was injured by a high-speed boat in 2003, but also recovered. A 2005 collision of a 

Southern Resident with a commercial whale watch vessel resulted in a minor injury to the whale, 

which subsequently healed. An additional Northern Resident calf was struck by a vessel in July 

2006. Scheffer and Slipp (1948) also remarked about several collisions between killer whales 

and boats, but gave no information on effects to the whales. 

Major oil spills are potentially catastrophic to killer whales and their environment, as illustrated 

by the probable impacts on the main resident and transient pods frequenting the area of the 

massive Exxon Valdez oil spill in Prince William Sound, Alaska, which occurred in 1989. Six of 

the 36 members of AB pod were missing within one week of the spill after being seen in heavily 

oiled waters and eight more disappeared within two years (Dahlheim and Matkin 1994, Matkin 

et al. 1994, 1999a, 2003, Matkin and Saulitis 1997). These were followed by the deaths of two 

orphaned calves in the winter of 1993-1994, as well as two adult males (including one fairly 

young individual) in 1994 and 1997 whose dorsal fins collapsed soon after the spill, indicating 

stress or ill health. AT1 pod lost eight of its 22 members by 1990 and two others by 1992. 

These mortality rates are unprecedented for the northeastern Pacific. Causes of death of the 

missing animals could not be confirmed because their carcasses were never located or fully 

necropsied, thus researchers were unable to directly attribute the deaths to oil contamination. 
January 2008 II-50 NMFS 

However, retrospective evaluation shows it highly likely that oil exposure contributed to their 

deaths or did so indirectly for orphaned calves. Deterioration of the social structure of AB pod, 

with subgroups traveling independently from the pod and certain members no longer consistently 

associating with their closest relatives, was an additional probable outcome of the spill (Matkin 

et al. 2003). The spill may have also contributed to AT1 pod’s failure to produce any offspring 

since 1984 (see Matkin et al. 2003). AB pod began recovering in 1996, but is not projected to 

regain its pre-spill size until about 2015 (Matkin et al. 2003). Five other resident pods seen 

swimming through oil-sheened waters after the spill did not experience losses (Matkin et al. 

1994). However, these pods likely spent less time in the spill area and were observed only in 

lighter sheens (C. O. Matkin, pers. comm.), which suggests that lesser degrees of exposure may 

not have been harmful to the whales. 

Live-captures for aquaria. Killer whales have been immensely popular as display animals in the 

world’s aquaria since the 1960s and currently represent the third most widely kept species of 

toothed whale after bottlenose dolphins (Tursiops truncatus) and belugas (Kastelein et al. 2003). 

Interest in the live-capture of killer whales for public exhibition began in southern California in 

1961, when Marineland of the Pacific captured a disoriented individual in California, which died 

shortly after (Bigg and Wolman 1975). An attempt to obtain a replacement animal followed at 

Haro Strait in 1962, but ended in the deaths of a female and possibly an accompanying male 

(Hoyt 1990). However, in 1964 and 1965, single whales were caught and held for periods of 3 

and 12 months at the Vancouver Public Aquarium and Seattle Marine Aquarium, respectively, 

resulting in much publicity and demonstrating the species’ highly appealing qualities when held 

in captivity. The development of a netting technique in 1965, the initiation of commercial 

netting operations in 1968, and an immediate demand for captive animals led to large increases 

in capture effort beginning in 1967 (Bigg and Wolman 1975). With the exception of an 

individual collected in Japan in 1972, Washington and British Columbia served as the only 

source of captive killer whales until 1976 (Hoyt 1990, OrcaInfo 1999). 

Operators working in Washington and British Columbia captured most whales by following a 

pod until it entered an appropriate bay, where netting could take place (Bigg and Wolman 1975). 

Nets were then quickly set across the bay’s entrance or pursed around the pod. The whales were 

held for several days or longer, which allowed them to calm down and be sorted for retention or 

release. Puget Sound was preferred as a capture site because it offered fewer escape routes and a 

number of bays with shallower waters, both of which aided netting efforts, and it had a large 

network of shore-based observers that provided movement updates on the whales (Bigg and 

Wolman 1975). Important capture sites included Penn Cove on Whidbey Island (102-113 

whales captured), Carr Inlet at the southern end of the Kitsap Peninsula (60-70 whales captured), 

and Yukon Harbor on the eastern side of the Kitsap Peninsula (40-48 whales captured) (Table 4). 

During these efforts, many individual whales were caught multiple times. 

From 1962-1977, 275-307 whales were captured in Washington and British Columbia, of which 

55 were transferred to aquaria, 12 or 13 died during capture operations, and 208-240 were 

released or escaped back into the wild (Table 4). However, these figures exclude a few 
January 2008 II-51 NMFS 

Table 4. Number of killer whales captured, retained for captivity, or died during capture from 

1962-1977 in Washington and British Columbia (Bigg and Wolman 1975, Asper and Cornell 

1977, Hoyt 1990, Olesiuk et al. 1990a). 

Datea

 Location 

No. of whales 

caughtb

No. of whales 

retained 

No. of whales 

that died 

 

Southern Residents 

Sept 1962 Haro Strait, Wash.c

 1d,e 0 1-2d,e

Jul 1964 Saturna Island, B.C. 1 1 0 

Oct 1965 Carr Inlet, Wash. 15 1 1 

Jul 1966 Steveston, B.C. 1e

 0 1 

Feb 1967 Yukon Harbor, Wash. 15e

 5 3 

Feb 1968 Vaughn Bay, Wash. 12-15 2 0 

Oct 1968 Yukon Harbor, Wash. 25-33 5 0 

Apr 1969 Carr Inlet, Wash. 11e

 2 0 

Oct 1969 Penn Cove, Wash. 7-9e

 0 1 

Feb 1970 Carr Inlet, Wash. 6-14e

 1 0 

Aug 1970 Penn Cove, Wash. 80 7 4 

Aug 1970 Port Madison, Wash. 1e,f 1 0 

Aug 1971 Penn Cove, Wash. 15-24 3 0 

Nov 1971 Carr Inlet, Wash. 19 2 0 

Mar 1972 Carr Inlet, Wash. 9-11 1 0 

Mar 1973 Ocean City, Wash. 1e,f 1 0 

Aug 1973 Pedder Bay, B.C. 2 1 0 

Aug 1973 Pedder Bay, B.C. 2 2 0 

Aug 1977 Menzies Bay, B.C. 1e

 1 0 

Subtotal 224-256 36 11-12 

 

Northern Residents 

Jun 1965 Namu, B.C. 2 1 0 

Jul 1967 Port Hardy, B.C. 1 1 0 

Feb 1968 Pender Harbour, B.C. 1 0 0 

Apr 1968 Pender Harbour, B.C. 7 6 0 

Jul 1968 Malcolm Island, B.C. 11g

 1 0 

Dec 1969 Pender Harbour, B.C. 12 6 0 

Subtotal 34 15 0 

 

Transients 

Mar 1970 Pedder Bay, B.C. 5 2h

 1 

Aug 1975 Pedder Bay, B.C. 6 2 0 

Mar 1976 Budd Inlet, Wash. 6 0 0 

Subtotal 17 4 1 

Total 275-307 55 12-13 a Captures are listed chronologically for Washington, followed by British Columbia. b The exact numbers of whales caught in Washington were often not known due to poor record keeping and the difficulty in 

counting the numbers of individuals present in large groups (M. A. Bigg in Hoyt 1990). c The exact location in Haro Strait is not known (Hoyt 1990), but is presumed here to have been in Washington. d An adult female was shot and killed after being captured, but an adult male was also shot once during the incident (Hoyt 1990). 

Bigg and Wolman (1975) and Olesiuk et al. (1990a) presumed that the male also died, but based on Hoyt’s (1990) account, 

there is no conclusive evidence of this (also see Asper and Cornell 1977). e Presumed to be Southern Residents (Olesiuk et al. 1990a). f Captured after stranding (Bigg and Wolman 1975). g Presumed to be Northern Residents (Olesiuk et al. 1990a). h Bigg and Wolman (1975) and Asper and Cornell (1977) listed three whales as being retained from this capture, but the 

accounts of Hoyt (1990) and Ford and Ellis (1999) disclosed the death of an adult female from apparent malnutrition in its 

holding pen. Her carcass was then secretly disposed of. 
January 2008 II-52 NMFS 

additional deaths that were never made public (K. C. Balcomb, pers. comm.). The Southern 

Residents were the most heavily affected population, with 36 whales collected and at least 11 

dying (Table 4). Peak harvest years occurred from 1967-1971, when 80 percent of the retained 

whales were caught. Due to public opposition (e.g., Haley 1970), capture operations declined 

significantly after 1971, with only eight whales removed beyond this date. The British Columbia 

provincial government prohibited further live-captures in 1975, although an injured female calf 

was sent to an aquarium for permanent rehabilitation in August 1977 (Hoyt 1990, Dahlheim and 

Heyning 1999). In 1982, the British Columbia government issued a final license to capture killer 

whales in Pedder Bay, but the license holder was unable to catch any whales because none 

entered the bay (R. W. Baird, pers. comm.). The Washington State Senate passed a resolution 

(Senate Resolution 1976-222) requesting the U.S. Federal Government to establish a moratorium 

on harassment, hunting, and live-capture of the species in 1976 after six transient whales were 

caught in Budd Inlet, Olympia (see Hoyt [1990] for an account of the events surrounding this 

capture). The total revenue generated from the sale of whales captured in Washington and 

British Columbia probably exceeded $1,000,000, with the prices of individual animals ranging 

from about $8,000 in 1965 to $20,000 in 1970 (Bigg and Wolman 1975). 

Based on slightly updated information from that presented by Olesiuk et al. (1990a), 70 percent 

(47 or 48 animals) of the whales retained or killed were Southern Residents, 22 percent (15 

animals) were Northern Residents, and 7 percent (5 animals) were transients. For the Southern 

Resident community, collections and deaths were biased toward immature animals (63 percent of 

the total) and males (57 percent of identified animals). Removed whales included 17 immature 

males, 10 immature females, nine mature females, seven or eight mature males, and four (three 

immatures, one adult) individuals of unknown sex. Only 15 of the whales were subsequently 

identified by pod, with nine animals coming from K pod, five from L pod, and one from J pod 

(Bigg 1982). These removals substantially reduced the size of the Southern Resident population, 

which did not recover to estimated precapture numbers until 1993 (Baird 2001). Furthermore, 

selective removal of younger animals and males produced a skewed age- and sex-composition in 

the population, which probably worked to slow later recovery (Olesiuk et al. 1990a). 

One Southern Resident whale from the live-capture era, known as Lolita and a member of L pod, 

remains alive in captivity at the Miami Seaquarim. Efforts have been made to raise support to 

relocate this whale to the wild and reunite her with the Southern Residents, although similar 

captive release efforts, involving one killer whale (e.g., Keiko) and other delphinids, have been 

largely unsuccessful. Lolita was captured in 1970 prior to the establishment of the MMPA and 

therefore, does not fall under the jurisdiction of NMFS. 

F. POPULATION STATUS 

Global Status: Past and Present 

Little information on the former abundance of killer whales is currently available from any 

portion of their range. Scammon (1874), who worked primarily in the northeastern Pacific, 

considered the species as “not numerous” in comparison to other delphinids, but anecdotal 

remarks such as this provide little basis for recognizing even gross changes in population levels 
January 2008 II-53 NMFS 

during the past 200 years. Nevertheless, it is likely that many populations have declined 

significantly since 1800 in response to greatly diminished stocks of fish, whales, and pinnipeds 

in the world’s oceans (Reeves and Mitchell 1988a). 

Killer whales have proven difficult to census in many areas because of their general scarcity as 

well as their widespread and often unpredictable movement patterns (Ford 2002). Many older 

characterizations of relative abundance may well reflect the amount of observation effort rather 

than actual differences in density among sites (Matkin and Leatherwood 1986). During the past 

few decades, populations have been surveyed primarily through the use of photo-identification 

studies or line-transect counts (Forney and Wade 2007). Photo-identification is capable of 

providing precise information on population size, demographic traits, and social behavior 

(Hammond et al. 1990), making it the preferred method in locations where the species is 

regularly seen. It requires intensive effort spread over multi-year periods and, due to the species’ 

mobility, should be conducted over large geographic areas to obtain accurate results. Photoidentification catalogs for killer whales were first established in the early 1970s for the resident 

communities of Washington and British Columbia (Balcomb et al. 1980, Sugarman 1984, Bigg 

et al. 1987, van Ginneken et al. 1998, Ford and Ellis 1999, Ford et al. 2000, Ellifrit et al. 2006) 

and have since been initiated for most areas where population studies have been undertaken (e.g., 

Heise et al. 1991, Black et al. 1997, Dahlheim 1997, Dahlheim et al. 1997, Matkin et al. 1999a). 

All photographic surveys rely on recognition of individual animals through their distinctive 

dorsal fins and saddle patches, although eye-patch traits are sometimes used to supplement 

identification (Baird 1994, Visser and Mäkeläinen 2000). Line-transect surveys from ships or 

aircraft have generally been undertaken in large areas of open ocean where photo-identification 

is impractical. The results of line-transect surveys are almost always accompanied by large 

confidence limits, making it difficult to establish true population sizes and to compare trends 

over time. Furthermore, the technique is unsuited for gathering most demographic data. 

As top-level predators, killer whales occur in low densities throughout most of their geographic 

range. Densities are typically much greater in colder waters with higher productivity than in 

tropical regions (Forney and Wade 2007). Reeves and Leatherwood (1994) reported the 

worldwide population as probably exceeding 100,000 whales, based on information presented in 

Klinowska (1991), but this was undoubtedly an overestimate influenced by preliminary count 

data from the Antarctic. Forney and Wade (2007) have recently revised this figure to a 

minimum of about 50,000 animals. A number of regional abundance estimates have been made 

in recent years, with emerging evidence suggesting that many populations are relatively small 

(Whale and Dolphin Conservation Society 2002, Forney and Wade 2007). In the northeastern 

Pacific, at least 2,250-2,700 resident, transient, and offshore whales are currently thought to exist 

from California to the western Aleutian Islands and Bering Sea (see population estimates below). 

Estimates for other northern populations include 500-1,500 animals in Norwegian coastal waters 

(Christensen 1988) and about 190 whales off Iceland (Klinowska 1991). New Zealand’s entire 

population is believed to number fewer than 200 animals (I. N. Visser, unpubl. data). A recent 

population estimate of about 25,000 killer whales in Antarctica (Branch and Butterworth 2001) is 

considered much more accurate than earlier projections (Hammond 1984; Butterworth et al. 

1994; T. A. Branch, pers. comm.). Densities in this region are highest near the ice edge 

(Kasamatsu et al. 2000). An estimate of 8,500 killer whales for the eastern tropical Pacific, as 

derived from shipborne surveys (Wade and Gerrodette 1993), is probably far too large, given that 
January 2008 II-54 NMFS 

densities are substantially reduced at lower latitudes. Abundance in many other areas remains 

poorly investigated (Whale and Dolphin Conservation Society 2002). Trend information is 

lacking for virtually all populations other than several resident and the AT1 transient 

communities of the northeastern Pacific. 

Status of Southern Resident Killer Whales 

Status before 1974. Several lines of evidence argue that the Southern Resident community may 

have numbered more than 200 whales until perhaps the mid- to late-1800s (Krahn et al. 2002), 

when Euro-American settlement began to impact the region’s natural resources. Recent genetic 

investigations using microsatellite DNA reveal that the genetic diversity of the population 

resembles that of the Northern Residents (Barrett-Lennard 2000, Barrett-Lennard and Ellis 

2001), indicating that the two were possibly once similar in size. This scenario would be 

unlikely if the Southern Resident population had remained small for many generations, which 

would have caused a gradual loss of genetic diversity. The presence of relatively few acoustic 

clans and pods in the Southern Residents (1 clan, 3 pods), as compared to the northern (3 clans, 

16 pods) and Southern Alaska Residents (2 clans, 11 pods), also implies that the southern 

population may have been larger (Krahn et al. 2002). Finally, reductions in salmon and other 

prey along much of the west coast of North America during the past 150 years, especially from 

Washington to California (Nehlson 1997, Kope and Wainwright 1998), have likely lessened the 

region’s carrying capacity for resident killer whales (Krahn et al. 2002). 

Efforts to determine killer whale population trends in the northeastern Pacific during the past 

century are hindered by an absence of empirical information prior to 1974. A report by Scheffer 

and Slipp (1948) is the only older account to mention abundance in the core range of the 

Southern Residents. It noted that the species was “frequently seen” during the 1940s in the Strait 

of Juan de Fuca, northern Puget Sound, and off the coast of the Olympic Peninsula, with smaller 

numbers occurring farther south along Washington’s outer coast. Palo (1972) put forth a 

tentative estimate of 225-300 whales for Puget Sound and the Georgia Basin in 1970, but was 

admittedly unsure of the figure’s validity. The authors of both reports were unaware of the 

different forms of killer whales, thus their estimates made no distinctions among resident, 

transient, and offshore populations. 

Olesiuk et al. (1990a) modeled the population size of the Southern Resident community between 

1960 and 1973 and projected an increase in numbers from about 78 to 96 whales from 1960 to 

1967 (Table 5, Figure 8). This was probably a result of the population recovering from the 

opportunistic shooting that was widespread before 1960 (see Mortality Associated with Killer 

Whale Depredation) and other human impacts, or may have been caused by some unidentified 

improvement in the region’s capacity to support the whales (Olesiuk et al. 1990a). Beginning in 

about 1967, removals of whales by the live-capture fishery caused an immediate decline in 

Southern Resident numbers (see Live-Captures for Aquaria). The population fell an estimated 

30 percent to about 67 whales by 1971 (Olesiuk et al. 1990a). Removals from the Southern 

Resident community are known to have included nine animals from K pod, five from L pod, and 

one from J pod (Bigg 1982). NMFS added the population number from 1971 (67) to the number 

of resident killer whales taken or killed during live-captures (68) and considered additional 
January 2008 II-55 NMFS 

Table 5. Population and pod sizes of Southern and Northern Resident killer whales in 

Washington and British Columbia, 1960-2005. Southern Residentsa Northern Residentsb

Year J pod K pod L pod Total Total 

1960 - - - 78 97 

1961 - - - 79 98 

1962 - - - 82 101 

1963 - - - 85 105 

1964 - - - 90 110 

1965 - - - 94 117 

1966 - - - 95 115 

1967 - - - 96 119 

1968 - - - 89 120 

1969 - - - 81 111 

1970 - - - 80 108 

1971 - - - 67 113 

1972 - - - 69 115 

1973 - - - 71 121 

1974 15 16 39 70 123 

1975 15 15 41 71 132 

1976 16 14 40 70 131 

1977 18 15 46 79 134 

1978 18 15 46 79 137 

1979 19 15 47 81 140 

1980 19 15 49 83 147 

1981 19 15 47 81 150 

1982 19 14 45 78 151 

1983 19 14 43 76 155 

1984 17 14 43 74 156 

1985 18 14 45 77 163 

1986 17 16 48 81 171 

1987 18 17 49 84 177 

1988 19 18 48 85 180 

1989 18 17 50 85 187 

1990 18 18 53 89 194 

1991 20 17 55 92 201 

1992 19 16 56 91 199 

1993 21 17 59 97 197 

1994 20 19 57 96 202 

1995 22 18 58 98 205 

1996 22 19 56 97 212 

1997 21 19 52 92 220 

1998 22 18 49 89 216 

1999 20 17 48 85 216 

2000 19 17 47 83 209 

2001 20 18 43 81 201 

2002 20 19 44 83 202 

2003 22 20 42 84 203 

2004 23 21 44 88 219 

2005 24 20 44 88 - 

2006 24 22 44 90 - 

2007 25 19 43 87 - a Southern Resident data from 1960-1973 are estimates based on projections from the matrix model of Olesiuk et al. 

(1990a). Data from 1974-2007 were determined through photo-identification surveys and were provided by the 

Center for Whale Research (unpubl. data). Data for these years represent the number of whales present at the end 

of each calendar year, except for 2007, when data extend only through October. Whales verified as missing are 

assumed to have died and may be removed from count totals within a calendar year, depending on date of 

disappearance (K. C. Balcomb, pers. comm.). Numbers for L pod and the entire Southern Resident community from 

2001-2005 include L98. b Northern Resident data from 1960-1974 are estimates based on projections from the matrix model of Olesiuk et al. 

(1990a). Data from 1975-2004 were determined through photo-identification surveys and were provided by J. K. B. 

Ford (unpubl. data) and Olesiuk et al. (2005). Count data represent the number of whales believed to be alive during 

a calendar year. Whales are counted through their last year of being seen (J. K. B. Ford, pers. comm., DFO 

Recovery Strategy 2007). 
January 2008 II-56 NMFS 

sources of mortality (i.e., shootings) to estimate a minimum historical population size of about 

140 animals. 

Status from 1974-2007. Photo-identification studies have been the foundation of all Southern 

Resident research since the early 1970s. Annual censuses of the community were initiated by 

Michael Bigg of Canada’s Department of Fisheries and Oceans in 1974 (Bigg et al. 1976). The 

Center for Whale Research assumed responsibility for the counts in 1976 (Balcomb et al. 1980) 

and has directed them since then. The surveys are typically performed from May to October, 

when all three pods reside near the San Juan Islands, and are considered complete censuses of 

the entire population. It should be noted that small discrepancies in the annual count totals of the 

Southern Residents (e.g., see Ford et al. [2000], Baird [2001], Taylor and Platt [2001], Krahn et 

al. [2002, 2004a], and Table 5 of this report) are due in part to differences in the reporting times 

of yearly numbers and whether or not whales that died were tallied during the year of their death. 

The count criteria used in this report appear in Table 5 and Figures 8 and 9. 

The population has gone through several periods of growth and decline since 1974 (Table 5, 

Figure 8), when live-captures were ending and numbers were judged as beneath carrying 

0

20

40

60

80

100

120

196019621964196619681970197219741976197819801982198419861988199019921994199619982000200220042006

Year

Number of whales

Figure 8. Population size and trend of Southern Resident killer whales, 1960-2007. Data from 1960-

1973 (open circles, gray line) are number projections from the matrix model of Olesiuk et al. (1990a). 

Data from 1974-2007 (diamonds, black line) were obtained through photo-identification surveys of the 

three pods (J, K, and L) in this community and were provided by the Center for Whale Research 

(unpubl. data). Data for these years represent the number of whales present at the end of each 

calendar year except for 2007, when data extend only through October. 
January 2008 II-57 NMFS 

capacity (Olesiuk et al. 1990a). Between 1974 and 1980, total whale numbers expanded 19 

percent (mean annual growth rate of 3.1 percent) from 70 to 83 animals. J and L pods grew 27 

percent and 26 percent, respectively, during this period, whereas K pod decreased by 6 percent. 

This was followed by four consecutive years of decrease from 1981-1984, when count results 

fell 11 percent (mean annual decline rate of 2.7 percent) to 74 whales. The decline coincided 

with periods of fewer births and greater mortality among adult females and juveniles (Taylor 

and Plater 2001). A distorted age- and sex-structure, likely caused by the selective cropping 

of animals during live-captures 8-17 years earlier, also appears to have been a significant 

factor in the decline (Olesiuk et al. 1990a). This resulted in fewer females and males 

maturing to reproductive age and a reduction in adult males that was possibly below the 

number needed for optimal reproduction. An unusually large cohort of females that stopped 

0

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30

40

50

60

70

19741976197819801982198419861988199019921994199619982000200220042006

Year

Number of whales

L pod J pod K pod

Figure 9. Population sizes and trends of the three Southern Resident killer whale pods (J, K, and L) 

from 1974-2007. Data were obtained through photo-identification surveys and were provided by the 

Center for Whale Research (unpubl. data). Data represent the number of whales present in each pod 

at the end of a calendar year, except for 2007, when data extend only through October (K. C. 

Balcomb, pers. comm.). 
January 2008 II-58 NMFS 

bearing young also played a role in the decline (Olesiuk et al. 1990a). Pod membership during 

this period dropped by 12 percent for L pod, 11 percent for J pod, and 7 percent for K pod (Table 

5, Figure 9). In 1985, the Southern Residents entered an 11-year growth phase, which began 

with a drop-off in deaths and a pulse in births caused partly by the maturation of more juveniles 

(Taylor and Plater 2001). Total numbers eventually peaked at 98 animals in 1995 (Table 5, 

Figure 8), representing an increase of 32 percent (mean annual growth rate of 2.9 percent) in the 

population. Pod growth during the period was 37 percent in L pod, 36 percent in K pod, and 29 

percent in J pod (Table 5, Figure 8). 

The Southern Resident community entered yet another period of decline in 1996, with a 17 

percent reduction (mean annual decline rate of 2.9 percent) in numbers occurring by 2001, when 

81 whales remained (Table 5, Figure 8). All three pods suffered reductions in membership 

during this period, with L pod falling 28 percent, J pod 14 percent, and K pod 11 percent (Table 

5, Figure 9). There is no indication that this decline was caused by any lingering demographic 

effects related to the live-capture era (Taylor 2004). Instead, it appears to have resulted more 

from an unprecedented 9-year span of relatively poor survival in nearly all age classes and both 

sexes and secondarily from an extended period of poor reproduction (Krahn et al. 2002, 2004a). 

During this decline, the status of L pod began to attract special concern because of its poor 

performance compared to J and K pods, including greater than normal mortality and lower 

fecundity (Taylor 2004). 

The population reversed its trend again in 2002 and had grown to 90 whales by September 2006 

(Table 5, Figure 9), but declined in 2007 with the loss of five individuals and the gain of two 

new calves. Growth by J and K pods accounts for most of this gain and both pods now exceed 

their largest sizes achieved in the 1990s. By comparison, L pod declined to just 42 members in 

2003, but numbered 43 animals in 2007. This pod has experienced means of 2.6 deaths and 1.5 

births per year since 1995 (Center for Whale Research, unpubl. data). 

At present, the Southern Resident population has declined to essentially the same size that was 

estimated during the early 1960s, when it was considered as likely depleted (Olesiuk et al. 

1990a). Since censuses began in 1974, J and K pods have increased their sizes by 60 percent 

(mean of 1.9 percent per year) and 38 percent (mean of 1.2 percent per year), respectively. The 

largest pod, L pod, has grown 28.6 percent (mean of 0.9 percent per year) during this period, but 

more importantly, experienced a 10-year decline from 1994-2003 that threatened to reduce the 

pod’s size below any previously recorded level. Despite hopeful data from 2002-2006 indicating 

that L pod’s decline may have finally ended, such a conclusion is premature. From 1974-2006, 

there was an average of 3.4 births and 2.7 deaths per year in the community as a whole (Center 

for Whale Research, unpubl. data). 

Olesiuk et al. (1990a) used data from 1974-1987 to estimate an intrinsic growth rate of 2.92 

percent per year for both resident populations combined. However, observed rates of increase 

differed substantially for the two communities (1.3 percent annually from 1974-1987 for the 

Southern Residents vs. 2.9 percent annually from 1979-1986 for the Northern Residents). Brault 

and Caswell (1993) also examined growth rates for both populations during the same periods, 

but used a stage-structured model and based their calculations on females only. Intrinsic and 

observed rates of growth among the Southern Residents were 2.5 percent and 0.7 percent per 
January 2008 II-59 NMFS 

year, respectively, with the observed rate being much lower than in the Northern Residents. 

Non-significant differences in intrinsic growth rates existed among the three southern pods (J 

pod, 3.6 percent per year; K pod, 1.8 percent per year; and L pod, 1.5 percent per year). This 

study concluded that population growth rates in killer whales were more sensitive to changes in 

adult survival, as would be expected in any long-lived species, than to changes in juvenile 

survival and fertility. 

Using data from 1974-2003, Krahn et al. (2002, 2004a) further analyzed the population dynamics 

of the Southern Residents in an effort to identify demographic factors contributing to the 

population’s latest decline. For their analyses, six age and sex classes were defined as follows: 

calves in their first summer (<1 year of age), juveniles of both sexes (1-10 years of age), females 

of reproductive age (11-41 years of age), post-reproductive females (42 years of age and older), 

young adult males (11-21 years of age), and older males (22 years of age and older). These 

studies found sizable differences in annual survival among age and sex classes, with an overall 

mean of 0.969 from 1974-2000 (Krahn et al. 2002). Modeling of annual survival data 

determined that overall survival was relatively constant within approximately seven-year 

periods, but differed greatly between consecutive periods (Figure 10; Krahn et al. 2004a). 

Greater than average survival rates were detected from 1974-1979, 1985-1992, and 2001-2002, 

but rates were below average from 1980-1984 and 1993-2000. Changes in survival were not 

related to stochastic variation caused by the population’s small size (e.g., random patterns in 

births or deaths) or to annual fluctuations in survival. Krahn et al. (2002) therefore suggested 

that survival patterns were more likely influenced by an external cause, such as periodic changes 

in prey availability or exposure to environmental contaminants. The lowest rates of survival in 

each of the population’s six age and sex categories occurred from 1993-2000 (Krahn et al. 

2004a). Survival fell most sharply in older males, whereas reproductive females showed the 

smallest decline in survival (Figure 11). From 1993-2001, the percentage of males 15 years of 

age or older in the population fell from 17 percent to 11 percent (Krahn et al. 2002), placing it 

much lower than the 19 percent necessary for a stable age and sex distribution (Olesiuk et al. 

1990a). Investigation of temporal patterns in survival rates found no differences among the three 

pods (Figure 12; Krahn et al. 2004a). Each pod experienced simultaneous reductions in survival 

during the declines of the early 1980s and the late 1990s. However, L pod has consistently 

displayed lower survival rates than J and K pods. 

Krahn et al. (2002, 2004a) also examined fecundity levels in the Southern Resident population. 

Based on numbers of calves that survived to their first summer, average fecundity of 

reproductive-aged females was estimated at 12 percent from 1974-2000, which corresponded to 

a mean interval of 7.7 years between surviving calves. Modeling revealed that annual birth rates 

best fit a periodic function with about eight years between peaks (Figure 13; Krahn et al. 2004a). 

Low points in the numbers of recruited calves occurred in 1974-1975, 1982, 1987, and 1996, and 

peaks occurred in 1976, 1985, and 1994. Considerable variability exists in the annual fecundity 

rate of the population, as expected in a small population with few reproductively active females 

(Krahn et al. 2002). However, because the data fit a periodic function, reproductive output also 

appears to be partially synchronized between females. Such a pattern might result from 

occasional poor environmental years causing high calf mortality, which might then lead to a 

pulse in births after conditions recovered (Krahn et al. 2002). Birthing synchrony might then be 

retained for a certain period of time thereafter. 
January 2008 II-60 NMFS 

Figure 10. Model-averaged estimates of crude survival (black line) for the entire Southern 

Resident population, 1974-2002 (Krahn et al. 2004a). Annual survival levels are represented by 

triangles. 

Figure 11. Model-averaged estimates of survival by age and sex category for the entire Southern 

Resident population, 1974-2002 (Krahn et al. 2004a). 
January 2008 II-61 NMFS 

 

Figure 12. Annual survival estimates by pod for the Southern Resident population, 1974-2002 

(Krahn et al. 2004a). 

Figure 13. The best fitting model of fecundity (based on viable calves per reproductive-age 

female), which is a periodic function with 3-year constant periods (gray line), for the Southern 

Resident population, 1974-2002 (Krahn et al. 2004a). The model average fecundity (black line) 

and annual fecundity rates (triangles) for the population are also shown. 
January 2008 II-62 NMFS 

From 1994-2006 , J and K pods appear to have increased or maintained their calf productivity 

when compared to the previous decade (Center for Whale Research, unpubl. data). In contrast, 

calf productivity in L pod has dropped by about 35 percent in the past 12 years, with only 18 

calves recorded through 2006. This may be partially due to the females of this pod having only 

one fully mature adult male from J and K pods to mate with between 1998 and 2003 (Taylor 

2004, Wiles 2004). Additionally, L pod has experienced higher calf mortality (6 of 18 viable 

calves born) than either J pod (0 of 12 viable calves) or K pod (3 of 11 viable calves) (Center for 

Whale Research, unpubl. data). 

Brief histories of the three Southern Resident pods are provided below. We used the mean age 

of maturity (15 years for females, 13 for males) from Olesik et al. 2005 to summarize the age 

class distribution. As of October 2007, the community as a whole had 17 mature males (19.5 

percent of the population), 23 reproductive females (26.4 percent), 13 post-reproductive females 

(14.9 percent), 15 juvenile males (17.2 percent), 13 juvenile females (14.9 percent), and 6 

immature animals of unknown sex (6.9 percent) (Ellifrit et al. 2006; Center for Whale Research, 

unpubl. data). This contrasts with the population’s structure in 1987, when about 21 percent of 

the animals were mature males, 19 percent were reproductive females, 15 percent were postreproductive females, and 45 percent were juveniles of both sexes (Olesiuk et al. 1990a). Older 

demographic information on the pods can be found elsewhere (Balcomb et al. 1980, 1982, 

Balcomb 1982, Bigg 1982, Balcomb and Bigg 1986, Bigg et al. 1987, Ford et al. 2000, van 

Ginneken et al. 2000). 

J pod. This pod’s overall expansion from 15 whales in 1974 to 25 whales in October 2007 has 

been mixed with several minor declines and increases during intervening years (Table 5, Figure 

9). The pod is currently comprised of four matrilines totaling three adult males, six reproductive 

females, two post-reproductive females, four immature males, eight immature females, and two 

immature animals of unknown sex (Ellifrit et al. 2006; Center for Whale Research, unpubl. data). 

The oldest member is J2, who is estimated to be in her eighties or nineties (Ford et al. 2000). J1 

is the oldest adult male and is thought to be in his mid-fifties. 

K pod. Membership in K pod has varied from 14 to 22 whales since 1974, with 19 animals 

present in October 2007 (Table 5, Figure 9). The pod currently holds four matrilines consisting 

of three mature males, six reproductive females, three post-reproductive or non-reproductive 

females, four immature males, one immature female, and two immature whales of unknown sex 

(Ellifrit et al. 2006; Center for Whale Research, unpubl. data). The oldest member is K7, who is 

believed to be in her eighties or nineties (Ford et al. 2000). The pod was without an adult male 

for several years in the late 1990s, following the death of K1 in 1997. The oldest male (K21) is 

now 21 years of age. This pod was cropped especially heavily during the live-capture era (Bigg 

1982). 

L pod. This is the largest of the three Southern Resident pods and grew from 39 whales in 1974 

to a peak of 59 whales in 1993 (Table 5, Figure 9). Pod membership has been largely in decline 

since then and totaled just 43 animals in October 2007. L pod currently contains 12 matrilines 

with 11 adult males, 11 reproductive females, eight post-reproductive females, seven immature 

males, four immature females, and two immature animals of unknown sex (Ellifrit et al. 2006; 

Center for Whale Research, unpubl. data). The percentage of immatures (40 percent) is currently 
January 2008 II-63 NMFS 

the lowest of any pod. Three matrilines in L pod are represented by single whales, either males 

or post- reproductive females, and are destined to eventually die out. The oldest females are L25 

and L12, and are estimated to be 79 and 74 years old, respectively (Ford et al. 2000, Ellifrit et al. 

2006). L41 and L57 are the oldest males and were both born in 1977. L98, a six-year-old male 

that lived solitarily in Nootka Sound on the west side of Vancouver Island after becoming 

separated from the pod in July 2001, is included in the population figures used in this document 

through 2005. He died in March 2006 after colliding with a tugboat. During the 1980s, Hoelzel 

(1993) believed that L pod had separated into three smaller pods, which were identified as L8, 

L10, and L35 pods. 

Future predictions. Several studies have used a technique known as population viability analysis 

(PVA) to assess the future risk of extinction of the Southern Resident population. PVAs rely on 

known life history parameters to reach their conclusions and usually assume that conditions 

observed in the past will continue in the future. Limitations in models can produce unreliable 

results for a variety of reasons, such as the use of inaccurate demographic data and failure to 

correctly consider environmental variables and parameter uncertainty (Beissinger and Westphal 

1998, Reed et al. 1998). Thus, PVA forecasts should be viewed with some caution. 

The initial PVAs of the Southern Residents conducted by Taylor and Plater (2001) and Krahn et 

al. (2002) have been recently updated by Krahn et al. (2004a), who examined demographic 

information from several time periods (1974-2003, 1990-2003, and 1994-2003) to estimate 

extinction risk. Mean survival rates varied among periods and were highest from 1974-2003 and 

lowest from 1994-2003. In contrast, the model used a single fecundity rate, averaged from 1974-

2003, for all simulations. The study considered seven values of carrying capacity for the 

population ranging from 100 to 400 whales, three levels of catastrophic event (e.g., oil spills and 

disease outbreaks) frequency ranging from none to twice per century, and three levels of 

catastrophic event magnitude in which 0, 10, or 20 percent of the animals died per event. 

Analyses indicated that the Southern Residents have extinction probabilities of <0.1-3 percent in 

the next 100 years and 2-42 percent in the next 300 years under the scenario that the population’s 

survival rates from 1974-2003 continue into the future. However, the likelihood of extinction 

was greater if future survival rates match those from 1990-2003 or 1994-2003. The most 

pessimistic predictions were associated with survival rates from 1994-2003, with extinction risks 

predicted at 6-19 percent in 100 years and 68-94 percent in 300 years. In all cases, higher 

extinction risks were linked to lower carrying capacities and more frequent and severe 

catastrophes. Krahn et al. (2004a) also assessed the population’s probability of slipping to a 

level of “quasi-extinction,” which was defined as the stage at which 10 or fewer males or 

females remained, thereby representing a threshold from which the population was not expected 

to recover. These simulations suggested that the Southern Residents have a 1-15 percent chance 

of reaching quasi-extinction in the next 100 years and a 4-68 percent chance in the next 300 

years if survival rates from 1974-2003 continue. Predictions were again most pessimistic using 

survival data from 1994-2003, with the risk of quasi-extinction predicted at 39-67 percent in 100 

years and 76-98 percent in 300 years. As before, higher risks within each category were tied to 

smaller carrying capacities and greater threats of catastrophic events. 
January 2008 II-64 NMFS 

Status of Other Killer Whale Communities in the Northeastern Pacific 

Population assessments of other regional killer whale populations provide useful insight into the 

status of the Southern Residents and are briefly summarized below. 

Northern Residents. As with the Southern Residents, this population was also in a depleted 

condition when researchers recorded 132 whales during an initial census in 1975. Although 

count data are not available before this date, modeling by Olesiuk et al. (1990a) suggests that the 

community expanded from about 97 to 120 whales between 1960 and 1968, then declined by an 

estimated 10 percent to about 108 whales by 1970 due to removals for aquaria (Table 5, Figure 

14). Causes of declines before 1960 probably resembled those for Southern Residents, with 

indiscriminate shooting and other human-related factors most likely involved (Olesiuk et al. 

1990a). 

Annual censuses of the Northern Residents have been conducted since 1975 (Bigg et al. 1990, 

Ford et al. 2000). These documented fairly steady growth in the population at a mean rate of 3.0 

percent per year from 1975-1997, when numbers expanded from 132 to 220 whales (Table 5, 

Figure 14) (Ford et al. 2000; J. K. B. Ford, unpubl. data). This rate of growth was similar to the 

predicted intrinsic rate of the population and was substantially higher than the observed rate of 

the Southern Residents during the same time (Olesiuk et al. 1990a, Brault and Caswell 1993). 

Several factors were presented as possible reasons for the relatively stable growth of the 

0

50

100

150

200

250

1960

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

Year

Number of whales

Figure 14. Population size and trend of Northern Resident killer whales, 1975-2004. Data from 

1960-1974 (open circles, gray line) are number projections from the matrix model of Olesiuk et al. 

(1990a). Data from 1975-2004 (diamonds, black line) were obtained through photo-identification 

surveys of the 16 pods in this community and were provided by J. K. B. Ford (unpubl. data) and 

Olesiuk et al. (2005). Data for these years represent whale numbers for entire calendar years; 

animals are counted through their last year seen.
January 2008 II-65 NMFS 

Northern Residents through 1997, including 1) the population’s larger size in comparison to the 

Southern Residents, which made it less sensitive to stochastic events in births and deaths, 2) the 

smaller amount of cropping that occurred during the live-capture fishery (Olesiuk et al. 1990a), 

and 3) possibly fewer environmental changes in the community’s geographic range in recent 

decades. The population experienced an 8.6 percent decline in numbers from 1997-2001, falling 

to 201 whales. Possible explanations for this decrease are similar to those put forth for the 

Southern Residents (Killer Whale Recovery Team 2005). Abundance has rebounded since then, 

with 219 whales counted in 2004 (Olesiuk et al. 2005). PVAs have not been conducted for this 

population. 

Southern Alaska Residents. In contrast to the losses experienced by AB pod after the Exxon 

Valdez oil spill (see Incidental human-related mortality), most pods in this community have 

steadily expanded in size since 1984, when annual censuses began (Matkin et al. 2003, C. O. 

Matkin unpubl. data). Count data exist for 11 pods in which membership is completely known. 

Excluding AB pod, the aggregate number of whales in seven pods from Prince William Sound 

and Kenai Fjords increased from 82 to 134 animals between 1984 and 2004, with five pods 

growing and two maintaining their size. Three other pods primarily inhabiting southeastern 

Alaska expanded from a total of 39 animals to 95 animals during this period. The combined 

annual growth rate for these 10 pods averaged 4.5 percent per year, greatly exceeding that 

recorded for the Northern Residents from the mid-1970s to late 1990s and the Southern 

Residents during the 1970s and from the mid-1980s to mid-1990s. Differences in the 

reproductive lifespan of females and calf output probably explain this greater rate of growth 

(Matkin et al. 2003). AB pod reversed its decline in 1996 and is now also slowly increasing 

(Matkin et al. 2003, C. O. Matkin unpubl. data). Although census data are incomplete for other 

pods in the population, the current total size of the Southern Alaska Resident community is 

estimated to number at least 501 whales (Angliss and Outlaw 2005; C. O. Matkin, unpubl. data). 

The population’s strong overall growth rate since 1984 suggests that the community has either 

been recovering from an artificially depleted condition that existed when censuses began or that 

environmental conditions (e.g., salmon abundance) have improved since the mid-1980s (Matkin 

et al. 2003). Like with the Southern and Northern Residents, a slight decline in abundance was 

detected among the seven pods from Prince William Sound and Kenai Fjords in the late 1990s. 

Numbers fell from 114 to 107 whales (6.1 percent) from 1998 to 1999, but have shown robust 

growth each year since then (Matkin et al. 2003; C. O. Matkin, unpubl. data). No similar decline 

was noted in the other four pods.

Western Alaska Residents. Based on photo-identification studies, the minimum size of this 

population has been variously listed as 505 whales (Angliss and Outlaw 2005) and 800 whales 

(Krahn et al. 2004a). An additional estimate of 991 (95 percent CI = 379-2,585) whales has been 

made using line transect methods (Zerbini et al. 2006). Population trend data are unavailable. 

West coast transients. This community also suffered serious prey losses between the late 1800s 

and late 1960s, and very likely experienced a sizable decrease in abundance as a result (Ford and 

Ellis 1999, Springer et al. 2003). During this period, overhunting caused dramatic declines or 

extirpations in pinniped and large whale populations along much of western North America. By 

about 1970, it is estimated that harbor seal and Steller sea lion populations in British Columbia 

had fallen to about 10 percent and 25-33 percent, respectively, of historic levels (Olesiuk et al. 
January 2008 II-66 NMFS 

1990b, Ford and Ellis 1999). Similar reductions in pinniped numbers occurred elsewhere 

between southeastern Alaska and California (Scammon 1874, Bonnot 1951, Newby 1973, 

Jeffries et al. 2003, Brown et al. 2005). Many large whale populations have also severely 

declined and have never recovered (Scheffer and Slipp 1948, Rice 1974, Gregr et al. 2000, 

Springer et al. 2003, Carretta et al. 2004). However, seal numbers in the region have grown 7 to 

12-fold since about 1970 and are now close to or at carrying capacity (Olesiuk 1999, Jeffries et 

al. 2003). Recovery of the gray whale population (NMFS 1993) and partial recovery of regional 

humpback whale populations have also occurred (Carretta et al. 2004). With the recovery of 

some pinniped populations, Ford et al. (2000) believed that transient whales no longer face a 

scarcity of prey. 

Cumulative numbers of photographically identified west coast transients expanded throughout 

the 1980s and 1990s as efforts to document the population continued (Bigg et al. 1987, Black et 

al. 1997, Ford and Ellis 1999). To date, about 320 individuals have been identified in the 

population, which includes about 225 transients in Washington, British Columbia, and 

southeastern Alaska (Ford and Ellis 1999; J. K. B. Ford, unpubl. data) and 105 animals off 

California (Black et al. 1997). At least 10 whales have been seen in both regions. Efforts to 

determine population size are complicated by the lack of a complete registry of individuals and 

the difficulty in establishing deaths over time (Ford and Ellis 1999, Baird 2001, Angliss and 

Outlaw 2005). Given the current level of knowledge, the population probably totals about 300-

400 whales. Trend information is lacking for the population because accurate assessments of 

abundance have not been made. 

Gulf of Alaska transients. Photo-identification data from the late 1990s to 2003 suggest that this 

community contains a minimum of 314 whales (Angliss and Outlaw 2005). Zerbini et al. (2006) 

estimated a population size of 251 (95 percent CI = 97-644) animals based on line transect 

analyses. Population trend is unknown. 

AT1 transients. This pod numbered 21 whales in 1988, but went into rapid decline after the 

Exxon Valdez oil spill in early 1989 and fell to just 11 members by 1992 (Matkin et al. 1999, 

Matkin et al. 2003, NMFS 2003). Additional deaths and a lack of births since 1984 have further 

reduced the pod’s size to no more than seven whales as of 2005 (C. O. Matkin, unpubl. data). 

Offshores. Two partial population estimates are available for offshore killer whales, but are not 

directly comparable because of differences in methodology and geographic coverage. Carretta et 

al. (2004) calculated a minimum estimate of 361 offshore whales along the coasts of 

Washington, Oregon, and California, as determined from shipboard line-transect surveys 

conducted in 1996 and 2001 and the percentage of offshore animals among all killer whales 

photographed off California (Black et al. 1997). Based on photo-identification studies from 

1989 to 2004, 350 individual whales have been recorded in California and Alaska waters (M. E. 

Dahlheim, unpubl. data). This figure is considered a minimum estimate of total numbers due to 

the continued detection of new individuals over time and because photographic records from 

British Columbia, Washington, and Oregon were not included in the analyses (M. E. Dahlheim, 

pers. comm.). Difficulties in substantiating mortalities and recognizing previously identified 

individuals not seen for long periods further complicate efforts to determine the size of this 

community using this technique. 
January 2008 II-67 NMFS 

G. EXISTING PROTECTIVE MEASURES 

Federal. Killer whales and other marine mammal populations in the United States are protected 

under the Marine Mammal Protection Act of 1972 (MMPA), which placed a moratorium on the 

taking (defined as harassing, hunting, capturing, killing, or attempting to harass, hunt, capture, or 

kill) and importation of these animals and products derived from them. The MMPA exempts 

harvest of marine mammals by Alaska Natives for subsistence purposes or for creating and 

selling handicrafts, but there is no current subsistence or handicraft harvest for killer whales. 

Some incidental take associated with commercial fisheries is also allowed. Under the MMPA 

permits may be issued for research, public display, and commercial/educational photography. 

Based on a review of the best scientific information available, consultation with the Marine 

Mammal Commission, and consideration of public comment, NMFS designated the Southern 

Resident killer whales as a depleted stock under the MMPA in May 2003 and announced the 

intention to prepare a conservation plan (NMFS 2003b). A designation of depleted status 

requires that the agency prepare a conservation plan for the purpose of conserving and restoring 

the stock to its optimum sustainable population. In July 2004, the AT1 transient stock of killer 

whales in Alaska was also designated as a depleted stock under the MMPA (NMFS 2004a). 

In response to a petition filed by a number of environmental organizations in 2001 (Center for 

Biological Diversity 2001), NMFS determined that listing the Southern Residents as threatened 

or endangered under the ESA was “not warranted” because the population did not meet the 

criteria of being a distinct population segment (DPS) of the worldwide killer whale taxon (Krahn 

et al. 2002, NMFS 2002). This decision was challenged in December 2003, and in December of 

that year a U.S. District Court in Seattle, WA remanded the decision to NMFS to re-evaluate its 

initial determination. The Biological Review Team (BRT) was reconvened to consider new 

information and update the status review for Southern Residents. Upon review of the BRT 

reports, co-manager comments, papers and reports of a cetacean taxonomy workshop, and other 

available published and unpublished information, NMFS determined in December 2004 that the 

Southern Residents are discrete and significant with respect to an unnamed subspecies of killer 

whales (North Pacific Residents), and proposed that the DPS be listed as threatened under the 

ESA (NMFS 2004b). In response to information and comments on the proposed listing, NMFS 

subsequently listed the Southern Resident DPS as endangered (NMFS 2005, 70 FR 69903). The 

ESA protects threatened and endangered species in several ways. An endangered listing includes 

prohibitions of take of listed species (similar to the take prohibitions under the MMPA). Under 

section 7 of the ESA, all Federal agencies must insure that any actions they authorize, fund, or 

carry out are not likely to jeopardize the continued existence of a listed species, or destroy or 

adversely modify its designated critical habitat. Consultations occur with Federal action 

agencies under section 7 of the ESA to avoid and minimize impacts of their activities on listed 

species. NMFS is currently engaged in consultations with Federal agencies regarding a variety 

of construction, transportation, fishery management and other Federal projects. Federal agencies 

should use the information in the recovery plan to develop Biological Assessments for projects 

and evaluate the effects of actions. The recovery plan will also serve as a mechanism to 

coordinate section 7 consultations and ensure they are consistent with recovery. NMFS also 

reviews non-Federal activities that may affect species listed under the ESA, and issues permits 

under Section 10 for incidental take of those species and for scientific research and enhancement 

purposes. 
January 2008 II-68 NMFS 

In 2006, NMFS designated critical habitat for Southern Resident killer whales (See Habitat Use). 

In June 2006 NMFS proposed critical habitat, received comments and addressed those comments 

in the final rule in November 2006 (NMFS 2006a, 71 FR 69054). The ESA requires that NOAA 

and the U.S. Fish and Wildlife Service designate critical habitat for species that have been listed 

as threatened or endangered. In so doing, the agencies must use the best scientific information 

available, in an open public process, within specific timeframes. Before designating critical 

habitat, careful consideration must be given to the economic impacts, impacts on national 

security, and other relevant impacts of specifying any particular area as critical habitat. The 

Secretary of Commerce may exclude an area from critical habitat if the benefits of exclusion 

outweigh the benefits of designation, unless excluding the area will result in the extinction of the 

species concerned. The ESA defines critical habitat as specific areas: 1) within the geographical 

area occupied by the species at the time of listing, if they contain physical or biological features 

essential to conservation, and those features may require special management considerations or 

protection; and 2) outside the geographical area occupied by the species if the agency determines 

that the area itself is essential for conservation. Based on the natural history of the Southern 

Residents and their habitat needs, we identified the following physical or biological features 

essential to conservation: (1) Water quality to support growth and development; (2) Prey species 

of sufficient quantity, quality and availability to support individual growth, reproduction and 

development, as well as overall population growth; and (3) Passage conditions to allow for 

migration, resting, and foraging. We held public meetings and reviewed all comments and new 

information provided by the public and other reviewers, and then incorporated minor revisions 

into the final designation. We designated three specific areas, (1) the Summer Core Area in Haro 

Strait and waters around the San Juan Islands; (2) Puget Sound; and (3) the Strait of Juan de 

Fuca, which comprise approximately 2,560 square miles of marine habitat within the area 

occupied by Southern Resident killer whales in Washington (Figure 7). Section 7 of the ESA 

requires all Federal agencies to ensure their actions are not likely to destroy or adversely modify 

the designated habitat. Another benefit of designation is that it provides notice of areas and 

features important to species conservation, and information about the types of activities that may 

reduce the conservation value of the habitat, which can be effective for education and outreach. 

Cetaceans also receive protection through observer programs aimed at monitoring and reducing 

bycatch, including marine mammals. The authority to place observers on commercial fishing 

and processing vessels operating in particular fisheries is provided by the MMPA or the 

Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA). These two acts 

require the government to collect data on activities which affect marine resources. Many of the 

programs also satisfy requirements of the ESA. The Pelly Amendment of the Fisherman’s 

Protective Act allows trade sanctions to be imposed on countries that violate international laws 

protecting marine mammals. The importation of wildlife and associated products taken illegally 

in foreign countries is prohibited under the Lacey Act. 

In addition to regulations there are voluntary guidelines to inform the public on best practices for 

viewing whales. Guidelines for viewing killer whales in the wild were developed under the 

MMPA in 1981 to advise boaters on how to watch whales without impacting their behavior or 

causing harassment. The guidelines have been modified over the years to reflect new 
January 2008 II-69 NMFS 

information on vessel activities that may affect the whales. By following the guidelines, boaters 

can view the whales in their natural environment without violating the MMPA or ESA. 

Treaty trust responsibilities. NMFS must also consider their treaty trust responsibilities to 

recognize the rights and authorities of Tribes related to the ESA and salmon and killer whale 

recovery. Executive Order 13175 (Consultation and Coordination with Indian Tribal 

Governments) outlines the responsibilities of the Federal Government in matters affecting tribal 

interests. In addition, Secretarial Order “American Indian Tribal Rights, Federal-Tribal Trust 

Responsibilities, and the Endangered Species Act” outlines NMFS’ responsibilities regarding 

Indian tribal rights and Federal trust responsibilities when implementing the ESA. 

Canadian Federal. Killer whales received Federal protection from disturbance under Canada’s 

Marine Mammal Regulations (MMR) of the Fisheries Act in 1994, when a change in definitions 

extended coverage to all cetaceans and pinnipeds (Baird 2001). Although these regulations 

allow killer whales to be hunted with the purchase of a fishing license, the license is granted at 

the discretion of the Minister of Fisheries and Oceans and no such licenses have ever been 

approved. The regulations broadly prohibit the disturbance of killer whales (except when being 

hunted), but give no definition of “disturbance.” Penalties include fines and imprisonment. 

Fisheries and Oceans Canada is currently proposing to amend the existing MMR (Fisheries and 

Oceans Canada 2002, Lien 2001). Amending the MMR will ensure that all Canadians clearly 

understand their responsibilities with regard to protecting marine mammals and that DFO has the 

tools to fulfill its mandate. As part of the regulatory amendment process, the Department is 

conducting consultations with the public to receive input and feedback on the proposed changes. 

The department has also participated in development of a set of voluntary trans-boundary 

guidelines to limit interactions between whale-watching vessels and resident killer whales. Until 

recently, there has been limited enforcement of the Marine Mammal Regulations or monitoring 

of the viewing guidelines by authorities (Baird 2001, Lien 2001). However, DFO has supported 

the Marine Mammal Monitoring group and Straitwatch in recent years, and in 2004, an 

American whale-watching operator was prosecuted under the Marine Mammal Regulations and 

fined CA$6,500 (US$4,875) for approaching two groups of Southern Resident whales too 

closely in the Gulf Islands. 

In 2001, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) 

categorized the four populations of killer whales in the country’s Pacific waters, as follows: 

Southern Residents, endangered; Northern Residents, threatened; transients, threatened; and 

offshores, special concern. COSEWIC had no legal mandate and served only in an advisory role. 

The Species at Risk Act (SARA) became Federal law in June 2003, with killer whale populations 

maintaining their same status as under COSEWIC. Under this regulation, the killing, 

harassment, and possession of killer whales are prohibited. Important habitats of the whales will 

also receive protection. SARA requires the preparation of recovery strategies and action plans 

for all listed species. A recovery team was established which contains both Canadian and U.S. 

representatives, including NMFS staff. The team released a draft National Recovery Strategy for 

Northern and Southern Resident Killer Whales in March 2005 (Killer Whale Recovery Team 

2005), which was followed by the Proposed Recovery Strategy in 2007 (Killer Whale Recovery 

Team 2007). The next step is for DFO to develop an action plan identifying necessary 

conservation activities. 
January 2008 II-70 NMFS 

Washington state. Killer whales were named a “state candidate species” by the Washington 

Department of Fish and Wildlife in June 2000, which qualified them for consideration as 

endangered, threatened, or sensitive under state law (Washington Administrative Code [WAC] 

232-12-011 and 232-12-014). After an evaluation by the Department (Wiles 2004), the state’s 

Fish and Wildlife Commission approved listing of the species as endangered in April 2004, with 

formal designation occurring in June 2004. All forms of killer whale found in the state (i.e., 

residents, transients, and offshores) are protected under the law. This prohibits the hunting, 

possession, malicious harassment, and killing of killer whales (RCW 77.15.120). Violations can 

be either a gross misdemeanor or a class C felony, with penalties ranging up to five years 

imprisonment and a $10,000 fine. The species also receives protection under WAC 232-12-064, 

which prohibits the capture, importation, possession, transfer, and holding in captivity of most 

wildlife in state. Killer whales are listed as a “Criterion Two” priority species on the 

Department’s Priority Habitat and Species List, which catalogs animals and plants that are 

priorities for conservation and management, especially at the county level. Criterion Two 

species include those species or groups of animals susceptible to significant population declines 

within a specific area or statewide by virtue of their inclination to aggregate. This status 

provides no mandatory protection for killer whales. In some situations, Federal laws may 

preempt the regulatory protections provided by state governments. Killer whales were 

designated as the official marine mammal of the State of Washington in 2005. 

In 2007 the State of Washington established the Puget Sound Partnership, a new agency 

consisting of an executive director, an ecosystem coordination board, and a Puget Sound science 

panel (RCW 90.21.210). The Partnership was created to oversee the restoration of the 

environmental health of Puget Sound by 2020, and is directed to create a long-term plan called 

the 2020 Action Agenda by September 2008. The Action Agenda will contribute to killer whale 

recovery by identifying and prioritizing actions, identifying funding, and tracking and reporting 

progress. 

County. In 2004 the San Juan County Board of Commissioners designated the entire marine 

waters of the county as a Marine Stewardship Area (MSA). Under the MSA, the county is 

working with other government agencies and using public input from Indian Tribes, county 

residents, non-resident landowners, visitors, and others with an interest in the county's marine 

ecosystems to closely look at their adopted goals, develop specific objectives, and determine 

what additional protections are necessary to achieve those objectives. The results of this work 

will be the designation of specific areas within the marine stewardship area where different 

levels of voluntary or regulatory protection could be established in a coordinated effort to meet 

the goals. 

In September 2007 the San Juan County Council enacted a local ordinance (No. 35-2007 

designed to prevent boaters from harassing Southern Resident killer whales that frequent county 

waters. The ordinance makes it unlawful to feed killer whales or “knowingly” approach within 

100 yards of a killer whale within San Juan County. 

Other state and provincial. Although not specifically named, killer whales are covered under 

state regulations in Oregon (OAR 635-044-0130) and California (CF&G code, section 4500(a)) 

that protect all marine mammals from being killed, hunted, chased, or possessed. Neither the 
January 2008 II-71 NMFS 

province of British Columbia nor the State of Alaska gives special legal protection to killer 

whales. 

International. International trade in killer whales and their body parts is regulated and monitored 

by the Convention on International Trade in Endangered Species of Wild Fauna and Flora 

(CITES). Killer whales were placed on the CITES Appendix II in 1979, which requires all 

international shipments of the species to be accompanied by an export permit issued by the 

proper management authority of the country of origin. The International Whaling Commission 

categorizes killer whales and most other odontocetes as “small cetaceans,” but there is 

disagreement among member countries as to whether the Convention applies to this group of 

species. The Commission officially included killer whales in their moratorium on factory ship 

whaling (Anonymous 1981), but other management measures (e.g., the Southern Ocean 

Sanctuary and the moratorium on commercial whaling) do not apply to killer whales (Baird 

2001). In 2002, killer whales were added to Appendix II of the U.N. Convention on the 

Conservation of Migratory Species of Wild Animals. This designation is given to migratory 

species that “have an unfavorable conservation status and require international agreements for 

their conservation and management, as well as those which have a conservation status which 

would significantly benefit from the international cooperation that could be achieved by an 

international agreement.” The World Conservation Union (IUCN) lists killer whales as a species 

of “Lower Risk/Conservation Dependent” on its Red List. 

H. POTENTIAL THREATS TO SOUTHERN RESIDENT KILLER WHALES 

Marine mammal populations are often exposed to many forms of environmental degradation, 

including habitat deterioration, changes in food availability, increased exposure to pollutants, and 

human disturbance. All of these factors have been identified as potential threats to killer whales 

in Washington and British Columbia (Ford and Ellis 1999, Ford et al. 2000, Baird 2001, Krahn et 

al. 2002, 2004a, Taylor 2004, Wiles 2004). Unfortunately, despite much study since the early 

1970s and great advances in knowledge of the species, researchers remain unsure which threats 

are most significant to the region’s killer whales. 

Section 4(a)(1) of the ESA and the listing regulations (50 CFR part 424) set forth considerations 

for listing species. We must list a species if it is endangered or threatened because of any one or 

a combination of the following factors: (1) the present or threatened destruction, modification, or 

curtailment of its habitat or range; (2) overutilization for commercial, recreational, scientific, or 

educational purposes; (3) disease or predation; (4) inadequacy of existing regulatory 

mechanisms; or (5) other natural or human-made factors affecting its continued existence. 

The 2004 BRT identified the factors that currently pose a risk for Southern Residents and 

discussed whether these might continue in the future. Important concerns included (1) 

reductions in quantity or quality of prey, (2) high levels of organochlorine contaminants and 

increasing levels of many “emerging” contaminants (e.g., brominated flame retardants), putting 

Southern Residents at risk for serious chronic effects similar to those demonstrated for other 

marine mammals (e.g., immune and reproductive system dysfunction), (3) sound and disturbance 

from vessel traffic, and (4) oil spills. Below, we discuss the various threats that have been 

identified, organized around the ESA section 4(a)(1) listing factors that we addressed in our 
January 2008 II-72 NMFS 

determination to list Southern Residents under the ESA. In addition to the factors identified in 

the listing, additional risks were identified during development of the recovery plan, such as 

disease and alternative energy projects, and these are also discussed below. 

Present or Threatened Destruction, Modification, or Curtailment of Habitat or Range. Several 

factors have modified the Southern Residents’ habitat, including changes in prey availability, 

contaminants, and vessel traffic. Salmon populations, the prey of Southern Residents, have 

declined due to degradation of aquatic ecosystems resulting from modern land use changes (e.g., 

agriculture, hydropower, urban development), harvest and hatchery practices. Since the early 

1990s, 27 evolutionarily significant units (ESUs) of salmon and steelhead in Washington, 

Oregon, Idaho, and California have been listed as threatened or endangered under the ESA. 

Reductions in prey availability may force the whales to spend more time foraging and could lead 

to reduced reproductive rates and higher mortality. In addition, climate variability and change, 

aquaculture of Atlantic salmon and competition with other non-native species all have the 

potential to affect populations of Pacific salmon and other killer whale prey. 

 

Despite the enactment of modern pollution controls in recent decades, studies have documented 

high levels of PCBs in Southern Resident killer whales (Ross et al. 2000, Ylitalo et al. 2001, 

Krahn et al. 2007). These and other chemical compounds have the ability to induce immune 

suppression, reproductive impairment, and other physiological effects, as observed in studies of 

other marine mammals. In addition, high levels of emerging contaminants, such as 

polybrominated diphenyl ethers (PBDEs; flame retardants), that may have similar negative 

effects have been found in killer whales and have an expanding presence in the environment 

(Rayne et al., 2004, Krahn et al. 2007). 

 

Commercial shipping, whale watching, ferry operations, and recreational boating traffic have 

expanded in recent decades. Several studies have linked vessels with short-term behavioral 

changes in Northern and Southern Resident killer whales (Kruse 1991, Kriete 2002, Williams et 

al. 2002a, 2002b, Foote et al. 2004). Potential impacts from vessels are poorly understood, but 

may affect foraging efficiency, communication, and/or energy expenditure through physical 

presence or increased underwater sound levels or both. Collisions with vessels are also a 

potential source of injury. 

Overutilization for commercial, recreational, scientific, or educational purposes. The capture of 

Southern Resident killer whales for public display during the 1970s likely depressed their 

population size and altered the population characteristics sufficiently to severely affect their 

reproduction and persistence (Olesiuk et al. 1990a). However, there have not been any removals 

for public display since the 1970s. Whale watching can be considered a form of utilization of 

Southern Resident killer whales. Under existing prohibitions on take under the MMPA, 

commercial and recreational whale watching must be conducted without causing harassment of 

the whales. While NMFS, commercial whale watch operators, and nongovernmental 

organizations have developed guidelines to educate boaters on how to avoid harassment, there 

are still concerns regarding compliance with the guidelines and potential violations of the 

MMPA, increased numbers of vessels engaged in whale watching, and cumulative effects on the 

whales. 
January 2008 II-73 NMFS 

Disease or Predation. While disease has not been implicated in the recent decline of Southern 

Resident killer whales, high contaminant levels may affect immune function in the whales, 

increasing their susceptibility to disease. The cohesive social structure and presence of all 

whales in a localized area at one time also has implications should a disease outbreak occur. 

Inadequacy of Existing Regulatory Mechanisms. Current levels of contaminants in the 

environment indicate that previous regulatory mechanisms were not sufficient to protect killer 

whales. While the use of PCBs and DDT is restricted or prohibited under existing regulations, 

they persist in the environment for decades and are also transported via oceans and the 

atmosphere from areas where their use has not been banned. In addition, there are new emerging 

contaminants that may have similar negative effects that are not currently regulated. 

Other Natural or Human-Made Factors Affecting Continued Existence 

Due to its proximity to Alaska’s crude oil supply, Puget Sound is one of the leading petroleum 

refining centers in the United States with about 15 billion gallons of crude oil and refined 

petroleum products transported through it annually (Puget Sound Action Team 2005a). In 

marine mammals, acute exposure to petroleum products can cause changes in behavior and 

reduced activity, inflammation of mucous membranes, lung congestion, pneumonia, liver 

disorders and neurological damage (Geraci and St. Aubin 1990). The Exxon Valdez oil spill was 

identified as a potential source of mortality for resident and transient killer whales in Prince 

William Sound, Alaska (Dahlheim and Matkin 1994, Matkin et al. 2003) and has raised concerns 

about potential implications for Southern Residents, particularly if the entire population is 

together in the vicinity of a spill. In addition, there may be additional anthropogenic factors that 

have not yet been identified as threats for Southern Resident killer whales, particularly in their 

winter range which is not well known. 

Overall, the BRT was concerned about the viability of the Southern Resident DPS and concluded 

that it is at risk of extinction because of either small-scale impacts over time (e.g., reduced 

fecundity or subadult survivorship) or a major catastrophe (e.g., disease outbreak or oil spill). 

Additionally, the small population size of this killer whale DPS makes it potentially vulnerable 

to Allee effects (e.g., inbreeding depression) that could cause a further decline. The small 

number of breeding males, as well as possible reduced fecundity and subadult survivorship in the 

L-pod, may limit the population’s potential for rapid growth in the near future. Although the 

Southern Resident DPS has demonstrated the ability to recover from lower levels in the past and 

has shown an increasing trend over the last several years, the factors responsible for the decline 

are unclear (NMFS 2002, NMFS 2004). These factors may still exist and may continue to 

persist, which could potentially preclude a substantial population increase. 

The factors considered in listing and potentially affecting recovery of Southern Resident killer 

whales are summarized in Table 6, which includes assessments of severity, likelihood and 

feasibility of mitigation. None have yet been directly tied to the recent decline of the Southern 

Resident population (Krahn et al. 2002), but continued research should provide further insight 

into relationships. The primary risk factors are discussed in greater detail below: prey 

availability, environmental contaminants, vessel effects and sound, and oil spills. In addition we 

discuss several potential factors, such as disease and alternative energy projects, that may have 

some effect on recovery in the future. We also discuss cumulative effects because it is likely that 
January 2008 II-74 NMFS 

Table 6. Factors considered in listing and potentially affecting recovery of Southern Resident killer 

whales. 

Threat Listing Factors Severity Likelihood Feasibility of Mitigation 

Prey 

availability 

Habitat High High High, many salmon recovery 

efforts underway 

Contaminants Habitat, Inadequacy 

of Existing 

Regulations 

High High Medium, Puget Sound clean-up 

efforts underway 

Vessel effects 

(commercial, 

recreational 

whale watch) 

Habitat, 

Overutilization, 

Inadequacy of 

Existing 

Regulations 

High High High, whale watching 

guidelines and outreach 

underway, NOAA evaluating 

regulations and/or protected 

areas 

Vessel effects 

(other vessel 

traffic not 

targeting 

whales) 

Habitat, Inadequacy 

of Existing 

Regulations 

Medium High Medium, safety and security 

considerations may limit ability 

to alter shipping lanes, MMPA 

and ESA mechanisms in place 

Sound Habitat, Inadequacy 

of Existing 

Regulations 

MediumHigh High Medium, MMPA and ESA 

mechanisms in place 

Oil spills 

(pipelines, 

container and 

oil tankers) 

Other Natural or 

Human-made 

Factors 

High Low High, regulations in place for 

prevention, response plan for 

killer whales in development 

Oil spills 

(small chronic 

sources) 

Other Natural or 

Human-made 

Factors 

Medium High Medium, permits and program 

in place to regulate point and 

non-point sources 

Disease Disease and 

Predation 

High Low Low, opportunistic monitoring 

in place 

Small 

population size 

Other Natural or 

Human-made 

Factors 

MediumHigh Medium Low, population monitoring in 

place 

Live-captures 

for aquaria 

Overutilization Low Low Live-captures discontinued, but 

potential population structure 

effects remain 

two or more of these factors are acting together to harm the whales (Ford et al. 2005b, see Sih et 

al. 2004). An example of how cumulative effects of multiple factors might be affecting whales 

would be vessel effects when combined with the stresses of reduced prey availability or 

increased contaminant loads (Williams et al. 2002a). Under such a scenario, reduced foraging 

success resulting from effects of vessels and declining salmon abundance may lead to chronic 

energy imbalances and poorer reproductive success, or all three factors may work to lower an 

animal’s ability to suppress disease. 
January 2008 II-75 NMFS 

Prey Availability 

Healthy killer whale populations are dependent on adequate prey levels. Reductions in prey 

availability may force whales to spend more time foraging and might lead to reduced 

reproductive rates and higher mortality rates. Human influences have had profound impacts on 

the abundance of many prey species in the northeastern Pacific during the past 150 years. 

Foremost among these, many stocks of salmon have declined significantly due to overfishing, 

poor artificial propagation practices, and degradation of freshwater and estuarine habitats 

through urbanization, dam building, and forestry, agricultural, and mining practices (National 

Research Council 1996, Slaney et al. 1996, Gregory and Bisson 1997, Lichatowich 1999, Lackey 

2003, Pess et al. 2003, Schoonmaker et al. 2003). Populations of some other known or potential 

prey species, such as marine mammals and various fish, have similarly declined or fluctuated 

greatly through time. Status assessments of the food resources available to killer whales in the 

region are complicated by numerous considerations, including a lack of detailed knowledge on 

the food habits and seasonal ranges of killer whales, uncertainties in the historical and current 

abundance levels of many localized populations of prey, and the cyclic nature of large-scale 

changes in ocean conditions. 

Current data suggest that Chinook salmon, the region’s largest salmonid, are the most commonly 

targeted prey of resident killer whales in Washington and British Columbia between late spring 

and early fall (Ford et al. 1998, Hanson et al. 2005, Ford and Ellis 2006). Other salmonids 

appear to be eaten less frequently, as are some non-salmonids such as rockfish, halibut, lingcod, 

and herring. Unfortunately, fewer than 125 feeding observations have been reported for the 

Southern Residents, and therefore, conclusions about their diet are preliminary. Furthermore, 

few feeding data exist for the winter months or for whales found away from inland waters. 

There has also been a reliance on surface feeding observations, which may underrepresent 

predation on bottom fish or other species. Further complicating an adequate understanding of 

Southern Resident-prey relationships is the possibility of dietary differences among pods and 

between sexes (Nichol and Shackleton 1996, Ford et al. 1998, Baird 2000). 

Another poorly understood facet of diet is the extent to which resident killer whales have 

depended on specific salmon runs, both in the past and currently (Krahn et al. 2002). Several 

researchers have compared Southern Resident distribution with salmon sport catch records, but 

none have attempted to identify targeted runs. The population’s annual presence in the vicinity 

of the San Juan Islands and Fraser River mouth from late spring to early fall suggests a 

dependence on salmon returning to this river system (Osborne 1999). This is reasonable given 

the river’s immense production of salmon (Northcote and Atagi 1997) many of which pass 

through Haro Strait and surrounding waters. Heimlich-Boran (1986) correlated killer whale 

occurrence with salmon sport catch in the San Juan Islands and portions of Puget Sound, but did 

not describe the species or runs selected. Felleman et al. (1991) added that some small-scale 

winter occurrences of the whales were related to the presence of juvenile Chinook, adult 

steelhead, and adult cutthroat trout (Salmo clarkii). Autumn movements of Southern Resident 

pods into Puget Sound roughly correspond with chum and Chinook salmon runs (Osborne 1999), 

as illustrated by the presence of whales in Dyes Inlet during a strong run of chum in 1997. Two 

California sightings and one off Westport, Washington, have coincided with large runs of 

Chinook salmon (K. C. Balcomb, unpubl. data; M. B. Hanson, pers. obs., in Krahn et al. 2004a). 
January 2008 II-76 NMFS 

Northern Resident occurrence in Johnstone Strait has been tied to the large seasonal runs of 

sockeye and pink salmon, as well as chum salmon to a lesser extent (Nichol and Shackleton 

1996), but new information indicates that linkages with sockeye and pink occurrence are 

coincidental (Ford and Ellis 2006). 

Research update 

Two recent studies have examined the relationships between salmon abundance and population 

dynamics of resident killer whales and support the belief that Chinook and chum salmon are 

most important to the Southern Residents. Both studies, however, are limited by incomplete data 

on salmon occurrence and year-round range use by the whales. Environmental factors common 

to both Southern Residents and salmon may also be driving the findings rather than direct 

predator-prey relationships. Ford et al. (2005b) compared survival rates of Northern and 

Southern Resident killer whales with measures of Chinook abundance from Alaska to Oregon 

derived from the Pacific Salmon Commission Chinook model for the 1970s to about 2004. They 

reported a strong positive correlation between changes in overall coast wide Chinook abundance 

and combined mortalities of both resident communities. On a local scale, Ford et al. (2005b) 

found a weak correlation between Southern Resident survival and abundance of Washington and 

Oregon Chinook (R2=.115). A weakly significant correlation between birth rates in both 

populations and coast-wide Chinook abundance was also detected. 

McCluskey (2006) compared population trends for Southern Residents to total run size estimates 

and escapement for five species of salmon in Washington and the Fraser River from the 1970’s 

to about 2005. McCluskey reported a significant positive correlation between the Southern 

Resident population trend and early chum, normal chum and Chinook runs. On a regional scale 

based on regions of escapement, the chum in all regions, Chinook in the Strait of San Juan de 

Fuca, Central and South Puget Sound, and Fraser River sockeye were the most significantly 

associated with the Southern Resident community. McCluskey (2006) also reported that all three 

pods showed reduced movements from late spring to fall during the early 1990s, when overall 

salmon abundance was higher and the Southern Resident population was increasing, as 

compared to the late 1990s, when salmon were less abundant and the whale population was 

decreasing, implying that a scarcity of salmon caused the whales to forage more widely. 

Chinook abundance was generally low throughout the decade. 

In former times, these whales may have simply moved to other areas with adequate food or 

shifted their diets to alternate fish stocks in response to the reduction of a heavily used run (Ford 

Both NOAA’s Northwest Fisheries Science Center and Canada’s Department of 

Fisheries and Oceans are analyzing killer whale prey samples to identify salmon stocks 

that the whales are eating (NWFSC and DFO unpublished data). Early results show the 

Southern Residents are consuming Fraser River origin Chinook in large numbers, but 

are also eating salmon from Puget Sound, Washington and Oregon coasts, the Columbia 

River, and Central Valley California. As the data are further analyzed, they will provide 

valuable information on which specific runs of salmon the whales are consuming in 

certain locations and seasons. 
January 2008 II-77 NMFS 

et al. 2000). These options may be less viable now due to broader declines of various fish 

populations in the region. 

As already noted, there is an absence of comprehensive and accurate estimates of salmon 

abundance for significant portions of the ranges of Southern and Northern Residents. In many 

cases, salmon population estimates from the 1800s to mid-1900s are crude or non-existent. 

Furthermore, estimates originate from a variety of sources and methods (i.e., catch data, 

escapement, or both) and therefore may not be comparable among or within locations (Bisson et 

al. 1992). Some include both wild and hatchery fish, whereas others tallied only one of these 

groups. Substantial interannual variability is also inherent in many stocks. Finally, concise 

summaries of specific run size information can be dauntingly difficult to locate within fisheries 

agency records. Despite these limitations, some general trends are apparent. Of greatest 

significance are the overall major reductions in the natural breeding populations of most species 

between the 1800s to mid-1900s (Table 7, Krahn et al. 2002, 2004). Many runs have continued 

to decrease since then, but others have partially recovered. Declines are particularly prevalent in 

Washington, Oregon, Idaho, California, and southern British Columbia due to greater human 

impacts on freshwater and estuarine habitats as well as ocean productivity cycles, whereas 

populations in Alaska have been little affected (Riddell 1993, Slaney et al. 1996, Nehlsen 1997, 

Wertheimer 1997, Yoshiyama et al. 1998, Kope and Wainwright 1998, Lackey 2003, 

Schoonmaker et al. 2003). Among naturally spawning salmon, 30 of the 49 ESUs in the western 

contiguous United States are currently listed as threatened or endangered, or are candidates for 

listing under the Federal Endangered Species Act (www.nwr.noaa.gov). Half or more of all 

Chinook, steelhead, and chum ESUs are listed. Some of the remaining 19 ESUs are predicted to 

become endangered unless specific recovery actions can be accomplished. Despite this overall 

pattern, an assessment of natural salmon stocks in Washington during the late 1980s and early 

1990s found that of 309 stocks with sufficient data to assess current status, 60.5 percent were 

healthy and 39.5 percent were depressed or of critical status (WDFW et al. 1993). A 

disproportionately greater number of healthy stocks were located in Puget Sound, whereas more 

depressed and critical stocks occurred in the Columbia River basin. 

Many wild salmon runs have been supplemented by significant numbers of hatchery-reared 

salmon since the 1950s and 1960s, when modern hatchery programs began being widely 

implemented (Mahnken et al. 1998). In Washington, hatchery fish now account for about 75 

percent of all Chinook and coho salmon and nearly 90 percent of all steelhead harvested. In 

Puget Sound and the Strait of Georgia, the amounts of artificially reared salmon are variable with 

species, but significant numbers of hatchery Chinook and coho are present in many runs (e.g., 

Sweeting et al. 2003). The extent that resident whales consume hatchery salmon is poorly 

understood, but hatchery fish are eaten (J. K. B. Ford, unpubl. data) and may represent an 

important part of the diet for Southern Residents. 
January 2008 II-78 NMFS 

Table 7. Summary of historical and recent estimates of salmon numbers (in thousands) produced by 

western North American river systems between the Strait of Georgia and central California a

. 

Species 

Region Period of time Chinook Pink Coho Chum Sockeye Steelhead 

 

Fraser Late 1800s to mid-1900s 750b 23,850b 1,230b 800b 925-40,200c nd 

River Mid-1900s to early 1980s 150b 1,900-18,700d 160b 390b 967-18,800c nd 

 Mid-1980s to early 1990s 140-280e

 7,200-22,180d 40-100b ca 1,300f 3,770-

22,000c

nd 

 Early 1990s to current 140-350e

 3,600-21,200d increasingf 13× greater 

since 1997f

3,640-

23,600c

12g

 

Puget 

Sound 

Late 1800s to early 1900s 250-700h 1,000-16,000h 700-2,200h 500-1,700h 1,000-

22,000h

nd 

Mid-1900s 40-100h 350-1,000i 200-600h 300-600i 150-400i nd 

 Mid-1980s to early 1990s 80-140i

 1,000-1,930j 300-800i 1,040-2,030k 92-622j >41l

 Early 1990s to current 118-280m 440-3,550i

 200-500h 570-3,390j 37-555i nd 

 

Coastal Mid- to late 1800s 190n nd nd nd nd 

Washington Mid-1900s nd nd 80-100i

 20-130i nd 

Mid-1980s to early 1990s 30-115i 40-130i 10-325i 15-80i 25-50i

 Early 1990s to current 50-65i 30-70i

 60-175i 20-80i 30-40i

 

Columbia Mid- to late 1800s 4,800-9,200o 900-1,780o 540-1,390o 2,600-2,840o 570-1,350o

River Mid-1900s 564-1,412p 21-786p 1-426p 11-335p 252-438p

 Mid-1980s to early 1990s 483-1,237p 262-1,575p 1-5p

 47-200p 292-559p

 Early 1990s to current 382-642p 89-624p

 1-5p 9-94p 240-428p

 

Mid- to 1900 300-600q 1,700q nd nd

northern Mid-1900s nd nd 130r nd

coastal Mid-1980s to early 1990s 115-420q,s 70q 29r >178l

Oregon Early 1990s to current nd nd nd nd 

 

Northern Mid- to late 1800s 300n 1,200t nd

coastal Mid-1900s 256t 200-500u nd

California Mid-1980s to early 1990s nd 13u nd

 Early 1990s to current ca 10-50v nd nd

 

Central Mid- to late 1800s 1,000-

2,000w

nd nd

Valley, Mid-1900s 117->612w nd nd

California Mid-1980s to early 1990s 137-387w nd nd

 Early 1990s to current 125->415w nd >12l

a Estimates may represent catch data, escapement, or estimated run size, and therefore may not be comparable between or within 

sites. Some estimates include hatchery fish. Early catch records for sockeye and pink salmon in Puget Sound are especially 

problematic because they include Fraser River salmon caught by American fishermen and landed in Puget Sound ports (J. Ames, 

pers. comm.). Periods without data for particular species are represented by “nd.”

b Northcote and Atagi (1997), catch and escapement; c I. Guthrie (unpubl. data); d B. White (unpubl. data); e DFO (1999), catch and 

escapement; f DFO (2001); g Simon Fraser University (1998); h Bledsoe et al. (1989), catch only; i Johnson et al. (1997b), wild run 

sizes only; j J. Ames (unpubl. data); k WDFW (2004); l Busby et al. (1996); m B. Sanford (unpubl. data), adult run size only, including 

both wild and hatchery fish, but excluding spring Chinook; n

 Myers et al. (1998); o Northwest Power Planning Council (1986); p

WDFW and ODFW (2002); q Kostow (1997); r

 Nickelson et al. (1992); s Nicholas and Hankin (1989); t California Department of Fish 

and Game (1965); u Brown et al. (1994); v Mills et al. (1997); w Yoshiyama et al. (1998). 
January 2008 II-79 NMFS 

For Southern Resident killer whales, salmon population levels are particularly important in and 

around the Georgia Basin and Puget Sound, which are the core areas for these whales during 

much of the year. Overall salmon abundance in Puget Sound has been roughly stable or 

increasing for the past several decades, due largely to the strong performance of pink and 

hatchery produced chum salmon. Both species have been at or near historic levels of abundance 

for the past 20-25 years (Hard et al. 1996; Johnson et al. 1997; WDFW 2004; J. Ames, unpubl. 

data). No recent changes in salmon populations are obviously apparent that may be responsible 

for the decline of L pod. 

Population trends of salmon stocks in the range of Southern Resident killer whales are 

summarized below, along with those of several other known prey species. Brief discussions of 

additional factors affecting salmon abundance and productivity are also presented. Detailed 

accounts of the life history of Pacific salmon can be found in Groot and Margolis (1991), with 

summaries of occurrence in Washington presented in Wydoski and Whitney (2003). 

Chinook salmon. Chinook are the least common species of salmon in the northeastern Pacific 

(Wydoski and Whitney 2003, Riddell 2004). Long- and short-term trends in the abundance of 

wild stocks are predominantly downward, with some populations exhibiting severe recent 

declines (Table 7). However, total abundance in Puget Sound, the eastern Strait of Juan de Fuca, 

and the lower Columbia River basin has been relatively high in recent decades due to production 

from hatcheries (Myers et al. 1998; B. Sanford, pers. comm.). All spring-run populations in 

these areas are depressed. Many of the formerly vast populations in the mid- to upper Columbia 

and Snake River basins have declined considerably or virtually disappeared, although some (e.g., 

fall runs in the upper Columbia) remain moderately large (WDFW et al. 1993, Myers et al. 1998, 

WDFW and ODFW 2002). Total abundance along the Washington and Oregon coasts is 

relatively high and long-term population trends are generally upward, but a number of runs are 

experiencing severe recent declines. In British Columbia, Chinook escapements were higher in 

the 1990s than at any other time dating back to the 1950s, but concern remains over the 

depressed status of stocks in southern British Columbia (Slaney et al. 1996, Northcote and Atagi 

1997, Henderson and Graham 1998, Riddell 2004). The status of stocks from southern Oregon 

to California’s Central Valley is variable, with a number of runs in poor condition or extirpated 

(Yoshiyama et al. 2000). Others (e.g., Rogue River, fall runs in the upper Klamath and Trinity 

Rivers and the Central Valley) remain fairly abundant, although hatchery fish tend to be a large 

component of the total escapements (Myers et al. 1998, Yoshiyama et al. 2000). 

Chum salmon. Chum salmon are abundant and widely distributed in Puget Sound and the Strait 

of Georgia, and currently comprise the majority of wild salmon in many river systems. Autumn 

runs are prevalent in both areas. Recent numbers in Puget Sound are at or near historic levels 

(Table 7), fluctuating between about 0.6 and 2.6 million fish (including hatchery fish) from the 

early 1980s to 1998 (WDFW 2004). Numbers dropped to fewer than 700,000 fish in 1999 and 

2000 due to unfavorable ocean conditions, but rebounded strongly in 2001 and 2002, with run 

size estimated at nearly 3.4 million fish in 2002 (WDFW 2002, 2004). Hatchery fish comprise 

19-47 percent of the total population in any given year. Although chum abundance in British 

Columbia is characterized by large annual fluctuations, overall escapements have been slowly 

increasing since the 1950s (Henderson and Graham 1998). However, numbers remain lower 

than those observed in the early 1900s (Henderson and Graham 1998). The Columbia River 
January 2008 II-80 NMFS 

once supported commercial landings of hundreds of thousands of chum salmon, but returning 

numbers fell drastically in the mid-1950s and never exceeded 5,000 fish per year in the 1990s 

(WDFW and ODFW 2002). Stock sizes are variable along the Washington coast, but are low 

relative to historic levels on the Oregon coast. 

Pink salmon. Pink salmon are the most abundant species of Pacific salmon (Wydoski and 

Whitney 2003) and reach the southern limit of their primary spawning range in Puget Sound. 

Most odd-year populations in the sound and southern British Columbia appear healthy and 

current overall abundance is close to historical levels or increasing (Hard et al. 1996; Northcote 

and Atagi 1997; J. Ames, pers. comm.), whereas even-year runs are naturally small. Numbers in 

Puget Sound have been high (mean odd year run size = 1.47 million fish, range = 440,000-7.4 

million) in most years since at least 1959 (J. Ames, unpubl. data). However, several populations 

along the Strait of Juan de Fuca and in Hood Canal are declining or possibly extinct. 

Considerable variation in run size can occur, as seen in the Fraser River, where odd-year runs 

varied from about 3.6 to 22.2 million between 1991 and 2001 (B. White, unpubl. data). Stocks 

in Puget Sound and British Columbia are comprised almost entirely of naturally spawning fish. 

Coho salmon. Abundance south of Alaska has declined despite the establishment of large 

hatchery programs (Kope and Wainwright 1998). A number of risk factors, including 

widespread artificial propagation, high harvest rates, extensive habitat degradation, a recent 

dramatic decline in adult size, and unfavorable ocean conditions, suggest that many wild stocks 

may encounter future problems (Weitkamp et al. 1995). Populations supplemented with large 

numbers of hatchery fish are considered near historical levels in Puget Sound and the Strait of 

Georgia, with overall trends considered stable (Weitkamp et al. 1995). Natural coho populations 

in British Columbia have been in decline since the 1960s (Slaney et al. 1996, Northcote and 

Atagi 1997, Henderson and Graham 1998, Sweeting et al. 2003, Riddell 2004), while those in the 

lower Columbia River basin and along the coasts of Oregon and northern California are in poor 

condition (Weitkamp et al. 1995). Most coho in the Strait of Georgia and Columbia basin 

originate from hatcheries. 

Sockeye salmon. Sockeye are the second most common species of salmon in the northeastern 

Pacific, with spawning populations usually associated with lakes for the rearing of juveniles 

(Wydoski and Whitney 2003). Only three of Washington’s nine sockeye salmon populations are 

considered healthy (WDFW et al. 1993) and many are naturally small (Gustafson et al. 1997). 

Declines are especially noticeable in the Columbia basin (Table 7; WDFW and ODFW 2002). 

From 1993-2002, run size of the introduced stock in the Lake Washington system averaged 

230,000 fish (range = 35,000-548,000) (J. Ames, unpubl. data). Sockeye numbers have been 

recovering in British Columbia since the 1920s (Northcote and Atagi 1997, Henderson and 

Graham 1998). The Fraser River holds the largest run, usually accounting for more than half of 

all sockeye production in the province. Huge runs occur cyclically every four years in the river 

and elsewhere in southern British Columbia, which may have a substantial effect on annual food 

availability for Southern Resident killer whales. Between 1990 and 2002, run sizes varied from 

about 3.6 to 23.6 million fish (I. Guthrie, unpubl. data). 

Steelhead. More than half of the assessed wild populations in Washington are considered 

depressed (WDFW et al. 1993) and many are declining (Busby et al. 1996). However, stocks 
January 2008 II-81 NMFS 

throughout the state are heavily supplemented with hatchery fish. Populations are largest in the 

Columbia River basin (Table 7), where summer runs have generally increased since the 1970s 

and winter runs have declined (WDFW and ODFW 2002). Wild coastal steelhead populations 

are considered healthy in Washington (WDFW 2002), but are largely in decline in Oregon and 

northern California (Busby et al. 1996). NMFS announced a proposal to list this DPS in March 

2006 and listed them as "threatened” in May 2007. 

Hatchery production. Hatchery production may have partially compensated for declines in many 

wild salmon populations and therefore has likely benefited resident killer whales to some 

undetermined extent. However, hatcheries are also commonly identified as one of the factors 

responsible for the depletion of wild salmon stocks (Sweeting et al. 2003, Gardner et al. 2004). 

This can occur through a number of processes. One of the most important of these is through 

mixed stock fishing, wherein wild fish are harvested unsustainably when they co-occur with 

large numbers of hatchery fish (Gardner et al. 2004). Physical and genetic interactions between 

wild and hatchery salmon can weaken wild stocks by increasing the presence of deleterious 

genes (Reisenbichler 1997, Reisenbichler and Rubin 1999). Substantial genetic ingress can 

occur in native salmon populations, as demonstrated by wild spawning coho salmon in the lower 

Nooksack and Samish Rivers of Washington, which are now genetically similar to the hatchery 

fish also present (Small et al. 2004). Competition for food and other resources between hatchery 

and wild fish may reduce the number of wild fish that can be sustained by the habitat (Flagg et 

al. 1995, Levin et al. 2001). Predation by hatchery fish and transfer of disease are other 

mechanisms in which wild populations may be harmed (Gardner et al. 2004). 

An additional way in which hatchery production may affect Southern Resident killer whales is 

through increased chemical contamination of prey. Hatchery policies that encourage longer 

residency periods in Puget Sound salmon, especially Chinook salmon, may result in substantially 

higher PCB contamination of the fish (O’Neill et al. 2005). 

Salmon size. Many North Pacific populations of five salmon species have declined in physical 

size during the past few decades (Bigler et al. 1996). For example, mean weights of adult 

Chinook and coho salmon from Puget Sound have fallen by about 30 percent and 50 percent, 

respectively (Weitkamp et al. 1995; Quinn et al. 2001; B. Sanford, pers. comm.). In the 

Columbia River, Chinook weighing 50-60 lb were once a small but regular component of runs, 

but are now a rarity. Decreases in mean weights have also been reported for adult chum (11-40 

percent), pink (20 percent), and sockeye (6 percent) salmon (Schoonmaker et al. 2003). Size 

reductions have been linked to abundance levels and ocean condition (Bigler et al. 1996, Pyper 

and Peterman 1999), but other factors such as harvest practices, genetic changes, effects of fish 

culture, and density-dependent effects in freshwater environments attributable to large numbers 

of hatchery releases may also play a role (Weitkamp et al. 1995). Heavy fishing pressure often 

produces younger age distributions in populations, resulting in fewer salmon maturing in older 

age classes and a smaller overall average adult size (Pess et al. 2003; J. Ames, pers. comm.). 

Hatcheries also have a tendency to produce returning adults that are younger and smaller (B. 

Sanford, pers. comm.). Reduced body size not only poses a number of risks to natural salmon 

populations, but may also impact killer whales and other predators. Smaller fish may influence 

the foraging effectiveness of killer whales by reducing their caloric intake per unit of foraging 

effort, thus making foraging more costly. A combination of smaller body sizes and declines in 
January 2008 II-82 NMFS 

many stocks means an even greater reduction in the biomass of salmon resources available to 

killer whales. Recent mean weights of adult ocean salmon, including both wild and hatchery 

fish, are as follows: Chinook, 3.3-8.3 kg; chum, 3.3-4.8 kg; coho, 1.8-3.2 kg; sockeye, 2.6 kg; 

and pink, 1.5 kg (Schoonmaker et al. 2003). 

Salmon body composition. Energy value and possibly nutritional quality differ among salmon 

species and populations. Osborne (1999) reported the caloric content of five Pacific salmon 

species as follows: chinook, 2,220 kcal/kg; sockeye, 1,710 kcal/kg; coho, 1,530 kcal/kg; chum, 

1,390 kcal/kg; and pink, 1,190 kcal/kg. Regional differences in caloric content have also been 

described among Chinook salmon populations, with those from Puget Sound having the lowest 

values among five regions sampled along the North American west coast (O’Neill et al. 2006). 

These types of differences mean that prey switching from a preferred but declining salmon 

species to a more abundant alternate species may result in lowered energy intake for resident 

killer whales. Additionally, Chinook salmon are unique in that spring run fish generally have 

greater fat concentrations than fall run fish (B. Sanford, pers. comm.). This is due to differences 

in life history strategies, with spring Chinook needing larger amounts of fat for swimming to 

spawning sites located farther upstream and to survive their longer residency period in rivers 

prior to spawning. This means that population reductions in spring Chinook (see Seasonal 

Availability) may result in the scarcity of a preferred and valuable food item for killer whales. 

Salmon distribution. Habitat alteration, hatchery and harvest practices, and natural events have 

combined to change regional and local patterns of salmon distributions during the past 150 years, 

but especially since about 1950 (Bledsoe et al. 1989, Nehlsen 1997). Some historically 

productive populations are no longer large, whereas other runs may have increased in abundance 

through hatchery production. Limited evidence indicates that hatcheries do not greatly change 

the pelagic distribution of coho salmon (Weitkamp et al. 1995), but they can strongly influence 

the nearshore presence of salmon and thus the availability of salmon for predators (Krahn et al. 

2002). Within Puget Sound and the Strait of Georgia, it is unknown whether changes in salmon 

distribution have accompanied long-term changes in abundance. However, salmon distribution 

is believed to have remained consistent in this region since at least the 1960s. In particular, pink 

and chum salmon currently occupy nearly all of the habitat that would have been available 

historically (J. Ames, pers. comm.). 

Perhaps the single greatest change in food availability for resident killer whales since the late 

1800s has been the decline of salmon in the Columbia River basin. Estimates of predevelopment 

run size vary from 10-16 million fish (Table 7; Northwest Power Planning Council 1986) and 7-

30 million fish (Williams et al. 1999), with Chinook salmon being the predominant species 

present. Since 1938, annual runs have totaled just 750,000 to 3.2 million fish (WDFW and 

ODFW 2002). Returns during the 1990s averaged only 1.1 million salmon, representing a 

decline of 90 percent or more from historical levels. With so many fish once present, salmon 

returning to the Columbia River mouth may have been an important part of the diet of Southern 

Resident whales. 

Similarly, California’s Central Valley once supported large numbers of Pacific salmon, but many 

runs are now severely diminished or gone entirely (Table 7; Yoshiyama et al. 1998, 2000). 

Chinook salmon were the primary salmonid in this basin as well. Appreciable numbers of 
January 2008 II-83 NMFS 

Chinook from the Central Valley are known to have migrated northward to Oregon, Washington, 

and British Columbia (Yoshiyama et al. 1998), and therefore may have been available as a 

significant dietary item for the Southern Residents. 

Seasonal availability. Even though salmon are currently considered relatively numerous in a 

number of areas (when hatchery fish are included), patterns of seasonal availability differ from 

historical patterns in some instances. Thus, resident killer whales may have lost some seasonally 

important sources of prey, while perhaps gaining others, as seen in the examples that follow. 

Natural salmon runs throughout the region have always been greatest from August to December, 

but there may have been more spring and summer runs in the past (J. Ames, pers. comm.). In 

particular, spring and summer Chinook salmon were abundant in the Columbia River until about 

the late 1800s (Lichatowich 1999). Populations of spring Chinook have also declined severely in 

Puget Sound, with most Chinook runs now dominated by later-timed fish, which return to rivers 

in late summer and fall (B. Sanford, pers. comm.). This problem may be partially offset by the 

relatively recent presence of “blackmouth” salmon, which are a hatchery-derived form of 

Chinook that tend to reside year-round in Puget Sound. Through deliberate management 

programs, these fish have been present in large enough numbers to support a recreational fishing 

season since the 1970s. Contractions in run timing can also affect food availability for killer 

whales, as seen in several Washington populations of hatchery coho salmon, where return timing 

was condensed from about 14 weeks to 8 weeks during a 14-year period even though total fish 

numbers remained about the same (Flagg et al. 1995). Selective spawning practices at hatcheries 

may also influence run timing (McLean et al. 2005). 

Climatic variability and change. A naturally occurring climatic pattern known as the Pacific 

Decadal Oscillation has recently been identified as a major cause of changing marine 

productivity and salmon abundance in the North Pacific (Mantua et al. 1997, Francis et al. 1998, 

Beamish et al. 1999, Hare et al. 1999, Benson and Trites 2002). The system is characterized by 

alternating 20-30-year shifts in ocean temperatures across the region, which produced cooler 

water temperatures from 1890-1924 and 1947-1976 and warmer water temperatures from 1925-

1946 and 1977 to at least 2001. Cooler periods promote coastal biological productivity off the 

western contiguous United States and British Columbia, but inhibit productivity in Alaska, 

whereas warmer phases have the opposite effect (Hare et al. 1999). Salmon are probably most 

affected through changes in food availability and survival at sea (Benson and Trites 2002), but 

associated terrestrial weather patterns may also be a factor. Higher rainfall at certain times of the 

year during warm regimes can cause greater stream flow and flooding in western Washington, 

thereby reducing salmon egg survival (J. Ames, pers. comm.). The most recent warm period has 

been strongly tied to lower salmon production south of Alaska (Hare et al. 1999). Greater 

salmon numbers in Washington during the past several years indicate that the latest warm phase 

has concluded. Evidence suggests that the Pacific Decadal Oscillation has existed for centuries, 

which implies that sizable fluctuations in salmon abundance are a natural phenomenon in the 

North Pacific (Beamish et al. 1999, Benson and Trites 2002). 

On shorter time scales, El Niño and La Niña events may also influence Pacific salmon 

populations, either beneficially or detrimentally, depending on salmon species, stock, and 

geographic range. Although not necessarily related to the to the climate patterns described 

above, changes in ocean temperature also directly influence salmon abundance in the Strait of 
January 2008 II-84 NMFS 

Juan de Fuca and the vicinity of the San Juan Islands. In years when ocean conditions are cooler 

than usual, the majority of sockeye salmon returning to the Fraser River do so via this route, but 

when warmer conditions prevail, migration is primarily through Johnstone Strait (Groot and 

Quinn 1987). 

Extensive climate change caused by the continuing buildup of human-produced atmospheric 

carbon dioxide and other greenhouse gases is predicted to have major environmental impacts 

along the west coast of North America during the 21st century and beyond. Warming trends in 

water and air temperatures are ongoing and are projected to disrupt the region’s annual cycles of 

rain and snow, alter prevailing patterns of winds and ocean currents, and result in higher sea 

levels (Glick 2005, Snover et al. 2005). These changes, together with increased acidification of 

ocean waters, will likely have profound effects on marine productivity and food webs, including 

populations of salmon and other fish used as prey by Southern Resident killer whales. Climate 

change is expected to impact salmon production in a number of ways. These include 1) 

alterations in river and stream flows and temperatures caused by changing patterns in 

precipitation and snowmelt that affect the survival of eggs, fry, smolts, and adults, as well as the 

ability of adults to migrate upstream for spawning, 2) loss of nearshore habitats important to 

juvenile salmon, and 3) changes in food availability in freshwater and marine habitats (Glick 

2005). Although no formal predictions of impacts on the Southern Residents have yet been 

made, it seems likely that any changes in weather and oceanographic conditions resulting in 

effects on salmon populations will have consequences for the whales. 

Aquaculture of Atlantic salmon. The intensive commercial farming of Atlantic salmon (Salmo 

salar) and smaller amounts of Chinook and coho salmon in marine netpens in British Columbia 

and Washington represents an additional potential, but highly debated, threat to wild Pacific 

salmon (Gallaugher and Orr 2000, Gardner and Peterson 2003). The region’s industry has grown 

dramatically in the past several decades and produces an estimated 50 million kg of salmon 

annually, about 90 percent of which comes from British Columbia (Amos and Appleby 1999). 

Licensed net-pen operations currently occur at about 126 sites in British Columbia and eight sites 

in Washington (A. Thomson, pers. comm.; J. Kerwin, pers. comm.). Concerns center primarily 

over 1) marine net-penned Atlantic salmon transmitting infectious diseases to adjoining wild 

salmon populations and 2) escaped Atlantic salmon becoming established in the wild and 

competing with, preying on, or interbreeding with wild Pacific salmon. Current evidence 

suggests that these concerns are largely unfounded in Washington and that Atlantic salmon 

aquaculture poses minimal risk to wild salmon stocks there (Nash 2001, Waknitz et al. 2002; J. 

Kerwin, pers. comm.). Escapes of penned Atlantic salmon exceeded 100,000 fish per year in the 

late 1990s in Washington (Amos and Appleby 1999), but improved management of salmon 

farms since then has greatly reduced this problem, resulting in far fewer free-ranging Atlantic 

salmon in the state’s waters (WDFW 2003). The situation in British Columbia is far more 

uncertain because of the much larger size of the industry (Gardner and Peterson 2003), which has 

resulted in larger numbers of escapes (mean = 47,150 fish per year from 1994-2002) and regular 

capture of free-ranging fish (mean = 1,713 fish reported per year from 1992-2002) (Morton and 

Volpe 2002, DFO 2003). Small numbers of naturally produced juvenile Atlantic salmon have 

been recorded in three rivers on Vancouver Island (e.g., Volpe 2000), but self-sustaining 

populations are not known to occur anywhere in the province (A. Thomson, pers. comm.). 
January 2008 II-85 NMFS 

However, limitations in stream monitoring make it difficult to rule out the absence of additional 

populations (Gardner and Peterson 2003). 

There is compelling evidence that sea lice (Lepeophtheirus salmonis) are transmitted from 

salmon farms to wild salmon (Krkošek et al. 2005), but the severity of impacts to wild fish 

remains uncertain (Gardner and Peterson 2003). Sea lice from farms have been linked to a 

decline of wild pink salmon populations in British Columbia’s Broughton Archipelago (Morton 

et al. 2004), although this finding has been disputed and may simply reflect a normal downward 

fluctuation in the populations. 

Salmon farms in British Columbia are concentrated along the central coast and on west-central 

Vancouver Island, and are projected to continue expanding in number in the future. The eight 

farms in Washington are located at Ediz Hook (Clallam County), Cypress and Hope Islands 

(Skagit County), and off southern Bainbridge Island (Kitsap County). 

Other non-native species. Several hundred exotic species are currently established in marine and 

estuarine areas occupied by southern resident killer whales (P. Heimowitz, pers. comm.), with 

numbers of new introductions steadily increasing over time (Meacham 2001, Wonham and 

Carlton 2005). More than half of these species are invertebrates, but fish, algae, and vascular 

plants are also well represented. Exotics are commonly introduced or spread through the 

discharge of ballast water in ships, hull and anchor fouling, boater activity, occurrence in 

shipments of shellfish and fish, and other pathways (Wonham and Carlton 2005). Puget Sound 

and the Georgia Basin are considered one of the more susceptible locations in the northeastern 

Pacific for invasions because of the area’s extensive shipping and other commercial activity. 

Although invasive species are not yet known to have direct effects on the southern residents, 

there is significant potential for future negative interactions through impacts on ecosystems and 

food webs. Filter feeding invasives, in particular, are potentially detrimental to salmon by 

affecting the bottom levels of food chains and reducing prey diversity (P. Meacham, pers. 

comm.). Other species, such as the European green crab (Carcinus maenas), can compete with 

young salmon for food and prey on salmon. 

Other fish species. Declines in abundance have also been recorded in some of the other known 

prey of resident killer whales. The Pacific herring stock in the Georgia Basin and Puget Sound 

collapsed from overharvesting in the 1960s, but recovered to high levels by the late 1970s 

through better management practices (DFO 2002a). However, some populations, such as those 

at Cherry Point and Discovery Bay in Puget Sound, remain at low levels (Stout et al. 2001, 

NMFS 2004c). Herring abundance has also decreased off western Vancouver Island since 1989, 

probably because of warm ocean temperatures (DFO 2001). Heavy fishing pressure was 

responsible for decreases in lingcod populations throughout British Columbia during the 1970s 

(DFO 2002b). Numbers generally responded to improved management and rebounded during 

the 1980s and early 1990s, but have again declined in subsequent years. Abundance has 

remained low in the Strait of Georgia since the 1980s. Excessive exploitation has also caused 

some rockfish stocks, especially those of larger species, to decrease along much of the Pacific 

coast in recent decades (Bloeser 1999, Love et al. 2002, Levin et al. 2006). Copper, brown, and 

quillback rockfishes are among the most affected species in Puget Sound. In contrast to the 

species mentioned above, catch data suggest significant growth in Pacific halibut populations in 
January 2008 II-86 NMFS 

British Columbia and Washington from the mid-1970s to late 1990s (International Pacific 

Halibut Commission 2002). Considerable fluctuation in total groundfish biomass was observed 

in Puget Sound and the southern Georgia Strait from 1987 to 2001 (Palsson et al. 2004). 

Competition for Prey with Other Species. Salmonids and other fish are important prey for a 

variety of predators other than killer whales, including fish, pinnipeds, and seabirds. Some 

predator populations have shown large increases in abundance in western North America in 

recent decades in response to reduced threats. For example, California sea lion numbers 

expanded from an estimated 50,000 individuals in the early 1970s to nearly a quarter million 

animals in 2001 (Carretta et al. 2004). California sea lions are capable of consuming significant 

numbers of adult fish at particular sites. For example, at the Ballard Locks, a highly publicized 

location in Puget Sound, California sea lions were documented taking up to 65 percent of 

returning adult steelhead at a fish passage facility (NMFS 1995) and are believed to be largely 

responsible for the ultimate collapse of the fish run. The eastern stock of Steller sea lions has 

roughly doubled to about 30,000 animals since the early 1980s (Angliss and Lodge 2004). 

Harbor seal numbers in British Columbia, Washington, and Oregon have grown 7 to 12-fold 

since about 1970 to about 120,000 seals (Olesiuk 1999, Jeffries et al. 2003, Carretta et al. 2004, 

Brown et al. 2005). The extent of competition, if any, between these species and Southern 

Resident killer whales for adult salmon is currently unknown. Other than observations at a few 

locations during specific times of year or in response to concerns over particular depressed fish 

runs, no estimates are available on the numbers of salmon consumed by pinnipeds along the west 

coast. 

Prey availability summary. Resident killer whales have likely been exposed to natural changes in 

the availability of salmon and other prey for millennia. During the past century and a half, 

human harvest pressures and alterations to the environment have undoubtedly caused important 

changes in food availability for resident whales. Recent research suggests that Chinook and 

chum salmon are major prey for the Southern Residents and that fluctuations in the abundance of 

both species of fish may limit the population in some years. However, much uncertainty about 

diet remains, including year-round prey selection, whether specific stocks of fish are important, 

and prey numbers required to achieve recovery of the population. 

Old estimates of the number of salmon that a Southern Resident population of 90 whales might 

need to consume each year were about 820,000 and new information on updated metabolic and 

diet as described in the “Food Requirements” section are much lower. These numbers seems 

small in light of the tens of millions of salmon that presumably overlap with the range of the 

whales. While overall biomass of salmon may not be a limiting factor, local depletion of specific 

runs may be, and assessing which species and runs of fish are available to the whales in 

particular locations seasonally is challenging. We also don’t have any information on foraging 

efficiency of the whales or how many salmon need to be present in the Southern Resident’s 

habitat or at what density so that they can catch enough fish to meet their metabolic needs. 

Favorable ocean conditions across the region in the next decade or two may temporarily alleviate 

possible food limitations by boosting overall salmon numbers. Nevertheless, the long-term 

prognosis for salmon recovery in the region is unclear. Improved management programs will 

undoubtedly benefit some salmon populations, but continued rapid human population growth and 
January 2008 II-87 NMFS 

urbanization, along with climate change, will place greater pressure on freshwater and marine 

ecosystems and challenge the efforts of managers seeking to achieve meaningful recovery 

(Langer et al. 2000). Wild salmon populations are particularly at risk, with some authors 

predicting that many, or perhaps most, stocks from British Columbia to California will continue 

to dwindle throughout the 21st century unless major changes in human life styles occur (Lackey 

2003). 

Environmental Contaminants 

Recent decades have brought rising concern over the adverse environmental effects resulting 

from the use and disposal of numerous chemical compounds in industry, agriculture, households, 

and medical treatment. Many types of chemicals are toxic when present in high concentrations, 

including legacy compounds such as organochlorines, polycyclic aromatic hydrocarbons 

(PAHs), and heavy metals that have long been recognized as problematic. However, a growing 

list of so-called “emerging” contaminants and other pollutants, such as brominated flame 

retardants (BFRs), perfluorinated compounds, and numerous other substances, are increasingly 

being linked to harmful biological impacts as well. Contaminant classes vary in their chemical 

properties and structures, persistence in the environment, pathways of transport through 

ecosystems, and effects on marine mammals and other wildlife. Despite their toxicity, most of 

these chemicals are still being manufactured or used in many countries. 

Organochlorines. Organochlorines are frequently considered to pose the greatest risk to killer 

whales (Ross et al. 2000a, Center for Biological Diversity 2001, Krahn et al. 2002) and comprise 

a diverse group of chemicals manufactured for industrial and agricultural purposes, such as 

polychlorinated biphenyls (PCBs), DDT, and certain other pesticides, or produced as 

unintentional by-products during industrial and combustion processes, such as the dioxins 

(PCDDs) and furans (PCDFs). Many organochlorines are highly fat soluble (lipophilic) and 

have poor water solubility, which allows them to accumulate in the fatty tissues of animals, 

where the vast majority of storage occurs (O’Shea 1999, Reijnders and Aguilar 2002). Some are 

highly persistent in the environment and resistant to metabolic degradation. Vast amounts have 

been produced and released into the environment since the 1920s and 1930s. The persistent 

qualities of organochlorines mean that many are ultimately transported to the oceans, where they 

enter marine food chains. 

Bioaccumulation through trophic transfer allows relatively high concentrations of these 

compounds to build up in top-level marine predators, such as marine mammals (O’Shea 1999). 

The toxicity of several organochlorines has led to bans or restrictions on their manufacture and 

use in northern industrial countries (Barrie et al. 1992). Most agriculture uses of DDT ended in 

the United States in 1972 and in Canada from 1970-1978. Production of PCBs stopped in the 

U.S. in 1977 and importation into Canada was prohibited in 1980. However, these compounds 

continue to be used widely in other parts of the world, including Asia and Latin America. 

Organochlorines enter the marine environment through several sources, such as atmospheric 

transport, ocean current transport, and terrestrial runoff (Iwata et al. 1993, Grant and Ross 2002, 

Garrett 2004, Hartwell 2004). As a result, these compounds have become distributed throughout 

the world, including seemingly pristine areas of the Arctic and Antarctic (Barrie et al. 1992, Muir 
January 2008 II-88 NMFS 

et al. 1992). Much of the organochlorine load in the northern Pacific Ocean originates through 

atmospheric transport from Asia (Barrie et al. 1992, Iwata et al. 1993, Tanabe et al. 1994). 

Killer whales are candidates for accumulating high concentrations of organochlorines because of 

their position atop the food web and long life expectancy (Ylitalo et al. 2001, Grant and Ross 

2002). Their exposure to these compounds occurs exclusively through their diet (Hickie et al. 

2007). Mammal-eating populations appear to be especially vulnerable to accumulation of 

contaminants because of the higher trophic level of their prey, as compared to fish-eating 

populations (Ross et al. 2000a). 

Several studies have examined contaminant levels in killer whales from the North Pacific (Table 

8). It should be noted that variable sample quality, limited background information, and 

different analytical techniques make direct comparisons between study results difficult (Ross et 

al. 2000a, Ylitalo et al. 2001, Reijnders and Aguilar 2002, Krahn et al. 2004b, 2007). 

Organochlorine concentrations are also known to vary in relation to an animal’s physiological 

condition (Aguilar et al. 1999). Most marine mammals lose weight during certain stages of their 

normal life cycles, such as breeding and migration, or from other stresses, including disease and 

reduced prey abundance and quality. The depletion of lipid reserves during periods of weight 

loss can therefore alter detected organochlorine concentrations, depending on whether a 

compound is redistributed to other body tissues or is retained in the blubber (O’Shea 1999). 

Perhaps most important, caution should be used when comparing contaminant levels between 

free-ranging presumably healthy killer whales and stranded individuals, which may have been in 

poor health before their deaths. Sick animals commonly burn off some of their blubber before 

stranding. 

Ross et al. (2000a) described the organochlorine loads of killer whale populations occurring in 

British Columbia and Washington. Male transient killer whales were found to contain 

significantly higher levels of total PCBs (ΣPCBs hereafter) than Southern Resident males, 

whereas females from the two communities carried similar amounts (Table 8). Both populations 

had much higher ΣPCB concentrations than Northern Resident whales. A similar pattern exists 

in Alaska, where transients from the Gulf of Alaska and AT1 communities contained ΣPCB 

levels more than 15 times higher than residents from the sympatric Prince William Sound pods 

of the southern Alaska community (Ylitalo et al. 2001). Profiles of specific PCB congeners were 

similar among the three killer whale communities from British Columbia and Washington, with 

congeners 153, 138, 52, 101, 118, and 180 accounting for nearly 50 percent of ΣPCB load (Ross 

et al. 2000a). Recent results from a much broader sample of killer whale communities from the 

North Pacific suggest that all transient populations and the Southern Residents possess high 

ΣPCB levels, whereas other resident populations and offshore whales have lower levels (G. M. 

Ylitalo et al., unpubl. data). 
January 2008 II-89 

Table 8. Contaminant concentrations (mean ± SE, mg/kg or μg/kg, lipid weight or wet weight) reported in tissue samples frpopulations in the North Pacific. 

Reference 

Populationa Age and sexb Sample sizec Sample locationsd Sample years 

ΣPCBse

(mg/kg) 

ΣDDTse

(mg/kg) 

p,p’-DDEe

(mg/kg) 

ΣPCNse(μg/kg) 

ΣPBD

(μg/k

Studies of free-ranging animals that were biopsied or otherwise testedf

Ross et al. WCT M 5 BC 1993-96 251 ± 55 (l) - - - - 

(2000a) WCT F 5 BC 1993-96 59 ± 21 (l) - - - - 

 SR M 4 BC 1993-96 146 ± 33 (l) - - - -  SR F 2 BC 1993-96 55 ± 19 (l) - - - -  NR AM 8 BC 1993-96 37 ± 6 (l) - - - -  NR AF 9 BC 1993-96 9 ± 3 (l) - - - 

Ylitalo et al. AT M, F 13 AK 1994-99 59 ± 12 (w) 83 ± 17 (w) 71 ± 15 (w) - -  (2001) AT M, F 13 AK 1994-99 230 ± 36 (l) 320 ± 58 (l) 280 ± 50 (l) - -  SAR M, F 64 AK 1994-99 3.9 ± 0.6 (w) 3.8 ± 0.6 (w) 3.1 ± 0.5 (w) - -  SAR M, F 64 AK 1994-99 14 ± 1.6 (l) 13 ± 1.8 (l) 11 ± 1.5 (l) - - Rayne et al. WCT AM, JM 6 BC 1993-96 - - - 167 ± 131 (l) 1,105  (2004) WCT AF, JF 7 BC 1993-96 - - - - 885 ±  SR AM, JM 5g BC 1993-96 - - - 20 ± 15 (l) 942 ± 

 NR AM, JM 13g BC 1993-96 - - - 22 ± 7 (l) 203 ± 

 NR AF, JF 8 BC 1993-96 - - - - 415 ± 

Herman et al. GAT - 5 AK 2002-03 150 ± 14 (l) 270 ± 26 (l) - - -  (2005) O - 2 AK 2001-03 66 ± 4.6 (l) 170 ± 36 (l) - - -  AKR - 14 AK 2002-03 15 ± 1.6 (l) 25 ± 2.7 (l) - - - Ono et al. (1987) U AM 1 JA 1986 410 (w) - - - -  U AF 2 JA 1986 355 ± 5 (w) - - - - 
January 2008 II-90 

Table 8. Continued 

Studies of stranded animalsCalambokidis WCT AM 1 BC 1979 250 (w) - 640 (w) - -  et al. (1984) SR AM 1 WA 1977 38 (w) - 59 (w) - - Jarman et al. U JM, 6 BC, WA 1986-89 22 (w) 32 (w) 28 (w) - -  (1996) AM, AF Hayteas and U JM 3 OR 1988-97 146 ± 135 (w) - 174 ± 106 (w) - -  Duffield (2000) U AF 1 OR 1996 276 (w) - 494 (w) - -  U JF 1 OR 1995 117 (w) - 519 (w) - - Krahn et al. SR AF 1 WA 2002 2.5 (w) 2.8 (w) - - -  (2004b) SR AF 1 WA 2002 28 (l) 31 (l) - - -  WCT AF 1 WA 2002 570 (w) 2,300 (w) - - -  WCT AF 1 WA 2002 1,100 (l) 4,700 (l) - - -  AT AM 1 AK 2003 130 (w) 190 (w) - - -  AT AM 1 AK 2003 490 (l) 640 (l) - - - 

a WCT, west coast transients; SR, southern residents; NR, northern residents; AT, Gulf of Alaska and AT1 transients; SAR, southern Alaska residents

transients; O, offshores; AKR, western Alaska and southern Alaska residents; and U, not identified. 

b M, males; F, females; A, adults; and J, juveniles. c Number of animals sampled. d BC, British Columbia; AK, Alaska; JA, Japan; WA, Washington; OR, Oregon. e Concentrations expressed on the basis of lipid weight (l) or wet weight (w). f The animals studied by Ono et al. (1987) were accidentally caught and killed by commercial fishermen. g Smaller samples were tested for ΣPCNs and ΣPBBs. 
January 2008 II-91 NMFS 

Relatively low amounts of ΣPCDDs and ΣPCDFs were detected in these whales, possibly because these 

compounds are more easily metabolized or excreted than many PCB congeners (Ross et al. 2000a). 

PCDD and PCDF levels detected in a small number of stranded whales from British Columbia and 

Washington also appear in Jarman et al. (1996). No detailed studies of ΣDDT concentrations in killer 

whales have been conducted to date in Washington or surrounding areas. However, preliminary evidence 

from stranded individuals in Oregon and Washington suggests that high levels of ΣDDTs and the 

metabolite p,p’-DDE may be present (Calambokidis et al. 1984, Hayteas and Duffield 2000, Krahn et 

al. 2004b). High concentrations of ΣDDTs, primarily p,p’-DDE, have also been detected in 

transient whales from Alaska (Ylitalo et al. 2001). Results from these studies establish the 

Southern Resident and transient populations of the northeastern Pacific as among the most 

chemically contaminated marine mammals in the world (Ross et al. 2000a, Ylitalo et al. 2001). 

This conclusion is further emphasized by the recent discovery of extremely high levels of ΣPCBs 

in a reproductively active adult female transient whale (CA189) that stranded and died on 

Dungeness Spit in January 2002 (G. M. Ylitalo, unpubl. data) (Table 8). While alive, this whale 

was recorded most frequently off California, thus its high contaminant load may largely reflect 

pollutant levels in prey from that region (Krahn et al. 2007.) 

Polychlorinated naphthalenes (PCNs) are another organochlorine group of concern. Evidence 

suggests that PCNs have the potential to bioaccumulate and exert “dioxin-like” toxicity (Rayne 

et al. 2004). PCNs most likely came from pulp mill discharges, with production ceasing in North 

America and Europe in the 1970s and 1980s. ΣPCN concentrations are relatively low in killer 

whales from the northeastern Pacific, with transients carrying the highest burdens, and much 

lower but similar levels occurring in Southern and Northern Residents (Table 8; Rayne et al. 

2004). 

Populations visiting Puget Sound have been exposed to PCBs and DDT for a number of decades. 

Sediment analyses indicate that large amounts of PCBs began entering marine ecosystems in the 

sound during the late 1930s, whereas inputs of DDT date back to the 1920s (Mearns 2001). The 

presence of both chemicals peaked in about 1960. Since then, environmental levels of many 

organochlorines (e.g., PCBs, dioxins, furans, organochlorine pesticides, and chlorophenols) have 

substantially declined (Gray and Tuominen 2001, Mearns 2001, Grant and Ross 2002). Mean 

ΣPCB concentrations in harbor seal pups from Puget Sound fell from more than 100 mg/kg, wet 

weight in 1972 to about 20 mg/kg, wet weight in 1990, but have since leveled off (Calambokidis 

et al. 1999). 

Concentrations of most organochlorine residues in killer whales are strongly affected by an 

animal’s age, sex, and reproductive status (Ross et al. 2000a, Ylitalo et al. 2001). Levels in 

juveniles of both sexes increase continuously until sexual maturity. Males continue to 

accumulate organochlorines throughout the remainder of their lives, but reproductive females 

sharply decrease their own burden by transferring much of it to their offspring during gestation 

and nursing. Because organochlorines are fat-soluble, they are readily mobilized from the 

female’s blubber to her fat-rich milk and passed directly to her young in far greater amounts 

during lactation than through the placenta during pregnancy (Reijnders and Aguilar 2002). As a 

result, mothers possess much lower levels than their weaned offspring, as well as adult males of 

the same age bracket (Ylitalo et al. 2001). After females become reproductively senescent at 

about 40 years old, their organochlorine concentrations once again begin to increase (Ross et al. 
January 2008 II-92 NMFS 

2000a). Similar patterns of accumulation have been reported in other marine mammals (Tanabe 

et al. 1987, 1994, Aguilar and Borrell 1988, 1994a, Borrell et al. 1995, Beckmen et al. 1999, 

Krahn et al. 1999, Tilbury et al. 1999). 

Research update 

Research update 

Birth order also influences the organochlorine burdens of killer whales. First-born adult male 

resident whales contain significantly higher levels of ΣPCBs and ΣDDTs than non-first-born 

males of the same age group (Ylitalo et al. 2001, Krahn et al. 2002). This pattern presumably 

exists among immature females as well. In other delphinids, females pass as much as 70-100 

percent of their organochlorine load to their offspring during lactation, with the first calf 

receiving by far the largest burden (Tanabe 1988, Cockcroft et al. 1989, Borrell et al. 1995). 

Thus, females that have gone through previous lactation cycles carry substantially lower 

organochlorine loads and transfer reduced amounts to subsequent young (Aguilar and Borrell 

Hickie et al. (2007) used models to estimate PCB concentrations in killer whales during 

the period of 1930 forward to 2030 and evaluated projected trends in the context of 

health effects thresholds for other marine mammals. The study acknowledged the 

management challenges in addressing contaminant levels in killer whales, including 

small sample sizes and the lack of dose-response relationships. Modelled PCB levels 

predicted peak concentrations in ~1969 and showed gradual declines in both Northern 

and Southern Residents, likely a result of their decreased use and therefore decreased 

presence in the environment. The model projections suggested that it may take up to 60 

years for PCB levels in Southern Residents to fall below the thresholds known to have 

health effects in other marine mammals (17mg/kg lipid). Hickie et al. (2007) did note 

that mitigation removing PCBs from the environment (such as through Superfund 

clean-ups) could accelerate the decline of levels in the whales. 

One new study (Krahn et al. 2007) compared results from biopsy samples from 1993-

1995 to those from 2004/2006 and found the mean levels of PCBs decreased in the later 

samples. They did note younger ages of the males in the later samples and methods to 

calculate PCB levels may have contributed to the observed decreases. In addition, even 

the lower levels of PCBs still exceeded the thresholds for health effects in other marine 

mammals. A surprising result of the study was that a three-year-old male had the 

highest concentrations of PBDEs, which may have come from its mother. Ratios of 

contaminants in the different pods support observations that J and L pods may be 

occupying different ranges in the winter. L pod had higher DDT ratios reflecting a 

“California signature” while J pod had higher relative PCB content which is consistent 

with high PCB concentrations in Puget Sound biota. 
January 2008 II-93 NMFS 

1994a, Ridgway and Reddy 1995). These observations indicate that first-born killer whales are 

the most likely to suffer from any organochlorine toxicity effects (Ylitalo et al. 2001). 

The effects of chronic exposure to moderate to high contaminant levels have not yet been 

ascertained in killer whales. There is no evidence to date that high organochlorine 

concentrations cause direct mortality in this species or other cetaceans (O’Shea and Aguilar 

2001). However, a variety of more subtle physiological responses in marine mammals has been 

linked to organochlorine exposure (Table 9), including impaired reproduction (Béland et al. 

1998, Reijnders 2003), immunotoxicity (Lahvis et al. 1995, de Swart et al. 1996, Ross et al. 

1995, 1996a, 1996b, Jepson et al. 1999, Ross 2002, De Guise et al. 2003), hormonal dysfunction 

(Gregory and Cyr 2003), disruption of enzyme function and vitamin A physiology (Marsili et al. 

1998, Simms et al. 2000), and skeletal deformities (Bergman et al. 1992). PCB-caused 

suppression of the immune system can increase susceptibility to infectious disease (Jepson et al. 

1999, Ross 2002, Ross et al. 1996b) and was implicated in morbillivirus outbreaks that caused 

massive die-offs of dolphins in the Mediterranean Sea during the early 1990s (Aguilar and 

Borrell 1994b) and harbor seals and gray seals (Halichoerus grypus) in the North Sea in the late 

1980s (de Swart et al. 1994, Ross et al. 1995, 1996a). Immune suppression may be especially 

likely during periods of stress and resulting weight loss, when stored organochlorines are 

released from the blubber and become redistributed to other tissues (Krahn et al. 2002). In 

captive bottlenose dolphins, females whose calves died before six months of age were found to 

have substantially higher levels of ΣDDTs and ΣPCBs than females with surviving calves 

(Ridgeway et al. 1995). In non-marine mammals, PCB exposure has been commonly linked to 

hearing deficiencies, which result from thyroid hormone deprivation during early development 

(Colborn and Smolen 2003). This problem could have profound implications for cetaceans if it 

extends to this group. 

Several studies have attempted to establish threshold levels at which organochlorines become 

toxic to marine mammals. However, susceptibility to PCBs varies substantially among mammal 

species, even within a genus, making it difficult to generalize about sensitivity (O’Shea 1999). 

Nevertheless, it is likely that all males from the three tested killer whale communities in 

Washington and British Columbia, as well as most female transients and Southern Residents, 

exceed the toxicity levels believed to cause health problems in other marine mammals (Ross et 

al. 2000a). 

Brominated flame retardants. Polybrominated diphenyl ethers (PBDEs) have attracted recent 

concern because of their expanding presence in the environment, wildlife, and humans, and their 

lipophilic, bioaccumulative, and persistent qualities (de Wit 2002, Hall et al. 2003, Hites 2004). 

PBDEs are widely used as a flame retardant in consumer products and probably enter the 

environment via manufacturing processes and wastewater effluents. Production and use are 

especially high in North America, where contamination levels have been doubling about every 

four to six years during the past several decades (Hites 2004). PBDEs have been linked to 

endocrine disruption, immunotoxicity, neurotoxicity, and early developmental problems in 

laboratory animals and wild seals (de Wit 2002, Darnerud 2003, Hall et al. 2003). Rayne et al. 

(2004) documented PBDE concentrations in killer whales from the northeastern Pacific using 

biopsy samples collected from 1993-1996. Southern Resident and transient whales carried 
January 2008 II-94 

Table 9. Summary of studies describing physiological effects resulting from exposure to different contaminants in marine Effect Type of contaminant Species RReduced resistance to disease and viruses PCBs Striped dolphin ADecreased lymphocyte response PCBs, DDT Bottlenose dolphin LDecreased lymphocyte proliferation Butyltin compounds, nonortho coplaner PCBs Bottlenose dolphin, Dall's porpoise, California sea 

lion, spotted seal 

N

Carcinogenic effects PAHs Beluga whales Disrupted immune function PCBs Harbor seal dDisrupted immune function Non- and mono-ortho coplaner 

PCBs 

Harbor seal pups, northern 

elephant seal pups 

S

Disrupted immune function, reduced T-cell function, reduced 

natural killer-cell function 

Dioxin-like PCBs and furans Harbor seal, grey seal R

Disrupted immune function, reduced T-cell response, reduced 

natural killer-cell function, increased polymorphonuclear granulocytes 

PCBs, PCDDs, PCDFs, TCDD Harbor seal d

Adrenocorticol hyperplasia Chlorinated hydrocarbons Harbor porpoise KSkin-oxidose activity Organochlorines Fin whale MReduced vitamin A and thyroid hormone production PCBs Harbor seal BImmunotoxicity and endocrine disruption PCBs Harbor seal M

T

Alterations in thyroid hormone levels PBDEs Gray seal HAdrenal bioactivation and effects on thyroid metabolism DDTs, PCBs Gray seal LReduced testosterone and immunoglobulin (pf IgG), suppression 

of antibody-mediated immunity, negative associations between PCBs and retinol and thyroid hormones in plasma 

PCBs Polar bear S

Plasma cortisol concentration alteration Organochlorines Polar bear OVariations in progesterone (P4) levels Plasma sigma PCBs Polar bear HImpaired reproduction Organochlorines, DDT Bottlenose dolphin RImpaired reproductive success in primiparous females PCBs Bottlenose dolphin SReproductive dysfunction PCBs Ringed seal AReproductive failure PCBs Harbor seal RPremature births PCBs, DDT California sea lion G

Premature births Organochlorines, DDT California sea lion DDNA strand breakage and repair Methyl mercury chloride Bottlenose dolphin T
January 2008 II-95 NMFS 

similar ΣPBDE levels that were considerably higher than in Northern Residents (Table 8). No 

age- or sex-related differences in contamination were noted, although this may have been an 

artifact of the small sample size. Lindström et al. (1999) reported substantially higher PBDE 

levels in immature long-finned pilot whales (Globicephala melas) than in adults, suggesting that 

maternal transfer during lactation and gestation may occur. Rayne et al. (2004) found that 

BDE47, BDE100, and BDE99 were the most prevalent congeners detected in killer whales from 

the northeastern Pacific. It is likely that substantial increases in the animals’ ΣPBDE 

concentrations have occurred since the samples analyzed by Rayne et al. (2004) were collected, 

mirroring continuing widespread gains in the environment. Krahn et al. (2007) reported that a 

three year old male had the highest concentrations of PBDEs of all the Southern Residents tested. 

Manufacture of two (penta-BDEs and octa-BDEs) of the three PBDE forms was terminated in 

the United States at the close of 2004. In 2007 Washington State passed a bill regarding use of 

PBDEs. The bill outlines a process to phase out use of PBDEs in common household products 

because of the high levels of these contaminants in the environment and people and the 

developmental effects that have been observed from exposure to PBDEs. 

Polybrominated biphenyls (PBBs) are a related type of flame retardant produced during the early 

1970s. ΣPBB levels in resident and transient whales sampled from 1993 to 1996 were much 

lower than for ΣPBDEs (Table 8), but showed similar patterns of occurrence, with Southern 

Residents and transients having significantly higher concentrations than Northern Residents 

(Rayne et al. 2004). 

Other chemical compounds. With up to 1,000 new chemicals entering the global environment 

annually, it is difficult for environmental agencies to monitor levels and sources of all 

contaminants, and to provide effective regulation (Grant and Ross 2002). Studies are beginning 

to identify many relatively new substances as potentially harmful to marine organisms, including 

perfluorinated compounds, polychlorinated paraffins (PCPs), polychlorinated naphthalenes 

(PCNs), polychlorinated terphenyls (PCTs), endocrine disruptors (e.g., synthetic estrogens, 

steroids, some pesticides), pharmaceuticals, and personal care products (e.g., diagnostic agents 

and cosmetics) (Grant and Ross 2002). For example, perfluorooctane sulfonate (PFOS), a type 

of perfluorinated compound that is persistent and biomagnified, has been recently detected in a 

variety of marine mammals species from the northern hemisphere (Kannan et al. 2001, Van de 

Vijver et al. 2003). Endocrine disruptors may affect thyroid function, decrease fertility, feminize 

or masculinize genital anatomy, suppress immune function, and alter behavior (Yamamoto et al. 

1996). The effects of all these compounds on killer whales remain unknown. 

Toxic elements. The three elements usually considered of greatest concern to cetaceans are 

mercury, cadmium, and lead (O’Shea 1999). Mercury, cadmium, and other metals accumulate 

primarily in the liver and kidneys, whereas lead is deposited mostly in bones (Reijnders and 

Aguilar 2002). Concentrations of most metals tend to increase throughout an animal’s life. 

Most metals are not lipophilic and females cannot significantly reduce their loads via 

reproductive transfer. There are, however, organic forms of metals such as methylmercury that 

accumulate in the lipids of prey species and killer whales. Many marine mammal species are 

able to tolerate high amounts of metals or detoxify them (Reijnders and Aguilar 2002) and 

published accounts of metal-caused pathology are scarce (O’Shea 1999). To date, there has been 

little investigation of metals in killer whales in Washington and British Columbia. Small 
January 2008 II-96 NMFS 

numbers of animals have been tested, with one stranded 17-year old male resident (L14) having 

high liver concentrations of mercury (reported as >600 mg/kg, wet weight, of which 14 percent 

was in the toxic methylated form, J. Calambokidis, unpubl. data; also reported as 1,272 mg/kg, 

wet weight, Langelier et al. 1990). An adult female transient (CA189) stranded at Dungeness 

Spit in January 2002 and carried the following metal levels (wet weight) in her liver: mercury, 

129 mg/kg; cadmium, <0.15 mg/kg; and lead, <0.15 mg/kg (G. M. Ylitalo, unpubl. data). 

Stranded resident whales appear to carry higher amounts of mercury than transients (Langelier et 

al. 1990, cited in Baird 2001). With the exception of mercury, most metals do not bioaccumulate 

and are therefore unlikely to directly threaten the health of killer whales (Grant and Ross 2002). 

However, their greatest impact may be on prey populations and habitat quality. 

Contaminant levels in prey and indicator species. Relatively few studies have measured 

organochlorine loads in known or potential prey species of killer whales in Washington, British 

Columbia, and adjacent areas. However, growing evidence suggests that Puget Sound is a major 

source of contamination in prey, especially Chinook salmon, which are thought to be a major 

food species for Southern Resident killer whales. New research indicates that Chinook salmon 

from the sound possess much higher mean ΣPCB and ΣPBDE levels than Chinook from other 

locations sampled along the western coast of North America (Table 10; O’Neill et al. 2005, 

2006). This work also reveals that Puget Sound Chinook with long residency times in the Sound 

have much greater ΣPCB and ΣPBDE burdens than those inhabiting the open North Pacific 

Ocean for much of their lives. In contrast, ΣDDT loads were similar among Chinook salmon 

populations from Puget Sound, the Columbia River, and central California, but higher than in 

those from British Columbia (O’Neill et al. 2006). Among the five salmon species occurring in 

Puget Sound, the highest ΣPCB loads were carried by Chinook, with moderate levels found in 

sockeye and coho, and low levels present in chum and pink salmon (O’Neill et al. 2005). Other 

research reveals that adult coho salmon returning to spawn in central and southern Puget Sound 

have higher ΣPCB concentrations than those returning to northern Puget Sound (West et al. 

2001a). Dissimilarity in contaminant burdens among salmon species and populations likely 

reflects differences in marine distribution (O’Neill et al. 2006). In English sole, rockfish, and 

herring, ΣPCB levels are influenced by the contaminant levels of local sediments. Thus, sole and 

rockfish living near contaminated urban areas often have higher burdens than those from nonurban sites (O’Neill et al. 1995, West et al. 2001b) and herring from central and southern Puget 

Sound possess greater burdens than those from northern Puget Sound and the Strait of Georgia 

(O’Neill and West 2001). In some long-lived fish species, PCB concentrations accumulate with 

age so that older individuals carry significantly higher burdens than younger individuals (O’Neill 

et al. 1995, 1998). In rockfish, this type of accumulation occurs only in males (West et al. 

2001b). Recent analyses of PCB levels in harbor seals indicate that seals and their prey in Puget 

Sound are seven times more contaminated than those in the Strait of Georgia (Cullon et al. 

2005). Pinnipeds and porpoises carry far greater amounts of PCBs and DDTs than baleen whales 

and fish (Table 10) because of their higher positions in food chains (O’Shea and Aguilar 2001, 

Reijnders and Aguilar 2002). 
January 2008 II-97 

Table 10. Summary of 

ΣPCB, 

ΣDDT, and 

ΣPBDE concentrations (mean ± SE, mg/kg, wet weight) in tissue samples from v

mammal species that are known or potential prey of resident and transient killer whales in Washington and neighboring are

combined for both sexes. A more complete listing of contaminant levels in marine mammals appears in Wiles (2004). 

Species Location Agea

Tissue 

analyzed 

Sample 

size ΣPCBs ΣDDTs ΣPBDEs Refe

Chinook salmon Puget Sound, s. Georgia Str, Wash. 4 muscle 66 .050 ± .005 .022 ± .001 O’NChinook salmon s. and c. Puget Sound, Wash. - muscle 34 .074 - O’NChinook salmon Puget Sound, Wash. A muscle - ~ .053 - O’NChinook salmon British Columbia A muscle - ~ .018 - O’NChinook salmon Washington coast A muscle - ~ .016 - O’NChinook salmon Columbia River A muscle - ~ .017 - O’NChinook salmon Oregon A muscle - ~ .010 - O’NChinook salmon Puget Sound, Wash. (fall runs) A whole body - ~ .043 ~ .029 ~ .018 O’NChinook salmon Puget Sound, Wash. (resident) A whole body - ~ .088 ~ .016 ~ .040 O’NChinook salmon Coastal B.C. A whole body - ~ .007 ~ .007 ~ .001 O’NChinook salmon Columbia River (spring runs) A whole body - ~ .035 ~ .035 ~ .010 O’NChinook salmon Columbia River (summer/fall runs) A whole body - ~ .016 ~ .020 ~ .004 O’NChinook salmon Sacramento River, Calif. A whole body - ~ .014 ~ .033 ~ .003 O’NSockeye salmon Puget Sound, Wash. A whole body - ~ .019 - O’NSockeye salmon Coastal B.C. A whole body - ~ .008 - O’NCoho salmon s. and c. Puget Sound, Wash. - muscle 32 .035 - O’NCoho salmon Puget Sound, Wash. 3 muscle 47 .019 ± .002 .011 ± <.001 WesCoho salmon Puget Sound, Wash. A whole body - ~ .014 - O’NCoho salmon Coastal B.C. A whole body - ~ .010 - O’NChum salmon Puget Sound, Wash. A whole body - ~ .006 - O’NChum salmon Coastal B.C. A whole body - ~ .003 - O’NPink salmon Puget Sound, Wash. A whole body - ~ .002 - O’NPink salmon Coastal B.C. A whole body - ~ .001 - O’NPacific herring Puget Sound, s. Georgia Str, Wash. 3 whole body 50 .102 ± .012 .029 ± .004 WesEnglish sole Puget Sound, s. Georgia Str, Wash. 6 muscle 113 .022 ± .002 .001 ± <.001 WesQuillback rockfish Puget Sound, San Juan Isl., Wash. 14 muscle 83 .028 ± .003 .001 ± <.001 Wes

Brown rockfish Puget Sound, San Juan Isl., Wash. 22 muscle 35 .027 ± .004 .002 ± <.001 WesHarbor seal s. Puget Sound, Wash. P blubber 7 17.1 ± 2.1 2.2 ± 0.3c Cala

Harbor seal e. Strait of Juan de Fuca, Wash. P blubber 7 4.0 ± 2.5 1.5 ± 0.8c CalaHarbor seal s. Puget Sound, Wash. P blubber 57 13.4 ± 1.1 2.0 ± 0.2 CalaHarbor seal s. Puget Sound, Wash. P blubber 17 18.1 ± 3.1 - Ross Harbor seal Georgia Strait, British Columbia P blubber 38 2.5 ± 0.2 - Ross Harbor seal Queen Charlotte Strait, B.C. P blubber 5 1.1± 0.3 - Ross Harbor porpoise Washingtond I,A blubber 8 17.3 ± 3.9 14.4 ± 3.2c Cala

Harbor porpoise British Columbiae C,I,A blubber 7 8.4f 8.2f Jarm

Gray whale Washington - blubber 38 .220 ± .042 .130 ± .026 Krah

a Expressed as years of age or age category (A, adults; P, pups; C, calves; and I, immatures). d Collected primarily from the outer coast. b Collected from Edmonds, Elliott Bay, Commencement Bay, and Bremerton. e Collected primarily from southern Vancouver c Only p,p’-DDE was measured. 
January 2008 II-98 NMFS 

Sources of contaminants. Marine ecosystems in the northeastern Pacific receive pollutants from 

a variety of local, regional, and international sources (Grant and Ross 2002, EVS Environmental 

Consultants 2003, Garrett 2004), but the relative contribution of these sources in the 

contamination of killer whales is poorly known. Because resident killer whales carry 

increasingly higher chemical loads from Alaska to Washington (Ross et al. 2000a, Ylitalo et al. 

2001), it is likely that pollutants originating within Puget Sound and the Georgia Basin probably 

play a greater role in contamination than those from other sources. This pattern is apparent in 

Chinook salmon with longer residency periods in Puget Sound, as they carry considerably higher 

burdens of PCBs than populations from other areas (O’Neill et al. 2005). Ross et al. (2000a) 

have suggested that elevated organochlorine concentrations in Southern Residents might result 

from their consumption of small amounts of highly contaminated prey near industrialized areas. 

Additionally, because most of the region’s salmon populations are pelagic for long lengths of 

time, atmospheric deposition of PCBs and other pollutants in the North Pacific may be an 

important route for food chain contamination (Ross et al. 2000a). Sources of pollutants in 

transient whales are also difficult to decipher. Transients are highly contaminated throughout 

much of their distribution, but this likely results from the higher trophic level and 

biomagnification abilities of their prey, as well as possibly from the widespread movements of 

many of these whales. PCBs, polycyclic aromatic hydrocarbons (PAHs), and a number of other 

pollutants appear to occur at substantially higher levels in Puget Sound than elsewhere in 

Washington and southern British Columbia, including the Strait of Georgia, based on studies of 

contaminant loads in harbor seals, herring, and mussels (Hong et al. 1996, Mearns 2001, O’Neill 

and West 2001, Grant and Ross 2002, Ross et al. 2004, Cullon et al. 2004). This geographic 

pattern undoubtedly stems from greater contaminant inputs into Puget Sound due to human 

activities as well as the sound’s lower rates of flushing and sedimentation (O’Neill et al. 1998, 

West et al. 2001a). 

Recent analyses indicate that 1 percent of the marine sediments in Puget Sound are highly 

degraded by chemical contamination, whereas 57 percent show intermediate degrees of 

deterioration and 42 percent remain relatively clean (Long et al. 2001). Hotspots for 

contaminated sediments are centered near major urban areas, where industrial and domestic 

activities are concentrated. Locations of particular concern include Bellingham Bay, Fidalgo 

Bay, Everett Harbor and Port Gardner, Elliott Bay, Commencement Bay, Sinclair Inlet and other 

sites near Bremerton, and Budd Inlet (Long et al. 2001, EVS Environmental Consultants 2003), 

but contamination can extend widely into even some rural bays. Some contaminated hot spots in 

Puget Sound are located in nursery areas for many of the species in the Sound. Analyses of 

contaminants in fish and mussels suggest that some pollutants are most abundant in central and 

southern Puget Sound (Mearns 2001, O’Neill and West 2001, West et al. 2001a, EVS 

Environmental Consultants 2003). Summaries of contaminant presence in the Canadian waters 

of the Georgia Basin appear in Garrett (2004). 

NMFS analyzed sediment data from several sources to identify locations within inland habitat of 

killer whales where sediment samples have been analyzed for contaminants of interest (Figure 

15). This information was analyzed further to identify locations where sediment sample analysis 

indicated that elevated levels of these contaminants were detected. NMFS identified those 

sampling locations where these contaminants were detected at concentrations that meet or exceed 

the "No Effects" and "Minor Adverse Effects" levels of the Washington State Sediment Quality 
January 2008 II-99 NMFS 

Standards (WAC 173-204). For some contaminants, no Washington State Sediment Quality 

Standards (WAC 173-204) exist. In some instances, NMFS used screening levels for these 

compounds in sediment developed by the U.S. Army Corps of Engineers to identify locations of 

interest (U.S. Army Corps of Engineers 2000). In other instances, no sediment criteria or 

screening level existed. In these cases, NMFS identified locations where these contaminants had 

been detected in sediment samples. NMFS integrated the marine sediment quality data from 

these sources into a geodatabase to create maps. In some instances, the data from these datasets 

were excluded from subsequent analysis because no sampling location information was available 

(e.g., latitude and longitude), the data did not address sediment samples or contaminants of 

interest, or the data could not be integrated readily into the geodatabase. 

Marine pollutants originate from a multitude of urban and non-urban activities, such as improper 

disposal of manufacturing by-products, processing and burning of fossil fuels, discharge of 

leachate from landfills and effluent from wastewater treatment plants (Appendix B), agricultural 

use of pesticides, and terrestrial runoff. The Canadian Proposed Recovery Strategy for Northern 

and Southern Resident killer whales in Canada includes a useful table identifying sources of 

contaminants known to harm marine mammals (Table 11, from Table 1 in Killer Whale 

Recovery Team 2007). The table identifies pollutants, their uses/sources, and information on 

whether they are persistent in the environment or bio-accumulate. 

During the past few decades, regulatory actions, improved waste handling, and ongoing cleanup 

efforts have led to marked improvements in regional water quality. Important actions taken 

include the cessation of PCB production and DDT use in the 1970s and the elimination of most 

dioxin and furan emissions from pulp and paper mills during the 1980s and early 1990s. As 

authorized by the Clean Water Act, the National Pollutant Discharge Elimination System 

(NPDES) permit program controls water pollution by regulating point sources that discharge 

pollutants into waters of the United States. Permits are issued for discharges from industrial and 

municipal wastewater facilities and describe limitations for allowed discharge based on 

technology or water quality standards. In most cases, the NPDES permit program is 

administered by authorized states. Since its introduction in 1972, the NPDES permit program is 

responsible for significant improvements to our Nation's water quality, however there are 

questions about whether permit requirements and standards are sufficient to protect the habitat 

and wildlife. The Puget Sound Action Team reported that between July 2004 and June 2006, the 

Washington Department of Ecology reissued 96 individual NPDES permits in the Puget Sound 

Basin, but stated it was not known if these actions reduced pollutants to the Sound (Puget Sound 

Action Team 2007.) 
January 2008 II-100 NMFS 

Table 11. Persistent organic pollutants that may pose a risk to resident killer whales. From Table 1 in 

Killer Whale Recovery Team 2007. 

Pollutant Use/Source Persistent Bio-accumulate Risk 

DDT 

(Dichlorodi-phenyl 

trichloroethane 

pesticide used in some countries, banned in North 

America, persists in terrestrial runoff 30 years post 

ban, enters atmosphere from areas where still in use

yes yes reproductive impairment, 

immunosuppression, adrenal and 

thyroid effects 

PCBs 

Polychlorinated 

Biphenyls 

electrical transformer and capacitor fluid, limited 

use in North America but enters environment from 

runoff, spills and incineration 

yes yes reproductive impairment, skeletal 

abnormalities, immunotoxicity 

and endocrine disruption 

Dioxins and Furans by-product of chlorine bleaching, wood product 

processing and incomplete combustion. Mills less 

of a source now. Current sources include burning of

salt-laden wood, municipal incinerators, and 

residential wood and wood waste combustion, in 

runoff from sewage sludge, wood treatment 

yes yes thymus and liver damage, birth 

defects, reproductive impairment, 

endocrine disruption, 

immunotoxicity and cancer 

PAHs 

Persistent 

Polycyclic 

aromatic 

hydrocarbons 

by-product of fuel combustion, aluminum smelting, 

wood treatment, oil spills, metallurgical and coking 

plants, pulp and paper mills 

yes no Carcinogenic 

flame retardants, 

esp. PBBs and 

PBDEs 

Polybrominated 

diphenyl ethers

flame retardants; in electrical components and 

backings of televisions and computers, in textiles 

and vehicle seats, ubiquitous in environment. 2/3 

product PBDEs banned in Europe. Same two 

products withdrawn from North American 

marketplace in 2005, but one (deca) product still 

used globally. 

yes yes endocrine disruption, impairs liver 

and thyroid 

PFOs 

Perfluro-octane 

sulfonate 

stain, water and oil repellent (included in 

Scotchgard until recently), fire fighting foam, fire 

retardants, insecticides and refrigerants, ubiquitous 

in environment 

yes yes but in blood, 

liver, kidney and 

muscle 

promotes tumor growth 

TBT, DBT 

Tributyltin 

Dibutyltin 

antifoulant pesticide used on vessels yes yes unknown but recently associated 

with hearing loss 

PCPs 

(Polychlorinated 

paraffins) 

flame retardants, plasticizers, paints, sealants and 

additives in lubricating oils 

yes yes endocrine disruption 

PCNs 

Polychlorinated 

napthalenes 

ship insulation, electrical wires and capacitors, 

engine oil additive, municipal waste incineration 

and chlor-alkali plants, contaminant in PCBs 

yes yes endocrine disruption 

APEs 

Alkyl-phenol 

ethoxylates 

detergents, shampoos, paints, pesticides, plastics, 

pulp and paper mills, textile industry found in 

sewage effluent and sediments 

moderate moderate endocrine disruption 

PCTs 

Polychlorinated 

terphenyls 

fire retardants, plasticizers, lubricants, inks and 

sealants, enters environment in runoff 

yes yes endocrine disruption and 

reproductive impairment 

References: Primarily Grant and Ross 2002, but also Lindstrom et al. 1999, Hooper and MacDonald 2000, Kannan et al. 2001, Hall et al. 

2003; Van de Vijver et al. 2003, Rayne et al. 2004, Song et al. 2005. 
January 2008 II-101 NMFS 

Update 

In 2001 the EPA, Fish and Wildlife Service and NMFS announced a Memorandum of 

Agreement (MOA) regarding enhanced coordination under the Clean Water Act and the 

Endangered Species Act (66 FR 11201; February 22, 2001). The agreement recognizes the 

complementary goals of the Clean Water Act and ESA in protecting the aquatic environment and 

listed species. The MOA describes procedures to coordinate implementation of existing 

statutory and regulatory authorities. The MOA includes National procedures for inter-agency 

coordination and consultation on water quality criteria, a research and data gathering plan, 

improved consultation procedures for EPA approval of State and Tribal water quality standards, 

and procedures for coordination with State and Tribal NPDES permits. In 2007 Washington 

State passed a bill regarding use of PBDEs. The bill outlines a process to phase out use of 

PBDEs in common household products because of the high levels of these contaminants in the 

environment and people and the developmental effects that have been observed from exposure to 

PBDEs. 

Significant progress has been made in the cleaning and containment of the 31 Superfund sites in 

the Puget Sound basin, of which at least 11 leaked contaminants into coastal waters (Appendix 

C). Advances in the control of point-source pollution have also taken place. Environmental 

levels of many organochlorine residues (e.g., PCBs, dioxins, furans, organochlorine pesticides, 

and chlorophenols) have declined significantly during this period (Gray and Tuominen 2001, 

Mearns 2001, Grant and Ross 2002, EVS Environmental Consultants 2003). For example, mean 

ΣPCB concentrations in harbor seal pups from Puget Sound fell from more than 100 mg/kg, wet 

weight in 1972 to about 20 mg/kg, wet weight in 1990 (Calambokidis et al. 1999). Despite these 

improvements, the presence of some chemicals (e.g., PCBs and DDE) in coastal habitats and 

wildlife has stabilized since the early 1990s and is not expected to decline further for decades 

(Calambokidis et al. 1999, Grant and Ross 2002). By contrast, environmental levels of many 

emerging contaminants, which are typically poorly regulated, are probably increasing. 

Atmospheric transport of pollutants is another important contaminant source for marine 

ecosystems. Due to the prevailing wind patterns of the Northern Hemisphere, a number of 

substances (e.g., PCBs, DDT, other pesticides, dioxins, furans, and metals) are carried in this 

manner from Asia to the northeastern Pacific (Iwata et al. 1993, Tanabe et al. 1994, Blais et al. 

In 2007, People for Puget Sound released a draft report on the impact of mixing zones 

on permitted discharges (Trim et al. 2007). Under Washington State regulations, 

facilities may discharge wastewater with levels of pollutants above water quality 

standards in an area around their outfall pipe called a “mixing zone.” Trim et al. (2007) 

examined toxic loading and mixing zones described in permits for 103 sewage 

treatment plants and 15 major industrial facilities in the Puget Sound basin through 

March 2007 and found most facilities are authorized to use mixing zones and almost all 

mixing zones were allocated at the maximum size allowable. The report recommends 

phasing out mixing zones and improving source control and treatment technologies to 

restore the health of Puget Sound. 
January 2008 II-102 

Figure 15. Contaminated sediments in Puget Sound that meet or exceed “Minor Adverse Effects” Level. 
January 2008 II-103 NMFS 

1998, Ewald et al. 1998, Jaffe et al. 1999, Ross et al. 2000a, Grant and Ross 2002, Lichota et al. 

2004). Such contamination particularly affects the open North Pacific Ocean, where migratory 

salmon populations spend much of their lives maturing, but also impacts the coastal waters and 

land areas of Washington and British Columbia. Locally produced airborne pollutants (e.g., 

certain PCBs, dioxins, and furans) also enter coastal marine waters (Lichota et al. 2004). 

Increased human population growth, urbanization, and intensified land use are projected for 

western Washington and southern British Columbia during the coming decades (Transboundary 

Georgia Basin-Puget Sound Environmental Indicators Working Group 2002) and will 

undoubtedly subject coastal ecosystems to greater contaminant input (Gray and Tuominen 2001, 

Grant and Ross 2002). Emissions from Asian sources are also expected to gradually expand and 

continue to reach the open North Pacific and mainland of northwestern North America. In 

particular, PCBs will likely remain a health risk for at least several more decades due to their 

persistence, their continued cycling in the environment through food webs and atmospheric 

processes, and the relative inability of marine mammals to metabolize them (Ross et al. 2000a, 

Calambokidis et al. 2001). Thus, exposure of the region’s killer whales to contaminants is not 

expected to change appreciably in the foreseeable future (Grant and Ross 2002, Krahn et al. 

2002). 

Update 

Vessel Effects and Sound 

Many marine mammal populations may be experiencing increased exposure to vessels and 

associated sounds. Commercial shipping, whale watching, ferry operations, and recreational 

boating traffic have expanded in many regions in recent decades, including the northeastern 

Pacific. Commercial fishing boats are also a prominent part of the vessel traffic in many areas. 

Vessels have the potential to affect whales through the physical presence and activity of the 

vessel, the increased underwater sound levels generated by boat engines or a combination of 

these factors. Vessel strikes are rare, but do occur and can result in injury. In addition, 

underwater sound can be generated by a variety of other human activities, such as, dredging, 

drilling, construction, seismic testing, and sonar (Richardson et al. 1995, Gordon and Moscrop 

1996, National Research Council 2003). Other than direct vessel strikes, potential impacts from 

all of these sources are poorly understood. 

Killer whales rely on their highly developed acoustic sensory system for navigating, locating 

prey, and communicating with other individuals. Increased levels of anthropogenic sound have 

In 2007 the State of Washington established the Puget Sound Partnership- a new agency 

consisting of an executive director, an ecosystem coordination board, and a Puget 

Sound science panel (RCW 90.21.210). The Partnership was created to oversee the 

restoration of the environmental health of Puget Sound by 2020, and is directed to 

create a long-term plan called the 2020 Action Agenda by September 2008. The Action 

Agenda will contribute to killer whale recovery by identifying and prioritizing actions, 

identifying funding, and tracking and reporting progress. 
January 2008 II-104 NMFS 

the potential to mask echolocation and other signals used by the species, as well as to 

temporarily or permanently damage hearing sensitivity. Exposure to sound may therefore be 

detrimental to survival by impairing foraging and other behavior, resulting in a negative energy 

balance (Bain and Dahlheim 1994, Gordon and Moscrop 1996, Erbe 2002, Williams et al. 2002a, 

2002b). In other cetaceans, hormonal changes indicative of stress have been recorded in 

response to intense sound exposure (Romano et al. 2003). Chronic stress is known to induce 

harmful physiological conditions including lowered immune function, in terrestrial mammals 

and likely does so in cetaceans (Gordon and Moscrop 1996). The threshold levels at which 

underwater sounds becomes harmful to killer whales remain poorly understood (Krahn et al. 

2002). 

Whale watching. Whale watching has become an important tourist industry in many localities 

around the world since the early 1980s (Hoyt 2001, 2002). In addition to boosting the economies 

of coastal communities and providing an economic reason for preserving whale populations, 

whale watching has also proven beneficial by increasing public awareness of marine mammals 

and the environmental issues confronting them (Barstow 1986, Tilt 1986, Duffus and Deardon 

1993, Lien 2001). In Washington and British Columbia, killer whales are the main target species 

of the commercial whale-watching industry, easily surpassing other species such as gray whales, 

porpoises, and pinnipeds (Hoyt 2001). Killer whale watching in the region is centered primarily 

on the Southern and Northern Residents, which can be found more reliably than transients or 

offshores. Viewing activity occurs predominantly in and around Haro and Johnstone Straits, 

which are the summer core areas of the two resident communities. However, Haro Strait 

supports a considerably greater industry because of its proximity to urban areas. Both 

commercial and private vessels engage in whale watching, as well as kayaks and small numbers 

of aircraft. In addition, land-based viewing is popular at locations such as Lime Kiln Point State 

Park, San Juan County Park, and the San Juan County land bank on San Juan Island, Turn Point 

on Stuart Island, and East Point on Saturna Island (K. Koski, pers. comm.). Lime Kiln Point 

State Park was established in 1984 by the Washington State Parks and Recreation Commission 

for the purpose of watching killer whales (Ford et al. 2000) and receives about 170,000 to 

200,000 visitors per year, most of whom hope to see whales (Koski 2006; W. Hoppe, pers. 

comm.). 

Commercial viewing of killer whales began in Washington and southern British Columbia in 

1977 and persisted at a small scale through the early 1980s, with just a few boats operating and 

fewer than 1,000 passengers serviced per year (Osborne 1991, Baird 2002, Koski 2004). The 

first full-time commercial whale-watching vessel began frequent service in 1987 (Baird 2002). 

Activity expanded to about 13 active vessels (defined as making more than one trip per week) 

and 15,000 customers by 1988 (Osborne 1991), then jumped sharply from 1989 to 1998, when 

vessel numbers grew to about 80 boats and passenger loads increased to about half a million 

customers per year (Osborne et al. 2002). Small reductions in the numbers of companies, active 

boats, and passengers have occurred since then. About 41 companies with 76 boats were active 

in 2006 and passenger levels were estimated at over 500,000 people (Koski 2007). Most 

companies belong to an industry organization known as the Whale Watch Operators Association 

Northwest, which was formed in 1994 to establish a set of whale viewing guidelines for 

commercial operators and to improve communication among companies (Whale Watch 

Operators Association Northwest 2003). The majority of commercial vessels were based in 
January 2008 II-105 NMFS 

Washington during the 1980s, but this has gradually shifted and Canadian boats comprised 71 

percent of the industry in 2006 (Koski 2007). Most companies are based in Victoria or the San 

Juan Islands, but others operate from Bellingham, La Conner, Everett, Port Townsend, 

Anacortes, and Vancouver. Commercial whale-watching boats range in size and configuration 

from open vessels measuring under 7 m in length and capable of holding 6-16 people to large 30-

m-long passenger craft that can carry up to 280 customers. Many boats routinely make two or 

three trips per day to view whales. Commercial kayaking operations include about six active 

companies that are focused on whale watching, plus another 18 companies or so that 

occasionally view whales (K. Koski, pers. comm.). At least one business offers occasional 

airplane viewing. The San Juan Islands and adjacent waters also attract large numbers of private 

boaters for recreational activities including cruising, fishing and diving. Many of these 

participate in viewing whales whenever the opportunity arises. Currently, over 50 percent of the 

craft seen with whales are commercially operated, with the remainder privately owned (Koski 

2007). Additionally, private floatplanes, helicopters, and small aircraft take regular advantage of 

opportunities to view whales (Marine Mammal Monitoring Project 2002). 

Hoyt (2001) assessed the value of the overall whale-watching industry in Washington at 

US$13.6 million (commercial boat-based viewing, $9.6 million; land-based viewing, $4.0 

million) and in British Columbia at US$69.1 million (commercial boat-based viewing, $68.4 

million; land-based viewing, $0.7 million) in 1998, based on estimated customer expenditures 

for tours, food, travel, accommodations, and other expenses. An estimated 60-80 percent of this 

value likely originated from the viewing of killer whales in the Georgia Basin and Puget Sound 

(R. W. Osborne, pers. comm.). More recent estimates of the economic value of whale watching 

in the region are unavailable. Expenditures by the users of private whale-watching vessels are 

also unknown. 

The growth of whale watching during the past two decades has meant that killer whales in the 

region are experiencing increased exposure to vessel traffic and sound (see Other Vessels for a 

historical context on exposure). Not only do greater numbers of boats accompany the whales for 

longer periods of the day, but there has also been a gradual lengthening of the viewing season. 

Commercial viewing activity during the summer now routinely extends from 9:00 a.m. to 9:00 

p.m., with the heaviest pressure between 10:00 a.m. and 12:00 p.m. and again from 2:00 p.m. to 

5:00 p.m. (Koski 2004, 2006). However, some viewing may begin as early as 6:00 a.m. (Bain 

2002) and more companies are offering sunset trips that stay out until nearly 10:00 p.m. Thus, 

many resident whales are commonly accompanied by boats throughout much or all of the day. 

The commercial whale-watching season now usually begins in April, is heaviest during MaySeptember, and largely winds down in October, but a small amount of traffic occurs throughout 

the winter and early spring whenever whales are present (Koski 2004). Viewing by private craft 

follows a similar seasonal pattern. J pod is considered the most commonly viewed pod, with L 

pod being the least viewed (Bain 2002; K. Koski, pers. comm.; R. W. Osborne, pers. comm.). 

The mean number of vessels following groups of killer whales at any one time during the peak 

summer months increased from five boats in 1990 to 18-26 boats from 1996-2006 (Osborne et al. 

1999, Baird 2001, Erbe 2002, Marine Mammal Monitoring Project 2002, Koski 2004, 2006, 

2007). However, the whales sometimes attract much larger numbers of vessels. Annual 

maximum counts of 72-120 boats were made near whales from 1998-2006 (Koski 2004, 2006, 
January 2008 II-106 NMFS 

2007). In these cases, commercial vessels totaled no more than 35 craft, thus the majority of 

boats present were privately owned. Baird (2002) described one instance of a fleet of 76 boats 

that simultaneously viewed about 18 members of K pod as they rested along the west side of San 

Juan Island in 1997. The ring of boats surrounding the whales included kayaks, sailboats, and a 

wide assortment of different-sized powerboats measuring up to about 30 m. Unusual 

occurrences of whales have the potential to draw even greater numbers of vessels. The monthlong presence of killer whales at Dyes Inlet in Bremerton in the autumn of 1997 attracted up to 

500 private whale-watching boats on weekends. While the maximum numbers of boats recorded 

in the vicinity of the whales are made up of much higher numbers of private vessels, the average 

number of vessels around the whales is higher for commercial whale watching vessels than for 

private boats (Koski 2007). 

Worries that whale watching may be disruptive to killer whales date back to the 1970s and early 

1980s, when viewing by relatively small numbers of vessels became routine (Kruse 1991). 

NMFS Northwest Region established whale watch guidelines in 1981 in response to concerns 

about vessel approaches to marine mammals, however, these were primarily for gray whales. 

The expansion of commercial and private viewing in recent years has greatly added to concerns 

(Osborne 1991, Duffus and Deardon 1993, Lien 2001, Erbe 2002, Williams et al. 2002a, 2002b). 

The Southern Residents in particular have been exposed to sound generated by whale-watching 

vessels since the early 1990s (Bain 2002). This has caused whale-watching activity to be cited 

as possibly an important contributing factor in the recent decline of this population (Baird 2001, 

Bain 2002, Krahn et al. 2002, Wiles 2004). Whale-watching vessels can produce high levels of 

underwater sound in close proximity to the animals. Acoustic outputs vary with vessel and 

engine type and become “louder” as speed increases (Bain 2002, Erbe 2002). Outboard-powered 

vessels operating at full speed produce estimated rms sound-pressure levels of about 160-175 

decibels with reference to one microPascal at one meter (dB re 1 μPa hereafter) (Bain 2002, Erbe 

2002). Inflatables with outboard engines are slightly “louder” than rigid-hull powerboats with 

inboard or stern-drive engines (Erbe 2002). Bain (2002) reported that the shift in predominance 

from American to Canadian-owned commercial craft during the 1990s has likely led to whales 

experiencing higher ambient noise levels in some frequency bands. Many Canadian boats are 

small outboard powered craft, whereas most American vessels are larger and diesel powered. By 

modeling vessel sounds, Erbe (2002) predicted that the sounds of fast boats are audible to killer 

whales at distances of up to 16 km, mask their calls up to 14 km away, elicit behavioral 

responses within 200 m, and cause temporary hearing impairment after 30-50 minutes of 

exposure within 450 m. For boats moving at slow speeds, the estimated ranges fall to 1 km for 

audibility and masking, 50 m for behavioral reactions, and 20 m for temporary hearing loss. It 

should be noted that underwater sound propagation can vary considerably depending on water 

depth and bottom type, thus acoustic measurements may not be applicable between locations 

(Richardson et al. 1995). 

Several studies have linked vessels with short-term behavioral changes in Northern and Southern 

Resident killer whales (Kruse 1991, Kriete 2002, Williams et al. 2002a, 2002b, Foote et al. 2004, 

Bain et al. 2006) although whether it is the presence and activity of the vessel, the sounds of the 

vessel or a combination these factors is not well understood. Individual whales have been 

observed to react in a variety of ways to whale-watching vessels. Responses include swimming 

faster, adopting less predictable travel paths, making shorter or longer dives, moving into open 
January 2008 II-107 NMFS 

water, and altering normal patterns of behavior at the surface (Kruse 1991; Williams et al. 2002a; 

Bain et al. 2006), while in some cases, no disturbance seems to occur (R. Williams, unpubl. 

data). Avoidance tactics often vary between encounters and the sexes, with the number of 

vessels present and their proximity, activity, size, and “loudness” affecting the reaction of the 

whales (Williams et al. 2002a, 2002b). Avoidance patterns often become more pronounced as 

boats approach closer. Kruse (1991) observed that Northern Resident whales sometimes reacted 

even to the approach of a single boat to within 400 m. This study also reported a lack of 

habituation to boat traffic over the course of one summer. However, further research by 

Williams et al. (2001, 2002a, 2002b) indicated a reduction in the intensity of Northern Resident 

responses to vessels between the mid-1980s and mid-1990s, possibly because of gradual 

habituation, changes in the avoidance responses of the whales, or sampling differences between 

the two studies. Bain et al. (2006) found that behavior of Southern Residents in the presence of 

vessels was consistent with that observed in Northern Residents regarding inhibition of feeding 

behavior, horizontal avoidance, and changes in surface active behavior. Foote et al. (2004) 

reported that call duration in the presence of whale-watching boats increased by 10-15 percent in 

each of the Southern Resident pods between 1989-1992 and 2001-2003, suggesting that animals 

were compensating for their noisier environment. Disturbance by whale-watching craft has also 

been noted to cause newborn calves to separate briefly from their mothers’ sides, which leads to 

greater energy expenditures by the calves (J. P. Schroeder, pers. comm.) and may interrupt 

nursing behavior that generally proceeds in a forward direction (B. Kriete, pers. comm.) 

Research update 

Transient killer whales also receive considerable viewing pressure when they venture into the 

Georgia Basin and Puget Sound (Baird 2001). No studies have focused on their behavioral 

responses to whale-watching vessels to determine whether they resemble those of residents. 

Because transients may depend heavily on passive listening for prey detection (Barrett-Lennard 

et al. 1996), their foraging success is more likely affected by vessel presence than with residents 

(Ford and Ellis 1999, Baird 2001). 

In 2007 Holt reviewed the current knowledge and data gaps regarding sound exposure 

to Southern Resident killer whales. The review provides an overview of acoustic 

concepts, killer whale sound production, ambient sound levels (Veirs and Veirs 2005), 

sound propagation in killer whale habitats, effects of sound exposure, and assessment of 

likely acoustic impacts on the Southern Residents. Holt used data on ambient sound 

and characteristics and sound levels of several different types of vessels (Hildebrand et 

al. 2006) to analyze impacts on the effective range of killer whale echolocation in 

detecting a salmon. The review concluded that vessel noise was predicted to 

significantly reduce the range at which echolocating killer whales could detect salmon 

in the water column. Holt (In Press) also suggests additional studies to further 

investigate the effects of vessel size, propulsion type, operating speed, and vessel 

orientation on sound levels, as well as studies to better measure temporary threshold 

shifts, behavioral response to sound and to measure killer whale auditory bandwidths. 
January 2008 II-108 NMFS 

Vessels engaged in whale watching activities generally employ two methods for approaching and 

viewing killer whales, both of which are in compliance with viewing guidelines (see below) 

when performed correctly. “Paralleling” involves a boat that slowly cruises alongside the 

whales, preferably at a distance of greater than 100 m, as specified under current guidelines. 

Another technique known as “repositioning” is done after the whales have passed a vessel by at 

least 800 m. The vessel then slowly engages its engines and travels at 5-7 knots until it is well 

behind and outside of the whales by about 1,500 m. It then speeds up and makes an arc outside 

of the whales, traveling 1.5-3 km ahead whereupon it moves back towards the whales’ expected 

route. When about 1,500 m from their path, the vessel slows to 5-7 knots and travels forward to 

position itself about 100 m outside and offshore of the whales’ anticipated path. The vessel then 

waits for the whales to arrive with its engines off or in idle, but continues to adjust its position as 

necessary to stay at least 100 m from their route to prevent having the whales travel underneath 

the vessel. Sometimes vessels either intentionally or unintentionally end up in the path of the 

whales, which is an infraction of the guidelines and recorded as an incident by monitoring 

groups. Parking in the path of the whales was the incident reported most frequently in 2005 and 

2006 (Koski 2007). 

A third method known as “leapfrogging” was commonly employed until about 1999, when its 

use became discouraged. It involved a vessel that moved ahead of the whales by paralleling 

them for some distance at a faster speed (Williams et al. 2002b). The vessel then turned 90o to 

place itself directly in the whales’ anticipated path and waited for their approach while sitting in 

a stationary position with its engines put in idle or turned off. If the whales maintained their 

approximate travel course, they often swam closely past the boat or even underneath it, providing 

a close-up viewing opportunity. Leapfrogging is not consistent with the recommended viewing 

guidelines, but still occurs occasionally by private boaters (K. Koski, pers. comm.). All three 

styles of watching can induce evasive responses by the whales, but leapfrogging appears to cause 

greater path deviation (Williams et al. 2002a, 2002b). Vessels speeding up to leapfrog also emit 

greater sound levels that are of higher frequency, and therefore have greater potential to mask 

communication in the whales than paralleling craft or stationary vessels sitting with the engines 

off or at idle beyond 100 m (Bain 2002). Furthermore, masking is more likely to occur from 

vessels placed in the path of the whales (Bain and Dahlheim 1994, Bain 2002). 

Researchers and photographers during the 1970s suspected that their own vessels affected killer 

whale behavior and developed an unofficial code of conduct intended to reduce the impacts of 

their activity on the whales (Bain 2002). These initial rules addressed the proximity between 

vessels and whales, vessel speeds, and the orientation of vessels relative to whales. As whale 

watching in Washington and southern British Columbia became increasingly popular, a set of 

voluntary guidelines was established in the early 1980s by NMFS to instruct commercial 

operators and recreational boaters on appropriate viewing practices. These also functioned as a 

proactive alternative to stricter legal enforcement of American and Canadian regulations (i.e., the 

Marine Mammal Protection Act and Fisheries Act, respectively), which prohibit harassment of 

the whales. In the late 1980s The Whale Museum also became involved in whale watching 

guidelines. In 1994, the newly formed Whale Watch Operators Association Northwest prepared 

an improved set of guidelines aimed primarily at commercial operators (Whale Watch Operators 

Association Northwest 2003). Regular review and updating of the guidelines has occurred since 

then. The current “Be Whale Wise” guidelines (Appendix A) were issued in 2006 with input 
January 2008 II-109 NMFS 

from the operators association, monitoring groups, whale advocacy groups, and governmental 

agencies, and are supported by 20 partner groups. These guidelines suggest that boaters parallel 

whales no closer than about 100 m, approach the animals slowly from the side rather than from 

the front or rear, and avoid putting their vessel within about 400 m in front of or behind the 

whales. Vessels are also recommended to reduce their speed to about 13 km/hr within about 400 

m of the whales and to remain on the outer side of whales near shore. A variety of other 

recommendations are also provided. Two voluntary no-boat areas off San Juan Island were 

designated for the whales and commercial operators have agreed not to accompany whales into 

these areas, an action that many private boaters follow as well. The first is a 1⁄2-mile (800 m)-

wide zone along a 3-km stretch of shore centered on the Lime Kiln lighthouse. The area was 

designated in 1996 to facilitate shore-based viewing of whales and to reduce vessel presence in 

an area used preferentially by the whales for feeding, traveling, and resting. The second is a 1⁄4-

mile (400 m)-wide zone along much of the west coast of San Juan Island from Eagle Point to 

Mitchell Point. This was established in 1999 for the purpose of giving whales uninterrupted 

access to inshore habitats. 

Several programs have been established to improve the awareness and compliance of private and 

commercial whale watchers, however, incidents where the guidelines are not followed do occur 

(Table 12). Recreational boaters are much less likely to know about the guidelines and proper 

viewing etiquette and may operate unsafely around whales (Lien 2001, Erbe 2002). In 

Washington, the Soundwatch Boater Education Program was created by The Whale Museum and 

has operated around the San Juan Islands since 1993, largely through private grants and 

donations. A Canadian counterpart program known as the Marine Mammal Monitoring Project 

(M3) part of the Veins of Life Watershed Society operated from 2001-2006, with principal 

funding from the Canadian Federal government. Both programs work cooperatively in the 

waters of both countries. In Johnstone Strait, a similar program known as Straitwatch has 

operated under the guidance of the Johnstone Strait Killer Whale Interpretive Centre Society and 

currently under Cetus Research and Conservation. Straitwatch also operated around the San 

Juans and worked cooperatively with Soundwatch in 2007. Additionally, a BC Parks warden 

project started in 1982 monitors the Robson Bight Michael Bigg Ecological Reserve from a 

distance and asks boaters to avoid the area. These programs educate the boating public through 

several methods, the most visible of which is the use of small monitoring boats that are on the 

water with whale-watching vessels on a daily basis during the peak whale-watching season. 

Crews do not have enforcement capability, but monitor and gather data on boater activities and 

inform boat operators of whale-watching guidelines. Monitoring groups record incidents of all 

craft not following the guidelines and provide feedback on commercial vessel incidents directly 

to the industry via “report cards.” Program staff serve in an on-water stewardship role and 

approach recreational vessels entering an area with whales to distribute informational materials. 

They also give public presentations to user groups off the water. These programs have been very 

successful in improving the overall behavior of recreational and commercial whale watchers, 

especially when their monitoring vessels are operating on the scene (J. Smith, unpubl. data; K. 

Koski, pers. comm.). While the monitoring data is useful for characterizing some trends in 

whale watching activity, the sampling methodology is often opportunistic based and the groups 

are conducting both stewardship and monitoring without accounting for effort, so caution should 

be used in interpreting the results regarding compliance with the guidelines. 
January 2008 II-110 NMFS 

Research update 

Aircraft are not specifically mentioned in the “Be Whale Wise” guidelines. However, 

recommendations for aircraft are incorporated into a broader set of regional whale-watching 

guidelines prepared by NMFS. These advise aircraft to maintain a minimum altitude of 300 m 

(1,000 ft) above all marine mammals, including killer whales, and to not circle or hover over the 

animals. Violations of these recommendations have dramatically risen in recent years and now 

represent about 10 percent of all incidents observed (Marine Mammal Monitoring Project 2002; 

Koski 2004, 2006). 

The potential impacts of whale watching on killer whales remain controversial and 

inadequately understood. Although numerous short-term behavioral responses to whalewatching vessels have been documented, no studies have yet demonstrated a long-term 

adverse effect from whale watching on the health of any killer whale population in the 

northeastern Pacific. Both resident populations have shown strong site fidelity to their 

traditional summer ranges despite more than 25 years of whale-watching activity (as well 

as even longer periods of intense commercial fishing vessel activity; see Other Vessels). 

Furthermore, Northern Resident abundance increased throughout much of this period, 

suggesting that this population was not affected to any great extent until perhaps recently. 

The recent decline of the Southern Resident population does not appear to follow a simple 

cause-and-effect relationship with the expansion of whale watching. While the statistical 

analyses of Bain (2002) most strongly indicated that the whale-watching fleet’s buildup 

tracked the decline of the population from 1991-2001, Bain (2002) speculated that a 

complex relationship with additional variables might be at work. Further confounding the 

matter is the fact that the most often watched pod (J pod) has shown an overall increasing 

trend in numbers since the 1970s and is currently at its highest recorded number. In 

contrast, L pod is considered the least viewed pod, but is the only one to undergo a 

substantial and continuing decline since 1996. 

The Soundwatch report for the 2006 whale watch season (Koski 2007) provides 

information on some recent trends in incidents observed. Koski (2007) reported a 

consistent decline in the number of incidents of vessels within the voluntary no-go 

zones on the west side of San Juan Island from 1998-2006 and suggests this may be in 

response to the active programs to educate recreational boaters as well as the 

commercial vessels setting a better example for others in recent years. The top 

percentages of vessel incidents continue to occur primarily by private boaters (over 

50% in 2006) followed by Canadian commercial operators (21%) and then U.S. 

commercial operators (9%). Kayaks, aircraft, research, and other vessels such as 

commercial fishing vessels make up the remaining percentage of incidents. Private 

boaters committed the majority of the top four incidents (Table 12) in all but one year 

(commercial Canadian vessels were recorded with the highest percentage in 2004). 

Commercial operators are more likely to “Park in the path” than other types of boaters. 

The report for the 2006 whale watch season also included maps of areas of high vessel 

traffic and incidents. 
January 2008 II-111 NMFS 

Table 12. Types and relative occurrence of infractions of voluntary whale-watching guidelines 

witnessed by the Soundwatch Boater Education Program in Washington and southern British 

Columbia, 1998-2006 (Koski 2004, 2006, 2007). Infractions were committed by commercial and 

recreational vessels, kayaks, and aircraft in the act of whale watching, as well as research vessels. 

 Percent of infractionsa

Type of infraction 1998 1999 2000 2001 2002 2003 2004 2005 2006 

Within the 400-m-wide San Juan 

Island no-boat zone 

 

 39 

 

 26 

 

 17 

 

 17 

 

 7 

 

 13 4 8 4 

Leapfrogging 37 31 23 1 na na na na na 

Under power within 100 m of 

whales 

 6 4 5 4 5 12 9 10 12 

Inshore of whales 5 29 24 25 19 16 22 18 17 

Crossing the path of whales 4 3 5 2 4 7 6 4 5 

Aircraft within 300 m of whales 4 2 4 7 14 6 6 4 6 

Chasing or pursuing whales 3 1 3 2 <1 4 3 1 2 

Within the 800-m-wide Lime 

Kiln no-boat zone 

 2 2 2 1 2 5 1 2 1 

Within 180 m of the San Juan 

Islands National Wildlife Refuge 

 0 1 3 1 2 2 1 0 <1 

Otherb 1 3 3 14 5 15 11 10 

Repositioning to be within 100 

m of whalesb

 7 7 na na na na na 

Within 200 m of shore with 

whales presentb

 4 4 2 <1 4 1 2 

Parked in the path of whalesb 26 24 17 19 27 26 

First approach of whales from 

head-on, behind, or shoreb

 4 2 1 <1 1 

Traveling fast (>5-7 knots) 

within 400 m of whalesb

 3 4 9 10 11 

Kayaks spread out with whales 

presentb

 <1 3 0 <1 1 

Kayaks with whales outside the 

400-m-wide San Juan Island noboat zoneb

 <1 1 0 <1 1 

Kayaks paddling within 100 m 

of whalesb

 3 0 <1 1 

Total ( percent) 100 100 100 100 100 100 100 96 100 

Total number of observed 

incidents 

 398 791 653 533 259 373 761 957 1281 

Estimated observation time 

(hours) 

 426 510 426 486 378 312 486 564 516 

a

 During 1998-2001, Soundwatch operated an average of 7 days per week from May to September. During 2002, it 

operated an average of 3 days per week from May to September. During 2003-2005, it operated an average of 5 

days per week from June to September. b

 Category was not used during all years. 

Research findings on the responses of the Northern Residents to vessel traffic are not necessarily 

applicable to the Southern Residents, which are exposed to much heavier viewing pressure 

(Williams et al. 2002a). The frequent presence of vessels around the Southern Residents has 

hindered researchers from studying the whales’ behavior in the absence of vessels to permit 

comparisons. Some researchers believe that the Southern Residents are more habituated to 
January 2008 II-112 NMFS 

vessel traffic and have perhaps adapted to some of its adverse impacts. Habituation, however, is 

a complex issue and even if whales have adapted and don’t overtly show reactions (i.e., tail 

slaps, changes in swimming patterns) to vessels, there may still be effects. Concerns remain that 

populations may be experiencing subtle cumulative detrimental effects resulting from frequent 

short-term disturbance caused by whale watching. If recent levels of whale watching are 

problematic for the Southern Residents, the population has much less opportunity than the 

region’s other killer whale communities to relocate to other productive feeding areas with less 

disturbance (Bain 2002). 

Other vessels. The inland waters of Washington and southern British Columbia formerly 

supported a major commercial fishing industry centered on salmon, halibut, and other groundfish 

that began rapid expansion in the late 1880s and 1890s. Motorized fishing vessels were 

introduced in 1903 and probably resulted in substantial noise exposure for the region’s killer 

whales by the 1910s or 1920s. Numbers of non-tribal commercial fishing boats in the greater 

Puget Sound area remained high through the mid-1970s, after which a steady downward trend 

occurred due to changes in fishing regulations and declining salmon abundance. Numbers of 

commercial salmon fishing licenses in this area, which generally reflect the numbers of nontribal vessels in operation, fell from 4,132 in 1974 to 286 in 2006 (D. Noviello, unpubl. data). 

During the peak decades of activity, under liberal fishing seasons, boats congregated in large 

numbers on productive fishing grounds for periods of weeks or months, especially from May 

through October. Little information is available on the effects of commercial fishing boats on 

killer whales during this time. However, the sound generated by the fleet was intense (K. C. 

Balcomb, pers. comm.) and the localized presence of so many vessels must have been significant 

at times. Observations from the 1970s indicate that the whales regularly mingled with 

commercial fishing vessels (K. C. Balcomb, pers. comm.). This information suggests that the 

Southern Residents were impacted by vessel effects for a number of decades before the buildup 

of commercial whale watching. However, effects from commercial fishing boats have 

undoubtedly declined with reductions in the fishing industry and their activities are different 

from those of whale watching vessels that follow the whales for extended periods. 

In recent decades, commercial shipping traffic has become a major source of low frequency (5 to 

500 Hz) human-generated sound in the world’s oceans (National Research Council 2003). The 

Georgia Basin and Puget Sound are among the busiest waterways in the world, with several 

thousand trips made per month by various types of commercial vessels. Haro Strait, which is 

frequently used by Southern Resident killer whales, is one of the region’s primary shipping 

lanes. Non-recreational vessel traffic in Puget Sound, the eastern Strait of Juan de Fuca, and the 

southern Strait of Georgia is dominated by cargo ships (34 percent of all traffic, as measured in 

total ship hours), passenger vessels (31 percent), tugs (17 percent), and tankers (9 percent) 

(Mintz and Filadelfo 2004a). The low-frequency sound radiated by these ships comes largely 

from cargo ships (71 percent), passenger vessels (13 percent), tugs (7 percent), and tankers (5 

percent) (Mintz and Filadelfo 2004b). Although large vessels have predominantly low frequency 

sound, studies have reported broad band sounds from large cargo ships including significant 

levels of noise above 2 kHz that may interfere with important biological functions (Hildebrand 

2006 summarized in Holt In Press). By comparison, traffic inside the western half of the Strait 

of Juan de Fuca and off the Washington coast is comprised mainly of cargo ships (51 percent), 

tugs (15 percent), tankers (14 percent), and fishing vessels (9 percent), with most sound coming 
January 2008 II-113 NMFS 

from cargo ships (86 percent), tankers (6 percent), and tugs (5 percent) (Mintz and Filadelfo 

2004a, 2004b). In both areas, Navy vessels typically make up 2-3 percent of the traffic and ≤1 

percent of the radiated engine sound, because of their sound-reducing designs (this excludes 

sound associated with high-power mid-frequency tactical sonar use). Koski (2004, 2006) 

reported that commercial shipping vessels made up 1-2 percent of the craft recorded near 

Southern Resident whales in and around the San Juan Islands during the summers of 2003-2005. 

Recreational fishing boats remain common in the area and comprised 11 percent of the vessels 

observed in the vicinity of the Southern Residents from June-September 2003 (Koski 2004). 

When operating at slow speeds or in idle, these boats usually do not appear to disrupt the whales’ 

behavior (Krahn et al. 2004a). 

Update 

Anthropogenic Sound. If sound levels received by marine mammals are high enough, temporary 

or permanent hearing loss may occur, and in severe cases, may result in hemorrhaging around 

the brain and ear bones. Killer whale hearing sensitivity ranges from 1 to 120 kHz with peak 

sensitivities from 20 to 50 kHZ (Szymanski et al. 1999) and fully covers the bandwidth generally 

considered as mid-frequency (2 to 10 kHz). Threshold levels at which underwater anthropogenic 

sound negatively impacts hearing and behavior are poorly understood. In dolphins, the onset of 

temporary threshold shift has been estimated to occur at received sound pressure levels of 195 

dB at 1 sec duration exposures (Schlundt et al. 2000, Finneran et al. 2005), while avoidance 

behaviors in several baleen whale species exposed to different sound sources, impulsive and low 

frequency sounds, have been observed at received levels of 140-160 dB (Malme et al. 1983, 

1984, 1988, Ljungblad et al. 1988, Tyack and Clark 1998). Under certain conditions, the high 

sound pressure levels generated by some sonar may impact marine mammals (U.S. Department 

of Commerce and Secretary of the Navy 2001, Balcomb and Claridge 2001, Brownell et al. 

2004, International Whaling Commission 2004). 

Military mid-frequency sonar. Current tactical military sonar designs, such as the U.S. Navy’s 

AN/SQS-53C tactical sonar produce signals with source levels of 235 rms dB re 1 μPa at 1 m. 

Strandings of cetaceans have been linked to naval sonar use (U.S. Department of Commerce and 

Secretary of the Navy 2001). In March 2000, a multi-species stranding of 17 cetaceans was 

discovered in the Bahamas and coincided with ongoing naval activity involving tactical midfrequency sonar. The 17 stranded animals comprised 9 Cuvier’s beaked whales, 3 Blainville’s 

beaked whales, 2 unidentified beaked whales, 2 minke whales (survived stranding and not 

examined) and 1 spotted dolphin (determined unrelated to the event). Gross findings during 

exams of the beaked whales that died included acute hemorrhage within the subarachnoid space, 

In March 2007 NMFS published an Advance Notice of Proposed Rulemaking to gather 

public input on whether and what type of regulation might be necessary to reduce vessel 

effects on Southern Residents (NMFS 2007b). The Notice requested comments on a 

preliminary list of potential regulations including codifying the Be Whale Wise 

guidelines, establishing a minimum approach rule, prohibiting particular vessel 

activities of concern, establishing time-area closures, and creating operator permit or 

certification programs. 
January 2008 II-114 NMFS 

and lateral ventricles (U.S. Department of Commerce and Secretary of the Navy 2001). A 

hypothesized mechanism for sonar-related marine mammal strandings, particularly beaked 

whales, is the formation of nitrogen bubbles in diving mammals exposed to intense acoustic 

exposures (Jepson et al. 2003). Validating this hypothesis and describing the exposure 

conditions required to induce such gas emboli in marine mammals, including killer whales, 

requires further research. 

The impacts of military mid-frequency sonar on killer whales have not been directly studied, but 

observations are available from an event that occurred in the Strait of Juan de Fuca and Haro 

Strait on 5 May 2003, when members of J pod were present off southwestern San Juan Island. A 

U.S. Navy guided-missile destroyer (USS Shoup) passed through the strait while operating its 

mid-frequency AN/SQS-53C sonar during a training exercise. Members of J pod were present in 

the strait and unusual behaviors by whales in response to the sound were reported by local 

researchers (NMFS 2004d, U.S. Navy, Pacific Fleet 2004). NOAA assessed the acoustic 

exposures and reported that it was unlikely that the whales experienced either temporary or 

permanent hearing loss. Based on the duration and received levels, and levels known to cause 

behavioral reactions in other cetaceans, J pod received exposure levels likely to cause behavioral 

disturbance, which is consistent with eyewitness accounts (NMFS 2004d). 

Only a few Navy vessels operating in the greater Puget Sound area are equipped with mid-range 

frequency active sonar. Typical Navy mid-frequency active sonar use in Puget Sound is limited 

to pier-side system maintenance and training on designated ranges. As a precautionary measure, 

any ship, submarine or unit wanting to use active mid-frequency sonar in Puget Sound, including 

the Strait of Juan de Fuca, is required to obtain prior permission from the Commander of the U.S. 

Pacific Fleet. 

Other military activities. Canadian military authorities maintain a munitions testing area near 

Bentinct Island and Pedder Bay at the southern tip of Vancouver Island. Underwater detonations 

are sometimes performed at the site and occurred on one occasion when J pod was less than 1.5 

km away, which caused the whales to suddenly change their direction of travel (R. W. Baird, 

pers. comm.). The U.S. Navy operates several ordnance training locations in Puget Sound. 

Ordnance training activities include procedures to ensure marine mammals are not in the vicinity 

and likely have little impact on the Southern Residents. 

Commercial sonar systems. Commercial sonar systems designed for fish finding, depth 

sounding, and sub-bottom profiling are widely used on civilian vessels and are often 

characterized by high operating frequencies, low power, narrow beam patterns, and short pulse 

lengths (National Research Council 2003). Frequencies fall between 1 and 500 kHz, thus some 

systems function within the hearing range of killer whales and may have masking effects. Little 

information is currently available on any potential impacts of multiple commercial sonars used in 

close proximity of killer whales, but impact zones would likely be very small, based on the high 

frequencies and short durations of most depth sounders and fish finders. 

Seismic exploration. Seismic surveying is the primary exploration technique for detecting oil 

and gas deposits, fault structures, and other geological hazards in offshore areas. Surveys are 

carried out by ships towing one or two arrays of air-guns, which generate intense low-frequency 
January 2008 II-115 NMFS 

sound pressure waves capable of penetrating the seafloor and are fired repetitively at 10-20-

second intervals for extended periods (National Research Council 2003). Arrays hold up to 70 

air-guns and commonly vary from 2,000-8,000 cu in (0.033-0.131 m3

) in total size. Most of the 

energy from the guns is directed vertically downward, but significant sound emission also occurs 

horizontally. Downward directed pulses that enter the deep sound channel (about 800 m depth or 

more) can be detected at distances exceeding 3,000 km (Nieukirk et al. 2004). Peak pressure 

levels from air-guns usually range from 5-300 Hz and reach about 235-240 dB re 1 μPa (RMS, 

far field measurement) (National Research Council 2003) and most of the energy is below 500 

Hz. Fish have experienced ear damage when exposed to air guns far more intensively than 

during typical seismic surveys (McCauley et al. 2003). In the United States, all seismic projects 

for oil and gas exploration and most research applications, with the potential to take marine 

mammals, are covered by incidental harassment authorizations under the MMPA. 

Construction activities. In-water construction activities such as pile driving can produce sound 

levels sufficient to disturb marine mammals under some conditions. Sound pressure levels of 

from 190 to 220 dB re 1 μPa have been reported for piles of different sizes in a number of 

studies. The majority of the sound energy associated with pile driving is in the low frequency 

range, < 1000 Hz (Illingworth and Rodkin, Inc. 2001, 2004, Reyff et al. 2002, Reyff 2003). 

Dredging operations also have the potential to emit sounds at levels that could disturb marine 

mammals. Depending on the type of dredge, peak sound pressure levels from 100 to 140 dB re 1 

μPa were reported in one study (Clarke et al. 2003). Similar to pile driving, most of the sound 

energy associated with dredging is in the low frequency range, < 1000 Hz (Clarke et al. 2003). 

Several techniques have been adopted to reduce the sound pressure levels associated with inwater construction activities or prevent exposure of marine mammals to sound. For example, a 

6-inch block of wood placed between the pile and the impact hammer used in combination with a 

bubble curtain can reduce sound pressure levels by about 20 dB. Alternatively, pile driving with 

vibratory hammers produces peak pressures that are about 17 dB lower than those generated by 

impact hammers (Nedwell and Edwards 2002). In addition, not scheduling in-water construction 

activities during times when marine mammals may be present reduces the risk of disturbance. 

Project proponents also monitor for marine mammals and stop sound-producing activities if 

marine mammals approach within buffer zones. 

Underwater acoustic devices. Acoustic harassment devices (AHDs) are another source of sound 

that may be disruptive to killer whales in Washington and British Columbia. AHDs used at 

salmon aquaculture farms emit “loud” signals that are intended to displace harbor seals and sea 

lions away from the farms, thereby deterring predation (Petras 2003), but can cause strong 

avoidance responses in cetaceans as well (Olesiuk et al. 2002). Morton and Symonds (2002) 

described one model that broadcast a 10 kHz signal at 194 dB re 1 μPa at 1 m and was 

potentially audible in open water for up to 50 km. During the early 1990s, the devices were 

installed at a number of salmon farms in Washington (including Cypress Island, Port Angeles, 

Rich Passage off Bainbridge Island, and Squaxin Island) and British Columbia, but were phased 

out of operation in Washington after just a few years (D. Swecker, pers. comm.; J. K. B. Ford, 

pers. comm.). Activation of the devices at a farm near northeastern Vancouver Island 

corresponded with drastic declines in the use of nearby passages and inlets by both resident and 
January 2008 II-116 NMFS 

transient whales (Morton and Symonds 2002). It is unknown whether the devices ever produced 

similar impacts on killer whales in Washington or elsewhere in British Columbia. The only 

AHD still in use in Washington operates at the Ballard locks in Seattle, where NMFS utilizes it 

to deter sea lions. 

Vessel strikes. Collisions between killer whales and vessels are rare in Washington and British 

Columbia, with several incidents documented since the 1990s (see Incidental Human-Related 

Mortality). Two strikes, and probably a third, have resulted in fatalities in recent decades. 

Oil Spills 

Exposure to petroleum hydrocarbons released into the marine environment via oil spills and 

other discharge sources represents another potentially serious health threat for killer whales in 

the northeastern Pacific. Marine mammals are generally able to metabolize and excrete limited 

amounts of hydrocarbons, but acute or chronic exposure poses greater toxicological risks (Grant 

and Ross 2002). Unlike humans, cetaceans have a thickened epidermis that greatly reduces the 

likelihood of petroleum toxicity from skin contact with oiled waters (Geraci 1990, O’Shea and 

Aguilar 2001). Inhalation of vapors at the water’s surface and ingestion of hydrocarbons during 

feeding are more likely pathways of exposure. Transient killer whales may be especially 

vulnerable after consuming prey debilitated by oil (Matkin and Saulitis 1997). Matkin et al. 

(1994) reported that killer whales did not attempt to avoid oil-sheened waters following the 

Exxon Valdez oil spill in Alaska. In marine mammals, acute exposure to petroleum products can 

cause changes in behavior and reduced activity, inflammation of the mucous membranes, lung 

congestion, pneumonia, liver disorders, and neurological damage (Geraci and St. Aubin 1990). 

Evidence of direct mortality in killer whales from spills is described elsewhere in this report (see 

Incidental Human-Related Mortality). Oil spills are also potentially destructive to prey 

populations and therefore may adversely affect killer whales by reducing food availability. 

Puget Sound is one of the leading petroleum refining centers in the United States, with about 15 

billion gallons of crude oil and refined petroleum products transported through it annually (Puget 

Sound Action Team 2005a). Inbound oil tankers carry crude oil to five major refineries in the 

sound, while outbound tankers move refined oil products to destinations along the U.S. west 

coast (Neel et al. 1997). In 2005, a total of 716 oil tankers passed through Washington’s waters 

bound for ports in Puget Sound, Canada, and along the Columbia River (Washington State 

Department of Ecology 2006). This volume of shipping traffic puts the region at risk of having a 

catastrophic oil spill. The possibility of a large spill is considered one of the most important 

short-term threats to killer whales and other coastal organisms in the northeastern Pacific (Krahn 

et al. 2002). 

Prior to the adoption of recent regulatory and other measures to prevent spills, Neel et al. (1997) 

reported that shipping accidents were responsible for the largest volume (59 percent; 3.4 million 

gallons [12.9 million liters]) of oil discharged during major spills in Washington from 1970-

1996. Other sources were refineries and associated production facilities (27 percent; 1.5 million 

gallons [5.7 million liters]) and pipelines (14 percent; 800,000 gallons [3.0 million liters]). There 

have been eight major oil tanker spills exceeding 100,000 gallons (378,500 liters) in the state’s 

coastal waters and on the Columbia River since the 1960s, with the largest estimated at 2.3 
January 2008 II-117 NMFS 

million gallons (8.7 million liters) (Table 13). Grant and Ross (2002) did not report any major 

vessel spills from British Columbia during this same period, but at least one of 100,000 gallons 

(379,000 liters) is known to have occurred in Canadian waters at the mouth of the Strait of Juan 

de Fuca in 1991 (Neel et al. 1997). In addition to these incidents, there have been a number of 

near accidents resulting from vessel groundings, collisions, power loss, or poor vessel condition 

(Neel et al. 1997). 

Puget Sound’s five oil refineries are coastally located at Anacortes (Shell Oil and Tesoro), 

Ferndale (ConocoPhillips), Blaine (BP), and Tacoma (US Oil). Over the past 34 years, four 

major spills have occurred at two of these facilities (Table 13), with each causing some discharge 

of petroleum into marine waters (D. Doty, pers. comm.). Pipelines connecting to refineries and 

oil terminals at ports represent another potential source of coastal spills. Three major pipeline 

leaks over the last 34 years have caused several major spills in western Washington, but only the 

1999 Olympic gasoline spill resulted in any discharge to marine waters (Neel et al. 1997; G. Lee, 

pers. comm.). 

Table 13. Oil spills of 100,000 gallons or more from vessels, production facilities, and pipelines in 

Washington from the 1960s to 2003 (from Neel et al. 1997, Puget Sound Water Quality Action 

Team 2002). 

Year Incident name Location 

Amount spilled 

(gallons) Type of product 

 

Vessels 

1972 General M. C. Meiggs Cape Flattery 2,300,000 Heavy fuel oil 

1964 United Transportation barge n. Grays Harbor Co. 1,200,000 Diesel fuel 

1985 ARCO Anchorage Port Angeles 239,000 Crude oil 

1988 Nestucca barge Ocean Shores 231,000 Heavy fuel oil 

1971 United Transportation barge Skagit County 230,000 Diesel fuel 

1984 SS Mobil Oil tanker Columbia R., Clark Co. 200,000 Heavy fuel oil 

1978 Columbia River barge Klickitat County 100,000 Diesel fuel 

1991 Tenyo Maru Strait of Juan de Fucaa

 100,000 Heavy fuel oil, diesel 

Refineries 

1991 US Oil Tacoma 600,000 Crude oil 

1993 US Oil Tacoma 264,000 Crude oil 

1991 Texaco Anacortes 210,000 Crude oil 

1990 Texaco Anacortes 130,000 Crude oil 

 

Pipelines 

1973 Trans-Mountain Whatcom County 460,000 Crude oil 

1999 Olympic Bellingham 277,000 Gasoline 

1983 Olympic Skagit County 168,000 Diesel fuel 

a Spill occurred in Canadian waters at the mouth of the Strait of Juan de Fuca and flowed into Washington. 

During the late 1980s and early 1990s, Washington significantly upgraded its efforts to prevent 

oil spills in response to increased numbers of spills in the state and the Exxon Valdez accident in 

Alaska. A number of state, provincial, and Federal agencies now work to reduce the likelihood 

of spills, as does the regional Oil Spill Task Force, which was formed in 1989. In addition, there 
January 2008 II-118 NMFS 

is an international body, the International Maritime Organization (IMO), which has adopted 

conventions, protocols, codes and recommendations concerning maritime safety, the prevention 

of pollution and related matters, including specific measures regarding oil spills. National 

statutes enacted in the early 1990s, including the U.S. Oil Pollution Act in 1990 (OPA) and the 

Canada Shipping Act in 1993, have also been beneficial in creating spill prevention and response 

standards. OPA serves as the leading Federal regulatory mechanism to prevent, respond to, and 

address damage caused by oils spill and created the Oil Spill Liability Trust Fund. OPA requires 

that all tank vessels greater than 5,000 gross tons operating in the U. S. waters be fitted with a 

double hull before January 2015. There is a Northwest Area Committee (NWAC) that develops 

and implements a NWAC plan. There are also a number of industry initiated safety practices. In 

additional there are local organizations such as the Island Oil Spill Association, a communitybased, nonprofit organization providing prompt first response for oil spills in the San Juan 

Islands, shoreline protection, wildlife rescue and training for containment and oiled wildlife 

responders. 

In 2001 the U.S. Coast Guard, EPA, Department of Interior, Fish and Wildlife Service and 

NOAA (NMFS and NOS) entered into an agreement that provides a framework for cooperation 

and participation in providing protection of listed species, improve oil spill planning and 

response procedures and streamline section 7 consultations under the ESA. Oil spill planning 

and response procedures are set forth in the National Oil and Hazardous Substances Pollution 

Contingency Plan (NCP). The agreement is intended to facilitate compliance with the ESA 

without degrading the quality of an oil spill response, improve oil spill planning and response 

process, and ensure inter-agency cooperation to protect listed species and critical habitat. 

Since 1999, Washington State has maintained a rescue tugboat at Neah Bay for about 225 days 

per year during the winter months to aid disabled vessels and thereby prevent oil spills. These 

measures appear to have been helpful in reducing the number and size of spills since 1991, but 

continued vigilance is needed. In general, Washington’s outer coast, the Strait of Juan de Fuca, 

and areas near the state’s major refineries are considered the locations most at risk of major spills 

(Neel et al. 1997). 

Chronic small-scale discharges of oil into oceans greatly exceed the volume released by major 

spills (Clark 1997) and represent another potential concern. Such discharges originate from 

numerous sources, such as the dumping of tank washings and ballast water by tankers, the 

release of bilge and fuel oil from general shipping, and the disposal of municipal and industrial 

wastes. Chronic oil pollution kills large numbers of seabirds (e.g., Wiese and Robertson 2004), 

but its impact on killer whales and other marine mammals is poorly documented. The long-term 

effects of repeated ingestion of sub-lethal quantities of petroleum hydrocarbons on marine 

mammals are also unknown. 
January 2008 II-119 NMFS 

Update 

Alternative Energy Projects 

In November 2006, the citizens of Washington voted in support of Initiative 937 (I-937), which 

established a renewable energy standard requiring the state's largest electric utilities to supply 15 

percent of their electricity sales from eligible renewable resources by 2020. It also required those 

electric utilities to pursue all low-cost energy conservation opportunities with their customers 

and in their communities. These renewable energy sources include new technologies to harness 

energy from waves, tides, and marine currents, and there has been increased interest in pursuing 

projects in the Northwest. The impacts to marine life including marine mammals from these 

alternative energy sources are largely unknown. Buoys moored to capture wave energy may 

generate sound or electromagnetic fields that have the potential to affect marine life. Some 

designs employ “open loop” technology that pumps sea water from the surrounding environment 

to drive internal turbines thus posing some risk of entrainment. Multiple anchored and 

connected buoys may also present an entanglement or collision risk. Underwater turbines to 

harness tidal or current energy may also present risks associated with fast moving blades or 

combined fields of large diameter turbines. The Federal Energy Regulatory Commission 

In 2007 the Washington State Department of Ecology published a new Spill Prevention, 

Preparedness, and Response Program Annual Report describing recent 

accomplishments (WDOE 2007). The plan describes new rules for oil transfer that 

were adopted in September of 2006 that provide more universal coverage relating to oil 

transfers over state waters. The report also shows trends in incidents per transit, which 

peaked in 2001 (over 2.5 percent), but have declined to a low of less than 1 percent in 

2004-2006. There have been notable decreases in large spills as well as the overall 

volume of oil spilled, particularly from 2001to 2006. New programs, industry 

compliance and state and federal oversight were cited as reasons for the declines. 

WDOE summarized all reports of chemical, oil and hazardous waste spills statewide 

and provided information on response accomplishments in 2006. The report describes 

the rescue tug program, contingency plan improvements, readiness drills, training, new 

equipment, enforcement and voluntary compliance programs as well as a number of 

education and outreach efforts in Washington and the entire region. 

The recently-adopted oil spill transfer program constitutes a significant new regulatory 

measure that expands the number of commercial operations regulated by WDOE’s oil 

spill program. Previously, WDOE only regulated major maritime shipping operations 

and large facilities such as oil refineries. The new spill prevention rules provide broad 

coverage relating to oil that is transfereed in bulk over state waters. Under the new 

transfer rules, there are four classes of facilities (major refineries, fuel trucks, terminals 

and fuels vessels and marinas with fuel docks) which each have planning and 

operational requirements specific to their operations. All facilities must also meet new 

equipment, reporting, preventative maintenance and operational requirements. DOE 

has added six new inspectors to oversee oil transfers and implement the new rules 

throughout the state, including the Strait of Juan de Fuca and Puget Sound. 
January 2008 II-120 NMFS 

(FERC) has issued several preliminary permits for ocean current, wave and tidal energy projects 

including proposed wave and tidal energy projects in Washington, Oregon and California. 

Several companies and public utilities in the Northwest have begun applying for FERC permits 

and will begin pilot projects to test new technologies and allow monitoring and study of aquatic 

resource impacts in the near future. Ocean Power Technologies, Inc (OPT) has announced 

development of the Reedsport OPT Wave Park located in Douglas County near Reedsport, 

Oregon. As part of the initial program, OPT expects to install a buoy system approximately 2.5 

miles off the coast at a depth of 50 meters. OPT has been issued a preliminary permit by FERC 

for up to 50 megawatt of capacity at the site, and plans to develop, own, and operate the initial 2 

megawatt wave power park. There is also a wave energy project proposed for Makah Bay and 

interest in tidal or current projects in locations such as Tacoma Narrows, Admiralty Inlet, Agate 

Pass, Deception Pass, Guemes Channel, Rich Pass, San Juan Channel and Spieden Channel. 

Monitoring of effects to marine mammals including killer whales will be an important part of 

early projects to help assess potential impacts. 

Disease 

Infectious diseases are not known to limit any killer whale population, nor have epidemics been 

recorded in the species. Nevertheless, a variety of pathogens have been identified in killer 

whales, while others occur in sympatric marine mammal species and may therefore be 

transmittable to killer whales (Buck et al. 1993, Gaydos et al. 2004). Several highly virulent 

diseases have emerged in recent years as threats to marine mammal populations. Of particular 

concern are several types of virus of the genus Morbillivirus. These include 1) dolphin 

morbillivirus, which killed several thousand striped dolphins (Stenella coeruleoalba) in the 

Mediterranean Sea during the early 1990s (Aguilar and Borrell 1994b) and unknown numbers of 

bottlenose dolphins in the western Atlantic during the late 1980s and Gulf of Mexico in the mid1990s (Kennedy 1999, 2001), 2) phocine distemper virus, which produced large die-offs of 

harbor seals and gray seals in Europe in the late 1980s and 2002 (Hall et al. 1992, Jensen et al. 

2002), and 3) canine distemper virus, which caused mass mortalities among Baikal seals (Phoca 

sibirica) in the late 1980s and Caspian seals (P. caspica) in 2000 (Kennedy et al. 2000, Kennedy 

2001). PCB-caused suppression of the immune system is thought to have increased 

susceptibility to the virus in many of these cases (de Swart et al. 1996, Ross et al. 1996b, Ross 

2002), although this conclusion is the subject of debate (O’Shea 2000a, 2000b, Ross et al. 

2000b). Genetic inbreeding may have also played a role in the deaths of some infected striped 

dolphins (Valsecchi et al. 2004). Morbillivirus infections have been diagnosed in a variety of 

other marine mammals from the Atlantic, but caused little mortality in most instances (Kennedy 

2001). Antibodies to dolphin morbillivirus have also been detected in common dolphins 

(Delphinus delphis) from southern California (Reidarson et al. 1998), placing the virus inside the 

ranges of transient and offshore killer whales and near the known southern limit of the Southern 

Resident community (Gaydos et al. 2004). Additionally, there have been recent detections of 

canine distemper virus in river otters in British Columbia (Mos et al. 2003) and evidence of 

exposure to a canine- or phocine-like morbillivirus in sea otters from the Olympic Peninsula (J. 

Davis, unpubl. data). Because of the mutation capabilities and species-jumping history of 

morbilliviruses, there is a possibility that these forms could infect killer whales even if they are 

not the dolphin type (J. Gaydos, pers. comm.). Limited testing evidence suggests that killer 

whales have not yet been affected by morbilliviruses in Washington, British Columbia, or 
January 2008 II-121 NMFS 

elsewhere in the world (Van Bressem et al. 2001), although small sample sizes preclude a 

thorough assessment of this issue. The fact that Southern Resident killer whales are likely 

seronegative suggests that they may be vulnerable if exposed to such a virus (P. S. Ross, pers. 

comm.). Morbillivirus outbreaks are also of concern because of their potentially rapid rates of 

spread (i.e., up to 4,000 km per year) in marine environments (McCallum et al. 2003). 

Other diseases such as Brucella spp. and cetacean poxvirus may impact killer whale populations 

by lowering reproductive success or causing greater mortality among calves (Gaydos et al. 

2004). The Southern Resident community is perhaps the most vulnerable of the four populations 

in Washington and British Columbia to a serious disease outbreak due to its gregarious social 

nature, smaller population, seasonal concentration near the San Juan Islands, and high levels of 

PCB contamination (Gaydos et al. 2004). Other contaminant levels, increasing ambient noise, 

and reduced prey are additional stressors, the cumulative effects of which increase the 

vulnerability of Southern Residents to a catastrophic disease event (J. P. Schroeder pers. comm.). 

Occasional harassment of other marine mammals by the Southern Residents represents a 

potential pathway of exposure to diseases (e.g., see Gaydos et al. 2005). 

Research 

There is an active research program to gather new information on Southern Resident killer 

whales. NOAA’s Northwest Fisheries Science Center held several workshops with a broad 

group of scientists to identify data gaps and research priorities for Southern Residents (NMFS 

2006b). Under the MMPA and ESA there are exemptions of the take prohibition for scientific 

research. Following the listing of Southern Residents under the ESA, researchers with MMPA 

permits for scientific research on killer whales were informed of new permitting requirements 

under section 10 of the ESA. The researchers submitted new applications and NMFS analyzed 

all of the proposed research takes under both NEPA and section 7 of the ESA prior to issuing 

new permits. There are currently 7 permits for research on Southern Residents and NOAA 

completed an Environmental Assessment and a Biological Opinion to analyze the effects of the 

research (NMFS 2006c, NMFS 2006d). While several of the permits are for research on killer 

whales and focus on Southern Residents, others include takes of Southern Residents that may be 

encountered opportunistically during other marine mammal research. The majority of activities 

currently authorized under permit involve non-invasive methods such as photo-identification 

studies, acoustic recordings, prey collection, focal follows, behavioral studies, aerial surveys, and 

thermal imaging. Several permits also include takes from more invasive techniques - biopsy 

sampling, tagging and breath sampling - where there is direct contact or potential for contact 

with the animals. NMFS worked with DFO and WDFW to develop a joint sampling plan for the 

biopsy program to coordinate all sampling efforts. Individuals were identified based on study 

objectives and samples are shared to support collaborative studies on genetics and contaminants. 

The addition of research impacts to the overall status of the Southern Resident is incrementally 

small, but was still a cause of concern. There were several factors that NMFS listed in the 

Biological Opinion (NMFS 2006d) that reduce the likely severity of the impacts, which we 

considered in making our determination: 

• Most of the research would involve non-invasive techniques; 
January 2008 II-122 NMFS 

• Fewer than 10 percent of the authorized takes for non-invasive research are likely 

to occur; 

• The permit conditions requiring coordination between permit holders would 

ensure that research will not be duplicative and that individual whales will not be subject 

to frequent taking; 

• Researchers are experienced operating vessels around killer whales and their permits 

require that their approaches be conducted in the manner that is least likely to disturb the 

animals; 

• The researchers would use a small number of vessels to conduct research activities and 

would rarely be conducting research simultaneously; and 

• There is a very small likelihood of ship strike from a research vessel. 

We also considered the following potential benefits from the proposed action in making 

our determination: 

• Continued population monitoring is necessary to provide new information on the 

status of Southern Residents; 

• Research activities will increase our knowledge and understanding of the threats 

to Southern Residents; 

• Research activities meet data needs as identified in the Recovery Plan; and 

• Research results will inform refining and prioritizing management actions. 

NMFS concluded that while issuing the permits was likely to adversely affect Southern 

Resident killer whales, the factors above reduced the likely severity of impacts, and that the 

proposed action was not likely to jeopardize the continued existence of the species. Any new 

permits or amendments to current permits will go through the same review process under NEPA 

and ESA. 

Cumulative Effects 

It is not clear, and may be impossible to quantify or model, which of the threats or combination 

of threats the Southern Resident killer whale population is subject to is the most important to 

address relative to recovery. It is likely that there is a cumulative effect, which could be more 

pronounced due to the small size of the Southern Resident population. Disruption of foraging 

behavior, either from vessel traffic and sound, or reduction of preferred prey species may 

introduce a stressor exacerbating the immunosuppressive effects of accumulated contaminants in 

the blubber and other tissues of each individual killer whale. Adequate nutrition is the basis for 

maintaining homeostasis, but if a killer whale is unable to eat for some period of time due to 

anthropogenic stressors, blubber stores become mobilized leading to higher contaminant blood 

levels and increased negative effects to health and/or fecundity. Multiple stressors can be far 

deadlier than one and laboratory experiments address only a small part of the complexity that 

occurs in nature (Sih et al. 2004). 

There are cumulative effects of chronic stressors within risk factors as well. The welldocumented effects of contamination by persistent organic pollutants on both immunologic 

dysfunction and reproductive abnormalities (Table 9) indicate they are linked. PCBs and other 
January 2008 II-123 NMFS 

oganochlorines affect both immune and reproductive systems. While it may not be possible to 

discern which effects have the most significant impact, it may be a combination of effects on 

both systems or there may be age and sex differences in whether immune or reproductive 

functions are most affected. Obviously, no breeding will occur if reproductive age killer whales 

die of disease due to reduced immune capacity. Reduced survival of neonates may also result 

from cumulative effects of contaminant loads, immune dysfunction and other outside stressors. 

Not all bacterial diseases cause death. Morbillivirus causes greater mortality than brucellosis, 

but a chronic brucellosis infection may cause stillborn calves and may eventually lead to death of 

the host due to secondary complications, generally related to an exhausted immune system. 

Some breeding can occur in spite of compromised immune systems. Polar bear studies (Skaare 

et al. 2002) indicate that birth rates and testosterone levels are reduced in contaminated animals. 

The immune system may become dysfunctional even at very low concentrations of contaminants 

and before other systems are compromised (Skaare et al. 2002). 

Individual or cumulative effects of the threats that may be driving the decline in Southern 

Residents may have reduced an already small population to a size that has additional risks. 

Small populations of animals can experience a host of problems that result in decreased per 

capita birth rates (i.e., inverse density dependence), a phenomenon known as the Allee effect. 

Under such conditions, factors such as loss of genetic variability, genetic drift, demographic 

fluctuations, and declining opportunities for cooperative behavioral interactions can work alone 

or additively to cause the eventual extinction of populations that have fallen below a critical 

density (Courchamp et al. 1999). A number of the killer whale communities in the northeastern 

Pacific contain fewer than 500 individuals, which is usually considered very small for discrete 

populations of most species (Barrett-Lennard and Ellis 2001, Frankham et al. 2002). 

Small population sizes often increase the likelihood of inbreeding, which can lead to the 

accumulation of deleterious alleles, thus causing decreased reproductive rates, reduced 

adaptability to environmental hazards such as disease and pollution, and other problems (BarrettLennard and Ellis 2001, Valsecchi et al. 2004). Such effects are highly variable among species, 

with some strongly impacted and others much less so. While the killer whale communities in the 

northeastern Pacific contain relatively small numbers of animals, these communities appear 

adept at avoiding matings between members of the same pod. This may be an adaptation to 

small group size and suggests that the populations are genetically more viable when small than 

those of most species (Barrett-Lennard and Ellis 2001). Recent analyses indicate that the 

Southern Residents are no less genetically diverse than other resident populations (Hoelzel 

2004). Thus, the Southern Residents may not have an immediate risk from inbreeding 

depression. However, because of the threats that may be responsible for its recent decline, this 

community now contains 40 reproductively active individuals. The deaths of several adult males 

in J and K pods between 1995 and 1998 left the females of L pod with only one fully mature 

adult male (J1) to mate with for several years. This situation could lead to a loss of genetic 

variability in the population (Center for Biological Diversity 2001, Krahn et al. 2004a), possibly 

resulting in inbreeding depression in the future. In recent years the dorsal fins of several males 

(K21, J26, and J27) have sprouted indicating they may have reached maturity. 
January 2008 II-124 NMFS 

Allee effects may influence small populations of killer whales in a variety of other ways that 

ultimately lower overall reproductive performance or survivorship. Because the species hunts 

cooperatively, declining group sizes may result in decreased foraging efficiency and energy 

acquisition per individual (e.g., Baird and Dill 1996). This may be particularly true for resident 

whales searching for aggregations of dispersed prey such as salmon. Changes in sex ratio and 

declines in various age cohorts may take on greater importance in small populations. For 

example, declines in numbers of breeding males, such as seen in the Southern Residents since 

1987, may increase the difficulty that sexually receptive females have in finding suitable mating 

partners. Resident killer whales display some of the most advanced social behavior of any nonhuman mammal, as evidenced by their highly stable social groupings, complex vocalization 

patterns, the presence of long-lived post-reproductive females, and behaviors such as cooperative 

foraging, food sharing, alloparental care, matriarchal leadership, and innovative learning. 

Maintenance of minimal group sizes is therefore probably necessary in preserving beneficial 

social interactions and in raising young.
January 2008 III-1 NMFS 

III. RECOVERY STRATEGY 

The overall goal of a recovery plan is to meet the recovery criteria and address threats to allow 

removal from the List of Endangered and Threatened Wildlife (List). In light of the small 

population size, recent declines, life history and potential threats, it is challenging to identify the 

most immediate needs for conservation and recovery of Southern Resident killer whales. For 

many listed species of marine mammals, there is a primary cause of direct mortality that can be 

attributed to a particular source (e.g., ship strikes, fishery interactions, or harvest), but this is not 

the case for Southern Residents. It is unknown which of the threats has caused the decline or 

may have the most significant impact on recovery of the population. It may be a combination of 

threats or the cumulative effects that are the problem. In addition, there are inherent risks for 

small populations. This plan addresses each of the potential threats based on current knowledge. 

 

To address the data gaps and uncertainties, there is an active research program underway. While 

researchers have been studying the Southern Residents for over 30 years, there has been 

increased interest and funding support in the last several years because of the status of the 

population. The research program administered by NOAA’s Northwest Fisheries Science Center 

has targeted specific questions that will assist in management and conservation. The research 

program is a long-term effort by many institutions and individuals and it will take time to 

discover answers. The management actions in this plan are based on the best available science 

and the current understanding of the threats. Because it is not possible at this time to identify 

exactly which actions will be required for recovery of the species, the plan represents an initial 

approach to begin addressing each of the threats. 

Research and monitoring are key components of the plan and they will make an adaptive 

management approach possible. Recovery of Southern Resident killer whales is a long-term 

cooperative effort that will evolve as more is learned from research and monitoring. Continued 

monitoring of the status of the population will assist in evaluating the effectiveness of 

management actions. Research will help refine actions that have been implemented and identify 

new actions to fill data gaps about the threats. An adaptive management approach will also 

provide information to adjust priorities as conservation progresses and to modify and update the 

plan. 

To carry out the adaptive management process as described in the plan, NMFS will hold ad-hoc 

workshops to gather input on specific actions to be implemented under the Final Recovery Plan. 

While some of the actions in the Recovery Plan are general and high level at this time, we 

envision using new information and public input to develop more specific actions based on the 

available science. Individuals, stakeholder groups and managers with interest, expertise and 

jurisdiction regarding specific threats can provide input to assist NMFS with integrating the 

latest research information and refining and prioritizing management actions. NMFS will 

develop topic-specific implementation plans which will receive public review and can be 

appended to the Recovery Plan or incorporated during periodic reviews of the plan. NMFS will 

also coordinate these activities with other initiatives such as salmon recovery and the Puget 

Sound Partnership. 
January 2008 III-2 NMFS 

The 2004 BRT identified the factors that currently pose a risk for Southern Residents and 

discussed whether these might continue in the future. Important concerns included (1) 

reductions in quantity or quality of prey, (2) high levels of organochlorine contaminants and 

increasing levels of many “emerging” contaminants (e.g., brominated flame retardants), putting 

Southern Residents at risk for serious chronic effects similar to those demonstrated for other 

marine mammals (e.g., immune and reproductive system dysfunction), (3) sound and disturbance 

from vessel traffic, and (4) oil spills. The Recovery Program includes measures to address the 

threats that have been identified, as well as other important efforts such as education and 

outreach, response to stranded killer whales, and coordination and cooperation. 
January 2008 IV-1 NMFS 

IV. RECOVERY GOALS, OBJECTIVES AND CRITERIA 

When a species is listed as threatened or endangered under the ESA, one of the three specific 

statutory requirements, set forth in section 4(f)(1)(B) of the ESA, is that each recovery plan 

incorporate objective measurable criteria which when met would result in a determination, in 

accordance with the provisions of this section, that the species be removed from the list. 

Recovery Goals 

The ultimate goal of this recovery plan is to achieve the recovery of the Southern Resident killer 

whale distinct population segment (DPS) and its ecosystem to a level sufficient to warrant its 

removal from the Federal List of Endangered and Threatened Wildlife and Plants under the ESA. 

The intermediate goal is to reclassify the DPS from endangered to threatened. 

To remove the Southern Residents from the federal List of Endangered and Threatened Wildlife 

and Plants under the ESA, NMFS must determine that they are not “likely to become endangered 

in the foreseeable future throughout all or a significant portion of its range.” To downlist the 

Southern Resident DPS from endangered to threatened, NMFS must determine that it is no 

longer “in danger of extinction throughout all or a significant portion of its range.” These 

determinations include consideration of the population’s abundance and demographic 

parameters, taken together with threats (as identified under the ESA section 4(a)(1) listing factors 

considered for listing.) 

Recovery Criteria - Background 

A decision to list or delist a species focuses on its biological performance and the threats to its 

existence. Our approach to developing objective measurable criteria focuses on two areas: 

performance of the population over a meaningful period of time (biological criteria) and the 

reduction of threats which may have caused the population decline or that limit recovery (threats 

criteria). The following sections provide the basis for the criteria and set out objective, 

measurable criteria for delisting and downlisting the Southern Resident DPS. 

Biological Criteria 

Population parameters such as abundance, growth rate, and demographics (e.g., age and sex 

ratios and distribution of individuals among different subpopulations) indicate the status of the 

species and were all considered during the decision to list. The biological criteria described 

below are designed to measure these parameters. The criteria also take into consideration 

representation, resiliency and redundancy. 

• Representation involves conserving the breadth of the genetic makeup of the species to 

conserve its adaptive capabilities, 

• Resiliency involves ensuring that each population is sufficiently large to withstand stochastic 

events, and 

• Redundancy involves ensuring a sufficient number of populations to provide a margin of 

safety for the species to withstand catastrophic events. 
January 2008 IV-2 NMFS 

The task in making a listing or delisting determination is to project the future performance of a 

biological unit, in this case a DPS. For us to project long-term sustainability of Southern 

Resident killer whales, we must see (1) positive population growth (i.e., more individuals 

entering the population than being removed) over a time frame long enough to encompass 

expected environmental and stochastic variability, and (2) an adequate number of individuals of 

both sexes and mixed ages, distributed among the three pods, to make it unlikely the population 

will fall below a threshold at which it is in danger of extinction during inevitable periods of low 

survival or productivity. We developed the following biological criteria using life history 

information from the Southern Resident killer whale status reviews and population viability 

analyses (Krahn et al. 2002, 2004a). To gauge whether the biological parameters were realistic, 

we considered them in light of the performance of the Northern Resident killer whale population, 

which is listed as threatened by Canada, but is more robust than the Southern Resident 

population with a larger number of animals, matrilines, and clans. We also considered the 

Canadian draft recovery strategy for Southern Residents (Killer Whale Recovery Team 2005) 

and the proposed recovery plan for Steller sea lions (Eumetopias jubatus) recently published by 

NMFS (NMFS 2006e). In addition, we relied on the NMFS’ interim recovery planning 

guidance. 

Researchers have documented periods of variable growth and decline in the Southern Resident 

population since 1974, when annual censuses began after the end of live captures for public 

display ended. Krahn et al. (2004a) examined growth patterns in the population and found that it 

increased from 71 to 83 whales between 1974 and 2003 at a mean annual rate of 0.4 percent. 

Within this 29-year trend, there were fluctuating periods of growth and decline (see Status of 

Southern Resident Killer Whales). From 1974 to 1980 the population increased at a mean rate of 

2.6 percent per year, then declined at 2.8 percent per year until 1984, then increased at 2.3 

percent per year until 1996, declined at 4.3 percent per year through 2001 and has increased by 

2.5 percent per year in 2002 and 2003. For comparison, the neighboring Northern Resident 

population increased from 120 to 205 whales over the same time frame. From 1974 to 1991 the 

population grew at approximately 3.4 percent per year. From 1991 to 1997 population growth 

slowed to 3.0 percent per year resulting in a peak population of 220 animals (Killer Whale 

Recovery Team 2005). This was followed by a 2.2 percent annual decline from 1997 to 2003. 

The population trends of both the southern and northern communities are shown in Figures 8 and 

14. 

 

We considered whether the performance of the Northern Residents serves as an appropriate 

model for growth in a recovering killer whale population. For example, the Steller sea lion 

recovery plan relies on the performance of the eastern stock, which had sustained growth over an 

extended period, to set a target growth rate for the western stock. The Southern Resident 

population, however, has never shown a growth rate as high as the Northern Residents. The 

Southern Residents grew at mean yearly rates of 2.6 percent for the six-year period from 1974-

1980 and 2.3 percent during the 12-year period from 1984 to 1996. In recognition that the 

population has shown the ability to sustain a 2.3 percent rate of growth in the past we believe it 

to be the most appropriate growth measure for this population. 

The longer a population sustains a positive growth rate, the more confident we can be that the 

population will continue to grow and become stable in the future and is resilient to stochastic 
January 2008 IV-3 NMFS 

events. Selecting an appropriate time frame depends on the past performance of the population 

and the environmental and stochastic factors affecting it. For example, the sea lion recovery plan 

adopts a time scale based on the Pacific Decadal Oscillation, which appears to have ecosystemscale effects influencing the performance of Steller sea lions (NMFS 2006e). If average sea lion 

population growth remains positive over more than one decadal oscillation (i.e., 15 years) 

confidence grows that the threats to the population have been addressed and the population is 

sufficiently healthy and resilient to sustain itself regardless of environmental variability. If the 

positive growth rate is robust and is sustained over several decadal oscillations (i.e., 30 years) 

then the population can be considered for delisting. 

We considered two factors in selecting a time frame for Southern Resident growth. The first is 

the fluctuating growth rates described above, and the uncertainty about their cause(s). Both of 

these concerns warrant a conservative time frame. The second is evidence that environmental 

fluctuations may be affecting Southern Resident survival. Krahn et al. (2002) looked at whether 

the North Pacific Decadal Oscillation may be influencing survival, but preliminary results did 

not support this hypothesis. Elements of their population viability analysis did reveal, however, 

a cyclic pattern in survival that was not random. Krahn et al. (2002 and 2004a) reported that the 

population has experienced an overall decline in survival since the collection of census data 

began in 1974, but the decline has not been linear. A “best fit” analysis for crude survival over 

all age and sex classes showed alternating periods of high and low survival forming a 14-year 

cycle, with seven years of high survival followed by seven years of low survival (Krahn et al. 

2004a and Figures 9, 10, and 11). The analysis did not establish any causal relationships 

between potential contributing factors and changes in survival rates, but did show that all age and 

sex classes were affected, suggesting external influences. 

 

The 14-year cycle of higher and lower survival provides the best information for selecting a time 

period that will encompass expected environmental variability. In the future, a specific variance 

criteria or coefficient of variation criterion could also be developed. The 14-year time period 

also allows sufficient time for calves born at the beginning of the time period to achieve sexual 

maturity. As in the sea lion model, sustained population growth over the 14-year up and down 

cycle may provide some confidence that growth will continue into the future. Population growth 

sustained over the span of more than one cycle would indicate that the population is resilient and 

no longer in danger of extinction. 

Threats Criteria 

The threats criteria are designed to evaluate the five statutory listing factors (see Potential 

Threats to Southern Resident Killer Whales) described in the ESA listing determination for the 

species. These same factors must be considered in delisting, with objectives related to each factor 

included as part of the recovery criteria. 
January 2008 IV-4 NMFS 

Delisting Criteria 

Biological criteria 

To remove the Southern Resident DPS from the Federal List of Endangered and Threatened 

Wildlife and Plants under the ESA, NMFS must determine that the species is neither in danger of 

extinction nor likely to become so “in the foreseeable future throughout all or a significant 

portion of its range.” To be considered for delisting, the following biological criteria must be 

met. 

1.The Southern Resident DPS has exhibited an increasing population trend at an average growth 

rate of 2.3 percent per year for 28 years (two full cycles). 

This criterion could be achieved under a variety of scenarios depending on when the time period 

starts. For example, beginning in 2001, with 81 animals and estimated average annual growth of 

2.3 percent over the succeeding 28 years, would result in a population of about 155 animals in 

2029. 

2. Available information on social structure, calf recruitment, survival, population age structure, 

and gender ratios of the Southern Resident DPS are consistent with the trend observed under 

Criterion 1 above and are indicative of an increasing or stable population. 

Quantitative measures for population parameters include: 

• Representation from at least three pods, 

• More than two reproductive age males in each pod or information that fewer males are 

sufficient, 

• A ratio of juveniles, adults, post-reproductive, male and female individuals similar to the 

Northern Resident population model [i.e., 47 percent juveniles, 24 percent reproductive 

females, 11 percent post-reproductive females, and 18 percent adult males] (Olesiuk et al. 

2005), 

• Adequate inter-birth intervals to allow for population growth, 

• No significant increase in mortality rate for any sex or age class. 

Our confidence in the continued persistence of the Southern Residents depends not just on a 

demonstrated positive growth rate or an absolute number of animals, but also on the presence of 

an adequate number of individuals in all sex and age categories, distributed among the three 

pods, to ensure the population will not fall below a threshold leading to extinction during 

inevitable periods of low survival or productivity. At the time of listing, NMFS considered 

several demographic conditions that caused concern, including the small number of breeding 

males, possible reduced fecundity, and sub-adult survivorship in L pod. NMFS also considered 

the small population size which could make the population vulnerable to inbreeding. Thus, in 

addition to the criterion of a positive growth rate, we have developed a second set of criteria 

addressing demographic conditions of the population. 

Survival rates, fecundity, calving interval, and sex and age class structure are among the useful 

demographic parameters for evaluating the status of a species. However, specific measures of 

these parameters have not been quantified for any stable non-threatened killer whale population 
January 2008 IV-5 NMFS 

against which the Southern Residents can be compared. One possible exception is the Northern 

Resident population, which has exhibited long-term growth and achieved some level of stability 

in recent years. Olesiuk et al. (2005) developed population models for Northern Residents 

during separate periods of unrestrained growth and of no net change. No major differences in 

reproductive parameters or the predicted sex and age structure existed between the two periods 

and their model may reflect the fundamental dynamics of a population under average conditions. 

Thus, when the first delisting criterion has been achieved for the Southern Resident DPS, 

comparing its population parameters to those of the Northern Residents may provide a suitable 

model for determining recovery. 

Resident killer whale populations exhibit a unique social structure based on stable matrilines and 

somewhat more flexible groupings of closely related matrilines (pods). Based on studies of 

Northern Residents, breeding outside of closely related matrilines (i.e., between pods) appears to 

be the mechanism reducing the potentially detrimental effects of inbreeding within these small 

populations. For the Southern Resident DPS, there is concern that the number of adult males, 

particularly in J and K pods, is very low. A population with three pods and at least two adult 

males in each pod would provide greater breeding opportunities outside of closely related 

individuals and expand genetic representation. In addition, recent studies (Hauser 2006) indicate 

that while the three pods largely share the same core areas, there are pod differences and each 

pod uses additional unique areas. Continued presence of all three pods provides for some level 

of redundancy. 

The current inter-calf interval among Southern Resident females appears to differ among pods 

and is longer than in the Northern Residents. In addition, there are Southern Resident females of 

reproductive age that have not produced viable calves. Both factors are relevant to the future 

reproductive capacity of the population, although we are currently unable to quantify target 

values for either parameter to achieve delisting. Generally, an inter-birth interval that is closer to 

that of the Northern Residents and an increase in the number of reproductive age females that are 

producing calves, would contribute to a positive growth trend. The presence of postreproductive females who may possess important cultural knowledge, is another factor that may 

be important to the viability of killer whale populations, although we are uncertain how to 

quantify their contribution or representation. The implications of these and other factors are not 

well understood, but need to be taken into consideration when evaluating whether there is a 

balanced population age structure and gender ratio that supports adequate replacement and longterm maintenance of the population. The biological criteria should be applied to ensure that the 

Southern Resident population is not likely to become endangered in the foreseeable future. 
January 2008 IV-6 NMFS 

Threats Criteria 

The threats criteria are designed to evaluate the ESA section 4(a)(1) listing factors as they relate 

to the Southern Resident DPS (see Potential Threats to Southern Resident Killer Whales). The 

same statutory factors must be considered in delisting as in listing, with objectives related to each 

factor included as part of the recovery criteria. 

Factor A: The present or threatened destruction, modification, or curtailment of a species’ 

habitat or range. 

Objective: Ensure adequate habitat to support a recovered population of Southern Resident killer 

whales. Habitat needs include sufficient quantity, quality, and accessibility of prey species. 

 

Criteria: 

A1. Observations indicating that lack of prey is not a source of mortality or a factor limiting 

recovery of Southern Residents. Consistent observations or measurements of good body 

condition in a significant number of individuals, and no or limited observations of reduced 

feeding behavior or recovery of emaciated stranded animals. 

A2. Sufficient knowledge of the foraging ecology of Southern Residents to determine that 

established fishery management regimes are not likely to limit the recovery of the whales. 

a. Fisheries management programs that adequately account for predation by marine 

mammal populations when determining harvest limits, hatchery practices, and other 

parameters. 

b. Fisheries management programs that are consistent with recovery of salmon stocks and 

that support sustainable salmon populations. 

A3. Contaminant levels in killer whales, prey species or surrogate marine mammal populations 

in the greater Puget Sound area that indicate a reduction or slowing of accumulation of 

legacy contaminants, such as PCBs and DDTs, and information on current baseline levels of 

emerging contaminants. This could include data showing that overall contaminant levels in 

the population are decreasing or accumulation is slowing, or information that younger 

animals have a proportionally reduced contaminant load. A decrease in the number of 

contaminated sites in Puget Sound would also indicate a reduction in contaminants in a 

portion of the habitat of Southern Resident killer whales. 

A4. Management actions in place to reduce vessel disturbance, auditory masking and risk of ship 

strikes. Voluntary guidelines, education programs and prohibitions under the MMPA, 

currently in place, should have remained in place. Regulations and/or protected areas should 

have been considered and put in place if it is determined that they will provide additional 

reduction in vessel effects. 
January 2008 IV-7 NMFS 

Factor B: Overutilization for commercial, recreational, or educational purposes 

Objective: Ensure commercial, recreational or educational activities are not affecting the 

recovery of Southern Residents, including vessel effects from whale watching. 

Criteria: 

B1. Reduction in impacts from commercial and recreational whale watching, or evidence that 

this activity does not cause population level effects. Reductions may be measured through 

fewer incidents reported in the vicinity of whales, increased audiences for education 

programs and establishment of regulations or protected areas if needed (see Criterion A4). 

B2. No permanent removals of individual Southern Residents from their habitat, including live 

capture for public display, and any incidental takes associated with fisheries or other 

commercial or recreational activities have been addressed through regulatory mechanisms to 

insure against recurrence. 

Factor C: Disease or predation 

Objective: Ensure that diseases and their effects on reproduction and survival are not a threat to 

the sustainability of the Southern Resident DPS. 

Criteria: 

C1. Sufficient knowledge to determine that disease is not limiting the recovery of Southern 

Resident killer whales. 

Factor D: The inadequacy of existing regulatory mechanisms 

Objective: Ensure that regulatory mechanisms other than the ESA are adequate to ensure that 

threats to the sustainability of the DPS do not recur. 

Criteria: 

D1. Baseline conditions of emerging contaminants, such as PBDEs, in Southern Residents, prey 

species, and surrogate marine mammal populations in the greater Puget Sound area have 

been determined, and trends and other information indicates that contaminant inputs into the 

Southern Residents’ habitat are not limiting recovery and sustainability of Southern 

Residents. 

 

D2. Regulations are in place to limit the introduction of harmful contaminants, and there is 

evidence of decreasing levels of contaminants detected in Southern Residents, prey species, 

or surrogate marine mammal populations, or evidence that the current level of contaminants 

causes no harm to the whales. 

D3. There is a reduction in impacts from commercial and recreational whale watching, or 

evidence that this activity does not cause population level effects. Reductions may be 

measured through fewer incidents reported in the vicinity of whales, increased audiences for 

education programs and establishing regulations/protected areas if needed (see Criterion A4). 
January 2008 IV-8 NMFS 

Factor E: Other natural or manmade factors affecting its continued existence. 

Objective: Maintain protection from oil spills and improve oil spill response techniques for 

killer whales. Continue monitoring the population and identify any new natural or manmade 

factors affecting the recovery of Southern Residents. 

Criteria: 

E1. Effective oil spill response plan is in place for killer whales, as part of the wildlife branch 

section of the NWACP. 

E2. Effective oil spill prevention plans are in place that are no less protective than those in place 

at time of listing. 

E3. An annual census is in place which has and will continue to assess the population status of 

Southern Residents. 

E4. Knowledge of distribution, habitat use and potential risks to the population in the coastal 

portion of the range of Southern Residents has been increased and determined not to affect 

the sustainability of the population. 

Downlisting Criteria 

Downlisting criteria are an intermediate goal that may be achieved prior to meeting the criteria 

for delisting. To downlist the Southern Resident DPS from endangered to threatened, NMFS 

must determine that the species abundance and population parameters, taken together with 

threats (as identified under the ESA 4(a)(1) listing factors considered for listing), no longer 

render the species “in danger of extinction throughout all or a significant portion of its range.” 

As a threatened species, however, the Southern Resident DPS would still be considered “likely to 

become endangered in the foreseeable future throughout all or a significant portion of its range.” 

In our listing determination we explained that we listed the Southern Residents as endangered 

rather than threatened: 

The peer reviewer and others highlight the ongoing and potentially changing nature of 

pervasive threats, in particular, disturbance from vessels, the persistence of legacy toxins 

and the addition of new ones into the whales’ environment, and the potential limits on 

prey availability (primarily salmon) given uncertain future ocean conditions. The peer 

reviewer correctly observed that these risks are unlikely to decline (and are likely to 

increase) in the future. The small number of reproductive age males and high mortality 

rates for this group are also a concern. And while the population of Southern Residents is 

not naturally large, the intensity of the threats is increased by the small number of 

animals currently in the population. The combination of factors responsible for past 

population declines are unclear, may continue to persist and could worsen before 

conservation actions are successful, which could potentially preclude a substantial 

population increase. 

To establish appropriate downlisting criteria for the Southern Resident DPS, we used many of 

the same assumptions and considerations described above for delisting criteria. 
January 2008 IV-9 NMFS 

Biological Criteria 

To be considered for downlisting, the following criteria must be met. 

1. The Southern Resident DPS has exhibited an increasing population trend at an average 

growth rate of 2.3 percent per year for 14 years (one cycle). 

Sustained growth at a level the Southern Residents have achieved in the past for a period 

covering one 14-year cycle of high and low mortality will guard against a steep decline or 

increased mortality and provide some indication that the Southern Residents are resilient to 

stochastic events. This criterion could be achieved under a variety of scenarios and depends on 

when the time period begins. For example, if beginning in 2001, with 81 animals and estimated 

average growth of 2.3 percent over the next 14 years, the population would have about 113 

animals in 2015. The Southern Residents came close to achieving this criteria during a 12-year 

period from 1984-1996, when the population grew at an average of 2.3 percent per year. 

2. Available information on social structure and population structure are consistent with the 

trend observed under Criterion 1 above, and they are indicative of an increasing or stable 

population. 

Quantitative measures for some population parameters: 

• Representation from at least three pods, and 

• At least two reproductive age males in each pod. 

Our confidence in the continued persistence of the Southern Residents depends not just on a 

demonstrated positive growth rate or an absolute number of animals, but also the presence of an 

adequate population structure to ensure the population will not fall below a threshold leading to 

extinction during inevitable periods of low survival or productivity. Progress toward a stable 

population structure, as described under Criterion 2 of the delisting criteria, will support the 

increasing population trend above. 

Threats Criteria 

To be considered for downlisting from endangered to threatened status, we must have some 

indication that we are making progress toward filling the data gaps on threats to Southern 

Resident killer whales. Intermediate steps to evaluate, prioritize, and address the threats along 

with a positive population trend will ensure that the Southern Resident DPS is no longer in 

danger of extinction. The endangered listing and the proposal to list the Southern Resident DPS 

as threatened included threats under the five listing factors and concerns about the DPS. The 

same factors must be considered in determining that the level of threat has been addressed to 

downlist from endangered to threatened. 

Factor A: The present or threatened destruction, modification, or curtailment of a species’ 

habitat or range. 

Objective: Ensure adequate habitat to support a recovering population of Southern Resident 

killer whales. Habitat needs include sufficient quantity, quality, and accessibility of prey 

species. 

 
January 2008 IV-10 NMFS 

Criteria: 

A1. Recovery or management plans for listed salmonids (and other prey species as appropriate) 

are in place to restore them to the point that they are self-sustaining members of their 

ecosystems. 

A2. Research is underway to increase knowledge of the foraging ecology of Southern Residents 

and inform fishery management programs that determine harvest limits, hatchery practices 

and evaluate consistency with recovery of salmon stocks and Southern Resident killer 

whales. 

A3. Baseline information on legacy and emerging contaminant levels in killer whales, prey 

species or surrogate marine mammal populations in the greater Puget Sound area is available 

to enable future monitoring of trends in contaminant levels in the whales and inputs into their 

habitat. 

A4. Voluntary guidelines, education programs and prohibitions under the MMPA to reduce 

vessel disturbance, auditory masking and risk of ship strikes, currently in place, should have 

remained in place. 

Factor B: Overutilization for commercial, recreational, or educational purposes 

Objective: Ensure commercial, recreational or educational activities are not affecting the 

recovery of Southern Residents, including vessel effects from whale watching. 

Criteria: 

B1. No permanent removals of individual Southern Residents from their habitat, including live 

capture for public display, and there is sufficient information on any incidental takes 

associated with fisheries or other commercial or recreational activities to inform management 

programs responsible for addressing incidental takes. 

Factor C: Disease or predation 

Objective: Ensure that diseases and their effects on reproduction and survival are not a threat to 

the sustainability of the Southern Resident DPS. 

Criteria: 

C1. Sufficient knowledge to determine that disease is not limiting the recovery of Southern 

Resident killer whales. 

Factor D: The inadequacy of existing regulatory mechanisms 

Objective: Ensure that regulatory mechanisms other than the ESA are adequate to ensure that no 

threats to the sustainability of the DPS recur. 

Criteria: 

D1. Regulations in place to limit the introduction of harmful contaminants are under evaluation 

to determine if they are sufficiently protective for Southern Residents. 
January 2008 IV-11 NMFS 

D2. Guidelines and regulations in place to reduce potential impacts from vessels have been 

evaluated to determine if additional regulations/protected areas are needed (see Criterion A4) 

Factor E: Other natural or manmade factors affecting its continued existence. 

Objective: Maintain protection from oil spills and improve oil spill response techniques for 

killer whales. Continue monitoring the population and identify any new natural or manmade 

factors affecting the recovery of Southern Residents. 

Criteria: 

E1. Effective oil spill prevention plans are in place that are no less protective than those in place 

at time of listing. 

E2. An annual census is in place which has and will continue to assess the population status of 

Southern Residents. 

E3. An effective research program is in place to evaluate risks to Southern Resident killer 

whales. 

E4. Research on the distribution, habitat use and potential risks to the population in the coastal 

portion of the range of Southern Residents is underway. 

 
January 2008 V-1 NMFS 

V. RECOVERY PROGRAM 

Below is an outline of recovery measures, and research and monitoring actions needed to achieve 

the plan’s goals and objectives. First is a Recovery Action Outline which lists the actions in 

outline format, followed by a Recovery Action Narrative which includes descriptions of all of 

the actions. These actions are intended to reduce threats and restore the Southern Resident killer 

whale population to long-term sustainability. The outline includes management and coordination 

actions, as well as research and monitoring actions to conserve Southern Resident killer whales. 

Ongoing programs in place to address killer whale conservation are also listed in the narratives. 

The narratives are intended to provide guidance to resource managers, stakeholders, industry, 

and the public. Parties with authority, responsibility, or expressed interest to implement a 

specific conservation action are identified in the Implementation Schedule. Note that the ranking 

of activities listed below does not imply an order of importance. The priority of each action, plus 

a cost and timeline for completion, are in the Implementation Schedule. Actions that will benefit 

from additional research are cross referenced with the Research and Monitoring section. 

A. Recovery Action Outline 

MANAGEMENT MEASURES 

1. Protect the Southern Resident killer whale population from factors that may be contributing 

to its decline or reducing its ability to recover. 

1.1 Rebuild depleted populations of salmon and other prey to ensure an adequate food base 

for recovery of the Southern Residents. 

1.1.1 Support salmon restoration efforts in the region. 

1.1.1.1 Habitat management. 

1.1.1.2 Harvest management. 

1.1.1.3 Hatchery management. 

1.1.2 Support regional restoration efforts for other prey species. 

1.1.3 Use NMFS authorities under the ESA and the MSFCMA to protect prey habitat, 

regulate harvest, and operate hatcheries. 

1.2 Minimize pollution and chemical contamination in Southern Resident habitats. 

1.2.1 Clean up contaminated sites and sediments. 

1.2.1.1 Identify and prioritize specific sites in need of cleanup. 

1.2.1.2 Remediate sites in need of cleanup. 
January 2008 V-2 NMFS 

1.2.2 Minimize continuing inputs of contaminants into the environment. 

1.2.2.1 Minimize the levels of harmful contaminants discharged by industrial, 

municipal, and other point sources of pollution. 

1.2.2.2 Minimize the levels of harmful contaminants released by non-point sources 

of pollution. 

1.2.2.3 Reduce impacts to Southern Resident killer whales from emerging 

contaminants. 

1.2.3 Minimize contamination in prey. 

 

1.3 Minimize disturbance of Southern Resident killer whales from vessels. 

1.3.1 Monitor vessel activity around whales. 

1.3.1.1 Expand efforts to monitor commercial and recreational whale-watching 

vessels. 

1.3.1.2 Evaluate the relative importance of shipping, ferry, fishing, research, military, 

and other vessel traffic to disturbance of killer whales. 

1.3.2 Continue to evaluate and improve voluntary whale-watching guidelines. 

1.3.3 Evaluate the need to establish regulations regarding vessel activity in the vicinity of 

killer whales. 

1.3.4 Evaluate the need to establish areas with restrictions on vessel traffic. 

 

2. Protect Southern Resident killer whales from additional threats that may cause disturbance, 

injury, or mortality, or impact habitat. 

2.1 Minimize the risk of oil spills. 

2.1.1 Prevent oil spills. 

2.1.2 Prepare for and respond to oil spills to minimize their effects on Southern Resident 

killer whales. 

2.1.3 Develop strategies to deter killer whales from entering spilled oil. 

2.2 Monitor and minimize the risk of infectious diseases in Southern Resident whales. 

2.3 Continue to use agency coordination and established MMPA mechanisms, such as 

incidental harassment authorizations, to minimize any potential impacts from human 
January 2008 V-3 NMFS 

activities involving acoustic sources, including Navy tactical sonar, seismic exploration, 

in-water construction, and other sources. 

 

2.4 Reduce potential for impacts of invasive species in Southern Resident habitats. 

2.4.1 Prevent the introduction and spread of invasive species. 

2.4.2 Eradicate existing populations of invasive species. 

3. Develop public information and education programs. 

3.1 Enhance public awareness of Southern Resident status and threats. 

3.1.1 Exhibits and programs at local museums, aquaria, parks, and other locations. 

3.1.2 School programs. 

3.1.3 Naturalist programs. 

3.1.4 Research programs. 

3.2 Expand information and education programs to reduce direct vessel interactions with 

Southern Resident killer whales. 

3.2.1 Expand the on-water educational efforts of the Soundwatch Boater Education 

Program, Marine Mammal Monitoring Project (M3), Straitwatch, and enforcement 

agencies. 

3.2.2 Outreach to private boaters. 

3.2.3 Encourage land-based viewing of killer whales. 

3.3 Educate the public on positive actions that they can take to improve environmental 

conditions for Southern Resident killer whales. 

3.4 Solicit the public’s assistance in finding killer whales. 

3.4.1 Solicit reports of killer whale sightings. 

3.4.2 Solicit reports of killer whale strandings from the public. 

4. Respond to killer whales that are stranded, sick, injured, isolated, pose a threat to the public, 

or exhibit nuisance behaviors. 

4.1 Manage atypical individual Southern Residents. 
January 2008 V-4 NMFS 

4.2 Respond to strandings of killer whales. 

4.2.1 Develop protocols for responding to stranded killer whales. 

4.2.2 Respond to live-stranded killer whales. 

4.2.3 Investigate strandings of dead killer whales. 

4.3 Respond to future resource conflicts between the Southern Residents and humans. 

5. Transboundary and interagency coordination and cooperation. 

5.1 Cooperative research and monitoring. 

5.1.1 Population monitoring and research. 

5.1.2 Stranding response coordination. 

5.2 Complementary recovery planning. 

5.2.1 Subject plans to periodic review. 

5.2.2 Encourage public participation. 

5.3 Inter-jurisdictional enforcement cooperation and coordination. 

RESEARCH AND MONITORING 

A. Monitor status and trends of the Southern Resident killer whale population. 

A.1 Continue the annual population census. 

A.2 Maintain a current photo-identification catalog for the Southern Residents and expert 

staff able to photographically identify the whales. 

A.3 Standardize the results of annual population surveys. 

B. Conduct research to facilitate and enhance recovery efforts for Southern Resident killer 

whales. 

B.1 Determine the distribution and habitat use of the Southern Residents. 

B.1.1 Determine distribution and movements in outer coastal waters. 

B.1.2 Improve knowledge of distribution and movements in the Georgia Basin and 

Puget Sound. 

B.2 Investigate the diet of the Southern Residents. 
January 2008 V-5 NMFS 

B.2.1 Determine the diet of the Southern Residents. 

B.2.2 Determine the importance of specific prey populations to the diet. 

B.2.3 Determine the extent of feeding on hatchery fish. 

B.3 Analyze the demographics of the Southern Residents. 

B.3.1 Determine mortality rates and potential causes of mortality. 

B.3.2 Evaluate population growth rates and survival patterns.

B.3.3 Evaluate population structure. 

B.3.4 Evaluate changes in social structure. 

B.4 Investigate the health and physiology of the Southern Residents. 

B.4.1 Assess the health of population members. 

B.4.2 Assess individual growth rates. 

B.4.3 Determine metabolic rates and energy requirements. 

B.5 Investigate the behavior of the Southern Residents. 

B.6 Assess threats to the Southern Residents. 

B.6.1 Assess the effects of changes in prey populations. 

B.6.1.1 Determine historical changes in prey abundance and distribution, and their 

effects on Southern Resident population dynamics. 

B.6.1.2 Assess changes in prey quality and their effects on Southern Resident 

population dynamics. 

B.6.1.3 Determine whether the Southern Residents are limited by critical periods 

of scarce food resources. 

B.6.1.4 Assess threats to prey populations of the Southern Residents. 

B.6.2 Assess the effects of human-generated marine sound and vessel traffic. 

 

B.6.2.1 Determine vessel characteristics that affect the Southern Residents. 

B.6.2.2 Determine the extent that vessels disturb or harm the Southern Residents. 
January 2008 V-6 NMFS 

B.6.2.3 Determine the extent that other sources of sound disturb or harm the 

Southern Residents. 

B.6.2.4 Determine the acoustic environment of the Southern Residents. 

B.6.2.5 Determine the hearing capabilities and vocalization behavior of the 

Southern Residents near sound sources. 

B.6.2.6 Assess the effects of human-generated marine noise on Southern Resident 

prey. 

B.6.3 Assess the effects of contaminants. 

B.6.3.1 Determine contaminant levels in the Southern Residents and other killer 

whale communities in the northeastern Pacific. 

B.6.3.2 Determine contaminant levels in Southern Resident prey. 

B.6.3.3 Determine the sources of contaminants entering Southern Resident prey. 

B.6.3.4 Determine the effects of elevated contaminant levels on survival, 

physiology, and reproduction in the Southern Residents. 

B.6.4 Determine risks from other human-related activities. 

B.6.5 Evaluate the potential for disease. 

B.7 Identify important habitats for the Southern Residents. 

B.8 Determine the effects of variable oceanographic conditions on the Southern Residents 

and their prey. 

B.9 Determine genetic relationships. 

B.9.1 Determine paternity patterns in the Southern Residents. 

B.9.2 Determine the risk of inbreeding. 

B.9.3 Determine historical population size. 

 

B.9.4 Determine genetic relationships among populations. 

B.9.5 Expand the number of genetic samples available for study. 

B.10 Improve research techniques and technology. 

B.11 Research support and coordination 
January 2008 V-7 NMFS 

B. Recovery Action Narrative 

MANAGEMENT MEASURES 

1. Protect the Southern Resident killer whale population from factors that may be contributing 

to its decline or reducing its ability to recover. 

Throughout the process to list the Southern Resident DPS as endangered, NMFS has received 

information on factors that may be contributing to the population decline. The primary 

potential risk factors for Southern Residents are prey availability; pollution and related 

effects; and ambient noise, discrete sounds from individual sources, and stress associated 

with vessel activities. In 2003 and 2004, NMFS held a series of workshops focusing on these 

topics to identify management actions to consider in this plan. While some actions can be 

taken immediately based on current knowledge, others will require considerable research 

before effective management actions can be developed and implemented. 

1.1 Rebuild depleted populations of salmon and other prey to ensure an adequate food base 

for recovery of the Southern Residents. 

The Southern Residents have experienced significant changes in food availability during 

the past 150 years because of human impacts on prey species. Widespread reductions in 

salmon abundance from British Columbia to California during this period have likely had 

the greatest effects on the whales. Wild salmon have declined primarily due to 

degradation of aquatic ecosystems resulting from modern land use changes (e.g., 

agricultural, urban, industrial, and hydropower development, and resource extraction), 

overharvesting, and hatchery production. Comprehensive reviews of the status of wild 

salmonid populations in Washington, Oregon, Idaho, and California have resulted in the 

listing of 26 evolutionarily significant units (ESUs) of Pacific salmon and steelhead as 

endangered or threatened under the ESA since the 1990s. Additionally, many non-listed 

populations are depressed and also in need of restoration. Additional information 

regarding the specific interactions between salmon and killer whales (Tasks B.1, B.2) 

will help identify priorities and provide support for ongoing salmon recovery efforts. A 

number of non-salmonid prey species (e.g., rockfish, lingcod, herring, Pacific halibut) 

have also declined and are the targets of regional restoration efforts, such as the Puget 

Sound Nearshore Ecosystem Restoration Project. 

1.1.1 Support salmon restoration efforts in the region. 

Because of inadequate information on specific salmon stocks utilized by the 

Southern Residents, both historically and currently, it is appropriate at this stage to 

support salmon restoration efforts on a region-wide basis, with preliminary 

emphasis placed on river basins that are or have the potential to be significant 

producers of Chinook and other salmonids. Successful salmon recovery programs 

must be broadly based and address the complex issues of land-use practices, 

commerce and energy demands, salmon harvest management, and hatchery 

management. Recovery efforts for listed ESUs of salmon are already underway or 

are being planned across the region through numerous programs involving federal, 

state, provincial, tribal, and local governments and private conservation groups. 
January 2008 V-8 NMFS 

These efforts will benefit the restoration of many non-listed salmonid populations 

as well. In Washington State, six major initiatives are taking place, including those 

by Shared Strategy for Puget Sound, Hood Canal Coordinating Council, Lower 

Columbia Fish Recovery Board, Yakima Subbasin Fish and Wildlife Planning 

Board, Upper Columbia Salmon Recovery Board, and Snake River Salmon 

Recovery Board. Each of these groups has prepared draft recovery plans and 

several of these plans have been finalized in 2006 and 2007 (e.g., Shared Strategy 

for Puget Sound 2007). The salmon recovery plans will drive integrated salmon 

conservation efforts in the state over the next decade. Various planning efforts are 

also underway in Oregon, California, and Idaho. Complementing initiatives in the 

United States, Canadian authorities have recently introduced their Wild Salmon 

Policy, which summarizes actions needed for restoring salmon populations in 

British Columbia (Fisheries and Oceans Canada 2004). Expansion of grant 

programs, especially the Pacific Coastal Salmon Recovery Fund, will aid the 

implementation of greater numbers of projects. Restoration measures for salmonids 

will require substantial actions across all categories of limiting factors and threats, 

as described in the following subtasks. It is vital that meaningful increases in 

salmon abundance be achieved above and beyond those associated with periods of 

favorable ocean productivity. 

1.1.1.1 Habitat management. 

Preservation, restoration, and rehabilitation of degraded freshwater, 

estuarine, and shoreline habitats is a major emphasis of salmon restoration 

programs and involves numerous activities, such as reforestation of riparian 

zones, installment of woody debris in stream channels, removal of fish 

passage barriers and other structures affecting habitat, land acquisitions, and 

aquatic/marine protected areas. Other necessary components of habitat 

improvement programs include expansion of local land-use planning and 

control (such as shoreline management plans and critical areas ordinances), 

including management of future growth and development to protect 

watershed processes; better management of streamflow through water 

allocation processes; water quality enhancement through prevention of 

chemical contamination, stormwater management, and other actions; and 

adequate regulatory mechanisms. It is important that restoration activities 

not be limited to forested portions of watersheds, and that they also occur in 

urban and agricultural settings. 

1.1.1.2 Harvest management. 

Salmon managers at the state, provincial, federal, and tribal levels should 

work through established planning processes to ensure that harvest goals are 

compatible with greater levels of natural escapement and other recovery 

needs of the fish. The Pacific Salmon Treaty provides a framework for the 

management of Pacific salmon, including conservation and sharing 

arrangements. Based on the principles of conservation and equity, the 
January 2008 V-9 NMFS 

Treaty embodies the commitment made by Canada and the United States to 

conduct their salmon fisheries in a manner which will prevent over-fishing, 

provide for optimum production, and ensure that both countries receive 

benefits equal to the production of salmon originating in their waters. 

Restoration of depressed naturally spawning salmon stocks will benefit from 

regular review and evaluation of harvest strategies, expanded monitoring of 

catch and escapement levels via improved count methods, greater targeting 

of hatchery fish in some fisheries, and use of improved gear to reduce 

incidental mortality of non-target fish in commercial and sport fisheries. 

There is also a need to expand the resources necessary for effective 

enforcement of fishery rules and regulations. 

1.1.1.3 Hatchery management. 

Reform of hatchery practices can reduce negative genetic and ecological 

interactions between hatchery and wild salmon (Brannon et al. 2004, 

Mobrand et al. 2005). Furthermore, hatcheries can directly assist in the 

restoration of some wild salmon populations (Flagg et al. 2004). A number 

of reform programs (e.g., the Hatchery Scientific Review Group, which 

covers Puget Sound and coastal Washington; Blankenship and Daniels 

2004) have been established in recent years to review hatchery activities and 

recommend management measures beneficial to the recovery of wild 

populations. It is particularly important that breeding, culture, and release 

practices be designed to reduce the potential effects of domestication, 

competition, and predation and that effective water quality and disease 

measures be implemented. Hatchery and Genetic Management Plans 

(HGMPs), which are required by NMFS, are one tool for addressing the 

effects of artificial propagation activities on certain listed species and have 

been prepared for most hatcheries. 

1.1.2 Support regional restoration efforts for other prey species. 

Southern Resident killer whales feed on a variety of non-salmonid prey, although 

current information suggests that these species (e.g., rockfish, lingcod, herring, 

and Pacific halibut) comprise only a small portion of the diet. Nevertheless, it is 

appropriate to support conservation and recovery measures for such prey species 

until more is known about their importance to the whales (Task B.2). 

Management plans exist for some of these species and cover harvest control rules, 

consideration of marine protected areas, habitat protection, and greater 

enforcement. 
January 2008 V-10 NMFS 

1.1.3 Use NMFS authorities under the ESA and the MSFCMA to protect prey habitat, 

regulate harvest, and operate hatcheries. 

Other measures to manage and recover listed salmon and other fish exist under 

the ESA and the Magnuson-Stevens Fishery Conservation and Management Act 

(MSFCMA). Section 7 of the ESA requires Federal agencies to ensure, through a 

consultation process, that any action they authorize, fund, or carry out is not likely 

to jeopardize the continued existence of listed species or result in the destruction 

or adverse modification of their critical habitat. Critical habitat designations exist 

for nearly all of the region’s endangered and threatened species of salmon. 

Section 10 of the ESA provides for permits and exemptions for otherwise 

prohibited activities. To issue permits for activities including research, hatchery 

operations, and harvest programs, NMFS must find that the taking will not 

appreciably reduce the likelihood of the survival and recovery of the species in 

the wild. The MSFCMA requires the development of biologically-based Fishery 

Management Plans (FMPs) that ensure the conservation and recovery of oceanharvested species, including Pacific salmon, groundfish, and Pacific halibut. 

FMPs include procedures for identifying, conserving, and enhancing Essential 

Fish Habitat for such species. 

1.2 Minimize pollution and chemical contamination in Southern Resident habitats. 

Chemical contamination represents another major threat to Southern Resident killer 

whales, despite the enactment of modern pollution controls in recent decades, which have 

been successful in reducing the presence of many contaminants in the environment. 

Recent studies have documented high concentrations of PCBs, DDTs, and PBDEs in 

Southern Resident whales. These and many other chemical compounds are of concern 

because of their ability to induce immune suppression, reproductive impairment, and 

other physiological damage, as observed in other marine mammals. Contaminants enter 

marine waters and sediments from numerous sources, but are typically concentrated near 

areas of high human population and industrialization. Freshwater contamination is also 

of concern because of its impacts on salmon populations during sensitive life stages. 

Because of projected human population growth in the region in coming decades, 

especially in Puget Sound and the Georgia Basin, greater efforts will be needed by 

governments, industry, and the public to minimize pollution. International coordination 

with Canadian efforts and broader international initiatives can also contribute to a cleaner 

environment. The EPA, Fish and Wildlife Service and NMFS have a Memorandum of 

Agreement regarding enhanced coordination under the Clean Water Act and the 

Endangered Species Act. The agreement recognizes the complimentary goals of the 

CWA and ESA in protecting the aquatic environment and listed species and describes 

procedures to coordinate implementation of existing statutory and regulatory authorities. 

The Puget Sound Action Team (PSAT) coordinates and implements Washington State’s 

environmental agenda for Puget Sound and adjacent waters. Actions to identify and stop 

pollution in the greater sound area are the primary focus of the 2005-2007 Puget Sound 

Conservation and Recovery Plan (Puget Sound Action Team 2005b). In late 2005, the 

Governor of Washington announced formation of a major new initiative to restore Puget 
January 2008 V-11 NMFS 

Sound and in 2007 the State of Washington established the Puget Sound Partnership- a 

new agency consisting of an executive director, an ecosystem coordination board, and a 

Puget Sound science panel (RCW 90.21.210). The Partnership was created to oversee the 

restoration of the environmental health of Puget Sound by 2020, and is directed to create 

a long-term plan called the 2020 Action Agenda by September 2008. The Action Agenda 

will facilitate implementation of recovery activities by identifying and prioritizing 

actions, identifying funding, and tracking and reporting progress. Extensive background 

on contaminant regulations in British Columbia and needs for cleanup, research, and 

management in the Georgia Basin appears in Garrett (2004). 

1.2.1 Clean up contaminated sites and sediments. 

Many contaminated locations have undergone remediation since the 1970s and 

some are now considered cleaned. Continuation of remediation efforts remains an 

important priority for protecting the Southern Residents and prey species. The 

long-range goal of this work is to clean up all sites exceeding recognized 

government standards for pollution that may be contributing to the contamination of 

the whales or their prey. It is also important to ensure that cleaned sites are not 

recontaminated by controlling sources of contamination (Task 1.2.2). Necessary 

actions for clean up are discussed in greater detail in other planning documents 

(e.g., Puget Sound Water Quality Action Team 2000, Puget Sound Action Team 

2007). 

1.2.1.1 Identify and prioritize specific sites in need of cleanup. 

Continued assessments are needed to identify and monitor contaminated 

marine sediments and upland sites in Puget Sound, the Georgia Basin, and 

other areas occupied by the Southern Residents and their prey. 

Comprehensive inventories of contaminated sites should be maintained and 

regularly updated, and should be used to prioritize sites in need of further 

investigation and remediation. A GIS project to identify and map 

contaminated sediments in Puget Sound has been completed to assist with 

identifying contaminated areas and prioritizing cleanup based on importance 

for killer whales along with other mapping efforts (Puget Sound Action 

Team 2007, see Figure 4-05). 

1.2.1.2 Remediate sites in need of cleanup. 

Cleanup actions are ongoing at numerous contaminated locations in the 

region (Washington State Department of Ecology 2005) and should continue 

until completion. Remediation of sites that have yet to be cleaned will also 

be needed. In both cases, site-specific cleanup plans require regular reevaluation, and updating, and may require identification of additional 

funding sources. Specific targets for cleaning up sites should be coordinated 

with the goals of the Puget Sound Partnership and Superfund programs. 
January 2008 V-12 NMFS 

Common methods for dealing with contaminated sediments and soils 

include capping, removing, and treating, but some areas can be left to 

naturally recover without remediation if the sources of contamination are 

controlled. Post-cleanup monitoring to ensure re-contamination is not 

occurring is also important and must be fulfilled. A comprehensive database 

that tracks sites and clean ups would be useful in assessing progress and 

evaluating success of cleanup methods. Management of sediment disposal 

should prevent release of toxic chemicals that could be a problem for 

Southern Residents. 

1.2.2 Minimize continuing inputs of contaminants into the environment. 

Conventional pollution control practices have greatly improved in North America 

during recent decades, yet much remains to be done in reducing the environmental 

inputs of a wide diversity of chemical compounds that are potentially harmful to the 

Southern Residents and their prey. Mitigation activities should be conducted at the 

local, state, provincial, national, and international levels. 

1.2.2.1 Minimize the levels of harmful contaminants discharged by industrial, 

municipal, and other point sources of pollution. 

Industries and municipal sewage treatment plants, commonly referred to as 

“point sources,” produce vast amounts of wastewater, which can be a 

significant source of contamination when insufficiently treated or when 

technology limits the treatment of certain classes of contaminants. 

Important point sources of contamination in the region should be identified 

(Task B.6.3.3) and prioritized for action. Necessary activities include 

adoption of revised water and sediment quality standards based on available 

information, requiring discharge permits to cover all pollutants of concern, 

upgrading treatment systems and pretreatment programs, improving permit 

compliance through inspections and enforcement, and elimination of 

unpermitted discharges (Puget Sound Water Quality Action Team 2000). 

1.2.2.2 Minimize the levels of harmful contaminants released by non-point sources 

of pollution. 

Non-point source pollution is another primary contributor of contamination 

in aquatic environments and originates from poor agricultural and forest 

practices, stormwater runoff, improper disposal of household hazardous 

wastes, certain recreational boating activities, failing septic systems, 

improper use of pesticides, and atmospheric deposition. Pollution from 

some of these sources is considered a major impairment of freshwater and 

estuarine salmon habitat in the region. Although water quality standards 

and management plans already exist to reduce pollution from non-point 

sources, government agencies and the public can do more to meet goals 

through education, financial and technical assistance, regulation, 
January 2008 V-13 NMFS 

enforcement, improved watershed planning, and implementation of best 

practices (Puget Sound Water Quality Action Team 2000, Garrett 2004). 

Water quality monitoring should continue and research on potential air 

quality effects on killer whales should be conducted (Task B.6.2.1.) 

International agreements designed to curb certain types of pollutants, 

especially atmospheric pollutants, should be considered. 

1.2.2.3 Reduce impacts to Southern Resident killer whales from emerging 

contaminants. 

Southern Resident killer whales and their prey may be impacted by 

numerous emerging chemical compounds entering the environment, 

including brominated flame retardants (BFRs), polychlorinated paraffins 

(PCPs), perfluorooctane sulfonate and other perfluorinated compounds, 

polychlorinated naphthalenes (PCNs), polychlorinated terphenyls (PCTs), 

and endocrine disruptors (e.g., synthetic estrogens, steroids, some pesticides, 

pharmaceuticals, and personal care products) (Grant and Ross 2002). 

Monitoring programs for these chemicals should be developed or expanded 

(Garrett 2004) to inform water quality standards and regulations to reduce 

threats as they are identified. New regulations pertaining to discharge as 

well as source control and treatment may also be needed. The U.S. 

Environmental Protection Agency will be identifying areas within their 

PBDE Project Plan to assist with recovery of Southern Residents. 

1.2.3 Minimize contamination in prey. 

 

Additional research is necessary to identify prey species of Southern Residents and 

monitor contaminant levels in prey (Tasks B.2 and B.6.1.2.) This information will 

allow managers to evaluate, if necessary, the most effective methods to minimize 

contamination in prey through Tasks 1.2.1 and 1.2.2. In particular, there is a strong 

need to evaluate the role of current hatchery rearing practices that encourage longer 

residency periods in Puget Sound by Chinook salmon, resulting in higher 

contaminant loadings in the fish. 

1.3 Minimize disturbance of Southern Resident killer whales from vessels. 

Increasing numbers of vessels around the Southern Residents were identified as a 

potential risk factor in the recent decline of the population, but, the relative importance of 

this concern is not well understood. Human-generated sound has the potential to mask 

echolocation and other signals used by the species, as well as to temporarily or 

permanently damage hearing sensitivity, whereas vessel presence has been implicated in 

increased energy expenditure for whales. Inhalation of significant amounts of potentially 

harmful airborne pollutants, such as polycyclic aromatic hydrocarbons (PAHs), emitted 

by engine exhausts of whale watching vessels is an additional concern. Vessel strikes are 

rare, but are another potential source of injury or mortality and should be monitored. 

Land-based viewing sites, voluntary no-boat zones, approach guidelines, and education 
January 2008 V-14 NMFS 

programs (Task 3.2) have been initiated in recent years to address concerns relating to 

vessels, but additional management measures, such as encouraging vessel owners to 

employ quieter designs, may be necessary to reduce vessel effects. Further research on 

many aspects of vessel impacts (Task B.6.2) is needed to guide future management 

recommendations. 

1.3.5 Monitor vessel activity around whales. 

1.3.5.1 Expand efforts to monitor commercial and recreational whale-watching 

vessels. 

Several on-water stewardship programs, Soundwatch, the Marine Mammal 

Monitoring Project (M3) and Straitwatch, currently monitor commercial and 

recreational vessels engaged in whale watching in the vicinity of the San 

Juan Islands and southernmost British Columbia. In addition to educating 

boaters about the “Be Whale Wise” guidelines for viewing whales, the 

programs document levels of boating activity near the whales and monitor 

vessel compliance with the guidelines. These programs should be expanded 

to allow daily coverage of primary viewing areas during the main viewing 

season (i.e., May to October), longer hours of coverage per day, and 

compilation of more complete whale-watching data. Continuation of 

current programs and additional efforts will assist in assessing impacts of 

vessels on whales and evaluating future guidelines, regulations, and 

protected areas. 

1.3.5.2 Evaluate the relative importance of shipping, ferry, fishing, research, military, 

and other vessel traffic to disturbance of killer whales. 

Numerous types of vessels have the potential to negatively affect the 

behavior of killer whales, but little information is available on this issue. 

The presence and activity patterns of non-whale-watching vessels in the 

vicinity of Southern Resident and other killer whales should be monitored 

and evaluated (Task B.6.2.1) to determine their potential effect. 

1.3.6 Continue to evaluate and improve voluntary whale-watching guidelines. 

There is a continual need for private boaters to be educated on boating practices in 

the vicinity of killer whales. The “Be Whale Wise” education campaign is a 

successful international program and was created with input from government, 

commercial and private organizations. In addition to the “Be Whale Wise” whale 

watching guidelines, the Whale Watch Operators Association Northwest has 

adopted a more comprehensive set of guidelines for use by commercial whale 

watch vessels. Guidelines should continue to be refined as more is learned about 

the impacts of vessels on killer whales (Task B.6.2) and research results should be 

shared to better inform the public and industry about how to view whales without 

affecting them. 
January 2008 V-15 NMFS 

1.3.7 Evaluate the need to establish regulations regarding vessel activity in the vicinity of 

killer whales. 

Regulations have been established for several ESA-listed species of whales in 

sensitive areas (e.g., humpback whales in Alaska and Hawaii, and northern right 

whales in the northwest Atlantic) to protect them from vessel impacts. These 

regulations generally apply to all types of vessels with exceptions for government 

vessels operating in the course of their duties. Regulations regarding vessel 

activities, such as speed or approach distance, should be evaluated to augment 

existing guidelines and increase enforceability to protect Southern Resident killer 

whales. Regulatory mechanisms should be supported by research (Task B.6.2) to 

ensure suitability for the whales and coordinated with enforcement to foster 

effectiveness with the public. Development of any U.S. regulations should be 

coordinated with Fisheries and Oceans Canada current proposal to amend their 

existing Marine Mammal Regulations (Task 5.3). 

1.3.8 Evaluate the need to establish areas with restrictions on vessel traffic. 

 

There are a variety of options to address vessel activity in sensitive areas for 

Southern Residents, including fixed seasonal restrictions, restrictions when whales 

are present, or restrictions for whale watching vessels only. Many commercial 

operators and private boaters already adhere to the voluntary closure of an area off 

western San Juan Island that is used preferentially by the whales for feeding, 

traveling, and resting. Evaluating this site will help to determine if area vessel 

restrictions are effective and whether additional voluntary or mandatory areas 

should be established. Criteria for selecting areas should be supported by research 

on habitat use (Task B.7) and vessel impacts (Task B.6.2). 

 

2. Protect Southern Resident killer whales from additional threats that may cause disturbance, 

injury, or mortality, or impact habitat. 

 The following issues were not identified as major risk factors in the recent Southern Resident 

decline, but, have been identified as potential factors that can be addressed to protect killer 

whales. For the most part, these factors are rare and unpredictable and may have variable 

effects depending on exposure, magnitude of event, and number of animals present. In some 

instances management measures are already in place to mitigate and reduce the possibility of 

injury or mortality. Many activities where impacts on protected resources may occur are 

addressed through incidental harassment authorizations under MMPA or through section 7 

consultations under the ESA. 

2.1 Minimize the risk of oil spills. 

While many measures are in place to reduce the probability of major oil spills, the effects 

of such spills are potentially catastrophic to the Southern Resident population, either 

through direct mortality or from harmful physiological effects, as shown by the 

significant declines in two groups of Alaskan killer whales that likely resulted from the 
January 2008 V-16 NMFS 

Exxon Valdez spill in 1989. Despite many improvements in spill prevention since the late 

1980s, much of the region inhabited by the Southern Residents remains at risk from 

major spills because of its heavy volume of shipping traffic and its role as a leading 

petroleum refining center. Chronic small-scale oil pollution originating mainly from 

small vessels is also of concern because of its cumulative long-term impacts on aquatic 

food webs. 

2.1.1 Prevent oil spills. 

There are a number of international, federal, state, provincial, multi-jurisdictional 

and industry regulatory programs in place to prevent oil spills including 

International Maritime Organization conventions, the Oil Pollution Act, and other 

programs for preventing spills (e.g., Pacific States/British Columbia Oil Spill Task 

Force) which should be fully supported. Recent legislation in Washington has 

created an Oil Spill Advisory Council to review the adequacy of oil spill 

prevention, preparedness, and response activities in the state. In 2007 the 

Washington State Department of Ecology published a new Spill Prevention, 

Preparedness, and Response Program Annual Report describing recent 

accomplishments (WDOE 2007). The plan describes new rules for oil transfer that 

were adopted in September of 2006 that provide more universal coverage relating to 

oil transfers over state waters. New spill prevention policies should be developed 

and implemented, as appropriate or if needs are identified. Measures that will 

further reduce the risk of marine spills include the continued conversion of shipping 

fleets to vessels with safer designs, improved salvage and rescue capabilities, 

prevention of pipeline spills near marine areas, prevention of waste oil dumping 

from vessels, and greater enforcement. Permanent funding is needed for the yearround deployment of a rescue tug at Neah Bay, Washington. Continued use of 

tanker escort tugs should also be required. Steps for reducing the occurrence of 

smaller spills include continuing to improve operating standards aboard vessels, at 

ports, and at oil handling facilities in compliance with MARPOL, and greater 

enforcement. Strategies also need to be developed to reduce oil-laden discharges 

from stormwater and small vessels (Task 1.2.2.) 

2.1.2 Prepare for and respond to oil spills to minimize their effects on Southern Resident 

killer whales. 

Oil spills should be cleaned up as rapidly as possible to minimize their impacts on 

the whales. Contingency planning, more training, and frequent re-evaluation of 

response efforts are needed to improve responses to future spills. Recent reviews of 

response efforts have identified needs for greater standardization of response 

procedures, more aggressive initial responses, better interagency coordination, 

additional cleanup equipment to be stationed throughout the region, procurement of 

improved spill detection equipment, increased targeting of sensitive habitats during 

cleanup efforts, and greater reliance on geographic response plans. Potential effects 

of oil spills on Southern Residents should be incorporated into the Washington Oil 

Spill Advisory Council reviews. In 2001 the U.S. Coast Guard, EPA, Department 
January 2008 V-17 NMFS 

of Interior, Fish and Wildlife Service and NOAA (NMFS and NOS) entered into an 

agreement that provides a framework for cooperation and participation in providing 

protection of listed species, improve oil spill planning and response procedures and 

streamline section 7 consultations under the ESA. In additional there are local 

organizations such as the Island Oil Spill Association, a community-based, 

nonprofit organization providing prompt first response for oil spills in the San Juan 

Islands, shoreline protection, wildlife rescue and training for containment and oiled 

wildlife responders. 

2.1.3 Develop strategies to deter killer whales from entering spilled oil. 

The use of acoustic harassment devices and other deterrent methods (see Petras 

2003) should be evaluated as possible techniques for keeping Southern Resident 

and other killer whales away from spilled oil. If effective methods can be found, 

deployment strategies for use during spills should be developed and incorporated 

into oil spill response planning. Appropriate deterrent methods may vary with spill 

size, location, and other circumstances. 

2.2 Monitor and minimize the risk of infectious diseases in Southern Resident whales. 

Gaydos et al. (2004) identified a number of virulent diseases that are potentially 

transmissible to the Southern Resident population, with morbillivirus, brucellosis, and 

cetacean pox virus being of greatest concern. Evidence of exposure to some of these 

pathogens has been detected in other marine mammal populations in or near the range of 

the whales. The Southern Resident community is vulnerable to a serious disease 

outbreak because of its high degree of sociality, small population size, and seasonal 

concentration near the San Juan archipelago. High contaminant levels may also 

contribute by compromising immune function, thereby increasing disease susceptibility. 

Activities that could be taken to prevent diseases in the population are fairly limited. 

Efforts to monitor diseases in the whales and sympatric marine mammals should continue 

(Tasks 4 and B.6.5). This will provide a better understanding of the role of disease in 

these populations and may alert scientists to outbreaks, perhaps allowing novel control 

responses to be devised. To minimize the potential for introducing new infectious 

diseases, complete disease screenings should be conducted on any killer whales 

translocated into the region prior to their being moved. The Southern Residents are also 

potentially vulnerable to several largely terrestrial diseases, such as toxoplasmosis and 

canine distemper virus. Improvements in managing sewage outflows, animal waste, 

agricultural runoff, and certain land use practices may help prevent the introduction of 

such pathogens into Southern Resident habitats. 

2.3 Continue to use agency coordination and established MMPA mechanisms, such as 

incidental harassment authorizations, to minimize any potential impacts from human 

activities involving acoustic sources, including Navy tactical sonar, seismic exploration, 

in-water construction, alternative energy projects and other sources. 
January 2008 V-18 NMFS 

The majority of requests for incidental harassment authorizations under the MMPA 

involve the incidental harassment of marine mammals by acoustic sources. Killer whale 

hearing ranges from 1 to 120 kHz (with peak sensitivity from 20 to 50 kHz, Szymanski et 

al. 1999), which fully covers the bandwidth generally considered as mid-frequency (2 to 

10 kHz). Threshold levels at which underwater anthropogenic noise adversely affects 

behavior and hearing are poorly understood. In other cetaceans, the onset of temporary 

hearing loss has been estimated to occur at received sound pressure levels of 195dB at 1 

sec duration exposures (Schlundt et al. 2000). Avoidance behaviors in a range of species 

exposed to different sound sources, other than mid-frequency sonar, have been observed 

at received levels of 140-160dB (Malme et al. 1983, 1984, 1988, Ljungblad et al. 1988, 

Tyack and Clark 1998). Effects of noise on killer whales depend on sound frequency, 

exposure level, and duration, as well as distance from the source, geographical features, 

and the animal’s hearing ability, exposure history, and motivational state. Additional 

acoustic monitoring and research on the effects of noise exposure are important to 

evaluate potential impacts from acoustic sources (Tasks B.6.2.2, B.6.2.3, and B.6.2.4). 

Committed to protecting marine mammals in Puget Sound, the Navy has and will 

continue to work closely with NMFS and has already proactively established procedures 

to minimize any potential harm to marine mammals from sonar use. The Navy avoids 

training in major marine mammal concentration areas when possible, listens for 

vocalizing animals with passive sonar before commencing exercises, and suspends or 

ceases sonar operations when marine mammals are detected to minimize any potential 

risk of harm. Navy protective measures also include posting highly trained lookouts that 

are especially adept at spotting and identifying small objects at sea under all conditions. 

Reports of marine mammal activity are passed on to command personnel to ensure Navy 

vessels avoid marine mammals. The Navy coordinates with NMFS on necessary 

authorizations under the MMPA and ESA on many activities where impacts on protected 

resources may occur as contemplated by the legislation. Continued coordination with 

NMFS as Federal partners will ensure that adequate conservation measures are put in 

place if future potential impacts are identified. 

 

2.4 Reduce potential for impacts of invasive species in Southern Resident habitats. 

Invasive species have the capacity to greatly alter ecosystem functions and food webs, 

and therefore pose a major threat to many rare or declining native species. Invasive 

species are not currently known to affect Southern Resident killer whales, but there is 

significant potential for serious negative interactions from future introductions, especially 

through impacts on prey. Several hundred non-native species already exist in marine and 

estuarine areas of the whales’ range (P. Heimowitz, pers. comm.), including at least 95 

species in Washington and British Columbia (Meacham 2001). Further introductions are 

inevitable, but greater vigilance and preventive management actions can reduce their 

incidence. 
January 2008 V-19 NMFS 

2.4.1 Prevent the introduction and spread of invasive species. 

It is far more practical to prevent new introductions of non-native species than to 

undertake control efforts after invasive populations are detected. Non-native 

marine and estuarine species are commonly introduced or spread through the 

discharge of ballast water in ships, hull and anchor fouling, boater activity, 

occurrence in shipments of shellfish and fish, and other pathways (Wonham and 

Carlton 2005). Many federal, state, and provincial regulations and programs are 

already in place to limit invasives, but should be revised or expanded, as needed. 

Many suggested management activities pertaining to aquatic invasive species in 

Washington and Oregon appear in Meacham (2001) and Hanson and Sytsma 

(2001). Continued monitoring for escaped Atlantic salmon and their wild 

progeny in the region is an important priority, but detection programs for other 

species are also needed (Cohen 2004). The Western Regional Panel on Aquatic 

Nuisance Species can be used to coordinate activities among jurisdictions. 

2.4.2 Eradicate existing populations of invasive species. 

Few tools or strategies are available for the management and control of invasive 

species in unconfined marine and estuarine habitats, which makes eradication 

nearly impossible for many species. Nevertheless, such programs may be 

practical for some species and should be attempted when favorable circumstances 

exist. Control efforts for marine invasives are usually costly and manpower 

intensive.

 

3. Develop public information and education programs. 

Public attitudes are a major part of the success or failure of conservation efforts for most 

endangered species, especially those occurring near major population centers. Killer whales 

already enjoy widespread popularity among much of the public living in coastal regions of 

western North America, but much remains to be done to publicize the plight of the Southern 

Resident population and to discourage potentially harmful human activities. While current 

education programs are focused in Washington, they should be expanded in the future to 

cover the entire range of Southern Residents and beyond. It is important to include messages 

regarding the cultural significance of killer whales to people in the Pacific Northwest 

including tribes. Indian tribes also have many stories of killer whales that can be 

incorporated into education programs. 

3.1 Enhance public awareness of Southern Resident status and threats. 

A number of tools and outlets are available to educate the public about the Southern 

Residents and their conservation. Each of the threats to the population will require an 

education and outreach component in order to improve the situation through changing 

people’s behavior, expressing political will, and gathering community support for 

management initiatives. Government agencies can partner with a variety of existing 

private organizations to provide information to the public. Private conservation groups 
January 2008 V-20 NMFS 

interested in conservation of the whales can assist by including appropriate information in 

their publications and news releases. 

3.1.1 Exhibits and programs at local museums, aquaria, parks, and other locations. 

The Whale Museum, Seattle Aquarium, Vancouver Aquarium Marine Science 

Center, Lime Kiln Point State Park, and Lighthouse Marine Park (at Point Roberts, 

Washington) have exhibits and other programs devoted to increasing public 

awareness about the biology, behavior, and conservation status of Southern 

Resident killer whales, as well as knowledge about marine ecosystems. In addition 

local non-profit groups have developed programs, such as the monthly lecture series 

offered by the Puget Sound Chapter of the American Cetacean Society, to increase 

awareness about whales and conservation issues. Such displays and activities reach 

both local and visiting audiences and raise basic level of knowledge regarding the 

ecosystem and killer whales. Placement of exhibits on ferries and along appropriate 

roadside locations through the Washington Scenic Byways program should be 

considered. New exhibits and expansion of current programs will enhance 

capabilities to reach new and larger audiences. 

3.1.2 School programs. 

Several education programs targeting at teachers and students already exist. 

Programs such as these should be greatly expanded to reach additional classrooms 

and school systems. 

3.1.3 Naturalist programs. 

Some of the most receptive audiences to learning about killer whales are people 

participating in marine wildlife viewing activities. Many whale watching 

companies already employ a naturalist on their cruises to provide guests with 

background information on killer whales and other aspects of the marine 

environment. Staff and visiting experts at Lime Kiln Point State Park also give 

summer interpretive talks on the whales at a land-based viewing site. Continuation 

of naturalist training programs, such as the ones offered by The Whale Museum and 

the Marine Mammal Research Group in Victoria, or establishing naturalist 

certification, would ensure that consistent and accurate messages are relayed not 

just to whale watchers but to other members of the public. 

3.1.3 Research programs. 

The NWFSC has held public workshops to provide information on current research 

programs, new research results, and progress toward filling important data gaps 

(Task B.11). In addition to workshops researchers are encouraged to publish their 

results in peer reviewed journals, so that new information is available to the public 

and managers. 
January 2008 V-21 NMFS 

3.2 Expand information and education programs to reduce direct vessel interactions with 

Southern Resident killer whales. 

Concerns that whale-watching vessels may disturb the Southern Residents have spawned 

several successful education programs aimed at reducing interactions between boaters 

and whales. Viewing guidelines for vessels were first developed in the 1970s and have 

gradually evolved into the current “Be Whale Wise” campaign, which is a transboundary 

program created through the cooperative efforts of the whale-watching industry, whale 

advocacy groups, and government agencies. The campaign has been promoted through 

on-water stewardship programs, brochures, advertisements, and enforcement agents to a 

variety of audiences including private boaters, fishers, and the general public. 

3.2.1 Expand the on-water educational efforts of the Soundwatch Boater Education 

Program, Marine Mammal Monitoring Project (M3), Straitwatch, and enforcement 

agencies. 

Maintaining on-water stewardship programs to educate vessel operators engaged in 

whale watching or boating in the vicinity of whales is essential for providing 

information on viewing guidelines and minimizing vessel impacts on Southern 

Resident killer whales (Task 1.3.1.1). Such programs should be expanded to allow 

daily coverage of primary viewing areas during the main viewing season (i.e., May 

to October) and longer hours of coverage per day. NMFS, WDFW, and DFO 

enforcement agents have also provided some on-water guidance to vessel operators 

since 2003 and should expand this activity in cooperation with stewardship 

programs. 

3.2.2 Outreach to private boaters. 

On-water stewardship programs (Task 3.2.1) cannot reach every boater. “Be Whale 

Wise” guidelines and other responsible wildlife viewing messages can be 

disseminated to private boaters and the general public through the distribution or 

posting of brochures, billboards, advertisements, and other information sources in 

coastal communities, marinas, and fishing and boating literature, at boating shows, 

boat dealers, and bareboat charters, during boating safety training courses, and in 

conjunction with vessel registration or licensing. 

3.2.3 Encourage land-based viewing of killer whales. 

Land-based viewing of killer whales should be advocated as a way for the public to 

see and enjoy the animals without the impacts of boat viewing. Groups such as The 

Whale Museum, Orca Relief, Lifeforce, and the Puget Sound Chapter of the 

American Cetacean Society have developed materials to promote land-based whale 

watching. Suitable on-land viewing sites should be identified (e.g., see Anonymous 

2005), promoted with a “Whale Trail” map, and improved with interpretative 

facilities and signs. Naturalist programs at land-based viewing sites would also 

provide valuable information to whale watchers (Task 3.1.3). 
January 2008 V-22 NMFS 

3.3 Educate the public on positive actions that they can take to improve environmental 

conditions for Southern Resident killer whales. 

Many private organizations promote environmentally responsible behavior to improve 

the condition of marine ecosystems within the Southern Residents’ range. Groups 

focused on the preservation of Puget Sound and the Georgia Basin may be particularly 

effective with campaigns on contaminant presence and cleanup efforts. Salmon recovery 

advocates can also assist in reaching the public with salmon concerns and their 

implications for killer whales. Existing programs range from campaigns encouraging 

communities and individuals to use environmentally safe lawn products and to safely 

dispose of hazardous waste to hands-on habitat restoration activities. Local government 

entities can also play a role, for example, the San Juan County Board of County 

Commissioners and the San Juan Marine Resources Committee have recognized a county 

wide stewardship area (Kennedy and Masters 2005) and have outreach campaigns to 

encourage public support for conservation of marine resources, including whales and 

salmon. Ongoing and new education efforts will build additional community-based 

support for killer whales, their prey, and habitats. 

3.4 Solicit the public’s assistance in finding killer whales. 

3.4.1 Solicit reports of killer whale sightings. 

Several sighting programs have been established along the west coast of North 

America to track killer whale and other marine mammal movements. The Orca 

Network’s Sightings Network receives reports of killer whales from the public via 

telephone (1-866-ORCANET) and email (info@orcanetwork.org) and posts them 

on a web site. The Whale Museum and BC Cetacean Sightings Network also gather 

local sighting information and additional efforts are underway to collect 

information outside Puget Sound and during winter months. Despite ongoing 

programs, much remains unknown about Southern Resident distribution, 

particularly during the winter and along the outer coast (Task B.1). Additional 

outreach should be directed at recreational boaters, fishers, vessel crews, and a 

variety of other groups to obtain sighting information that will assist in filling 

critical data gaps. 

3.4.2 Solicit reports of killer whale strandings from the public. 

The public should be continually requested to contact regional stranding networks 

whenever beached killer whales are encountered. Staffed by government biologists 

with help from volunteers, network phones are monitored daily, including 

weekends and holidays. Prompt notification is necessary to facilitate rapid rescue 

of live animals or to investigate dead whales as soon as possible to obtain 

information about disease, contaminants, and cause of death (Task 4). 
January 2008 V-23 NMFS 

4. Respond to killer whales that are stranded, sick, injured, isolated, pose a threat to the public, 

or exhibit nuisance behaviors. 

4.1 Manage atypical individual Southern Residents. 

Marine mammal managers in Washington and British Columbia have twice dealt with 

young resident calves separated from their pods in the past few years (i.e., L98, “Luna”, a 

Southern Resident, from 2003-2005; and A73, “Springer”, a Northern Resident, in 2002). 

It is conceivable that other situations may occur involving solitary Southern Residents 

that are out of their normal range, separated from their pod, sick, injured, or interacting 

negatively with humans. The need for intervention by resource agencies in such 

situations should be evaluated on a case-by-case basis, based on health of the animal, 

levels of interactions with people, potential threats, distance separated from other pod 

members, and other appropriate factors. Transboundary consultations, cooperation, and 

coordination will be needed, as well as community support. 

4.2 Respond to strandings of killer whales. 

Killer whale strandings are relatively rare in the northeastern Pacific and normally 

involve single animals. Strandings generate intense scientific and public interest. 

Successful responses to strandings must address both interests in a timely and consistent 

manner. Improved reporting of stranded whales by educating the public (Task 3.4.2) and 

other monitoring efforts are crucial to enabling response. Any marine mammal stranding 

occurring from central California to northern British Columbia could involve Southern 

Residents and should be responded to in a way that ensures that a rare opportunity to 

obtain samples and measurements is not lost. Samples and measurements obtained 

during killer whale stranding (resident, transient, or offshore) increase knowledge of 

killer whale physiology. Marine mammal stranding investigations in Washington and 

Oregon are conducted by the Northwest Marine Mammal Stranding Network (NMMSN), 

which includes resource agencies, local officials, veterinarians, biologists, and volunteer 

individuals and organizations. Strandings in British Columbia are handled through the 

Vancouver Aquarium Marine Science Center and DFO. 

4.2.1 Develop protocols for responding to stranded killer whales. 

The NMMSN currently has the capability to respond to stranded killer whales, but 

advanced planning is crucial to improve rapid and efficient responses to strandings. 

Response protocols for strandings of live, dead, or entangled whales should be 

prepared by a working group of resource agencies, members of the NMMSN, 

cooperating scientists, and education specialists. Protocols should include 

information on response team personnel, caching and mobilization of equipment, 

identification of necropsy facilities and testing labs, triage decision making, animal 

identification, contact lists for geographical areas, communications policies, and 

disposal practices. Response efforts should be capable of reaching and functioning 

in remote locations, and should have the capacity to handle multiple animals, given 
January 2008 V-24 NMFS 

the history of mass strandings in British Columbia during the 1940s. 

Transboundary coordination is desirable in these efforts (Task 5.1.2). 

4.2.2 Respond to live-stranded killer whales. 

Live-stranded animals require immediate rescue actions and provide unique 

opportunities to learn more about the threats facing killer whales. Responses to 

strandings of live animals should follow the protocols developed under Task 4.2.1 

as quickly and safely as possible for responders and the stranded whale. Policies on 

the collection of samples, hearing testing, and attachment of research tags to 

released animals are needed. 

4.2.3 Investigate strandings of dead killer whales. 

The carcasses of all stranded killer whales found in the range of the Southern 

Residents should be examined and fully necropsied to obtain valuable information 

on identity, physical condition, disease status, cause of death, contaminant loads, 

genetic relationships, physiology, and diet. Responses to strandings of dead 

animals should follow the protocols developed under Task 4.2.1. Necropsies 

should follow the standard protocol developed by Raverty and Gaydos (2004). 

4.3 Respond to future resource conflicts between the Southern Residents and humans. 

Interactions between fisheries and resident killer whales have been reported in Alaska. In 

the event that a Southern Resident-fishery conflict arises, co-managers should take 

cooperative proactive steps to reduce the conflict. The NMMSN is in place, including 

members with expertise and equipment, to address immediate needs of individual whales. 

Management strategies consistent with the MMPA and ESA, and with consideration of 

public concerns, should be developed and evaluated to resolve such conflicts. 

5. Transboundary and interagency coordination and cooperation. 

Southern Resident killer whales are listed as endangered under the ESA. Washington State’s 

killer whales were added to the state’s list of endangered species in 2004, and in Canada, the 

Southern and Northern Residents are listed as endangered and threatened, respectively, under 

the Species at Risk Act. These designations carry with them an added responsibility for 

resource agencies to prepare plans or strategies to recover these populations to a healthy 

condition. The definitions and mandates imposed by each listing are specific to the laws or 

regulations under which each of the listings are made. Nevertheless, the overarching goals of 

conservation and population recovery are remarkably similar regardless of jurisdiction. It is 

recommended that recovery plans and research efforts be coordinated within and among 

responsible federal, state or provincial agencies to ensure that conservation goals are met and 

that resources for conservation are optimized. 

Funding for research and conservation measures to benefit the recovery of the Southern 

Resident population was secured by the Washington State congressional delegation during 
January 2008 V-25 NMFS 

fiscal years 2003 - 2007. Nevertheless, this recovery plan contains recommended 

management actions that are inter-departmental, inter-jurisdictional, and international in 

nature. Long-term funding for management initiatives to implement the recommended 

actions is needed and should be planned for in agency budgets as appropriations allow. 

5.1 Cooperative research and monitoring. 

To the extent practicable, research into the biology and conservation concerns of the 

region’s killer whale populations should be coordinated among resource agencies, 

especially in the transboundary area. Interagency cooperation should be encouraged as 

much as possible through collaborative research planning, complimentary study design, 

cost or resource sharing, and liberal data dissemination practices. While cooperation and 

sharing of information is important, professional courtesy and ethical data utilization 

policies must be maintained to preserve the integrity of the intellectual property of the 

agencies and individuals participating in the research efforts. 

5.1.1 Population monitoring and research. 

To the extent practicable, killer whale photo-identification, censuses, population 

demographic studies, and other investigations should be conducted using 

compatible methodology to allow for consistency and comparison within and 

among populations, especially in the transboundary area. 

5.1.2 Stranding response coordination. 

To the extent practicable, killer whale stranding investigations should be 

coordinated to encourage interagency and international participation and data 

sharing, especially in the transboundary area (Task 4.2). 

5.2 Complementary recovery planning. 

It should be a goal of resource agencies involved in conservation or recovery planning for 

Southern Resident whales to communicate and coordinate during the planning process. 

Recovery plans and recovery strategies, action plans, and site-specific management 

measures should be complementary to the extent practicable given the nuances and 

mandates of the legislation under which each plan is prepared. 

5.2.1 Subject plans to periodic review. 

Recovery plans should be responsive to the current scientific understanding of the 

factors affecting the decline or recovery of the Southern Resident population. To 

remain useful as a tool for improving the current condition, plans should be subject 

to periodic review and amendment, and incorporate the findings of ongoing 

research studies as understanding of the factors affecting decline or recovery 

improves. 
January 2008 V-26 NMFS 

5.2.2 Encourage public participation. 

The public shall be encouraged to participate in Southern Resident conservation 

efforts. Resource agencies should communicate the progress, successes, and 

failures of implementing recommended management actions contained in recovery 

plans. 

5.3 Inter-jurisdictional enforcement cooperation and coordination. 

To the extent practicable, federal, state, and local law enforcement and legal authorities in 

the United States and Canada should cooperate and encourage the development and 

implementation of consistent enforcement and prosecution policies, especially in the 

transboundary area. Where possible, legal impediments to inter-jurisdictional 

enforcement actions should be streamlined or removed to encourage enforcement 

efficiency and transparency for the public. A comprehensive legal review of the 

applicable sections of the laws and regulations in the United States (MMPA, ESA, 

Washington Administrative Code) and Canada (Fisheries Act, SARA, Provincial Code) 

should be undertaken to illuminate the similarities and differences between the various 

laws and regulations. Based on the review, recommendations should be developed for 

administrative changes to promote consistent interpretation of protective regulations and 

foster efficient enforcement and prosecution of violations against Southern Residents and 

other killer whales. Enforcement and prosecution standards should be transparent and 

easily understood by the public and based on sound wildlife management principles, 

recognizing the limitations of science in substantiating clear cause-and-effect 

relationships between action and reaction in the marine environment. 

RESEARCH AND MONITORING 

Research is necessary to better understand the effects of potential risk factors that have been 

linked to periods of decline in the Southern Residents. Study results will be an important 

resource for developing science-based management actions to address the threats. Many 

research tasks should involve repeated sampling efforts to monitor future trends and to assess 

the effectiveness of management actions. Monitoring is necessary to track the status of the 

population and the effectiveness of the conservation measures. Note that the ranking of 

activities listed below does not imply an order of importance. The priority of each action, 

plus a cost and timeline for completion, appear in the Implementation Schedule. Research 

and monitoring will support an adaptive management approach, as new information is 

obtained, priorities can be adjusted. The NWFSC held a “Symposium on Southern Resident 

Killer Whales” in April 2006 to bring researchers together to present recent study results. 

The proceedings from the conference and a Draft Southern Resident Killer Whale Research 

Plan are posted on the NWFSC web page 

(http://www.nwfsc.noaa.gov/research/divisions/cbd/marine_mammal/marinemammal.cfm). 
January 2008 V-27 NMFS 

A. Monitor status and trends of the Southern Resident killer whale population. 

A.1 Continue the annual population census. 

Annual photo-identification surveys remain one of the most important activities 

involving Southern Resident killer whales. Counts are performed by the Center for 

Whale Research and provide a complete yearly inventory of the population dating back 

to 1974. Counts are conducted by boat primarily in and around the San Juan Islands 

during June and July, with supplementary information gathered whenever the whales 

can be observed during the remainder of the year. The surveys yield vital information 

on annual population changes and demographic parameters, such as sexual 

composition, age class structure, longevity, birth and survival rates, and reproductive 

performance of individual females. These data are crucial to determining population 

trends, analyzing threats, and studying population viability. 

A.2 Maintain a current photo-identification catalog for the Southern Residents and expert 

staff able to photographically identify the whales. 

The photo-identification catalog for the Southern Residents is an integral part of 

identifying individual whales during annual censuses and other encounters throughout 

the year, and should be maintained as a long-term resource. The Center for Whale 

Research has managed the catalog since 1976. It is equally important to keep at least 

one expert skilled in photographic identification of individual whales on the staff of the 

organization or agency holding the catalog. 

A.3 Standardize the results of annual population surveys. 

Small discrepancies exist in the annual count results used by different agencies and 

organizations. The results should be reviewed and standardized dating back to the 

1970s to eliminate minor confusion among users. Refinement of data on births and 

deaths will improve population modeling and demographic analyses. 

B. Conduct research to facilitate and enhance recovery efforts for Southern Resident killer 

whales. 

Long-term studies of the Southern Residents have gathered unprecedented data on the 

individual whales in this small population. However, many important gaps in our 

understanding of these whales remain, and substantially more research is required to address 

critical questions about the biology and conservation of the population. Killer whales are 

inherently difficult to study for a variety of reasons, including their marine habits, large body 

size, intricate social structure, large geographic ranges, and long life span. In 2003 – 2007, 

funding was made available to expand the research and conservation of Southern Resident 

killer whales. Studies are needed to address some of the complex cause-and-effect 

relationships to determine the relative impacts of various extrinsic and intrinsic factors on 

Southern Resident whales. This research will necessarily require the application of new 

techniques, the use of more sophisticated and costly technology, the collection of larger 
January 2008 V-28 NMFS 

sample sizes, and for some, the use of moderately invasive methods (e.g., tissue sampling, 

telemetry). Long-term commitments of funding and support will be needed to sustain much 

of this work. Intergovernmental coordination is desirable in these efforts (Task 5.1). 

 

Outlined below are 11 of the most critical research tasks, with subtasks, that need to be 

addressed by future investigations of the Southern Resident population. For many of these 

tasks, studies should ideally be designed to identify both similarities and differences among 

the three commonly recognized Southern Resident pods: J, K, and L. Recent data have 

highlighted some interesting pod-specific demographic and distribution patterns, and future 

studies should be designed to identify factors that may be causing disproportionate changes 

in some pods. When appropriate, research results should be compared to similar data from 

other North Pacific killer whale populations, especially the Northern Residents and southern 

Alaskan residents, to gain a broader perspective on biological issues and risks to the Southern 

Residents. Studies of captive killer whales and other marine mammal species may also be 

useful, particularly on health-related issues, contaminants, and the development of 

techniques. For a number of topics, examination of archived data is recommended to 

compare past and present conditions. 

B.1 Determine the distribution and habitat use of the Southern Residents. 

The population inhabits an extensive geographic range that is currently known to extend 

from northern British Columbia to central California. Movements are relatively well 

known during the warmer months of the year when the whales regularly occupy the 

protected inland waters of Washington and southern British Columbia, but are very 

poorly understood when the animals visit the outer coast. 

B.1.1 Determine distribution and movements in outer coastal waters. 

One of the highest research priorities is to document the population’s use of 

offshore areas, where only 38 sightings have been verified over a 33-year period. 

Considerable time is spent in this portion of the range, especially during the 

winter and early spring, with ranging patterns varying among pods. Information 

is needed on areas of regular occurrence, movement patterns, distances traveled 

offshore, habitat selection, and relationships with spatial/temporal occurrence of 

prey. 

B.1.2 Improve knowledge of distribution and movements in the Georgia Basin and 

Puget Sound. 

Much remains to be learned about distribution and movements in inland waters, 

especially for individual pods and matrilines. Such information will be useful for 

identifying interpod differences in range, diet, habitat use, and threats; changes in 

range use over time; and areas worthy of special protection. 
January 2008 V-29 NMFS 

B.2 Investigate the diet of the Southern Residents. 

Many aspects of diet are poorly known for the population and require study. Such 

information will shed light on many vital issues, including potential contaminant 

sources and whether prey abundance is sufficient to support the population. Whenever 

possible, pod-specific and matriline-specific diet preferences should be identified. 

B.2.1 Determine the diet of the Southern Residents. 

Another urgent priority is to identify the year-round food habits of the Southern 

Residents in all parts of their range. Salmonids, especially Chinook, are generally 

thought to be important prey. However, prey selection likely varies both in time 

and space. Therefore additional dietary information is needed to confirm the 

relative importance of Chinook and to identify the contributions of other prey, 

including other salmon species, groundfish, herring, and squid. Information on 

preferred prey size, annual variation in diet, and prey selection by age and sex 

class of whale in relation to species availability is also of interest. 

B.2.2 Determine the importance of specific prey populations to the diet. 

Seasonal salmonid runs from particular river systems likely play a large role in 

the diet and distribution of the Southern Residents, but researchers have thus far 

failed to correlate whale occurrence with the presence and availability of any 

specific prey population. Identification of prey populations of special 

significance to the whales is needed (Task 2.1). 

B.2.3 Determine the extent of feeding on hatchery fish. 

Hatchery fish comprise a large portion of salmonid populations in much of the 

range of the Southern Residents, but few data exist on the importance of these fish 

to the diet of Southern Residents. This should be established because the 

characteristics (e.g., energy content and contaminant loads) of hatchery salmon 

may differ somewhat from those of wild salmon. This information may also help 

evaluate whether future changes in hatchery management and production levels 

will impact the whales. 

B.3 Analyze the demographics of the Southern Residents. 

The population history and maternal genealogy of the Southern Residents are 

completely known for individual whales born after 1974. Existing studies of these data 

(Olesiuk et al. 1990a, 2005, Krahn et al. 2002, 2004a) have been quite useful in 

describing the dynamics of the population, but efforts should be expanded to provide 

more comprehensive analyses. This information will provide greater insight into the 

processes affecting the Southern Resident population, especially during periods of 

decline, and will improve the accuracy of future population viability analyses. 
January 2008 V-30 NMFS 

Demographic comparisons should be made among pods and with other resident 

populations. 

B.3.1 Determine mortality rates and potential causes of mortality. 

Mortality rates are one of the most important factors affecting population changes 

in killer whales. Comprehensive studies of mortality patterns and associated 

influences are therefore needed for the Southern Residents. Two high priority 

tasks are to determine the reasons behind the alternating 7-year periods of higher 

and lower mortality in the population, and L pod’s disproportionately higher death 

rate since the mid-1990s. 

Definitive causes of death have not been established for any of the more than 80 

Southern Residents that have died since 1974. This is largely due to the lack of 

carcasses for necropsy and difficulties in distinguishing direct causes of death 

(e.g., starvation and disease) from indirect factors impacting health (e.g., 

contaminant burdens, food limitations, and vessel interactions). Although few 

killer whales strand, necropsies to determine causes of mortality for all age and 

sex classes should be conducted on all available carcasses (Task 4.2.3).

B.3.2 Evaluate population growth rates and survival patterns.

Reproductive patterns also affect population trends and should be described in 

detail for the Southern Residents. Major influences on birth rates and 

reproductive trends should also be investigated. Areas of particular interest 

include the reasons for 1) the population’s cyclic periods of higher and lower birth 

rates, 2) its longer mean interval between births of viable calves, as compared to 

other resident populations, 3) L pod’s poor reproductive success during the 1990s, 

and 4) temporal trends of sex-bias in the production of calves. In addition, 

identification of factors causing poor reproductive success in females is 

important. Increased monitoring of the population during the winter and spring 

will allow researchers to better determine true birth rates. Determination of 

paternal genealogy is also needed (Task B.9.1). 

B.3.3 Evaluate population structure. 

More detailed analyses of age and sex structure patterns over time in the Southern 

Resident population are needed to assess threats, determine effects on population 

stability, and predict future growth. Potential constraints on population growth, 

such as a limited number of reproductive age males, should be evaluated. 

B.3.4 Evaluate changes in social structure. 

Highly stable matrilines are a major feature of Southern Resident biology. 

Detailed assessments of social structure dynamics (e.g., intrapod structure or 

associations) should be made to search for evidence of potential stresses on the 
January 2008 V-31 NMFS 

population and to examine effects on population stability. Evaluation of changes 

in intrapod structure on survival and fecundity, and the impacts of reduced 

population size on social structure are also needed. One particular topic deserving 

study is the consequences of the losses of key individuals from the population, 

particularly matriarchal and post-reproductive females, which could result in 

reduced alloparenting and loss of long-term cultural knowledge, thereby lowering 

population fitness. 

B.4 Investigate the health and physiology of the Southern Residents. 

Knowledge of individual health and physiology of the species is beneficial in 

evaluating a population’s status, dynamics (e.g., survival and fecundity), and threats. 

Both topics require much additional study for the Southern Residents. 

B.4.1 Assess the health of population members. 

Hormone levels, blubber depth, respiratory conditions, reproductive status, and 

other aspects of physical condition should be assessed in sufficient numbers of 

individual whales representing particular age and sex classes to appraise the 

population’s health. Evaluations should be done through the application of 

proven tissue sampling methodologies, or the application of emerging healthmonitoring techniques (e.g., collection of respiratory gases, blowhole residues, 

and fecal samples; use of ultrasound) that do not require the physical restraint or 

capture of animals. 

B.4.2 Assess individual growth rates. 

Growth rate comparisons among different cohorts of calves may offer another 

way of evaluating the effects of changing environmental conditions on the 

Southern Residents. This work will require the development of suitable 

morphometric indices. Dorsal fin measurements, which are obtainable from 

photographs taken during regular population monitoring, may achieve this need 

and have the added benefit of being retrievable from photos archived since the 

1970s. Monitoring changes in body condition following seasonal movements 

would be helpful in determining if prey availability limits the growth of 

individuals. 

B.4.3 Determine metabolic rates and energy requirements. 

Earlier studies of captive killer whales have provided limited data on the species’ 

energy demands, but may not accurately reflect the needs of the Southern 

Residents. More comprehensive metabolic and energetic studies should be 

conducted on captive killer whales using modern techniques. Knowledge of yearround metabolic rates and caloric requirements of different age and sex groups 

will help determine whether critical periods of the year exist when prey levels are 
January 2008 V-32 NMFS 

inadequate. Physiological indicators of nutritional stress should also be 

developed. 

B.5 Investigate the behavior of the Southern Residents. 

Comparisons of behavioral data are potentially valuable for evaluating changes in 

activity patterns over time that may indicate stresses on the population. Information on 

numerous behaviors (e.g., foraging, socializing, traveling, resting, diving, vocalizations, 

responses to vessels, and habitat selection) should be collected year-round and analyzed 

at the individual and group levels, and when possible compared with past data. 

Consistency and coordination of behavioral data collected by different researchers will 

assist with comparisons. Other needs include further clarification of the contexts of 

different behaviors and determination of nighttime activity patterns. 

B.6 Assess threats to the Southern Residents. 

Southern Resident whales face a number of threats, with reduced prey abundance, 

elevated contaminant burdens, excessive marine ambient sound and vessel interactions, 

lack of knowledge about risk factors outside of the Georgia Basin and Puget Sound and 

elevated contaminant burdens usually cited as the most serious conservation concerns 

(Task 1). Additional research is needed to characterize these problems and their effects 

on the population, and to identify other possible extrinsic factors affecting it. One goal 

of this work should be to determine whether synergistic effects are occurring, whereby 

multiple factors act in combination to harm the whales. Whenever possible, research 

activities should assess threats at the level of the pod or matriline to examine 

differences in exposure to the identified threat factors. 

B.6.1 Assess the effects of changes in prey populations. 

Human activities have profoundly altered populations of salmon and other 

Southern Resident prey during the past 150 years. The role that changes in prey 

abundance, availability, and quality have played in past declines of the Southern 

Residents or are playing in limitation of population growth requires further study. 

B.6.1.1 Determine historical changes in prey abundance and distribution, and their 

effects on Southern Resident population dynamics. 

Collection of data and comprehensive assessments of past and present 

prey abundance and availability are needed throughout the Southern 

Resident’s range at both regional and watershed scales. These data should 

be used to understand the role that changes in prey populations may have 

had on the Southern Residents’ population dynamics. In particular, Ford 

et al. (2005b) suggestion of a direct relationship between Chinook 

abundance and whale mortality needs fuller evaluation for the Southern 

Residents. With improved information on dietary preferences, efforts can 

be focused on current favored prey species, but a broad perspective is also 
January 2008 V-33 NMFS 

desirable to consider other prey that may have been formerly important to 

the whales. 

B.6.1.2 Assess changes in prey quality and their effects on Southern Resident 

population dynamics. 

Better data are needed on body condition traits (e.g., size; age; caloric, fat, 

and nutrient content; and contaminant burdens) of important prey. Such 

information should be gathered for a variety of prey subcategories, 

including different populations and age groups within a species, and wild 

versus hatchery fish. When possible, these studies should make inferences 

on changes in body condition between past and present prey populations. 

This information should be used to consider potential impacts on Southern 

Resident health and population dynamics. 

B.6.1.3 Determine whether the Southern Residents are limited by critical periods 

of scarce food resources. 

Information on the Southern Residents’ distribution, movements, diet, 

foraging behavior, and physiology and changes in prey abundance, 

availability, and quality should be collected and analyzed to determine 

whether the Southern Residents face critical periods when food resources 

limit the population, either annually or more infrequently. 

B.6.1.4 Assess threats to prey populations of the Southern Residents. 

Research should continue on a variety of known threats affecting 

populations of salmon and other prey species, including loss and alteration 

of spawning and rearing habitat, overharvest, pollution, food limitations, 

hatchery impacts, and climate change. The role of salmon aquaculture in 

transmitting sea lice to free-ranging salmon needs further evaluation, as do 

threats posed by invasive species, such as Atlantic salmon, cordgrass, and 

invertebrates that may disrupt food chains for salmon. The potential for 

diseases to cause significant changes in prey populations should also be 

monitored. 

B.6.2 Assess the effects of human-generated marine sound and vessel traffic. 

 

The Southern Residents are exposed to increasing levels of marine sound and 

vessel traffic over much of their range, and in inland waters, high levels of 

commercial and recreational whale watching. Excessive noise from vessels, 

sonar, in-water construction, and other anthropogenic sources may interfere with 

the whales’ communication, foraging, and navigation, may increase daily 

energetic costs, and may produce physiological trauma. Vessel presence 

regardless of sound is also potentially problematic under some circumstances and 

may inhibit important behaviors. There is an urgent need for greater study of the 
January 2008 V-34 NMFS 

impacts of marine noise and vessel interactions. Research on Northern Resident 

whales may be helpful in testing some hypotheses, but not all findings can be 

extrapolated to the Southern Residents. 

B.6.2.1 Determine vessel characteristics that affect the Southern Residents. 

Research is needed to evaluate which vessel traits (e.g., vessel type and 

activity; sound-pressure and sound-exposure levels; distance, size, speed 

and direction of travel; duration of interaction; and density and number of 

vessels present) may cause changes in the killer whales’ behavior. Studies 

should focus both on commercial and private whale-watching craft, as 

well as commercial fishing vessels, ferries, and other vessel types 

encountered by these whales either for prolonged periods or in high 

numbers. Investigations should attempt to determine whether problems 

caused by vessels are largely acoustic or non-acoustic in nature. 

Numerous study methods can be employed, but the use of controlled 

experiments, and land- and boat-based observations and acoustic 

techniques are particularly appropriate. Research is also needed to 

determine if vessel exhaust and air quality may have adverse effects on the 

whales. 

B.6.2.2 Determine the extent that vessels disturb or harm the Southern Residents. 

Studies should resolve whether interference from whale-watching craft 

and other vessels causes significant behavioral changes or physical 

injuries among the whales, and if so, whether these effects are serious 

enough to reduce survival or reproduction in the population. Threshold 

levels at which impacts occur should also be established (Task 3.3). Data 

on vessel numbers and activity should be compiled for the entire 

distribution of the Southern Residents. The Whale Museum and 

Soundwatch have gathered whale-watching statistics for the Georgia Basin 

and Puget Sound since the 1980s, including the size of the commercial 

fleet, the amount of viewing activity by commercial and private craft, and 

infractions of whale-watching guidelines. These efforts should be 

continued so that future trends in viewing pressure can be evaluated and 

perhaps correlated with changes in the Southern Resident population. 

Assessments of impacts on foraging efficiency and energy acquisition, and 

whether energy expenditures increase in the presence of vessels are 

particularly needed. Changes in habitat use patterns and other necessary 

behaviors such as resting, socializing, and parental care also require 

evaluation. Additional topics to be addressed are whether cumulative 

effects on behavior appear over time (e.g., during the course of the whalewatching season) and whether the Southern Residents display any 

habituation to vessel presence. 
January 2008 V-35 NMFS 

B.6.2.3 Determine the extent that other sources of sound disturb or harm the 

Southern Residents. 

The Southern Residents are exposed to numerous other sources of marine 

sound, such as military and non-military sonar, seismic testing, and marine 

construction. The impacts of these sounds on the behavior and health of 

the whales should be assessed. The effects of non-marine sound from land 

and aerial sources also need investigation. 

B.6.2.4 Determine the acoustic environment of the Southern Residents. 

Little information exists on the types and levels of marine sound to which 

these killer whales are exposed. Inventories of acoustic conditions are 

needed throughout the range of the Southern Residents, but especially in 

areas of high vessel traffic, such as the San Juan Islands. Studies of sound 

production by vessels and ambient sound conditions are the highest 

priority, but other acoustic sources should also be described. Historical 

trends in ambient noise levels should be estimated as well. An additional 

need is to examine the characteristics of sound propagation in the areas 

used by whales. 

B.6.2.5 Determine the hearing capabilities and vocalization behavior of the 

Southern Residents near sound sources. 

Sound from vessels and other sources may impair the hearing abilities of 

killer whales, thereby masking important signals associated with 

communication, foraging, and navigation. Better information is required 

on the critical distances that the Southern Residents need for these 

activities and whether the whales are able to partially compensate for 

masking noise. Acoustic responses to sound, including changes in the 

composition, rates, lengths, and “loudness” of calls, also require 

evaluation. For example, Foote et al. (2004) reported that call duration of 

the Southern Residents increased over time as the number of whalewatching vessels increased in the area. 

B.6.2.6 Assess the effects of human-generated marine noise on Southern Resident 

prey. 

Fish are also considered vulnerable to intense underwater sounds. 

Increased levels of background sound can mask sounds critical to fish 

survival, decrease auditory sensitivity, and modify behavior. Research is 

needed to determine whether prey populations change their behavior in 

response to anthropogenic sound, making the capture of individual fish 

more difficult for the Southern Residents. 
January 2008 V-36 NMFS 

B.6.3 Assess the effects of contaminants. 

Southern Resident whales carry high concentrations of PCBs and other persistent 

organic pollutants and likely have rapidly increasing levels of PBDEs, making 

them by far the most contaminated resident killer whale community in the 

northeastern Pacific. The levels are high enough to cause reproductive failure and 

other physiological effects in some marine mammal species, therefore, it is 

critical to evaluate the effects on this population. The sources of these and other 

chemical pollutants in the whales are unknown, but probably stem in part from the 

population’s occurrence in the heavily developed Georgia Basin and Puget Sound 

during much of the year. It is essential to learn more about the contaminant 

burdens carried by the whales, their impacts on the population, and levels of 

exposure. 

B.6.3.1 Determine contaminant levels in the Southern Residents and other killer 

whale communities in the northeastern Pacific. 

Two studies (Ross et al. 2000, Rayne et al. 2004) have described 

concentrations of PCBs (and their various components), PCDDs, PCDFs, 

PBDEs, PBBs, and PCNs in live Southern Resident whales, but were 

based on a small number of biopsy samples collected from 1993-1996. 

Updated and expanded tissue sampling of more members of the population 

is needed to obtain contaminant trend information and to examine 

differences among individual whales, age and sex categories, pods, and 

birth order rankings. Continued periodic sampling and testing for a 

broader range of compounds are strongly recommended. Tissue sampling 

of stranded individuals should also continue. Sampling of other regional 

killer whale populations may help clarify the sources of contaminants. 

B.6.3.2 Determine contaminant levels in Southern Resident prey. 

Aside from the recent findings of O’Neil et al. (2005), who characterized 

PCB levels in Chinook salmon from California to British Columbia, 

relatively little information is available on pollutant concentrations in 

Southern Resident prey. Better data are needed for virtually all prey 

species to provide a greater understanding of exposure to the whales. 

Levels of contamination should be assessed for a variety of compounds 

and prey subcategories (see Task B.6.1.2). 

B.6.3.3 Determine the sources of contaminants entering Southern Resident prey. 

Better data should be gathered on the pathways through which prey 

become contaminated. This work will require expanded assessment of 

pollutant levels in food webs and the general environment throughout the 

Southern Residents’ distribution, and can be achieved through review of 

existing data sources and increased survey efforts. Estimates of inputs 
January 2008 V-37 NMFS 

from specific point and non-point sources (e.g., through development of 

numerical source loading models) are needed. Monitoring of contaminant 

levels in biota at various trophic levels (e.g., harbor seals, harbor 

porpoises, other fish, and mussels) and sediments will provide essential 

information on spatial and temporal patterns of contamination across the 

region, including additional sites requiring cleanup or management (Task 

1.2). 

B.6.3.4 Determine the effects of elevated contaminant levels on survival, 

physiology, and reproduction in the Southern Residents. 

Exposure to moderate to high contaminant concentrations has been linked 

to a number of negative health effects in marine mammals, including 

impaired reproduction, immunotoxicity, hormonal and enzyme 

dysfunction, and skeletal deformities. Studies are needed to establish 

whether the Southern Residents are experiencing similar physiological 

effects and whether these are influencing life history parameters and 

population trends. Factors (e.g., nutritional stress or age) that may 

exacerbate the impacts of contaminants should also be investigated. 

B.6.4 Determine risks from other human-related activities. 

A variety of other anthropogenic threats (e.g., oil and chemical spills, seismic 

testing, certain military activities, fisheries-related entanglements and interactions, 

direct persecution, and ship collisions) are potentially harmful to the Southern 

Residents (Tasks 2.1 and 2.3). Although programs such as the MMPA reporting 

system are already established for fishermen to report injuries and deaths of 

marine mammals (insert website), improved documentation and monitoring of a 

variety of activities and any impacts on the whales are needed. Moreover, 

disaster response strategies developed for oil and chemical spills (Task 2.1.2) 

should include post-event tissue sampling to assess exposure and evaluate 

physiological responses. This task will become especially relevant as more is 

learned about the outer coastal areas occupied by the population. 

B.6.5 Evaluate the potential for disease. 

A recent summary of disease threats to the Southern Residents identified several 

high priority pathogens warranting further study (Gaydos et al. 2004). 

Surveillance for these and other diseases should be expanded to cover all 

populations of killer whales and cetaceans in the northeastern Pacific (Task 2.2). 

B.7 Identify important habitats for the Southern Residents. 

These habitats include sites that are regularly visited for feeding and other necessary 

activities, as well as locations of importance to major prey species. Such sites can 

likely be determined by examining movement and distribution patterns and identifying 
January 2008 V-38 NMFS 

areas of repeated use by both whales and their prey. Site visits to investigate reasons 

for use (e.g., foraging or other behavior) of specific locations may be needed, especially 

for offshore areas. The value of many important habitats to the whales will probably 

differ among pods and vary seasonally with prey occurrence. Habitat assessment is 

also necessary in determining critical habitat and evaluating potential sites for protected 

areas. 

B.8 Determine the effects of variable oceanographic conditions on the Southern Residents 

and their prey. 

Cyclic changes in climate trends across the North Pacific Ocean, such as the Pacific 

Decadal Oscillation, produce fluctuating oceanographic and atmospheric conditions 

that strongly affect ocean productivity and prey abundance. These changes presumably 

influence prey availability for the Southern Residents and therefore may affect the 

whales’ survival, movements, and other life history traits. The consequences of 

changing oceanographic patterns on the population should be examined as more is 

learned about the biology of the whales and the biotic and abiotic effects of these 

climate regimes. Similarly, more information is needed on effects to prey populations. 

The influences of global climate change on regional climate regimes and prey 

abundance should also be evaluated. 

B.9 Determine genetic relationships. 

A better understanding of the genetic relationships within and among killer whale 

communities in the northeastern Pacific is needed to assess rates of gene flow and risk 

from inbreeding, and to solve taxonomic concerns affecting population management. 

B.9.1 Determine paternity patterns in the Southern Residents. 

Additional genetic analyses should be made to establish paternity in the Southern 

Residents. This will yield important information on the contribution of individual 

males in siring calves, and whether mating takes place strictly among the 

Southern Resident pods, or if genetic exchange occurs on a limited basis with 

neighboring Northern Resident and offshore populations. Such knowledge will 

help assess the risk of inbreeding in the Southern Resident population. Given the 

low numbers of mature males in J and K pods, it will also assist evaluations of 

recent patterns of reproductive success in L pod. 

B.9.2 Determine the risk of inbreeding. 

 The Southern Residents may be at risk from inbreeding depression because of the 

population’s small size. Only 34 breeding adults remain in the population, but 

effective population size is perhaps even smaller. Assessments are needed to 

determine if genetic diversity is decreasing over time, and to genetically 

determine the mating system of the population. 
January 2008 V-39 NMFS 

B.9.3 Determine historical population size. 

 

The historical abundance of the Southern Resident population is unknown. 

Estimating historical population size is important, both for setting recovery goals 

and understanding the vulnerability of the population to inbreeding depression. 

B.9.4 Determine genetic relationships among populations. 

 Better data are needed on the genetic relationships among killer whale 

communities in the northeastern Pacific to estimate rates of gene flow among 

groups and resolve taxonomic issues, such as the status of Southern Residents as a 

distinct population segment. Comparisons of physical and other biological 

parameters should also be conducted to determine relationships among killer 

whale populations. This information will improve understanding of the degree to 

which the Southern Resident population is evolutionarily isolated and 

demographically closed. 

B.9.5 Expand the number of genetic samples available for study. 

Acquisition of a substantially larger set of tissue samples is an important priority 

for conducting future genetic analyses of the Southern Residents and other 

regional populations (Barrett-Lennard and Ellis 2001). Samples can be obtained 

using proven remote biopsy darting methods and should be gathered from all or 

most of the Southern Residents. Priority should be given to sampling the oldest 

population members before these animals die. 

B.10 Improve research techniques and technology. 

Improvements in study methods and equipment will greatly benefit future research efforts 

and allow important long-standing questions to be answered. Needs include: 1) better 

methods for assessing the physical condition of animals, analyzing genetic and 

contaminant samples, evaluating diet and prey abundance, and conducting acoustic 

surveys, and 2) improved equipment for telemetry and other tagging studies, and acoustic 

surveys. Development of non-invasive techniques is especially desirable. In some cases, 

new techniques and technology should be tested on other species or non-threatened killer 

whale populations before application to the Southern Residents. 

B.11 Research support and coordination 

The NWFSC conducts workshops with the research community to evaluate research 

needs, discuss methodology, and identify priorities. A long-term research plan is in 

development and will be coordinated with WDFW and DFO (NMFS 2006b). Outreach 

to educate the public on research goals, new results, and progress in filling data gaps is 

also important (Task 3.1.4). 
January 2008 VI-1 NMFS 

VI. IMPLEMENTATION SCHEDULE AND COSTS 

The following table shows the priorities and estimated costs for the actions set forth in this 

recovery plan. It is a guide for meeting the recovery goals outlined in this plan. The following 

table includes action numbers, action descriptions, priorities, the parties responsible for actions 

(either funding or carrying out), duration of actions, and estimated costs. Responsible parties are 

agencies or organizations with authority, responsibility, or expressed interest to implement a 

specific conservation action. When more than one party has been identified, the proposed lead 

party is the first party listed. The listing of a party in the table does not require the identified 

party to implement the action(s) or to secure funding for implementing the action(s). Costs are 

estimates for the Fiscal Year (FY) in thousands of dollars ($K) and are not corrected for 

inflation. Costs are included for specific actions under an outline heading or are listed as costs 

for an outline heading without further breakdown for specific costs. Estimates of costs came 

from a variety of sources including comments submitted during comment periods, discussion 

with government agencies and organizations about current expenditures and readily available 

budget information for ongoing programs. Costs for FY03-FY07 are shaded and have been 

included to provide information on conservation and research actions that have already occurred 

and the costs that were associated with completing those actions. There are many ongoing 

programs in place that benefit Southern Resident killer whales, but would be carried out 

regardless of the status of killer whales. Only some estimates of partial costs of these large-scale 

ongoing programs (e.g., oil spill prevention, contaminated site clean up, salmon recovery) that 

can be directly linked to recovery of Southern Resident killer whales are included at this time. 

Priorities are assigned as follows: 

Priority 1 Actions that must be taken to prevent extinction or to prevent the species from 

declining irreversibly. 

Priority 2 Actions that must be taken to prevent a significant decline in the population or its 

habitat quality, or in some other significant negative impact short of extinction. 

Priority 3 All other actions necessary to provide for full recovery of the species. 

Research and monitoring priorities are assigned as follows: 

Priority 1 Actions that must be taken to identify those actions necessary to prevent 

extinction. 

Priority 2 Actions that must be taken to prevent a significant decline in the population or its 

habitat quality, or in some other significant negative impact short of extinction. 

Priority 3 All other necessary research actions for full recovery. 
January 2008 VI-2 NMFS 

Responsible parties and involved collaborators for research actions may include NWFSC, DFO, 

WDFW, Center for Whale Research and researchers from other organizations. For ongoing 

research projects, responsible parties have been identified. 

Key to Acronyms Used in the Implementation Schedule 

CTC Concurrent Technologies Corporation 

CWR Center for Whale Research 

DFO Fisheries and Oceans Canada 

EC Environment Canada 

EPA U.S. Environmental Protection Agency 

ITOS International Tug of Opportunity System 

M3 Marine Mammal Monitoring Project 

NGO Non-Governmental Organizations 

NMFS NMFS Fisheries 

NMMSN Northwest Marine Mammal Stranding Network 

NWACP Northwest Area Contingency Plan

NWFSC NMFS, Northwest Fisheries Science Center 

ODEQ Oregon Department of Environmental Quality 

ODFW Oregon Department of Fish and Wildlife 

OLE NMFS, Office of Law Enforcement 

PSAT Puget Sound Action Team 

PSP Puget Sound Partnership 

SA Seattle Aquarium 

Soundwatch Soundwatch Boater Education Program 

SWFSC NMFS, Southwest Fisheries Science Center 

TWM The Whale Museum 

USCG U.S. Coast Guard 

USFWS U.S. Fish and Wildlife Service 

UW University of Washington 

VA Vancouver Aquarium 

WDFW Washington Department of Fish and Wildlife 

WDNR Washington Department of Natural Resources 

WDOE Washington State Department of Ecology 

WSP Washington State Parks and Recreation Commission 

WWOANW Whale Watch Operators Association Northwest 
January 2008 VI-3 

RECOVERY MEASURES AND COSTS 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

1 

Protect Southern Resident killer whales from factors causing decline 

1.1 

Rebuild depleted populations of salmon and other prey to ensure an adequate food base for recovery of the Southern Residents 

Many salmon recovery efforts and management programs are curagencies and stakeholders. It is possible that there could be additidentified based on recovery needs of Southern Resident killer wdo not have sufficient information to estimate those potential coswhich they would fall. 

1.1.1 

Support salmon restoration efforts in the region 

 See 1.1 

1.1.1.1 Habitat management 2 

NMFS, state/tribal/ local recovery initiatives, NGO, DFO 

See 1.1 

1.1.1.2 Harvest management 2 

NMFS, state/tribal/ local recovery initiatives, NGO, DFO 

See 1.1 

1.1.1.3 Hatchery management 2 

NMFS, state/tribal/ local recovery initiatives, NGO, DFO 

See 1.1 
January 2008 VI-4 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

1.1.2 

Support regional restoration efforts for other prey species 

3 

NMFS, state/tribal/ local recovery initiatives, NGO, DFO 

See 1.1 

1.1.3 

Use NMFS’ authorities under the ESA and the MSFCMA to protect prey habitat, regulate harvest, and operate salmon hatcheries 

2 NMFS See 1.1 

1.2 

Minimize pollution and chemical contamination in Southern Resident habitats 

Many pollution control and site cleanup efforts are currently ongsupport from a variety of agencies and stakeholders; (i.e., $570 mby PSP, $182 million for PSAT 2005-2007) although these funds Additional costs which may be incurred to guide specific cleanup Resident killer whales are shown below. 

1.2.1 Clean up contaminated sites and sediments See 1.2 1.2.1.1 

Identify and prioritize specific sites in need of cleanup 

2 

CTC, NMFS, EC, DFO, EPA, WDOE, WDNR 

100 30 40 

1.2.1.2 Remediate sites in need of cleanup 1 

EPA, WDNR, potentially responsible/ liable parties, Superfund sites See Appendix C 

See 1.2 
January 2008 VI-5 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

1.2.2 

Minimize continuing inputs of contaminants into the environment 

 See 1.2 

1.2.2.1 

Minimize the levels of harmful contaminants discharged by industrial, municipal, and other point sources of pollution 

3 

WDOE, EPA, ODEQ, DFO, local/ municipal/ provincial 

See 1.2 

1.2.2.2 

Minimize the levels of harmful contaminants released by non-point sources of pollution 

2 

WDOE, EPA, ODEQ, DFO, local/ municipal/ provincial 

See 1.2 

1.2.2.3 

Reduce impacts to Southern Resident killer whales from emerging contaminants 

3 

WDOE, EPA, EC, local/ municipal 

See 1.2 

1.2.3 Minimize contamination in prey 3 

WDFW, ODFW, NMFS, USFWS, tribes, DFO 

See 1.2 

1.3 

Minimize disturbance of Southern Resident killer whales from vessels 

1.3.1 Monitor vessel activity around whales 1.3.1.1 

Expand efforts to monitor commercial and recreational whalewatching vessels. 2 Soundwatch, M3, NMFS Ongoing, see also B.6.2.2 150 150 150 150 150 215 
January 2008 VI-6 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

1.3.1.2 

Evaluate the relative importance of shipping, ferry, fishing, research, military, and other vessel traffic to disturbance of killer whales. 

3 

NMFS, CTC, USCG, US Navy, industry associations 

Initial report completed with FY06 funds; 1 year task to update report 

10 25 

1.3.2 

Continue to evaluate and improve voluntary whale-watching guidelines. 

2 

NMFS, M3, Soundwatch, DFO, NGO, WWOANW 

Update guidelines in alternate years 

10 20 

1.3.3 

Evaluate the need to establish regulations regarding vessel activity in the vicinity of killer whales. 

2 

NMFS, DFO, USCG, WDFW, tribes, industry associations 

2 year task coordinated with 1.3.4 

25 50 

1.3.4 

Evaluate the need to establish areas with restrictions on vessel traffic or closures to vessel traffic. 

2 

NMFS, DFO, USCG, WDFW, tribes, industry associations 

2 year task coordinated with 1.3.3 

20 50 

2 

Protect Southern Resident killer whales from additional threats that may cause disturbance, injury, or mortality, or impact habitat 

2.1 Minimize the risk of large oil spills 
January 2008 VI-7 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

2.1.1 Prevent oil spills 1 

USCG, WDOE, EC, industry associations 

There are many ongoing oil spill programs including: Rescue Tu(1.44 million/yr) and ITOS (100K/yr) 

2.1.2 

Prepare for and respond to oil spills to minimize their effects on Southern Resident killer whales 

1 

NMFS, USCG, WDOE, WDFW, NW Contingency Plan Wildlife Section Working Group, industry associations 

One year task to develop Contingency Plan and training in alternate years, FY is TBD 

 

2.1.3 

Develop strategies to deter killer whales from entering spilled oil 

2 NMFS, WDFW One year project 22 

2.2 

Monitor and minimize the risk of disease pathogens in Southern Resident habitats 

Part of stranding response see 4 
January 2008 VI-8 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

2.3 

Continue to use agency coordination and established MMPA mechanisms to minimize any potential impacts from human activities involving acoustic sources, including Navy tactical sonar, seismic exploration, in-water construction, and other sources. 

2 NMFS

Ongoing actions include section 7 consultations; no additional costs specific to killer whale listing or recovery currently identified 

2.4 

Reduce the impacts of invasive species in Southern Resident habitats 

2.4.1 

Prevent the introduction and spread of invasive species 

3 

WDFW, USFWS, NMFS, USCG, WDOA, ODEQ, DFO, industry associations 

Washington State has ongoing invasives prevention program (2.5 

2.4.2 

Eradicate existing populations of invasive species 

3 

WDFW, USFWS, NMFS, WDOA, ODEQ, DFO, industry associations 

Washington State has ongoing invasives eradication program (3.
January 2008 VI-9 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

3 

Develop public information and education programs 

3.1 

Enhance public awareness of Southern Resident status and threats 

3.1.1 

Exhibits at local museums, aquaria, parks, and other locations 

3 

SA, TWM, WSP, VA, Tribes, NMFS 

FY03- FY07 costs were for creation of a new orca exhibit and materials for SA 

25 25 25 25 50 25 

3.1.2 School programs 3 NGO, Tribes 

FY05-FY07 costs for Killer Whale Tales, FY07 costs also for Springer Story 

25 40 27 40 

3.1.3 Naturalist programs 3 NGO, TWM 

Support training in alternate years 

 

3.1.4 Research programs 3 

NWFSC, CWR, DFO and other researchers 

Periodic research conferences, costs included under B.11 
January 2008 VI-10 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

3.2 

Expand information and education programs to reduce direct vessel interactions with Southern Resident killer whales 

3.2.1 

Expand the on-water educational efforts of Soundwatch, M3, and enforcement agencies 

2 

NMFS, Soundwatch, M3, WDFW, DFO 

NMFS costs are included here, additional costs are in 1.3.1.1 

17 35 25 25 25 25 

3.2.2 Outreach to private boaters 3 

NMFS, Soundwatch, M3, WDFW, DFO, CG 

Costs are included under 1.3.1.1 

2 

3.2.3 

Encourage land-based viewing of killer whales 

3 

TWM, Orca Relief, Lifeforce, WSP, NGO 

Update program in alternate years 

10 25 

3.3 

Educate public on positive actions they can take to improve the current condition for Southern Resident killer whales 

2 NGO, NMFS 

Some costs included under 3.1 

 25 

3.4 

Solicit the public’s assistance in finding killer whales 
January 2008 VI-11 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

3.4.1 Solicit reports of killer whale sightings 3 

NMFS, TWM, OrcaNetwork, CWR, BC Sighting Network 

Costs included under B1.1 

25 25 10 

3.4.2 

Solicit reports of killer whale strandings from the public 

3 

NMFS, NMMSN, OrcaNetwork, CWR, BC Sighting Network 

Education and outreach for NWMMSN program 

2 2 2 2 1 2 

4 

Respond to killer whales that are stranded, sick, injured, isolated, pose a threat to the public, or exhibit nuisance behaviors 

It is not possible to estimate costs for stranding response. Killer and the cost of stranding response varies greatly depending on sicapabilities, status and number of whales. The NWMMSN is invresponse and the advent of the Prescott stranding grant program hincreasing NWMMSN capabilities to respond to all strandings incontracted with UC Davis FY05-FY07 for $30K to assist with anthe west coast (4.2.3). 

4.1 

Manage atypical individual Southern Residents 

3 

NMFS, WDFW, DFO 

Dependent on severity of situation, costs could range 100K500K based on past atypical cases 

4.2 Respond to strandings of killer whales See Task 4 4.2.1 

Develop protocols for responding to stranded killer whales 

3 

NMFS, NMMSN, DFO, VA 

Action completed 

10 
January 2008 VI-12 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

4.2.2 Respond to live- stranded killer whales 2 NMFS, NMMSN, DFO, VA See Task 4 4.2.3 Investigate strandings of dead killer whales 3 NMFS, NMMSN, DFO, VA 

Cost for response to stranded killer whales in OR, CA 

10 10 10 

4.3 

Respond to future resource conflicts between the Southern Residents and humans 

3 

NMFS, others as identified 

As identified in the future 

5 

Trans-boundary and interagency coordination and cooperation 

5.1 Cooperative research and monitoring 3 NMFS, DFO, WDFW, researchers Future costs included under B.11 8 45 50 5.1.1 Population monitoring 3 

NMFS, DFO, WDFW, CWR 

Costs included under A.1 

5.1.2 Stranding response coordination 3 NMFS, DFO, WDFW 

Costs estimated as < 1K per stranding event, see 4 

5.2 

Complimentary conservation and recovery planning 

No costs identified at this time 

5.2.1 Plans are subject to periodic review 3 NMFS, DFO, WDFW 1 year task to update plan 5.2.2 Encourage public participation 3 NMFS, DFO, WDFW 1 year task to update plan 10 10 
January 2008 VI-13 

Task 

No. Task Description Priority 

Responsible 

Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 

5.3 

Inter-jurisdictional enforcement cooperation and coordination 

3 NMFS, DFO, WDFW 15 10 15 25 30 20 

 TOTALS 227 412 307 417 397 477 

TOTAL FY03- 

FY07 $1,760 TOT
January 2008 VI-14 

RESEARCH AND MONITORING 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

A 

Monitor status and trend of Southern Resident killer whales 

A.1 

Continue the annual population census 2 CWR 15 16 21 88 71 100 10

A.2 

Maintain a current photo-identification catalog for Southern Residents and staff able to photographically identify whales 

2 CWR 

Costs included under A.1 

A.3 

Standardize the results of annual population surveys 

3 CWR, DFO, NMFS 1 year task FY to be determined 

B 

Conduct research to facilitate and enhance conservation efforts for Southern Resident killer whales 

B.1.1 

Determine distribution and movements in outer coastal waters 1 

NWFSC, DFO, WFDW, researchers 

90 285 290 290 336 775 77
January 2008 VI-15 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

B.1.2 

Improve knowledge of distribution and movements in the Georgia Basin and Puget Sound 

1 

NWFSC, SWFSC, UW, TWM 

31 95 29 64 250 20

B.1.3 

Determine the effects of prey abundance and availability, and other factors on whale distribution and movements 

1 

NWFSC, UW, TWM, researchers 

Costs included under B.2.1 

B.2 

Investigate the diet of the Southern Residents 

NWFSC, DFO, WFDW, researchers 

B.2.1 

Determine the diet of the Southern Residents 

1 34 103 94 79 74 190 1

B.2.2 

Determine the importance of specific prey populations to the diet 

1 

Costs included under B.2.1 

B.2.3 

Determine the extent of feeding on hatchery fish 

3 

Costs included under B.2.1 

B.3 

Analyze the population dynamics of the Southern Residents 

NWFSC, DFO, WFDW, researchers 

Total costs for B.3.1- B.3.5 

31 29 83 68 130 1

B.3.1 Determine causes of mortality 1 B.3.2 Evaluate survival patterns 2 
January 2008 VI-16 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

B.3.3 Evaluate reproductive patterns 2 B.3.4 Evaluate population structure 2 B.3.5 Evaluate changes in social structure 2 B.4 

Investigate the health and physiology of the Southern Residents 

NWFSC, DFO, WFDW, researchers 

B.4.1 Assess the health of population members 2 Future costs TBD 50 B.4.2 Assess individual growth rates 2 TBD B.4.3 

Determine metabolic rates and energy requirements 

1 NWFSC 40 41 49 28 75 7

B.5 

Investigate the behavior of the Southern Residents 

3 

NWFSC, DFO, WFDW, researchers 

Some costs included under B.6.2.1 

B.6 Assess threats to the Southern Residents 

NWFSC, DFO, WFDW, researchers 

B.6.1 

Assess the effects of changes in prey populations 

1 
January 2008 VI-17 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

B.6.1.1 

Determine historical changes in prey distribution and abundance, and their effects on Southern Resident population dynamics 

1 NWFSC, UW 26 27 125 12

B.6.1.2 

Assess changes in prey quality and their effects on Southern Resident population dynamics 

1 NWFSC, UW 75 7

B.6.1.3 

Determine whether the Southern Residents are limited by critical periods of scarce food resources 

1 

Costs included under B.6.1.1 and B.6.1.2 

B.6.1.4 

Assess threats to prey populations of the Southern Residents 

2 

Costs included under B.6.1.1 and B.6.1.2 

B.6.2 

Assess the effects of human-generated marine noise and vessel traffic 

B.6.2.1 

Determine vessel characteristics that affect the Southern Residents 

1 

NWFSC, DFO, UW, researchers 

112 202 95 116 63 150 1
January 2008 VI-18 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

B.6.2.2 

Determine the extent that vessels disturb or harm the Southern Residents 

1 

NWFSC, DFO, UW, researchers 

Costs included under B.6.2.1 

B.6.2.3 

Determine the extent that other acoustic sources disturb or harm the Southern Residents 

2 

NWFSC, DFO, UW, researchers 

Costs included under B.6.2.4 

B.6.2.4 

Determine the acoustic environment of the Southern Residents 

2 

NWFSC, DFO, UW, researchers 

88 50 10 25 68 175 17

B.6.2.5 

Determine the hearing capabilities and vocalization behavior of the Southern Residents near sound sources 

2 

Some costs included under B.6.2.4 

B.6.2.6 

Assess the effects of human-generated marine sound on Southern Resident prey 

3 TBD 

B.6.3 Assess the effects of contaminants 
January 2008 VI-19 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

B.6.3.1 

Determine contaminant levels in the Southern Residents and other killer whale communities in the northeastern Pacific 

1 

NWFSC, DFO, WDFW 

60 40 40 40 135 1

B.6.3.2 

Determine contaminant levels in Southern Resident prey 

1 

NWFSC, DFO, WDFW 

Costs for FY07-FY11 included under B.6.3.1 

30 

B.6.3.3 

Determine the sources of contaminants entering Southern Resident prey 

1 

Costs included under B.6.3.1 

B.6.3.4 

Determine the effects of elevated contaminant levels on survival, physiology, and reproduction in the Southern Residents 

1 65 75 7

B.6.4 

Determine risks from other human-related activities 

2 As identified 

B.6.5 Evaluate the potential for disease 3 No costs identified at this time 
January 2008 VI-20 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

B.7 

Identify important habitats for the Southern Residents 

1 

NWFSC, DFO, WFDW, researchers 

Costs included under B.1.1- B.1.3 

B.8 

Determine the effects of variable oceanographic conditions on the Southern Residents and their prey 

1 

NWFSC, DFO, WFDW, researchers 

Costs included under B.1.1- B.1.3 

B.9 Determine genetic relationships 

NWFSC, DFO, WFDW, researchers 

105 65 67 40 37 150 10

B.9.1 

Determine paternity patterns in the Southern Residents 

2 

Costs included under B.9 

B.9.2 Determine the risk of inbreeding 1 Costs included under B.9 B.9.3 Determine historical population size 2 Costs included under B.9 B.9.4 

Determine genetic relationships among populations 

2 

Costs included under B.9 

15 

B.9.5 

Expand the number of genetic samples available for study 2 

Costs included under B.9 
January 2008 VI-21 

Task 

No. Task Description Priority 

Responsible Parties Comments FY03 FY04 FY05 FY06 FY07 FY08 FY

B.10 

Improve research techniques and technology 

3 

NWFSC, DFO, WFDW, researchers 

10 10 10 43 50 5

B.11 Research support and coordination 2 NWFSC 208 212 131 342 175 17 TOTALS 580 1098 1004 1060 1170 2630 25

TOTAL 

FY03-FY07 $4,912 TO

FY08
January 2008 VII-1 NMFS 

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abundance of killer whales in the nearshore waters of the Gulf of Alaska and Aleutian Islands using 

line-transect sampling. Marine Biology. <http://dx.doi.org/10.1007/s00227-006-0347-8> 
January 2008 A-1 NMFS 

Appendix A. The current “Be Whale Wise” guidelines recommended for vessels, kayaks, and 

other craft watching killer whales in Washington and British Columbia by the Soundwatch 

Boater Education Program and Marine Mammal Monitoring Project (M3). ____________________________________________________________________________________________ 
January 2008 B-1 NMFS 

Appendix B. List of major sewage treatment plants and pulp and paper mills in the Puget Sound and 

Georgia Basin regiona

.

 

Sewage treatment plants 

Washington 

Bellingham STP Lakota STP, Federal Way 

Anacortes WWTP Tacoma Central No. 1 

Mt. Vernon STP Tacoma North No. 3 

Everett STP Chambers Creek, University Place 

Lynnwood STP Puyallup STP 

Edmonds STP Sumner STP 

Metro Alki Point, Seattle Enumclaw STP 

Metro West Point, Seattle LOTT, Olympia area 

Salmon Creek WWTP, Burien Port Angeles STP 

Metro Renton, Renton Kitsap County Central Kitsap, Poulsbo 

Miller Creek WWTP, Normandy Park Bremerton STP 

Midway Sewer District, Des Moines Shelton STP 

Redondo STP, Des Moines 

 

British Columbia 

Campbell River Chilliwick 

Comox Valley Regional Northwest Langley 

Powell River Nanaimo 

Westview French Creek, Nanaimo 

Squamish Ladysmith 

Lion’s Gate, Vancouver Salt Spring Island 

Iona Island, Vancouver Sydney 

Lulu Island, Vancouver Clover Point, Victoria 

Annacis Island, Vancouver Macaulay Point, Victoria 

 

Pulp and paper mills 

Washington 

Georgia Pacific, Bellingham Kimberley-Clark, Everett 

Daishowa America, Port Angeles Simpson Tacoma Kraft, Tacoma 

Rayonierb

, Port Angeles Sonoco, Sumner 

Port Townsend Paper, Port Townsend Stone Consolidated (Abitibi)a

, Steilacoom 

 

British Columbia 

Norske Skog Canada, Elk Falls Western Pulp Limited Partnership, Squamish 

Pacifica Papers, Port Alberni Howe Sound Pulp & Paper, Port Mellon 

Pope & Talbot, Harmac Norampac Paper, New Westminster 

Norske Skog Canada, Crofton Scott Paper, New Westminster 

Pacifica Papers, Powell River 

a Adapted from Grant and Ross (2002), with additional information from the Washington State Department of 

Ecology. Many of these sites discharge their effluent directly into marine waters and may have once been 

significant polluters. b Now closed. 
January 2008 C-1 NMFS 

Appendix C. Past and present Superfund sites located in the greater Puget Sound region, with a 

listing of primary contaminants (U.S. Environmental Protection Agency 2006). 

Site name Location Contaminated media Major contaminants 

 

Northwest Transformer, 

Mission Polea

Everson, Whatcom 

Co. 

Soils, sludges PCBs, others 

Northwest Transformer, S. 

Harkness St.a

Everson, Whatcom 

Co. 

Soils, sludges PCBs, heavy metals 

Oeser Company Bellingham, Whatcom 

Co. 

Soils, sludges Others 

Whidbey Island Naval Air 

Station, Ault Field 

Whidbey Island, 

Island Co. 

Soils, marine and 

freshwater sediments, 

groundwater 

PCBs, pesticides, dioxins, 

heavy metals, others 

Whidbey Island Naval Air 

Station, Seaplane Basea

Whidbey Island, 

Island Co. 

Soils, sludges, 

groundwater, surface 

water 

Pesticides, heavy metals, 

others 

Tulalip Landfilla

 Marysville, 

Snohomish Co. 

Surface water, soils, 

marine and freshwater 

sediments, groundwater 

PCBs, DDT, heavy metals, 

others 

Harbor Island Seattle, King Co. Soils, marine and 

freshwater sediments, 

sludges, groundwater 

PCBs, heavy metals, 

petroleum products, others 

Lower Duwamish 

Waterway 

Seattle, King Co. Freshwater sediments, 

surface water 

PCBs, others 

Pacific Sound Resources Seattle, King Co. Marine and freshwater 

sediments, groundwater 

PCBs, heavy metals, others 

Pacific Car and Foundry 

(PACCAR) 

Renton, King Co. Soils PCBs, heavy metals, 

petroleum products, others 

Midway Landfill Kent, King Co. Groundwater Heavy metals, others 

Seattle Municipal Landfill Kent, King Co. Groundwater Heavy metals, others 

Western Processing 

Company 

Kent, King Co. Soils, freshwater 

sediments, groundwater 

PCBs, dioxins, heavy metals, 

others 

Queen City Farms Maple Valley, King 

Co. 

Soils, sludges, 

groundwater, surface 

water 

PCBs, heavy metals, others 

Port Hadlock Detachment, 

U.S. Navya

Indian Island, 

Jefferson Co. 

Marine sediment, shellfish, 

soils, groundwater 

PCBs, pesticides, heavy 

metals, others 

Naval Undersea Warfare 

Center 

Keyport, Kitsap Co. Soils, marine sediments, 

shellfish, groundwater 

PCBs, heavy metals, 

petroleum products, others 

Bangor Naval Submarine 

Base 

Silverdale, Kitsap Co. Soils, sludges, surface 

water, groundwater 

Heavy metals, others 

Bangor Ordnance Disposal, 

U.S. Navy 

Silverdale, Kitsap Co. Soils, sludges, surface 

water, groundwater 

Others 
January 2008 C-2 NMFS 

Appendix C. Past and present Superfund sites in the greater Puget Sound region (cont’d). 

Site name Location Contaminated media Major contaminants 

 

Wyckoff Company/Eagle 

Harbor 

Bainbridge Island, 

Kitsap Co. 

Soils, marine sediments, 

groundwater 

Dioxins, furans, heavy 

metals, others 

Jackson Park Housing 

Complex, U.S. Navy 

Bremerton, Kitsap 

Co. 

Soils, sludges, surface 

water 

Heavy metals, others 

Puget Sound Naval Shipyard 

Complex 

Bremerton, Kitsap 

Co. 

Soils, sludges, marine 

sediments, 

groundwater 

PCBs, heavy metals, 

petroleum products, 

others 

Old Navy Dump/Manchester 

Lab 

Manchester, Kitsap 

Co. 

Soils, sludges, marine 

sediments, surface 

water, shellfish 

PCBs, heavy metals, 

petroleum products, 

others 

Commencement Bay 

Nearshore/ Tideflats 

Tacoma, Pierce Co. Surface water, soils, 

marine sediments, 

groundwater 

PCBs, heavy metals, others 

Commencement Bay South 

Tacoma Channel 

Tacoma, Pierce Co. Surface water, soils, 

marine sediments, 

groundwater 

PCBs, heavy metals, 

petroleum products, 

others 

American Lake Gardens, 

McChord AFB 

Tacoma, Pierce Co. Groundwater Others 

McChord AFB (Wash 

Rack/Treat)a

Tacoma, Pierce Co. Groundwater Petroleum products, others 

Lakewood Site Lakewood, Pierce Co. Soils, sludges, 

groundwater 

Others 

Hidden Valley Landfill (Thun 

Field) 

Puyallup, Pierce Co. Groundwater Heavy metals, others 

Fort Lewis (Landfill No. 5)a

 Fort Lewis, Pierce 

Co. 

Groundwater Heavy metals, others 

Fort Lewis Logistics Center Fort Lewis, Pierce 

Co. 

Groundwater Heavy metals, others 

Palermo Well Field Tumwater, Thurston 

Co. 

Soils, surface water, 

groundwater 

Others 

a Cleanup activities considered complete with some sites removed from the National Priorities List.