Final Recovery Plan for 

Steller Sea Lions 

Eumetopias jubatus 

U.S. Department of Commerce 

National Oceanic and Atmospheric Administration 

National Marine Fisheries Service 

OEce of Protected Resources 
The illustration on the front cover is reproduced 

with permission of the artisis, Katherine Zecca, 

NMFS/Northwest Fisheries Science Center. 
RECOVERY PLAN 

for the 

ST- SEA LION 

muneto~ias jubatus] 

'Prepared by the 

!3XUER SEA LION RECOVERY TEAM 

for the 

OFFI(:=E OF PROTE- RESOURCFS 

NATIONAL NWE HSHERlES SERVICE 

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION 

SILVER. SPRING, MARYLAND 

December 1992 

Approved: 

Wfiam W. Fox, Jr. 

Assistant Administrator for Fisheries 
Ftecovery plans delineate reasonable actions which are believed to be required to recover 

and/or protect the species. Plans are prepared by the U.S. Fish and Wildlife Service and the 

Nationall Marine Fisheries Service, sometimes with the assistance of recovery teams, contractors, 

state agencies, and others. The Steller Sea Lion Recovery Plan was prepared by a recovery team 

and approved by the National Marine Fisheries Service. It does not: necessarily represent official 

positions nor approvals of all the ream niernbers or cooperating ageincies, other than the National 

Marine 1;isheries Service, involved in the plan formulation. The plan represents the official position 

of the National Marine Fisheries Service only after it has been signed by the Assistant Administrator 

for Fisheries as approved. Approved recovery plans are subject to modification as dictated by new 

findings, changes in species stahls and completion of tasks described in the plan. Goals and 

objectives will be attained and funds expended contingent upon agency appropriations and 

priorities. 

'This final plan incorporates the rlevv format that has become standard in recovery plans in 

recent years. It is intended to seIve as a :guide that delineates and schedules those actions believed 

necessary to restore the Steller sea lion as a viable self-sustaining element of its ecosystem. It is 

recognized that some of the tasks described in the plan are 'already undetway. The inclusion of 

these ongoing tasks represents an awareness of their importance, and offers support for their 

continuation. 

Literature Citation should read as follovvs: 

National Marine Fisheries Service. 19!32. Recove~y Plan for the Steller Sea Lion (Eumetopias 

jubatus). Prepared by the Steller Sea Lion Recovery Team for the Naiional Fvlarine Fisheries Service, 

Silver Spring, Maryland. 92 pp. 
TABLE OF CONTENTS 

PREiFACE ............................................................... i 

MEMBERS . . OF THE STELLER SEA LION R.EC.OVERY TEAM ......................... n 

ACKNOWLEDGEMENTS ................................................... iii 

LIST OF 1BBREVIATIONS .................................................. iv 

LISTOF1rABLES ........................................................ v 

LIST OF FIGURES ............ ., .... , ...................................... vi 

EXECUTIVE SUMMARY ....... ., .......................................... vii 

I . NATUIXAL HISTORY 

A . Species Description ............................................... 1 

B . Life History ..................................................... 1 

Distribution and Movements ...................................... 1 

Habitatuse .................................................. 2 

Reproduction ................................................ 3 

Natural Mortality .......................... ., .................. 4 

Feeding and Energetics .......................................... 4 

C . Population Status and Trend ......................................... 6 

Russia ...................................................... 7 

Alaska ..................................................... 7 

British Columbia ............................................. 9 

Washington. Oregon. and California .............................. 10 

D'. Natural Factors Influencing the Population ............................. 11 

Predation .................................................. 11 

Parasitism and Disease ........................................ 11 

Environmental Change ........................................ 12 

2 . KNOWN AND POTENTIAL HUMAN IMPACTS 

Commercial Harveslt .......................................... 13 

Subsistence Harvest .......................................... 13 

Fishery-related Taking ........................................ 14 

CompetitionforFood ......................................... 15 

ToxicSubstances ............................................ 16 

Entanglement in Debris ....................................... 17 

Disturbance ................................................. 17 
TA13LIE OF CONTENTS 

3 . SUMMARY AND CONCLUSIONS ......................................... 18 

4 . REFERENCES .......................................................... 20 

5 . TABLES ............................................................. 30 

PART I1 

1 . RECOVERY ACTIONS AND IMPLEMENTATION 

A . Goal and Objectives ............................................. 48 

B . Reclassification Criteria ........................................... 48 

C . Application of Evaluation Criteria ................................... 49 

D . Delistingcriteria ................................................ 50 

E . Stepdown Outline ................................. , .............. 50 

F . Narrative ..................................................... 54 

G . Implementation Schedule ......................................... 86 

2 . APPENDICES 

Appendix A . List of rookeries and haulouts to be counted annually 

and used in an.alysis of Steller sea lion populatioin trend ............. 89 

Appendix B . List of selected rookeries and schedule for conduct of Steller sea lion 

pupcounts ................................................ 91 
PREFACE 

On April 5, 1990, the National Marine Fisheries Service (NMFS) published an emergency 

rule listing the Steller sea lion as a threatened species under provisions of the Endangered Species 

Act (ESA). This action resulted in part from a petition submitted by the Erivironmental Defense 

Fund, which requested that Steller sea lions be designated as an endangered species. A protective 

listing was deemed appropriate because of a major, rapid decline in sea lion numbers that had 

occurred throughout most of Alaska. The final listing, published on November 26, 1990, became 

effective on December 4, 1990. 

Section 4(f) of the ESA requires that recovery plans be developed1 for endangered and 

threatened species unless the appropriat-e Secretary finds that such a plan will not promote 

conservation of the species. Each plan must incorporate: (1) a description of site-specific 

management actions that may be necessary to achieve goals for conservation and survival of the 

species; (2) objective measurable criteria that can be used to determine whether a species can be 

removed from a list; and (3) estimates of the time and costs for carrying out actions needed to 

achieve the plan's goal. 

NMFS has determined that a recovery plan would promote the ~ons~ervation of the Steller 

sea lion. This plan was wrilten by the Steller Sea Lion Recovery Team at the request of the 

Assistant Administrator for Fisheries, NMF'S. A preliminary draft Steller Sea Lion Recovery Plan was 

prepared by members of the Recovery Team and circulated to a select group of technical experts 

for review (see Acknowledgements). A revised Technical Draft was submitted to NMFS on 

February 20, 1991, and NMFS made this draft available for public review and comment. A final 

draft of the Steller Sea Lion Recovery Plan, which incorporated, to the maximum extent possible, 

all relevant comments received, was submitted by the Recovery Team to NMFS on October 3, 1991. 

11 Recovery Plan identifies the specific management actions that must be taken to ensure 

that the species of concern recovers to the point that it can be remolved from ESA listing. Unlike 

the situation with many other species where the problems and necessary remedial actions can be 

clearly identified, the factors that have caused the decline in Steller sea lion abundance are poorly 

known. It has therefore been difficult to design and evaluate the probable effectiveness of potential 

management actions. The plan recommends continuation of ongoing research and development of 

new programs designed to improve our understanding of sea lion management needs. Although 

the amount of research being conducted on Steller sea lions is increasing, it may still be a long time 

before we will understand the role of all of the factors that may be influencing the population. 

Because of these uncertainties, the Recovexy Team recognized as an immediate objective the need 

to identlfy actions that are most likely to stop the decline of the Steller sea lion population. Actions 

that are likely to have such an effect are given the highest priority in the Recovery Plan. 

When it was possible to identify a specific management action that the Team thlought likely 

to help stop the population decline or to enhance recovery of the Steller sea lion population, that 

action has been specifically recommen,ded in the Recovery Plan. The Team also described a 

monitoring program that should be conducted in order to allow a continuing evaluation of the 

population trend and status of Steller sea lions. Results from research and monitoring programs 

will be considered in subsequent revisions and modifications to this Recovery Plan. 
The goal of this Recovery Plan will be met when the Steller sea lion population has 

recovered to the extent that it can be removed from ESA listings. It is possible that at that point 

the species would still qualify for listing as depleted under terms of the MMPA, and it would 

therefore be necessaly for a conservatioin plan to be in place. In ithat case, the Recovery Plan 

should be reviewed and revised as necessary to reflect MMPA requirements and the biological and 

ecological situations at that time. 

MEMBERS OF THE SELLER SEA LION RECOVERY TENM 

Dayton 1,. Alverson, Natural Resources Clonsultants 

Jim Branson, North Pacific Fisheries Management Council (retired) 

Vernon IByrd, U. S. Fish and Wildlife Service 

Donald Calkins, Alaska Department of Fish and Game 

Robert Gisiner, Department of the Navy 

Carolyn Heath, Fullerton College 

Pete Isleib, Pacific States Marine Fisheries Commission 

Jack Lentfer, Marine Mammal Commission 

Thomas Loughlin, National Marine Fisheries Service 

Lloyd Lowry (Chairman), Alaska Departlnent of Fish and Game 

Donald Siniff, University of Minnesota. 
ACKNOWLEDGEMENTS 

The Steller Sea Lion Recovery Team is appreciative of the assistance provided by Dr. Nancy 

Foster, Director, and Dr. Charles Karnella, Deputy Director, of the Office of Protected Resources, 

National Marine Fisheries Service (NMFS:), and NMFS personnel who served as advisors to the 

Team: Jim Balsinger, Georgia Cranmore, Karl Gleaves, Sue Mello, Mike Payne and Dr. Steve 

Zirnmerm;an. 

The Recovery Team and NMFS wo~uld also like to to acknowledge and thank the following 

individuals and institutions for their review of the preliminary technical draft of the Steller Sea Lion 

Recovery Plan: David Ainley (Point Reyes Bird Observatory), Jay bar lo^^ (NMFS, Southwest 

Fisheries Center), Robin Brown (Oregon Department of Fish and Wildlife), John Bums (Alaska 

Departmelnt of Fish and Game, leetired), Mike Castellini (University of Alaska), Dan Costa 

(University of California at Santa Cruz), William Gilmartin (NMFS, Southwest Fisheries Center) 

Hans Harzman (University of Washington), Terry Haynes (Alaska Department of Fish and Game), 

Robert Hofman (Marine Mammal Commi:jsion), Anne Hoover-Miller (Pacific Rim Research), Karl 

Kenyon (U.S. Fish and Wildlife Service, retired), Jon Lewis (Alaska Department of Fish and Game), 

Richard Merrick (NMFS, National NIarine Mammal Laboratory), Karl Schneider (Alaska Department 

of Fish and Game). 

The Recovery Team and NMFS are very grateful to the institutions and agencies that 

supported the Recovery Team members' participation and logistics in the planning effort. These 

include the Alaska Department of Fish and Game, U.S. Fish and Wildlife Service, Natural Resources 

Consultants, U.S. Department of tlhe Navy, Fullerton College, the Pacific States Marine Fisheries 

Commission, Marine Mammal Comrnissio~n, and the University of Minnesota. 
ABF 

ADFG 

CDFG 

DOS 

DFO 

ESA 

FWS/NWR 

MMPA 

NMFS 

NMML 

NPFMC 

ODFW 

PRBO 

PSMFC 

USCG 

VNIRO 

LIST OF ABBREWATIONS 

Alaska Board of Fisheries 

Alaska Department of Fish and Game 

California Department of :Fish and Game 

U.S. Department of State 

Department of Fisheries and Oceans, Canada 

Endangered Species Act of 1973, as amended 

U.S. Fish and Wildlife Service, National Wildlife Refuge System 

Marine Mammal Protection Act 

National Marine Fisheries Service 

NMFS, National Marine Elllamma1 Laboratory 

North Pacific Fisheries Management Council 

Oregon Department of Fish and Wildlife 

Point Reyes Bird Observatoiry 

Pacific States Marine Fisheries Commission 

United States Coast Guard 

All-Union Research Institute for Fisheries and Oceanography, Moscow, Russia 
Table 1. 

Table 2. 

Table 3. 

Table 4. 

Table 5. 

Table 6. 

Table 7. 

Table 8. 

Table 9. 

Table 10. 

Table 11. 

Rank order of importa.nce of prey in the stomach of Steller seai lions collected in 

Alaska. 

All prey identified from stomachs of Steller sea lions collected inthe Gulf of Alaska 

during 1975-78 (n= 153) and 1985-86 (n=74). 

Major prey identified :from stomachs of Steller sea lions collecte:d near Kodiak 1975- 

78 (n=49) and 1985-.86 (n==74). 

Counts of Steller sea lions in Russia during 1988-89 and prior to the decline in 

abundance. 

Counts and percent declines of adult and juvenile Steller seis lions at a11 sites in 

spring and summer 1956 to 1989 in the Aleutian Islands and Gulf of Alaska. 

Counts of Steller sea lion pups at sites in the Aleutian Islands and Gulf of Alaska, 

1978-89. 

Comparison of counts and ]percent declines of adult and juvenile Steller sea lions in 

the central and western Gulf of Alaska and eastern and central Aleutian Islands based 

on data from all sites counted (from Table 5) and 77 trend sites. 

Counts of Steller sea lions in the eastern Gulf of Alaska, 1976-1991. 

Counts of Steller sea lions at rookeries in southeast Alaska, 1979-1991. 

Summer aerial counts of Steller sea lions at major rookeries .in Oregon, 1975-1989. 

Summer counts of adult and juvenile Steller sea lions at major rookeries in 

California, 1927- 1989. 
LIIST OF FIGURES 

Fig. 1. Map of the North Pacific Clcean showing the general range of Steller sea lions (stippled 

area) and the location of mlajor rookeries (arrows). 

Fig. 2. Overall trend in Steller sea. lion counts in the region from the Ke~lai Peninsula to Kiska 

Island, 1960-1989 (from M~errick et al., 1990). 

Fig. 3. Locations of Steller sea lion rookeries and major haulouts in the Kuril Islands and Okhotsk 

Sea. 

Fig. 4. Locations of Steller sea lion rookeries on Kamachatka and the Commander Islands. 

Fig. 5. Locations of Steller sea lion1 rookeries in the Aleutian Islands and Bering Sea. 

Fig. 6. Locations of Steller sea lion, rookeries in the Gulf of Alaska and southeast Alaska. 

Fig. 7. Locations of Steller sea lion. rookeries and major haulouts in British Columbia. 

Fig. 8. Locations of Steller sea lion rookeries and major haulouts in lOrego11 and Califoirnia 
EXECm SUMMARY 

A major decline in the abundancz of Steller sea lions has occurred throughout their range 

over the past 30 years. Counts of adults and juveniles in the region from the Kenai Peninsula to 

Kiska Island (i.e., the central and westenn Gulf of Alaska, and the eastern and central Aleutian 

Islands) declined 63% between 1985 anld '1989. The greatest decline oclcurred in the eastern 

Aleutian Islands, where 10,802 sea lions were counted in 1985 but only 3,145 in 1989. The 

number of sea lions at Seguam Island, a rookery in the central Aleutiain Islands, declined 80% from 

1985 to 1989; pup counts at Seguarn also declined 80% from 1985 to 1989. A comparison of trend 

sites (roolkeries and haulouts that h~ave been counted during every major suivey) between the late 

1950s and 1990 showed an overall decline of 78%. Population modeling suggests that decreased 

juvenile survival was the most likely cause of the decline in sea lions in the central Gulf of Alaska 

during 11375-1985. Analysis of 1991 counts indicates an additional decline of approximately 5% 

in the overall number of animals on the trend sites since 1989-1990. 

The number of adult and juvenile animals in the Gulf of Alaska and Aleutian Islands 

formerly represented about 75% of the world population (Gulf of Alaska = 38%; Aleutian Islands 

= 37%); however, the proportion is changing as the Alaskan portion of th.e population declines. 

Both natural and human-caused factors h~ave been hypothesized as clontributing to these declines. 

Changes in the quantity or quality of available prey may influence the health anti fitness of 

individu(a1 sea lions. Evidence that major shifts have occurred in the abundance of fish in the 

Bering Slea over the past several decades is well documented. In the 1950s and early 1960s, the 

most abundant pelagic species was Pacific herring, whose biomass exceeded ,3-5 million metric tons. 

However, rapid increases in the estimatedl size of walleye pollock stocks in both the Bering Sea and 

Gulf of Alaska occurred between the 19610s and 1980s. In the late 1070s, walleye pollock biomass 

increased significantly, from an estimated 0.8 million to more than 3.5 million metric tons. Recent 

estimates indicate that the pollock biomass has accounted for nearly 85% of the pelagic fish 

populatilon in that region. Walleye pollock have been shown to be an important prey of Steller sea 

lions in the Gulf of Alaska, Bering Sea, and North Pacific Ocean. Commercial fisheries which 

target on several of the most impc~rtant prey species of Steller sea lions, including pollolck, remove 

millions of metric tons of fish, much of which is potential sea lion food. The development and 

expansion of commrnercial fisheries throughout the species' range may have caused detrimental 

changes in the sea lions food supply. However, the complexity of ecosystem interactions, and 

limitations of data and models make it difficult to determine how fishery removals may have 

influenced the population. 

Natural changes in the environment may also be partly responsible for the decline in 

numbers of Steller sea lions in solme areas. The factors responsible for producing these changes, 

however, are not well known. 'Thus, although there is evidence suggestive of changes in the 

abundance of major fish species and rhe environment, the causeis of tlnese changes and their 

influence on Steller sea lion population trend are largely unknown. 

vii 
The overall goal of this Recovery Plan is to promote recovery of the Steller sea lion 

population to a level appropriate tlo justify removal from ESA listings. Immediate objectives are to ( 

identify lfactors that are limiting the population, to propose a set of actions that will minimize any 

human-induced activities that may be debimental to the survival or recovery of the population, and 

actions necessary to cause the populatior~ to increase. Although it is not clear what factors have 

contributed to the Steller sea lion population decline, and it is apparent that a great deal of 

information vital to the effective management of the species is lacking, theire is an urgent need to 

take immediate actions to safeguard against further population declines, and to provide for recovery 

of the species. Immediate actions that should be taken include efforts to reduce human-caused 

mortality to the lowest level practicyable, protection of important habiltats through buffer zones and 

other means, and enhancement of population productivity by ensuring that there is an ample food 

supply available. Conservation and management measures implemented when Steller sea lions were 

listed unider the ESA, and since, have addressed some of these needs. Additional management 

actions are described in the Recovlery Plan. Progress toward achieving these goals and objectives 

will be measured by criteria for delisting of the species which are described in the Plan. 

The Recovery Team believes that management designed to provide for recovery of the sea 

lion population should be based on biological principles and ecodogical, understanding. The 

research program recommended by the Recovery Team will require a considerable amount of funds, 

time, and effort to produce the information needed to design a complete and effective set of 

conservation measures. Management agencies therefore should not p~reclude consideration of more 

immediate conservation measures or mainagement experiments that could further reduce human 

impacts, or that would respond to proposals by the scientific community designed to evaluate 

certain hypotheses. 

. . . Vlll 
I. NATU1.N HISTORY 

k Species Description 

Sea lions belong to the Order Carnivora, Suborder Pinnipedia, Family Otariidae, and 

Subfamily Otariinae. The family contains the extant genera Arctocephalus, Callorhinus, 

Eumetopias, Neophoca, Otaria, Phocarctos, and Zalophus. The genus Eumetopias contains one 

species, the Steller (northern) sea lion, E. iubatus. Unless noted otherwise, all references to sea 

lions in this document are to Steller sea lions. 

Steller sea lions are the largest ottariid and show marked sexual dimorphism, males being 

larger than females. The average adult standard length is 282 cm far males and 228 cm for 

females (maximum of about 325 cm and 290 cm); weight of males averages 566 kg and females 

263 kg (maximum of about 1,120 kg ancl 350 kg) (Fiscus, 1961; Cabs and Pitcher, 1982; 

Loughlin and Nelson, 1986). The light buff to reddish brown pelage is slightly darker on the 

chest and abdomen. Naked parts of the skin are black (King, 1954). Adult males have long, 

coarse hair on the chest, shoulder:;, and back; the chest and neck are massive and muscular. 

Newborn pups are about 1 m long, weigh 16-23 kg, and have a thick, dark-brown coat that 

molts to lighter brown after 6 months. A more detailed description is provided in Loughlin et 

al. (1987) and Hoover (1988). 

B. Life History 

Distribution and Movements 

Sea lions probably evolved in temperate waters of the North Pacific Ocean (Repenning 

and Tetiford, 1977). The earliest known remains of an otariid are between 10 and 12 million 

years olld (Repenning, 1976). Three to four million year old fossil remains of Steller sea lions 

have been found in California. 

The present range of SteUer sea lions (Figure 1) extends around the North Pacific Ocean 

rim from northern Japan, the Kulril Islands and Okhotsk Sea, through the Aleutian Islands and 

Bering Sea, along Alaska's southern coast, and south to California (Kenyon and Rice, 1961; 

Loughlin et al., 1984). In the western Pacific, animals occasionally haul out as far south as 

Hokkaido Island in Japan. 

The centers of abundance and distribution are the Gulf of Alaska and Aleutian Islands. 

Seal Rocks, at the entrance to Prince William Sound, Alaska, is the northernmost rookery 

(60°09'N). Most large rookeries are in the Gulf of Alaska and Aleutian Islands (Kenyon and 

Rice, 1961; Calkins and Pitcher, 1982; Loughlin et al., 1984; Merrick et al., 1987). Afro Nuevo 

Island off central California is the southernmost rookery (37"06'N), although up until 1981 

some pups were born at San Mipel Island (34O05'N). Most of the information on Steller sea 

lion distribution has been colleclted during summer months. Distribution during late fall and 

winter is poorly known. 
Steller sea lions are not known to migrate, but they do disperse widely at times of year 

other than the breeding season. Males that breed in California are rarely seen in California or 

Oregon except for May through August, and appear to spend the non-breeding months in Alaska 

and British Columbia. During fall and winter in Alaska, sea lions may occur at rookeries and 

haulouts that are used during the summer; they are also seen near sea ice and islands in the 

northern Bering Sea. Females generally return to rookeries of their birth to pup and breed 

(Kenyon and Rice, 1961; Calkins and Pitcher, 1982; Loughlin et al., 1984; Calkins, 1986; 

Kajirnuria and Loughlin, 1988). Animals marked at rookeries in the Gulf of Alaska have been 

sighted in southeast Alaska and British C:olumbia; some marked in British lColumbia have been 

seen at Cape St. Elias, Alaska; some marked in the eastern Aleutians have been seen in eastern 

Bristol Ray, Alaska; and some marked in Oregon have been seen in northern California, 

Washing~on, British Columbia, anti southeast Alaska (Calkins and Pitcher, 1982; Calkins, 1986; 

R. Brown, personal communicatio~n; NMIVIL. files). In most cases, resights have been of juvenile 

animals on haulouts. Pups tagged in the Kuril Islands have been resighted in China's Yellow 

Sea at the Bo Hai bar, and in Japan as far south as Yokahama (NMIVIL files). 

There have been limited studies to develop biological criteria1 for separating animals in 

different geographic regions into separate populations. A single study of biochemical variation 

in Steller sea lions suggested little genetic variation within the Gulf of Alaska (Lidicker et al., 

1981). Comparisons are being made among animals from more widely separated locations. The 

work on this subject is ongoing at the NIMML. Since animals disperse widely after the breeding 

season and intermix with animals from other areas, it is difficult to identify individual animals 

once away from the rookery as belonging to a specific reproductive population. 

Habitat 

Steller sea lion habitat includes marine and terrestrial areas that are used for a variety of 

purposes. The most well-known h~abitats a.re the rookeries where aclult animals congregate for 

pupping and breeding. Rookeries usua1l:y occur on beaches of relatively remote islands, often in 

areas exposed to wind and waves, where access by humans and other mammalian predators is 

difficult. Substrates include sand, gravel, cobble, boulder, and bedrock. Rookeries may extend 

across low-lying reefs and islands, or ma,y be restricted to a re1ativel.y narrow strip of beach by 

steep cliffs. Rocky points may divide the animals using an area into subgroups. 

F:emale sea lions appear to select places for giving birth that are gently sloping and 

protected from waves (Sandegren, 1970; Etlie, 1977). Pups normally stay on land for <about 

2 weeks,, then spend an increasing amount of time in intertidal area:; and swimming near shore. 

A haulout is the term used to describe areas used by adult sea lions during times other 

than the breeding season, and by inon-breeding adults and subadults throughout the year. Sites 

used as irookeries in the breeding season may also be used as haulouts during other tinnes of 

year. Many other rocks, reefs, ancl beaches are also irregularly used as resiting sites. Sea lions 

are sometimes seen hauled out on jetties and breakwaters, navigational aicls, floating docks, and 

sea ice. Many animals also use traditional rafting sites, which are places where they rest on the 

ocean surface in a tightly packed group (Bigg, 1985; NMML files). 
Although rookeries and haul~~uts occur in many types of areas, the locations that are 

used are specific and change little from year to year. Factors that influence ithe suitability of a 

particular area may include substrat~e, exposure, proximity to food resources, tradition of use, 

and season (Calkins and Pitcher, 1982), as well as the extent and type of human activities in the 

region (Johnson et al., 1989). Thermoreglulatory factors may play an important role in site 

selection (Gentry, 1970; Sandegren, 1970). 

Wlnen not on land, Steller sea lions; have been seen from nearshore, out to the edge of 

the continental shelf. Some individuals may enter rivers in pursuit of prey (Jameson and 

Kenyon, 1977), while in the Gulf of' Alaskis, they commonly occur near the 200 m depth contour 

(Kajirnura and Loughlin, 1988). They have been caught on fishing lines at (depths of 183 m 

(Kenyon, 1952; Fiscus and Baines, 1966). 

Ongoing studies using satellite telemetry are providing detailed information on feeding 

areas and diving patterns (NMML, iunpublished data). Tagging effort has concentrated on adult 

females in the central Gulf of Alaska and Aleutian Islands. Preliminary analysis of data from six 

animals tagged in the summer indicated tlhat they stayed close to the rookeries (within 30 km), 

took brief trips to sea (2 days or less), and made shallow dives (mean depth less than 30 m, 

with a maximum of 120 m). Data from five animals followed during winter indicate longer 

trips to sea (up to 4 months), farther offshore (over 450 km), and deeper dives (mean depths up 

to 84 m, with a maximum of 273 nn). 

Breeding adult animals, anti some subadults, occupy rookeries during the breeding 

season, which extends from late May to early July (Pitcher and Calkins, 1981; Gisiner, 1985). 

Some breeding may occur at haulout sites between females which are not giving birth and males 

which cannot hold temtories. Pregnant females arrive at the rookery about 3 days before pups 

are born (Gentry, 1970). Females frequently return to the same pupping site in successive 

years, and the pupping site may be the same as or near the site of the female's birth 

(Sandegren, 1970). Females of reproductive age which were tagged as pups at Rogue Reef, 

Oregon have been seen at Orford Reef aind St. George Reef rookeries (32 km to the north and 

56 km to the south, respectively) during the breeding season; one of these females was nursing 

a pup (R. Brown, personal commtmnication]. Copulation generally occurs on the territories at 11 

to 14 da~ys postpartum (Gentry, 1970; Sandegren, 1970). Females usually copulate with only 

one male, not necessarily within the territory where her pup was born (Gentry, 1970; Gisiner, 

1985). Once a territory is acquired, a male may occupy it for up to seven consecutive breeding 

seasons (Gisiner, 1985). Subadult and adult males that are not able to hold territories 

frequently occupy areas adjacent to rookery areas. 

In samples collected during the rnid-1980s, 34 of 35 females age 6 years and older had 

ovulated (Calkins and Goodwin, 1988). Implantation of the embryo occurs late September 

through early October, after a del,ay of 3 to 4 months (Pitcher and Calkins, 1981). Implantation 

is probably linked to the photoperiod 8.5 months prior to birth (J. Tempe, personal 

communication). Twenty-two of 24 animals (92%) between ages 7 and 2,O years were pregnant 

when they were collected in October (Calkins and Goodwin, 1988). Resorption of the fetus or 

premature births may occur throughout gestation. Viable births occur from late May through 
early July (Pitcher and Calkins, 1981). Birth rates, based on the percent c)f breeding age 

females pregnant in April to May, are about 60-75% throughout the range (Belkin, 1966; 

Pitcher and Calkins, 1981; Caha and (Goodwin, 1988). The sex ratio at birth is close to parity 

but slightly favors males; twmm . . g is rare. 

The pregnancy rate of sexually nnahre females collected in the Gulf of Alaska during 

April-May 1985 was 6094, which was lower than the 67% found there in 1975-1978, although 

the difference was not statistically significant (Pitcher and Calkins, 1981; Calkins and Goodwin, 

1988). There are no data on rep~roductive rates prior to 1975. 

Females reach sexual maturity between 3 and 6 years of age and rnay produce young 

into their early 20s (Mathisen et al., 1962; Pitcher and Calkins, 1981). Adult females are 

monestu-ous and most breed annually (Pitcher and Calkins, 1981). Males reach sexual. maturity 

between 3 and 7 years of age and physi~cal maturity by age 10 (Perllov, 1971; Pitcher and 

Calkins, 1981). Thorsteinson and Lensbnk (1962) found that 90% of males holding territories 

on rookeries in the western Gulf of Alaska were between 9 and 13 years of age. 

Natural Mortality 

Causes of pup mortality include drowning, starvation caused by selparation froin the 

mother, crushing by larger animals, disease, predation, and biting by females other than the 

mother (Oar and Poulter, 1967; Eldie, 1977). Pup mortality on rookeries has not been 

thoroughly studied. The number of juve!niles counted at Ugamak Island was much lower in 

1985-1986 than in the 1970s, which may indicate that the mortality of pups increases after 

leaving the rookery (Memck et al., 19881). 

Steller sea lions are probably eaten by killer whales and sharks, but the possible impact 

of these predators is unknown. The occurrence of shark predation on other North Pacific 

pinnipeds has been documented, but not: well quantified (Ainley et al., 19435). 

Calkins and Pitcher (1982) used life tables constructed from sampl~es collected in the 

Gulf of Alaska in 1975-1978 to estimate mortality rates. The estimated mortality rate from birth 

to age 3 was 0.53 for females and 0.74 for males. Mortality rate for females dropped to 0.11 by 

the sixth year and remained at about that level in older age classes. Male mortality rates 

decreased from 0.14 in the third year to O:12 in the fifth year. Females may live to 30 years and 

males to1 about 20 (Calkins and Pitcher, 1982). 

J'ork (in preparation) produced a revised life table for female Steller sea lions using the 

same data as Calkins and Pitcher (1982) but a different model (based on the Weibull survivor 

function). The estimated annual mortality from York's life table wars 0.22 for ages 0-2, dropping 

to 0.07 at age 3, then increasing g~adually to 0.15 by age 10 and 0.'20 by age 20. Population 

modellir~g suggested that decreased juveide survival was the most likely cause of the decline in 

sea lions in the central Gulf of Alalska du~ri~ig 1975-1985 (York, in preparation). 
Feeding and Energetics 

Diet studies conducted over the past 15 years show that Steller sea lions eat a variety of 

fishes and invertebrates; demersal and off-bottom schooling fishes predominate (Jones, 1981; 

Pitcher, 1981). Harbor seals, spotted seals, bearded seals, ringed seals, fur seals, and sea otters 

are also occasionally eaten (Gentry and .lohnson, 1981; Pitcher and Fay, 1982; D. Calkins, 

unpublished data). 

A small number of sea lions collected at sea, or found dead on shore, in California and 

Oregon had eaten rockfish, hake, flatfish^, cusk eel, other fishes, squid, andl octopus (Fiscus and 

Baines, 1966; Jones, 1981; Treacy, 1985). In the Rogue River, 87%) of the observations of prey 

being eaten at the surface were off lamprey (Jameson and Kenyon, 1977). Feeding on lamprey 

in estuaries and river mouths has also been documented at other sites in Oregon and California 

(Jones, 1981; Treacy, 1985). Prirlcipal prey identified from stomachs and scats collected in 

British Columbia included hake, herring, octopus, Pacific cod, rockfish, and salmon (Spalding, 

1964; Olesiuk et al., 1990). While these data are not comprehensive, especially for California 

and Oregon, they do show that rockfish and hake are consistently important components of the 

diet. In the Kuril Islands, Atka mackerel, sand lance, rockfish, and loctopus have been identified 

as important sea lion foods (Panina, 1966). 

Results of major diet studies conducted in Alaska since 1975 are summarized in Table 1. 

Walleye pollock was the principal prey iin all areas and years, with Pacific cod, octopus, squid, 

herring, flatfishes, and sculpins also consumed. Smaller collections of material from the central 

Bering Sea and eastern Aleutian Islands also indicated that pollock has been an irnpoirtant food, 

with octopus, squid, rockfish, herring, cod, flatfish, and other fishes also eaten (Lowry et al., 

1982; T. R. Loughlin, unpublished data). 

Based on measurements of undigested otofiths from stomachs of 90 sea lions collected in 

the Beling Sea during 1976-1981, the lengths of walleye pollock e<aten ranged from 8.2 to 64.2 

cm, with a mean fork length of 29.3 cni (Frost and Lowry, 1986). The estimated mean lengths 

of walleye pollock consumed ranged from 21.8 to 46.9 cm in nine collections made at various 

locations in the Bering Sea and (3ulf of Alaska during 1976-1986 (Lowry et al., 1989). 

Seasonal aspects of prey utilization have not been analyzed in detail. Many reports have 

lumped samples collected at various times of year which may give a false impression of the 

overall importance of prey species. Pitlcher (1981) noted that in the Gulf of Alaska, salmon and 

capelin were eaten primarily in spring and summer. In the Kodiak Islancl area where samples 

were collected in all seasons, walleye pollock, cod, and octopus were eaten througholut the year 

(Calkins and Pitcher, 1982). 

During the breeding season females with pups feed principally at night (Higgins et al., 

1988); territorial males remain on land and fast during the breeding season (Spalding, 1964; 

Gentry, 1970; Withrow, 1982; Gisiner, 1985). 

Recent collections have not been thoroughly analyzed for possib1.e variations in diet 

among different age and sex classes. ldecause of large differences in body size, and in the 

behavior of animals of different reprotluctive status, such variations in tlne diet may be 

substantial (Spalding, 1964). Frost and Lowry (1986) measured otolith:~ from the st:omachs of 
88 sea lions collected in the westeirn Bering Sea in March-April 1981, and found that sea lions 

less than 4 years old ate sigdicantly smaller walleye pollock than did older animals (estimated 

mean fork length 22.4 cm versus 26.9 cm). 

Historical data on stomach contents of sea lions collected in Alaska may indicate some 

long-tern1 changes in diet. Walleye pollock was not a major food of animals collected at 

Chernabura Island in 1958 (Mathisen et al., 1962), or in Unirnak Pass and other locations in 

1960 (Fiscus and Baines, 1966). This is in marked contrast to results from 1975-1978; however, 

the sampling was not comparable in the various studies (Pitcher, 1981). In 1945-1946, seven of 

eight stomachs examined from southeastern Alaska and five of seven from the Kodiak-Kenai 

area contained mostly walleye pollock (Inller and Sarber, 1947). 

A more recent comparison has been made of stomach contents in sea lions collected in 

the Gulf of Alaska in 1975-1978 and 198!5-1986 (Calkins and Goodwin, 1988). A major 

difference was that capelin was one of the main prey species in the earlier collection, but did 

not occur at all in 1985-1986 (Table 2). 'This was thought to be in part a result of the timing of 

collections. The relative importancle of octopus and flatfish in the diet was much greater in 

1985-1986, while herring and squid were of lesser importance. Whein the clverall diet in the 

Gulf of Alaska for the mid-1970s is compared to samples from Kodialc in 1985-1986, wadeye 

pollock were eaten more frequently (66% versus 58%) and comprised a greater proportion of 

the stomach contents (58% versus 42%) iin the earlier sample. 

If only Kodiak area samples are co:mpared (Table 3), walleye pollock. was eaten more 

frequently in the 1980s than the 1970s (58Vo versus 39%). Walleye pollock consumed in 

1985-1986 were of smaller average size (25:4 cm fork length versus 29.8 cm). Capelin and 

salmon were both important foods 1x1 the ]mid-1970s but were insignificant items in 1985-1986. 

The average volume of stomach contents for animals collected in the Kodiak area was much 

greater in 1975-1978 (1,317 ml) than in 1985-1986 (745 ml). 

Al1:hough there is information availlable on feeding rates of pinnipeds in general (e.g., 

Innes et al., 1987), the food and energy requirements of Steller sea lions are not well known. 

Keyes (1968) concluded that adult, nonpregnant, nonlactating individuals would require 6-10% 

of their body weight in food per day. Hovvever, this estimate was derived from feeding rates of 

captive seis lions and may not reflect the energy requirements of free-ranging animals. Daily 

food consumption by an average individual in the population has been estimated to be about 

14.3 kg (Calkins, 1988). The amount of food required to provide for energetic needs can vary 

greatly depending on the energy content of the food and physiological status of the animal 

(Innes et al., 1987). Pups grow rapidly during their first weeks of life and require a substantial 

intake of energy which is supplied by the rnother. Steller sea lions pups at Mo Nuevo Island 

consumed 1.5-2.4 liters cjf milk per day while nursing (Higgins et al., 1988). The milk 

contained 23-25% fat. Perez and Mooney (1986) determined that the average daily feedling rate 

for lactating northern fur seals was 1.6 times higher than for nonlactating females. 

C. Population Status and Trend 

Although there is currently no reliable estimate of the total number of Steller sea lions, 

index counts of animals present on land at standardized dates and times indicate a major 
decline has occurred over the past :30 yeairs (Figure 2). Furthermore, a survey throughout the 

sea lion range in 1989 revealed that the decline is widespread, with a majoir reduction 

throughout the area from the Kenai Penir~sula to the Kuril Islands (Loughlirl et al., 1989; 

Merrick et al., 1990). 

It is difficult to obtain an accurate census of the population because an unknown 

number of animals are away from the rookery or haulout site and are missed during surveys. 

Therefore, available counts represent an index of population size, and not an estimate of the 

total nunnber of sea lions. An estimate of the total population size requires correction factors 

for missed animals. Correction factors must account for the amount of time the missed animals 

spend at sea, and the age/sex composition of the uncounted segments of the population. Pup 

production should also be added to the count for a complete population estimate. Ongoing 

research using satellite telemetry may provide some of the data needed to calculate correction 

factors. Based on an analysis of age/sex composition and survival rates, Calkins and Pitcher 

(1982) suggested that the total number of animals present at the end of th.e pupping season in 

the Gulf of Alaska was about 4.5 times the number of pups born. This multiplier was derived 

from collections made in the mid-1970s ,and may not be applicable to the current poprrlation. 

ti survey that counted sea lions tlhroughout most of their range wa:j completed in 1989 

and the data are currently being prepared for publication by U.S. and Russian biologists. 

Currentlly available data on population status and trend for each geographical region are 

summarized below. However, it must be remembered that these regions are based on 

geographical and political boundaries, and do not necessarily represent discrete stocks or 

management units. 

Russia (Figures 3 and 4) 

A comparison of recent and historic counts of Steller sea lions in the Russian Federation 

indicates that the present number of animals is about one-third of historic levels (Table 4). In 

some instances, the decrease in numbers has been accompanied by complete disappearance of 

rookeries (Perlov, 1991). Numbers of adult and juvenile sea lions at major rookeries and 

haulouts in the Kuril Islands have decliined 74%, from 14,076 in 1969 to 3,615 in 1989 (Memck 

et al., 1990). Most of the decline occurred between 1969 and 1974. The numbers since about 

1974 appear to have remained stable. Pup numbers have declined 60%, from 3,673 in 1963 to 

1,476 in 1989. Based on 1989 counts Burkanov et al. (1991) estirnated that the total number of 

sea lions, including those on haulouts, rookeries and those observed swirnming in the water 

near the site at the time of the survey, along the Kamchatka Peninsula and the Commander 

Islands was 3,500-3,800. Estimates for this region made in 1982-1985 were 1.6 to 3.5 times 

larger. This decline is similar to what has occurred in the U.S. portion of the Bering Sea, and is 

thought likely to continue (Perlov, 1991). There are about 2,000 sea lions on a few small 

island:; in the Sea of Okhotsk, where numbers are reduced from previous levels, but :stable 

(Perlov, 1991). 

Alaska (Figures 5 and 6) 

The first reported count:; of Steller sea lions in Alaska were made in 1956-1960 (Kenyon 
and Rice, 1961; Mathisen and Lopp, 1963). The results suggested that there were at least 

140,0001 Steller sea lions in the Giulf of Alaska and Aleutian Islands at that time (Merrick et al., 

1987). Subsequent surveys have shown a major decline in numbers, first detected in the eastern 

Aleutian Islands in the mid-1970s (Braham et al., 1980). The decline appears to have spread 

eastward to the Kodiak Island are,a during the late 1970s and early 1980s and westward to the 

central and western Aleutian Islantds during the early and mid 1980s (Merrick et al., 1987; Byrd, 

1989). The greatest declines were observed in the eastern Aleutian Islandls and western Gulf of 

Alaska, but declines also occurred in the central Gulf of Alaska and central Aleutian Islands 

(Table 5). Sighting data collected1 from 1976-1979 indicated a total of approximately 104,000 

sea lion:; counted in this region. 

Counts of adults and juverliles in the region from the Kenai Peninsula to Kiska Island 

(i.e., the central and western Gulf of Alaska, and the eastern and central Aleutian Islands) 

declined 63%, from 67,617 to 24,953, between 1985 and 1989 (Lou~ghlin et al., 1990). The 

greatest decline occurred in the eastern Aleutian Islands, where 10,€102 sea lions were counted 

in 1985 but only 3,145 in 1989 (Table 5). The greatest decline at any one rookery occurred at 

Seguam Island in the central Aleutian Islands. The number of sea lions counted at Sepam 

declined 80% from 2,942 animals in 1985 to 602 in 1989; pup counts at Seguam also declined 

80% from 1985 to 1989 (Table 6). At NIarmot Island (in the Gulf of Alaska), a 38% decline 

occurredl from 1986 to 1989 in the adult count, and 48% in the pup count. Pinnacle Rock 

rookery in the western Gulf of Alaska shlowed the smallest decline of adults and juveniles (at 

14%). No surveyed location showed a sigmficant increase. 

Aerial and ship-based surveys weire again conducted in the Kenai to Kiska region in 1990 

(Merrick et al., 1991). The total number of adults and juveniles counted was 27,860. 

Compared to 1989, there was a decreaseld number of animals counted in the central Gulf of 

Alaska, and an increased count in the other three regions (Table 5). Between 1989 and 1990 

number of adults and juveniles increased at 12 of 25 rookeries counted. Large declines also 

occurred at some sites, particularly in the area from Sugarloaf to Chernabura Island. Pup counts 

at Bogoslof and Seguam Islands increased by 29% from 1989 to 1990, while the pup 

count at Kiska Island decreased by 25% (Table 6). In most cases, the changes in counts from 

1989 to 1990 may be within the range of natural fluctuations and variability inherent in the 

survey techniques, and therefore slhould inot be interpreted as evidence for a trend. 

Some of the apparent variability in abundance based on totall counts is almost certainly 

due to variations in the number of sites that are counted in that year. For example, the higher 

total count in 1990 represented 1512 sites, while only 87 sites were counted1 in 1989, artd this 

produced a lower total count (Loughlin e!t al., 1990; Merrick et al., 1991). It is obvious that 

abundance estimates can be biased due to more or fewer sites being counted in a particular 

year. Th~erefore, the analysis of relative population size and trend should be based on sites that 

are counted in every survey. Merrick et al. (1991) presented an analysis of' counts fronn 77 

trend sites (rookeries and haulouts) that have been counted during every major survey. A 

comparison of the count from trend sites in the late 1950s (105,289) with that from 1990 

(22,754) showed an overall decline of 78% (Table 7). The total trend site count was similar in 

1989 (23,064) and 1990 (22,754), but th~ere was a substantial change in the central Gulf of 

Alaska where the count dropped from 8,552 to 7,050. The pattern was sirrdar at rookeries and 

haulouts. Analysis of 1991 counts indicates an additional decline of appro:cimately 5% in the 

overall number of animals on the trend sites (Merrick et al., 1992). 
Data on sea lion numbers in the Kenai-Kiska region from the trend site analysis show a 

generally similar pattern of decline when compared with data from all sites counted (Table 7). 

Since the mid-1970s the number counteid on the 77 trend sites has comprised 82-92% of the 

total number counted. In the late! 1950s, however, the trend site count was only 75% of the 

total count. This may be due partly to the fact that the earlier cou~its were made without 

regard 1-0 time of year, and they may not be directly comparable with later counts which were 

all made during June. 

Rookeries and haulouts in the western Aleutians have not always been counted on the 

same schedule as areas to the east. A ccsmparison of that region's non-pu:p counts made in 1988 

with data collected in 1977-1980 showeld a decline of 65%, from 27,228 to 9,516 (Byrd and 

Nysewamder, 1988). Subsequent counts have indicated a continued decline (Douglas and Byrd, 

1990). Counts in 1990 at Buldir Island and Agattu Island showed decreases of 40% and 23% 

compared with 1988. Alaid Island counts declined 62% from 1984 to 1990. 

Counts of sea lions older than pups at Walrus Island (Pribilof Islarids) have declined 

from 4,000-5,000 in 1960 to about 600 in 1982 (Kenyon, 1962; Loughlin et al., 1984). Counts 

in 1987 and 1988 were less than 500. Pup production at Walrus Island fell from 2,866 in 1960 

to about 334 in 1982 and to 50 in 19911 (NMML, unpublished data). 

In the region from the Kenai Peninsula east to Cape St. Eliais, coullts of adult ;and 

juvenile sea lions began to decline sometime after 1980 (Table 8). The 1991 count at Seal 

Rocks was 59% lower than the peak number counted in 1979. At both Seal Rocks and Cape St. 

Elias the decline appears to have been rapid during 1989-1991. Counts of pups at Seal Rocks, 

the only major rooke~y in the area, have ranged from 491 to 799 cluring 1978-1991, with no 

detectable trend (ADFG, unpublished data). 

Counts of sea lions in southeast Alaska show a stable or possibly increasing trend (Table 

9). The number of animals older than pups counted has ranged from 5,391 to 6,962 during 

1979-1 991. While no real trend is shown by the non-pup counts, pup colunts have increased 

steadily from 2,220 in 1979 to 4,164 in 1991. A new rookery has become established at Hazy 

Islands, where about 900 non-pups and 30 pups were counted in 11979; this increased to 1,278 

non-pups and 808 pups in 1991.. More recently, the White Sisters has begun to be used for 

pupping. An increase in pup production has occurred at Forrester Island with 3,261 pups 

counted there in 1991, up from 2,187 :in 1979 (ADFG, unpublished data). In 1989-1991, 

Fonester Island was the largest Steller sea lion rookery in the world. 

The number of adult and juvenile animals in the Gulf of Alaska and Aleutian Islands 

forme~rly represented about 75% of the world population (Gulf of Alaska = 38%; Aleutian 

Islands = 37%); however, the proportjo~n is changing as the Alaskan portion of the population 

declines (Braham et al., 1980; Merrick et al., 1987). 

British Columbia (Figure 7) 

In British Columbia, major Steller sea lion rookeries occur at North Danger RLocks, Cape 

St. James, and Triangle, Sartine, and Beresford islands. Extensive sea lion reduction programs 

were conducted at many locatiolns in British Columbia from 1912 through 1966. In 1913, 
10,000-12,000 animals (includes pups) were counted; in 1965 the number was about 4,000 

(Bigg, 1985). Pup counts in the 1970s and 1980s have ranged from aboui: 1,000 to 1,400 with 

no identifiable trend. The most recent clensus was in 1987 when 1,084 pups and 6,109 nonpups were counted (P. Olesiuk, personal communication). Bigg (1988) speculated that a 

northward shift in distribution may have occurred from rookeries in British Columbia, which 

could partly explain the increase in sea lion numbers in southeast Alaska. 

Washinsgon, Oregon, and Califom& (Figure 8) 

There are no Steller sea lion rookeries in Washington State, although animals do occur 

there during some times of year. Jagged Island and Split Rock are used as summer haulouts, 

and Umistilla Reef is used during the winter (NMML, unpublished data). Cape Flattery is 

occasionlally used for hauling out. There -re no data available that can be used to evaluate 

trends in numbers of Steller sea lions in Washington. 

Counts of Steller sea lions in Oregon have been relatively statble since 1981 at ;about 

2,000-3,000 animals. Statistical analysis of' all data collected since 1976 indicates an increase in 

numbers, but this may be an artifact of improved surveys in recent years (Brown, 19901). 

Rookeries at Rogue Reef account for 1,0100-1,250 non-pups and 200-400 pups; at Orford Reef 

there are 700-900 non-pups and about 100-200 pups born each year (Table 10). Counts at 

both localities have been variable, and generally show no strong trend. However, the count of 

adults ai~d juveniles at Orford Reef decliined from 1986 through 1989 coincident with increased 

sea urchin harvesting activity near the rolokery (Brown, 1990). Restrictions of urchin harvest 

near Orf'ord Reef rookeries appear to have resulted in an increase in counts in 19"O (R. Brown, 

personal communication). 

Numbers in California have declined, especially in southern Califonnia (Table 11). San 

Miguel Island was the southernmost rookery within recent historical record, but no adults have 

been seen there since 1983 and no births have been recorded since 1981 (R. DeLong, personal 

communication). Currently the southernmost breeding site is Afio Nuevo Island. Historically, 

peak counts ranged between 1,500 and ;!,500. Since 1984, counts there diuring the breeding 

season h~ave consistently been below 1,200. Counts in 1988 and 1990 resulted in a total of less 

than 600 adults and juveniles (Le Boeuf and Morris, 1990; R. Gisiner, personal cornrnu~nication). 

Aiio Nuevo Island produces more pups than any other rookery in California. Pup production 

from 19130-1985 was about 300 pups per year (M. Pearson, personal comm~unication); a 

minimurn of 139 pups was born there in 1990 (Le Boeuf and Morris, 1990). At the Farallon 

Islands, adult and juvenile numbers during the breeding season have declined from 

approximately 200 in the late 1970s and early 1980s, to less than 100 individuals in 1989 and 

1990 (D. Ainley, personal communication). Pup production has steadily declined over this time; 

only three pups were born there each year in 1988, 1989, and 1990. It is ]possible that the 

Farallon Islands may cease to be a breeding site in the near future. Bonnell et al. (1983) 

counted approximately 900 non-pups and 117-137 pups at the Sugarloaf/Cape Mendocino 

rookery during the 1980-1982 breeding seasons. In May 1989, approximately 300 adults and 

juveniles were seen on Sugarloaf. The 1989 count was made several weeks before peak 

numbers of sea lion adults and pups are usually attained, and based on seasonal trend:; in 

numbers, it is likely that 800-900 adults and juveniles would have been present during JuneJuly. During 1980-1982, about 250 non--pups and 10-25 pups were seen on the St. George Reef 
rookery each year. A count of 674 non-pups and 124 pups was reported fronn the St. George 

Reef rookery in 1990 (R. Brown, personal communication). Statewide, coun1:s between 1927 

and 1947 ranged between 5,000 and 7,000 non-pups with no apparent trend, but have 

subsequenrly declined by over 50%) remaining at about 2,000 to 2,500 non-pups between 1980 

and 1990. 

These data, together with a ljunited number of counts made during other times of year by 

Bonnell et al. (1983) and Bonnot and Ripley (1948), suggest that there may have been a 

northward shift in the species7 distribution in California. Changes in breeding season numbers 

have been less pronounced and slower than changes in distribution outside the breeding season, 

perhaps due to breeding site fidelity. Tagging, satellite telemetry, and coordinated counts with 

other parts of the species' range are needed to determine the relative contributions of 

emigration and reduced productivity to the decline in numbers of SteUer sea lions in California. 

D. NaturaJ. Factors Influencing the I'opulaltion 

Predation 

Although Steller sea lions are preyed upon by certain other species (e.g., killer whales and 

sharks), there is no scientific evidence to suggest that the incidence of' predation has increased in 

recent years. It seems unlikely that increased predator activity could explain the recent widespread 

decline in sea lion numbers. 

Parasitism. and Disease 

Parasites of Steller sea lions include intestinal cestodes; trematodes iin the intestine and bile 

duct of the liver; nematodes in the stomach, intestine, and lungs; acainthocephalans in the 

intestine; acarian mites in the nasopharynx and lungs; and an anopluran skin louse (Dailey and 

Hill, 1970; Dailey and Brownell, 1972). Shults (1986) reported 11 species of helminth parasites 

from sea lions in the Gulf of Alaska, and nine species from the Bering Sea. A severe infection of 

nematodes can cause stomach ulcers, but ]the number of deaths attributable to this cause is 

probably very small. However, there has mot been adequate research to assess the nature and 

importance of parasitism in sea lior~s. 

The prevalence of disease is difficult to evaluate because most specimens analyzed have 

come from animals that appeared healthy when they were collected. In addlition to gas& 

ulceration mentioned above, histopatho10,gical analyses have revealed1 mild cases of he~~atitis, 

myocarditis, and pneumonia (T. Spraker, personal communication). 

Rleproductive failure and neonate, juvenile, and adult mortality resulting from disease 

probably occur in Steller sea lions. Antibodies to two types of bacteria (Leptospira and 

Chlamydiia), one marine calicivirus (San lilipel Sea Lion Virus), and seal herpesvirus (SeHV), 

which could produce such effects, were present in blood taken from Steller sea lions in Alaska 

(Barlough et al., 1987; Vedder et al., 1987; Calkins and Goodwin, 1988). Leptospires are 

spirochete bacteria and are suspected agents of abortions and adult mortality in California sea lions 
and northern fur seals. Calkins andl Goodwin (1988) found a low incidence of Leptospirosis and 

concluded1 that it was not a significant factor in the decline of Steller sea lions in the Kodiak area 

in the 1980s. San Miguel Sea Lion Virus lzas been associated with reproductive failures or 

neonatal deaths in California sea lions and northern fur seals (Smith et al., 1974; Gilmanin et al., 

1976). CJamydia had not been studied hi sea lions prior to the work of Ca~lkins and Goodwin 

(1988). These and other agents are currei~tly under study to examine their possible adverse effects 

on Steller sea lions, but much additional work is needed. 

Environmental Change 

Sea lion behavior and survival could be influenced by changes in environmental conditions 

which might affect the suitability of the enwironment for sea lions. No trends have been observed 

that relate the decline in Steller sea lion numbers to such changes. Data bases on weather and 

oceanography in the North Pacific are extensive. York (in press) examined the relationship 

between sea surface temperature and early survival of Pribilof fur seals. While a significant 

positive correlation was found, cause and effect relationships could not be identified. A model 

constructed by Trites (1990a) has shown that thermal conditions on land could affect early survival 

of fur seal pups, but that the animals generally are able to tolerate the range of conditions to 

which they are normally exposed. The data that have been collected on Steller sea lions are not 

adequate for use in such analyses (Anonymous, 1990), and it is likely that attempts to do 

environmental correlation studies for sea lions would be even more inconclusive than foir fur seals. 

Furthermore, sea lions inhabit an area encompassing approximately 30 degrees of latitude, and 

they therefore must be able to tolerate a relatively wide range of environmental conditions. It 

seems very unlikely, overall, that changes i~ meteorologic and clirnatologic conditions per se could 

directly explain the major decline in sea lion numbers that has occurred in the core of their range. 

If environmental changes affected the abundance or availabilit]~ of a necessary food 

resource, the survival and productivity of sea lions could be reduced. These types of responses by 

pinniped populations have occurred as a result of El Nifto events (Trilllmich and Ono, 1991). A 

study of foraging patterns and energetics of Antarctic fur seals showed a dra~matic effect of changes 

in prey (krill) availability on nutrition and growth of pups (Costa et aK., 1989). Lactating females 

provided tlheir pups with the same amount of milk each time they came ashore regardless of 

whether food was abundant or scarce. However, in a year when krill were less abundant and more 

dispersed, feeding trips were almost twice as long (8.4 days versus 4.5 days). This resulted in the 

pups receiving about half as much rrdlk per day, and correspondingly low pup growth rates. In the 

year of low food availability, 32% of the pups died, 68% due to starvation. 'Ilese values were 

approximately double the normal rat-es. 

Evidence that major shifts have occurred in the abundance of fish and shellfish in the 

Bering Sea over the past several decades is well documented. Naumentko et al. (199O), for 

example, note that "in the last four decades the community of pelagic fishes in the westeirn Bering 

Sea has shlown considerable structur<al change." In the 1950s and early 1960s, the most abundant 

pelagic species was Pacific herring, whose biomass exceeded 3-5 million metric tons. However, in 

the late 1970s, walleye pollock biomass increased sigrhcantly (from an estimated 0.8 million 

metric tons to over 3.5 million) and more than doubled the herring biomass. Recent estimates 

indicate that the walleye pollock biomass has accounted for nearly 85% of the pelagic fish 

population in that region. 
Others have noted major shiifts in rhe abundance of fish and shellfisll stocks in the eastern 

Bering Sea characterized by rapid growth of the salmon, Pacific cod, and flatfish populations in the 

early 1980s, with corresponding delclines in shrimp and crab populations. Rapid increases in the 

estimated size of walleye pollock stocks in both the Bering Sea and Gulf of Alaska occurred 

between ithe 1960s and 1980s (Natural Resources Consultants, 1983; Larkin et al., 1990; Quinn 

and Collie, 1990). 

The factors responsible for producing these changes, however, are not well known. A 

number of authors note that there has been a general warming in the Bering and Okhotsk seas 

over the past three decades and theorize that shifts in temperature and wind patterns may have 

influenced recruitment and fish and shellfish population trends, but supporting oceanographic data 

are largely absent (Swan and Ingraham, 3 984; Khen and Glebova, 1990; Rodinov and Krounin, 

1990). Furthermore, many of the population changes in both fish and shellfish have occurred 

during and following periods of intense fishing activity. Thus, although there is evidence 

suggestive of changes in the abundance of major fish species and the environment, the causes of 

these changes and their influence on Stel'ler sea lion population trend are largely unknown. 

Further studies to examine these relationships would be useful as an aid to evaluating natural 

versus human factors that may be influencing sea lion population changes. 

2. KNOWN AND POTENTTAL HUMAN IhdPACIS 

Commercial Harvest 

There is currently no commtercial harvest for Steller sea lions. They were commercially 

harvested in the eastern Aleutian Islands and Gulf of Alaska from 1959 to 1972 (Merrick et al., 

1987). lin experimental harvest int 1959 resulted in 616 adult males being taken (Thorsteinson 

and Lensink, 1962). A total of 45,178 pups of both sexes were harvested in the eastenn Aleutian 

Islands and Gulf of Alaska between 1963 and 1972 (Merrick et al., 1987). The largest harvests 

were conducted between 1963 ancl 1972 at Sugarloaf and Marmot islands where 16,7613 and 

14,180 pups were killed, and between 1970 and 1972 at Ugamak antd Akurtan islands vvhere 3,773 

and 6,03)6 pups were killed. The pup harvests, which sometimes reached 50% of the total pup 

producti~on from a rookery, could ]have depressed recruitment in the short term. This may partially 

explain the declines at some sites through the mid-1970s. However, it does not explain why 

numbers declined in areas where no hanrest occurred (Merrick et al., 1987), or why declines did 

not occur until approximately 20 years after the harvests (e.g., at Marmot and Sugarloaf islands). 

During the period from 1912 through 1968, thousands of Steller sea lions were killed on 

rookeries and haulouts in British (2olumbia (Bigg, 1985). Information on rthe harvest of sea lions 

in the Soviet Union is not available. 

Subsistence Harvest 

The MMPA authorizes Alaska Natives to harvest and use Steller sea lions. This use can 

continue even if the species is listed as dlepleted, as long as it is for subsist:ence purpos'es and is 

done in a non-wasteful manner. 'The ESA also contains provisions that allow for the continued 
subsistence use of listed species. Both the: ESA and the MMPA contain provisions that allow the 

subsistence harvest of endangered, threatened, or depleted species to be regulated, if necessary. 

The archaeological record confirms that coastal Alaska Natives have for centuries harvested 

and used sea lions for subsistence purposes. Historical sources document continuous use in Alaska 

since Russian contact. Most parts of the animal were used as food or fashioned into tools, 

clothing, and decorative crafts. Seal lions historically were and presently are used primarily in areas 

dominated by a Pacific maritime climate, here they replace the Pacific wahrus which fills a similar 

role in more northern areas. 

Dilring the past decade, the subsisi:ence harvest of sea lions has been documented in Prince 

William Sound, lower Cook Inlet, Kodiak !Island, Alaska Peninsula, Pribilof Islands, and to some 

extent in the Aleutian Islands (Haynes and Mishler, 1991). Less is known about the extent of 

subsistence uses in Bristol Bay, the Yukon-Kuskokwim Delta, and southeast Alaska. Annual 

statewide harvest levels have not been systematically documented, but single year estimates or 

reported harvest data are available for sonne communities, including: Akhiok (7 in 1989); Atka (15- 

25 in 1982-1983); Chenega Bay (I!> in 1984); English Bay (2 in 1989); Ma~nokotak (15 in 1985); 

Old Harbor (26 in 1989), Penyvllle (10 in 1989-1990); Quinhagak (16 in 1982); St. George (35- 

40 in 1980-1981); St. Paul (35 in 1980-19831); Tatitlek (14 in 1989-1990); and Unalaska (20 in 

1981-1982). Sea lions remain an important traditional food resource today in these and other 

cornmuniiies. Systematic fieldwork is required to estimate accurately the statewide subsistence 

harvest and to determine whether the annual harvest levels in these alnd other communities 

fluctuate significantly from year to year. 

Fishew-related Taking 

Many Steller sea lions have been taken incidental to commercial fishing operations in the 

Bering Sea and North Pacific Ocean.. In 1978-1981, the estimated annual mortality for all foreign 

vessels was 724 animals (Loughlin let al., l983). That did not include animals taken by U.S. 

fishermen fishing either in joint ventures, or independently. The incidental take of sea llions by 

U.S. trawlers in 1982 in the Shelikof Strait (near Kodiak Island, A1ask.a) walleye pollock joint 

venture fishery was estimated to be 958 to 1,436 sea lions (Loughlin and Nelson, 1986). The 

estimated take declined to less than 400 per season in 1983 and 19841, probably due to changes in 

fishing techniques and the area andl times fished. Less than 100 per year were estimated to have 

been taken during 1985-1987 as the fishery diminished in total fish take and effort (T. Loughlin, 

personal communication). 

Perez and Loughlin (1990) found that about 3,000 Steller sea lions were observed 

incidentally caught in foreign and j~oint venture trawl fisheries during 1973-1988. For the period 

1978-1988, the observed take was extrapolated with fish catch data to obtain an estimate of 6,543 

sea lions incidentally caught. Using observer data and fisheries statishcs for 1973-1977, they backcalculatedl for the period 1966-1975' and estimated that about 14,830 sea lions were killed 

incidental to trawl fisheries during that period. The total estimated incident-a1 catch of !:teller sea 

lions during 1966-1988 in foreign a~nd joint-venture trawl fisheries was over 20,000 animals. Perez 

and Loughlin concluded that incidental catch was a contributing factor to the sea lion decline 

during the 1970s. 
In California there has been a small incidental take (less than five indiividuals per year) in 

gillnet fisheries for California halibut, flounder, and sharks (Wild, 1986). An1 experimental shark 

gillnet fishery operated off Oregon in 1986-1988; one Steller sea lion was recorded taken in 1987. 

Since 1976 Steller sea lions have been occasionally taken (approximately one every other year) in 

the joint venture trawl fishery for haLke that operates off Oregon, Washingtorl, and northern 

California (J. Scordino, personal communication). 

An observer program mandated by amendments to the MMPA in 19813 requires observer 

coverage on some domestic fishing vessels. The amount of observer coverage in particular fisheries 

varies according to the anticipated or documented frequency with which maline mammals are 

taken incidentally. A final compilation of information from the observer program on incidental 

catch of marine mammals in 1989 is not yet available, but preliminary results indicate that the 

level of observed catch of Steller sea lions is :much lower than it was previou.sly. 

In some areas Steller sea lions are ltnown to have been shot deliberately by fishermen, but 

it is unclear how such killing may have affected the population. Fishermen :have been seen killing 

adult animals at rookeries, haulout sites, and in the water near boats, but the magnitude of this 

take is generally unknown. One of the few estimates of shooting mortality is reported by Matkin 

and Fay (1980) who calculated that 305 Steller sea lions were killed directly (shot) while 

interfering with fishing operations in the spring 1978 Copper River Delta salmon gdlnet fishery. 

Data from a 1988-89 study of the Copper :River salmon gillnet fishery indicated that the level of 

directed kill of sea lions was significantly less than during 1978 (Wynne, 1990). During the 1960s, 

Steller seaL lions were killed at sites in the eastern Aleutian Islands anti used for bait by crab 

fishermen. This killing may have had a significant effect in local areas and imight have caused 

animals to move away from certain rookeries and haulout sites (Loughlin and Nelson, 1986; 

Merrick et al., 1987). 

Competition for Food 

Commercial fisheries target on several of the most important prey species of Steller sea 

lions. In combination, these fisheries remove millions of metric tons (of fish, much of which is 

potential sea lion food. However, the conlplexity of ecosystem interactions, and limitations of data 

and models make it difficult to determine whether fishery removals have influenced the population 

of sea lio:ns, or any other marine mammal species (Lowry et al., 1982; Harwood and Croxall, 1988; 

Loughlin and Memck, 1989). 

Changes in the quantity or quality of available prey may influence the health and fitness of 

individual sea lions, resulting in reduced reproductive potential or perhaps death (Loughh and 

Memck, 1989). Walleye pollock have been shown to be an important prey of Steller sea lions in 

the Gulf of Alaska, Bering Sea, and North Pacific Ocean (Klumov, 1957; Pitcher, 1981; Calkins and 

Goodwin, 1988; Lowry et al., 1989). Age-structured population models indicate that since the 

1960s, walleye pollock biomass in Ithe eastern Bering Sea has fluctuated twiice between 4 million 

metric tons and 10 million metric tons. Peaks in biomass occurred in the early 1970s and the mid1980s due to strong year classes in 1965-7 968, and 1978, 1982, and 1984 (Bakkala et id., 1987). 

While the overall biomass of pollock has remained relatively high, low abundance of certain age 

classes in some years could have resulted in fewer fish available in the size range usually consumed 

by sea lions (Lowry et al., 1989). .Availability of certain sized prey may be particularly important 
for juvenile sea lions which on avera.ge feed on smaller fishes (Frost and Lo~ny, 1986). During the 

period 1988-1990 there was a 10-15% annual decline in biomass of walleye pollock in the Aleutian 

Basin (Niemeier and Kelsky, 1990). 

In the Gulf of Alaska, the walleye pollock stock is smaller than in the Bering Sea. Trawl 

surveys have been used to estimate clemersal walleye pollock biomass and hydroacoustics have 

provided estimates of the off-bottom component of the population. Hydroacoustic surveys showed 

that the wislleye pollock biomass in Shelikof Strait declined from 3.7 million metric tons in 1981 to 

0.29 million metric tons in 1989, with a small increase in 1990 (Hollowed, 1991). Gulf-wide 

bottom trawl surveys indicate that the demersal component of the populatior~ has been relatively 

stable sincle 1984, ranging between 0.69 artd 0.85 million metric tons. Stock assessments based on 

an age-structured model suggest that walleye pollock biomass in the Gulf increased from 1-2 

million metric tons in the late 1970s, peaked in 1982 at about 4 rnillioln metric tons, then declined 

to about the late 1970s level (Hollowed, 1991). The increase was attributed to five consecutive 

strong year classes from 1975 to 195'9. Relatively weak year classes oclcurrecl in 1980-1983, 1986, 

and 1987. 

Botly sizes of sea lions in the Gulf of Alaska (girth, weight, and standard length) were 

significantly less for age 1-10 animalls sampled in 1985-1986, as compared to the 1970s (Calkins 

and Goodwin, 1988). This difference was interpreted as a reflection of nutritional stress in sea 

lions which was caused by changes in prey availability in the Gulf of Alaska ecosystem. 

From British Columbia southward to California, hake, rockfish, and herring are important 

Steller sea lion prey. The expansion of cornrnercial fisheries for these species may be correlated 

with the decline in numbers of sea lions at major rookeries (D. Ainley,, personal communication). 

Shifts in the abundance and distribution of' herring, possibly related to fisheries, may have 

influenced the distribution and recovery of sea lions in British Columbia (Bigg, 1988). 

Fish resource assessment surveys provide the only data available for evaluating th~e status of 

sea lion food resources. These surveys, however, encompass large regions and may not reflect the 

amount, size, and species of prey av,ailable in actual sea lion feeding areas. Sampling is usually 

done in spring or summer and may not provide an adequate measure (of prey distribution at 

important times. Also, commercial fish resource surveys generally do inot include or do not 

adequately sample many potentially important prey species such as calpelin, eulachon, herring, 

squid, and octopus. In spite of these limitations, additional analyses o~f information contained in 

resource assessment databases may be of some use in understanding sea lion feeding ecology. 

In addition to larger scale changes in abundance of food, fisheries could affect sea lion 

nutrition by causing localized prey clepletion or by disrupting fish behavior als nets pass 1:hrough 

schools. Such changes could result in sea lions expending more energy to obtain prey. 

Toxic Sublstances 

Organochloride pollutant residues in the tissues of California sea lions have been associated 

with reproductive failure (DeLong et al., 1973; Gilmartin et al., 1976) and have been shown to 

cause reproductive failure in harbor seals in the Dutch Wadden Sea (Reijnders, 1987). 

Contaminants also have the potential to affect the immune system which could make animals more 
susceptible to disease (P. Reijnders, personal communication). 

NMFS has begun analyzing tissues from Steller sea lions collected in Alaska for 

organochloride pollutant residues and other toxic substances. Preliminary shldies found generally 

low levels of contaminants, with the exception of two young males from southeast Alaska that had 

relatively high levels of PCBs and DDTs in the blubber (U. Varanasi, unpublished data). Additional 

analyses are being conducted. A study conlducted at the Farallon Islands was inconclusive (Huber 

et al., 1984). Relatively low levels of cadm.ium and zinc were found in tissues of sea lions 

collected from Hokkaido, Japan (Hamanaka et al., 1982). 

Seal lions contacted oil in 1989 during the Exxon Valdez oil spill, and analysis of tissue 

samples indicated some evidence of (exposure to hydrocarbons. However, there was no conclusive 

evidence that exposure to oil resulted in inju~y or death to sea lions (ADFG, unpublished data). 

Entanglement in Debris 

Data collected from 1975 to 1985 1n the Gulf of Alaska and southeast Alaska showed that 

Steller sea lions may become entangled in lost and discarded fishing gear, and that closed packing 

bands and net material (principally trawl net) accounted for the majo~rity of observed 

entanglements (Calkins, 1985). Animals over 2 years old (of both sexes) were susceptible, 

although more adult females were observe~d entangled than males. NO records of entangled sea 

lion pups or yearlings were reported. There were no data presented on the number of animals 

observed entangled or the rate of entanglement in relation to the Gulf of Alaska or southeast 

Alaska sea lion population. 

A study conducted in the Aleutian ]islands during June-July 1985 found that a very low 

percentage (approximately 0.07%) of observed sea lions were entangled in net or twine; none were 

entangled in packing bands (Loughlin et al., 1986). The data from the initial study were 

inadequate to address the magnitude or nature of entanglement of pups-of-the-year since most 

pups were too young during the survey to have encountered debris in the water or away from the 

rookery. A follow-up study was conducted during November 1986 to assess the magnitude of 

entanglement of sea lion pups in the eastern Aleutian Islands. No entangled pups were seen, and 

only one entangled juvenile was seen out of a total of 3,847 sea lions observed during the study 

(Loughlin et al., 1986). 

In summary, adult ~teher sea lions entangled in packing bands and net fragments have been 

observed, but rarely. Entangled pulps and juvenile animals are infrequently observed, but 

entangled. animals may die at sea aind thus not be seen on land. Based on existing information, 

however, it seems unlikely that entanglement in debris is a major factor in t:he observed population 

decline. 

The possible impacts on Steller sea lions by various types of disturbance have not been 

specifically studied. Close approaclh by humans, boats, or aircraft will1 cause hauled-out sea lions to 

go into the water. Disturbances that cause stampedes on rookeries may cause trampling or 
abandonment of pups (Calkins and Pitcher:, 1982; Lewis, 1987). The discharge of firearms at or 

near hauled out animals may have a particiularly dramatic effect. Areas subjected to repeated 

disturbance may be permanently aba.ndoned (Kenyon, 1962). Repeated disturbances that result in 

abandonmlent or reduced use of rookeries by lactating females could negatively affect condition 

and survivid of pups through interruption of normal nursing cycles. Low levels of occasional 

disturbance may have little long-term effect. 

There have been relatively few well-documented instances of disturbance. Disturbance of 

rookeries at Orford Reef, Oregon (R. Brown, personal communication) and tile Farallon Islands, 

California (D. Ainley, personal communication), resulting from the activities (of sea urchin 

fishermen, has been reported. At the Farallon Islands, this disturbance resulted in a distributional 

shift of a breeding group to a nearby, undi:stu~rbed site. The harassment andl killing of sea lions in 

British Columbia (before 1970) resullted in the cessation of breeding at some rookeries and 

abandonment at others (Bigg, 1988). 

Development such as would be associated with Outer Continental Shelf oil exploration and 

production may result in a substantial amount of onshore and offshore activity in Steller sea lion 

habitat. Alctivities such as sea floor mining could disrupt feeding areas, and result in lowered 

condition, particularly for lactating females and pups. The increased dlisturbance that maLy result 

from such human activities could have subt-le, but significant, impacts on recovery of the sea lion 

population. 

3. SUMMW AND CONCLUSIONS 

Altl~ough the data available on abundance of Steller sea lions, ,and changes that hiave 

occurred over time, are not as comprehensive as is desirable, it is certain that: a major population 

decline has occurred. The decline has beer1 most dramatic in the core of the species' range, the 

central and western Gulf of Alaska and Aleutian Islands, where total counts dropped by more than 

100,000 animals from 1960 to 1990. Numbers of sea lions have also declined in the central Bering 

Sea and waters of the Soviet Union. In the! region from southeast Alaska through Oregon, Steller 

sea lion numbers appear to have remained relatively stable, and no significant declines have been 

noted in recent years. However, the number of Steller sea lions has decreased greatly at rookeries 

in central and southern California. 

Both natural and human-caused factors have been hypothesized as contributing to these 

declines. Natural changes in the environment may be partly responsible for the decline in numbers 

of Steller sea lions in some areas. Through~out most of the species' range, census data have been 

collected only in the past 30 years, and there is no way to know what kind of population1 

fluctuations may have occurred previous to that period. Similarly, theire is no way to evaluate 

whether or- not the high population levels of the late 1950s were indicative olf the long-term ability 

of the ecosystem to support sea lions. Factors such as disease and preldation may have h,ad an 

influence on the population, but there is not sufficient information to evaluate their possible 

impact. 

A variety of human activities may have influenced Steller sea lions. It: is certain tlhat many 

thousands of animals were killed in commercial harvests, control programs, fisheries, andl 

subsistence hunts. Marine debris does not appear to have had a major impact on sea lion numbers. 
Although studies of chemical pollutant loads are incomplete, the relatively lolw level of industrial 

activity in the central portion of the specie:; r<ange would suggest that pollution has not been a 

cause of the decline. Increased human presence in the marine envirorunent has resulted in the 

disturbance of important habitats such as rookeries. The development- and expansion of 

commercial1 fisheries throughout the species' range may have caused detrimeintal changes in the sea 

lions' food supply. 

The Recovery Team is aware that fur seals on the Pribilof Islands and harbor seals in parts 

of the Gulf of Alaska have also shown substantial population declines (Fowler, 1990; Pitcher, 

1990). Causes for those declines are unclear. Entanglement in debris has contributed to the 

problem with fur seals (Fowler, 1985), and food limitation of juveniles has also been suggested as 

a possible factor (Trites, 1990b). Several of the principal prey species of Steller sea lions are the 

same as those used by fur seals and harboir seals. However, many other life history features and 

ecological characteristics differ considerably among the three species. The coincidence of these 

declines in fish-eating pinniped population~s emphasizes the need for a broad approach to 

investigation of the problem and development of solutions. 

Overall, it is not clear what factors have contributed to the Steller sea lion population 

decline, and it is apparent that a great deal of information vital to the effective managernent of the 

species is lacking. In spite of these information voids, there is an urgent need to take immediate 

actions to safeguard against further population declines, and to provide for recovery of the species. 

Immediate actions that can and should be taken include efforts to reduce human-caused mortality 

to the lowest level practicable, protection (of important habitats through buffer zones and other 

means, antd enhancement of population productivity by ensuring that there 11s an ample food supply 

available. Conservation measures implemented when Steller sea lions were listed under the ESA 

have addressed some of these management needs. Additional management actions are tiescribed in 

the Recovery Plan. 

The Recovery Team believes that management designed to provide for recovery of the sea 

lion population should be based on biological principles and ecological understanding. The 

research program recommended by the Re:covery Team and described in the Narrative Section of 

this Recovery Plan will require a considerable amount of funds, time, and effort to produce the 

information needed to design a complete and effective set of conservation measures. Management 

agencies therefore should not preclude consideration of more immediate coinservation measures or 

managem.ent experiments that could further reduce human impacts, or that would respond to 

proposals by the scientific community designed to evaluate certain hypotheses. 

The Recovery Team is aware that some of the research activities proposed may themselves 

have negative impacts. However, rather than limit the Recovery Planis range of action lby 

excluding such activities, we have included them if they may result in infonaation that is critical to 

understanding the sea lion problem. The potential positive and negative impacts should be 

examinedl on a case-by-case basis using the best current information at the time scientific research 

permits are requested. 
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5. TABLES 

Table 1. Rank order of importance of prey found in the stomach:; of Stt4ler sea lions 

collected in Alaska (based on Combined Rank Index). 

- - -- -- 

Gulf of Alaska1 Kodiak kea2 Southeast Bering sea3 

Alaska2 

Walleye Pollock Walleye Pollock 

Squids Octopus 

Pacific Herring Flatfishes 

Capelin Pacific Sand 

lance 

Pacific Cod Pacific Cod 

Pacific Salmon ]Pacific Salmon 

Octopus !Squids 

Walleye Walleye 

Pollock Pollock 

Pacific Clod Pacific Cod 

Squids Sculpins 

Flatfishes Herring 

Pacific Herring Octopus 

Pacific Salmon Flatfishes 

Octopus Squids 

Pitcher, 198 1 

Calkins and Goodwin, 1988 

D. Calkins, unpubl. data 
Table 2. All prey identified from stomachs of Steller sea lions collected in the Gulf of Alaska 

during 1975-1978 (n = 153) and 1985-19136 (n = 74) (adapted from Calkins and Goodwin, 

1988) 

Occurences Volume 

1970s 1980s 1970s 1980s 

PREY No. % No. To ml Yo ml Yo 

INVERTEEl RATES 

Snails 

Octopus 

Squid 

Mollusc 29. 

Shrimps 

Tanner crab 

Spider Crab 

Crab m. 

FISHES 

Hemng 

Salmon 

Capelin 

Sand Lance 

Walleye Pollock 

Saffron Cod 

Pacific Cod 

Pacific Tomcod 

Gadid a!. 

Eelpout 

Rockfish 

Sculpins 

Sturgeon Poacher 

Pacific Sandfish 

Flatfishes 

Skates 

OTHER ITEMS 

Harbor Seal 

0 

14,379 

50 

0 

trace 

0 

0 

trace 

trace 

3;!0 

0 

1,580 

23,370 

0 

1,205 

0 

0 

0 

0 

325 

0 

0 

13,910 

0 

TOTALS 261 98 373,184 55,1:39 
Table 3. Major prey identified from sitomachs of Steller sea lions collected near Kodiak 

1975-1978 (n = 49) and 1985-86 (n = 74) (adapted from Calkirks and Pitcher, 1981 and 

Calkins and Goodwin, 1988). 

- 

Kodiak 1975-78l Kodiak 1985-86 

010 Frequency % Volume % Frequency % Volume 

-- 

Walleye 

Po1loc:k 

Capelin 

Pacific Salmon 

Pacific Cod 

Flatfish 

Octopus 

Mean Volume of 

Contents 

1317 rnl 745 ml 

Data shown here are for a subsample of the 153 animals shown in Tablle 2. 
Table 4. Counts of Steller sea li.ons in Russia during 1988-1989 and prior to 

the decline in abundance (adapted from Perlov, 1991). 

Location 1988-1989 Prior 1:o Decline 

Kamchatka 3,500-3,800 10,0010-14,000 

Kuril Islands 5,000-7,000 15,0010-20,000 

Commander Islands 2,400-2,600 10,000 

Iony Island 1,500 5,000-6,000 

Iamskiy Island 900 1,000 

Tyulenii Island 200 200 

Opasnosti Rock 300 300 

- 

TOTAL 13,800-16,300 42,500-52,300 
Table 5. Counts and percent declines of adult and juvenile Steller sea lion!; at all sites in spring 

and surnmer 1956 to 1989 in the Aleutian Islands and Gulf of Alaska (from1 Merrick et al., 1987, 

1990, 1991; Loughlin et al., 1990)'. 

YEAR 

Central Gulf Wes~tern Gulf Eastern Aleutian Central 

of Alaska of Alaska Islands Aleutian 

Islands TOTAL 

Decline Overall4 

Dashes indicate that no counts were made 

Based on 1956 count for western Gulf of Alaska, 1957 count for central Gulf of Alaska, 1958 

count for central Aleutian Islands, and 1960 count for eastern Aleutialn Islands 

Based on 1976 counts for central Gulf o:f Alaska, western Gulf of Alaska, and eastern Aleutian 

Islands, a:nd 1979 count for central Aleutian Islands 

Declines calculated from earliest survey date 
Table 6. Counts of Steller sea lion pulps at sites in the Aleutian Islands and Gulf of Alaska, 

1979-1990 (from Early et al., 1980; Calkins and Pitcher, 1982; Menick 1.t al., 1987, 1990, 

1991: Calkins and Goodwin, 1988; Byrd, 1989; Loughlin et al., 1990; NMML files)'., 

ISLAND 

Western Aleutians 

Agami I. 

Buldir I. 

Central Aleutians 

Kiska I. (Lief Cove) 

Ayugadak I. 

Ulak I. 

Tag I. 

Gramp Rock 

Adak 1. 

Kasatochi I. 

Agligadak I. 

Seguam I. 

Yunaska I. 

Eastern Aleutians 

Aduga.k I. 

Ogchul I. 

Bogoslof I. 

Akutaa 1. 

Akun I. 

Ugamak I. 

Western Gulf 

C1ubb:ing Rocks 

Pinnacle Rocks 

Chernabura I. 

Atkins I. 

Central Gulf 

Chowjiet I. 

Chirikof I. 

Marmot I. 

Sugarloaf I. 

Outer I. 

Dashes indicate that no count was made 

35 
Table 7. Comparison of counts and percent declines of adult and juvenile Steller sea lions in 

the central and western Gulf of Alaska and eastern and central Aleutian Islands based on data 

from all sites counted (and Table 5) and :77 trend sites (from Menick et al., 1991)'. 

All Sites 

- - -- 

Trend Sites 

YEAR(S) Number % Decline Number % Decline Percent of Total on 

Trend Sites 

Percent declines are calculated from the earlier survey period 

Table 8. Counts of Steller sea lions: in the! eastern Gulf of Alaska, 1976-1991 (ADFG, unpubl. 

data)*. 

Location 

Seal Rocks Cape St. Ellias 

YEAR non-pups PUPS non-pups 

' Dashes indicate that no count was made 

36 
Table 9. Counts of Steller sea lions at rookeries in southeast Alaska, 1979-1991 

(AIIFG, unpubl. data)'. 

Location 

Forrester Island Hazy Islands White Sisters -- 

YEAR non-pups PUPS non-pups pups non-pups PUPS 

D,ashes indicate that no count was made 
Table 10. Summer aerial co~unts of Steller sea lions at imajor irookeries 

in Oregon, 1975-1989 (from Brown, 1990)'. 

Location 

Rome Reef Orford Reef 

YEAR non-pups PUPS non-pups PUPS 

Dashes indicate that no cc~unt was made 
Table 11. 

California, 

R. Gisiner, 

Summer counts of adult anti juvenile Steller sea lions at major rookeries in 

1927-1989 (from Bo~nnott amd Ripley, 1948; Bonnel et al., 1983; Pearson, 1987; 

D. Ainley, R. Brown, and B. LeBoeuf, pers. communications)'. 

Location 

YEAR San Miguel Axial Nuevo Farallons Mentdocino Gt. George 

1927 595 1,500 700 700 1,500 

Dashes indicate that no count was made 

Estirnate derived from May 1989 count of 286 animals 
Figure :l. Map of the North Pacific Ocean showing the general range of SteUer sea lions 

(stippled area) and the location of major rookeries l arrow:^). 

PACIFIC OCEAN 

140.E 150' 160" 170" 180'' 170° 16P 150" 140° 130" 120. W 
Figure 2. Overall trend in Steller se!a lion counts in the region from the Kenai Peninsula to 

Kiska Island, 1960-1989 (from Merrick et al., 1990). 

Number of Sea Lions 

Kenai to Kiska 

Thousands 

160 

140 .................. ................ 1 4 0 --.-- ,. ., \ 

........................................... ...................................... ......................................... 1 20 --..-- .. \ 

.......... ..................... 

............. .......... 

llLlflllllllll 

4 0 .--- - 

20 .- 

O-lrl'lllllltl 

65 60 65 70 75 80 85 90 

Year 
Figure 3. Locations of Steller sea lion rookeries and major haulouts in the Kuril Islands and 

Okhotsk Sea. 
Figure 4. Locations of Steller :sea lion rookeries on Kamachatka ;and the Commander Islands. 

. . . . 

: .. 

. . . . .. . ._ . . 

GVd~otsk Sea 

. _ .. Cape - 29 

Shipunskiy Cape - 8 

1 50°E 

I 

155" 

I 

160" 

I 

165" 

I 1- 

170" 
Figure 5. Locations of Steller sea lion rookeries in the Aleutian Islands and Bering Sea. 

Bering Sea 

Walrus I. 

0, / 

Q 

sea ~ianp \, :-;.. - 

Aku~n I. 

mutan I./ 

Bogos~f 1. \4De, 

Attu L Semisopochnoi I. Adugak ,.< 1- 

Kasa~tochi I.Seguarn I. \. 

P 6 \ Ogchul I. 

Yunarka 1. 

a / . I Agligadak I. 

Adak I. 

Amchitka I. 

Ulak I. Grannp Rock 

Gulf of Alaska 

' 61" SO'N 

- 50" 00 
Figure 6. Locations of Steller sea lior~ rookeries in the Gulf of Alaska ar~d southeast Alaska. 
Figure 7. Locations of Steller sea Lion rookeries and major haulou~ts in Blridsh Columbia. 
Figure 8. Locations of Steller sea lion rookeries and major hauloluts in Oregon and Wornia 

1 Three Arch Rock -+ b~illamook Head 

Oregon 

Orford Reef + ,.':~od'~rchard l'.. 

St. George Reef + I 

. . f ........ 

Sugar Loaf I. + ..... .... 

. . California 1 . -. .... 

..... I 
PART I1 

1. RECOVERY ACTIONS AND IMPLEMENTATION 

A. Goal ar~d Objectives 

The overall goal of this Recovery Plisn is to promote recovery of the Steller sea lion 

population to a level appropriate to just@ removal from ESA listings. The p~imary purpose of the 

Plan is to Fropose a set of actions that will minimize any human-induced activities that may be 

detrimentall to the siurvival or recovery of the population. Immediate objectives are to identify 

factors that are limiting the population, actions necessary to stop the population decline, and 

actions necessary to allow the population to increase. 

B. Reclassification Criteria for Evaluating Population Status of the SteXler Sea Lion 

The Recovery Team recommended that reclassification and delisting should consider the 

following criteria: 

(1) Counts and trend in counts of S'teller sea lions older than pups (called Adult/,Juvenile 

Trend Count) on rookeries and haubouts in the region from the Kenai Peninsula to Kiska 

Island (hereafter referred to a:s the K:enai-Kiska area)(a suggested list of index sites to be 

included is presented in Appendix A:,; 

(2) counts and trend in counts of pi~ps at index sites within the Kenai-Kiska area (called 

pup production index) (sites to be included are indicated in Appendix 13); and 

(3) the status and trend of sea lions in other parts of the species' range. 

The Recovery Team further recommended that delisting and reclassific<ation under criterion 

(1) should consider I-he current population index in relation to the long-term ability of the KenaiKiska area to support Steller sea lions. The Recovery Team recommended that a benchmark figure, 

representing an estimate of the equilibrium ]population for the region, should be established and be 

reassessed, and changed if necessary, as new information becomes available. 'The Recovery Team 

recommended an initial benchmark of 90,000 animals older than pups counted on trend sites in 

the Kenai-IOiska area during the peak of the breeding season (late May-early July). This number is 

equivalent to the trend site count of animals older than pups in the mid 1970s (89,100) (see Table 

7). While a higher trend site count (1 05,289) resulted from data collected in the late 1950s, the 

Recovery Team does not believe that is an appropriate benchmark figure. The earlier counts were 

performed by nonstandard techniques and were so widely spaced in time that it is difficult to use 

the data to estimate the overall number of ainimals in the Kenai-Kiska area. Furthermore, pup 

counts, which provide independent verificatiion of population size and trend, were not conducted 

prior to the mid 1970s. 

It is difficult to propose specific measures by which the status and trend of Steller sea lions 

in areas other than the Kenai-Kiska region can be evaluated. Existing data sets are of variable 

quality and completeness, and future research plans are uncertain. 'The Recovery Team 
recommended that the evaluation of population status should be basedl on relatively large regions 

representing logical geographical units, andl each should include several rookeries and contain 

generally comparable numbers of arhals. 'The regions initially recommended were: (1) Russia, 

(2) the western Aleutians, (3) eastemn Gulf of Alaska, (4) southeast Alaska, (15) British Columbia, 

and (6) California-Clregon-washing on. The designation of regions should be revised, if necessary, 

based on results of studies to define biological subspecies or stocks. 

C. Application of Evaluation Criteria 

The Recovery Team suggested that an objective evaluation of whether- and how Steller sea 

lions should be listed under provisions of the ESA can be made by comparing: the most recent data 

available with the measurable criteria described in the previous section. 

The Recovery Team recommended t:hat evaluation criteria should be applied as follows: 

(1) if the current Adult/Juvenile Trend Count in the Kenai-Kiska area is less than 

17 percent of the benchmark value, the species should be listed as endangered; 

(2) if the current Adult/Juvenile Trend Count in the Kenai-Kiska area is greater than 17 

percent but liess than 40 percent of the benchmark value, the species should be listed as 

threatened, except; 

(3) if the current Adult/Juvenile Trend Count in the Kenai-Kisyka area is greater than 17 

percent but lless than 25 percent of Ithe benchmark value the species should be listed as 

endangered if one or more of' the following situations exists: 

(a) The Kenai-Kiska Adult/Juvenile Trend Count has declined by at least 10 percent 

over 3 or more consecutive survey years, 

(b) the overall Pup Production Index (count data combined in 2 year blocks) in the 

Kenai-Kiska area has declined by 10 percent over the count in the previous 2-year 

block, 

(c) the number of animals hias declined by at least 10 percent over a three-year 

period since 1989 in three o:r more of the six other regions (Russia, western 

Aleutians, eastern Gulf of Al,aska, southeast Alaska, Bribish Columbia, and CaliforniaOregon-Washington) . 

It is; the intent of NMFS to support rthe recovery activities outlirled in the Recovery Plan. 

However, concerns associated with the proposed evaluation criteria regarding the quantitative 

measures flor changing status under the ESA require further analysis and discussion. Thus NMFS 

will not implement Part 11, Section LC, of the draft recovery plan at this time. NMFS believes that 

the strategy in this section focuses on small, short-term changes (e.g., jin II.1.6(3), a 10 percent 

decline over 3 years) but neglects an analysis of long-term trends and the effects of stochastic 

variability. NMFS supports and will evaluate a combination of techniques, like populatialn viability 

analysis and analysis of data on historical trends, to provide a more robust estimation of the 

likelihood of extinction. At the conclusion of these analyses, NMFS will reconsider the threshold 
levels proplosed by the Recovery Team, as well as other criteria which emerge as part of the 

analytical ]?rocedure. A final set of criteria will then be established and implemented. 

D. DelistiT~g Criteria 

Section 4 of the ESA requires that an objective, measureable criteria be incorporated into 

each Recovery Plan which, when met, would result in a determination that the species be removed 

from the list. The data currently available on Steller sea lion relative abundance and trend come 

from aerial photographic surveys of adults and juveniles and land-based counts of pups (see section 

II.E.3). Preblirninary simulation studies condlucted at the April 1992 workshop indicate that the 

confidence interval around the recent aerial estimates of adult and juvenile numbers of sea lions is 

quite small; therefore, for the present, NMFS will adopt the delisting criteria proposed by the 

Recovery T~eam as follows: 

(1) If the current Adult/Juvenile Trend Count in the Kenai-Kiska area is greater than 

40 percent of the benchmark value of 90,000 animals older than pups, and 

(2) the number of animals is stable or increasing in at least three of the six other iregions 

described in section II.B, 

then. delist the species. 

Using such a system, a benchmark populaticln of 90,000 and these criteria, dellisting woulcf not 

occur until the Adult/Juvenile Trend Counl' reached 36,000. However, these criteria will be 

evaluated as part of the risk analysis to determine their adequacy for long-tenn protection of the 

species. 

E. Stepdown Outline 

Items in this outline are not in order of priority. Priorities are identified in Section 1I.F. 

1. Identify habitat requirements and protect areas of special biolodcal simificm 

11. Identify current and historical use areas 

11 1. Map, describe, and evaluate rookeries and major haulouts 

112. Map, describe, and evaluate feeding areas 

12. Detennine seasonal use patterns 

13. Docurnent effects of disturbance caused by human activities 

14. Prepare guidelines and regulations to control potentially disruptive activities 
15. Ideniify and designate "Critical Habitsat" areas 

2. Identify manazement stocks 

21. Conduct visual marking/taggirlg studies 

211. 'Tag and brand pups on selected rookeries 

212. ]Monitor rookeries for occurrence of' marked animals 

22. Determine if biological parameters indicate different stocks of sea lions; 

23. Compile and analyze data 

3. Monitor status and trend of sea lions 

31. Develop statistically valid survey procedures 

32. Conduct Alaska statewide survey every year 

321. Conduct aerial survey of adults and juveniles at all rookeries and major-haulouts 

322. Conduct pup counts at selected rookeries 

33. Conduct surveys of pups and non-pups at rookeries in California and Oregon every other 

year 

34. Conduct range-wide survey every 5 years 

341. Conduct aerial survey of adults and juvenile at all rookeries and major hau1ou.t~ 

342. Conduct pup counts at selected .rookeries 

4. Monitor health, condition, and vital parameters 

41. Examine and sample dead animals from rookeries, incidental take, su'bsistence harvests, and 

those located by stranding networks and carcass surveys 

42. Collect and sample animals 

43. Develop methods for non-lethal sampling 

431. Develop and evaluate capture techniques 

432. Develop indices of condition 
44. Conduct studies on rookeries 

441. Determine sex and age class of animals on shore 

44.2. Determine rates of pup production and mortality 

44:3. Tag and brand pups and adult: females 

444. Monitor status of tagged animals 

445. Obtain measurements and samlples using non-lethal techniques 

45. Compile a catalog of all tissues and other samples 

46. Conduct laboratory analysis of sarrlples for diseases and parasites, contaminant levels, and 

nut.ritiona1 status 

47. Cc~mpile and analyze data 

5. Assess and minimize causes of rnortaliiy 

51. Determine causes of mortality and their relative contributions to total mortality 

51 1. Implement/expand stranding networks 

512. Survey selected areas for dead animals 

513. Monitor incidental take iin commercial fisheries 

514. Investigate entanglemenl in debris 

515. Determine and monitor level of' subsistence take in Alaska 

516.. Evaluate causes and extent of olther deliberate killing 

517. Evaluate mortality caused by non-human predators 

52. Minimize injury and mortality 

521. Develop and implement methods to reduce incidental take 

522. Develop non-hannful deterrents for use by commercial fishermen 

523. Improve and continue programs to minimize marine debris 

524. Develop methods to reduce loss rate in subsistence harvests 
53. Review and revise recommendatia~ns for maximum allowable levels of lethal take 

6. mitigate feeding ecolow and factors affecting energetic status 

61. Investigate sea lion feeding ecology 

61 1. Describe foods eaten by sea lions 

61 11. Collect and analyze stomach contents 

6112. Collect and analyze scats 

612. Determine food and energy requirements 

61 3. Investigate feeding areas and feeding strategies 

6 13 1. Identify feeding areas 

6132. Investigate diving behavior and feeding cycles 

614. Assess significance of various prey 

6141. Characterize geographic and seasonal patterns of prey availability and 

utilization by sea lions 

6142. Determine nutritional value of prey 

61.5. Compile and analyze data 

62. Iilvestigate interrelationships betvieen prey abundance and sea lion growth and productivity 

621. Measure growth and productiivity in areas with different food availability 

6;!2. Develop models for individual and population energetics, growth, and productivity 

63. Determine effects of fisheries on sea lion prey 

631. Measure effects of fisheries on sea lion prey in feeding areas 

632. Model effects of fishing on prey composition, distribution, abundance, and behavior 

64. Ehsure adequate food availability in feeding areas 

641. Regulate fishing areas, seasons, and types of operations 

642. Regulate fishery catches 
7. Implement Recovery Plan and coordinate recovery activities 

71. Establish a Steller sea lion recovery coordinator staff position 

72. Maintain the Steller Sea Lion Recov~ery Team 

73. Monitor Section 7 ESA requests for consultation 

74. Develop mechanisms for international conservation efforts 

741. Distribute Recovery Plan ro other involved nations 

742. Develop bilateral or multilateral conservation agreements 

75. Con'duct information and educational programs 

76. Enforce regulations 

761. Develop and improve systems foir reporting violations 

762. Provide adequate and effective field enforcement programs 

F. Narrative 

1. Identifv habitat requirements and protect areas of special biological significance 

As indicated in the introduction, a great deal is known about the major land areas used by 

sea lions during summer. Nevertheless, available data for most sites include oidy general 

descriptions of locations. More detailed delineation and evaluation are needed to determine how 

best to minimize potentially disturbing activities, and for documenting changes in habitat 

characteristics and use patterns. Once assembled this information will be difficult to summarize, 

analyze, or alccess manually, and therefore a computer database needs to be developed. Desirable 

characteristics of such a database include ease of access, ability to evaluate variables, and capability 

for overlay mapping. Managers of areas used by sea lions need rapid access to informatiorl for 

regulating potentially disturbing uses, and researchers could use the files to look for patterns that 

might help explain reasons for observed population trends. The compiled information shoilld be 

made available in the form of a catalog. 

Certain habitats such as rookeries are of obvious importance to the Steller sea lion 

population and will need careful protection. It is not clear whether all haulouts and other use 

areas are of equal biological importance. Also, it is likely that the various parts of the current 

overall range are of different biological significance to the population. To the extent possible, the 

importance of these various habitats and regilons should be evaluated in conjun~ction with the 

collection and cataloging of data. 
11. Identify current and historical use: areas 

111. Map, describe, and evaluate rookeries isnd major haulouts 

The database/catalog should include! all areas where pups are currently being born or 

where they have been produced withii the past 20 years. Current and historical counts of pups 

and non-pulps should be tabulated, and histlorical and modem rookery boundaries should be 

delineated (as accurately as possible. Availalble photographs should be iincluded to facilitate interyear comparisons of the extent of area used at occupied sites. 

Haulouts should be identified in the database/catalog. All available counts shoulcl be 

included in the database; however, at intenlsive study sites, only the average and range of counts 

for a particular time period (i.e., season) need be included in the catalog. 

The sigmficance of rookeries and haulouts should be evaluated based on factors siuch as the 

current and historical numbers of animals using them, their contributialn to o'verall and regional 

population productivity, distance fro~n adjacent rookeries or haulouts, etc. 

112. Map, 'describe, and evaluate feeding areas 

In order to properly manage sea lions and their habitat it will ble necessary to identify the 

areas where they go to feed. With existing data it will probably only be possible to identify a few 

general areas that are used for feeding. Oblservers on fishing vessels may provide additional 

anecdotal information about at-sea distribution of sea lions. Aerial and shipktoard surveys, 

particularljr in the vicinity of selected rookeries, could also provide useful information. However, 

monitoring with aid of satellite telemetry holds the greatest promise for delineation of miajor 

feeding areas. 

All available data should be used to map and describe feeding ;areas as specifically as 

possible. Emphasis should be put on sex/age classes thought to be likely to experience nutritional 

problems (e.g., juveniles). Once feeding areas have been identified, their significance should be 

evaluated based on the number of animals using them, location relative to ro'okeries, etc. Much of 

the data required for this purpose will be collected in the studies described in Section 6. 

12. Determine seasonal use patterns 

Seasonal patterns of sea lion use are known for a few intensively monitored terrestrial sites, 

but most past research on this topic has focused on the timing of use at rookeries in summer. 

There is very little information available on seasonal use of nearshore and open ocean habitats. 

Direct observations of sea lions on a year-round basis is impractical at most major use areas; 

however, time-lapse photography could provide a means to gather information about the patterns 

of abundance of animals on shore at a number of relatively accessible sites. Site visits by 

researchers and management personnel conducting other activities at times of year other than the 

breeding season could provide valuable information on distribution, dispersal, and seasoinal 

movements. Nevertheless, telemetry, both satellite and conventional (VHF), may be the best way 

of describing in detail the seasonal habitat use patterns of individuals on shore and at sea. 

Although :much of this information may be obtained in conjunction with other activities (e.g., 

Section 61 3), specific research projects may be required at certain areas. 
13. Document effects of disturbance caused by human activities 

Much information on the possible effects of disturbance caused by human activities is 

contained in unpublished sources. Information about the causes and impacts on sea lions of 

disturbance caused by human activities (e.g., noise from aircraft, boat:;, or other vehicles; shooting; 

habitat alterations; etc.) should be archived and summarized. An effort should be made to 

carefully document the response of sea lions to disturbance in areas where such observations can 

be readily made (e.g., at rookeries in California and Oregon). Little is known about disturbance of 

sea lions in feeding areas other than the intentional or incidental take associated with commercial 

fishing operations. Instances of disturbance should be recorded by observers who are now in place 

on commercial fishing vessels. New information that is gathered should be incorporated into a 

data base. 

Huiman activities that might contribute to the population decline should be described by 

area and evaluated in relation to populatiom trends of Steller sea lions in management units (see 

Section 2). 

14. Prepare ~uidelines and re~ulatiorls to control potentially disruptive activities 

Some regulations, such as buffer zones around certain rookeries, are currently in place to 

control hurnan activities that may affect sea lions and their habitats. Based upon information 

collected in Section 13, regulations and guidelines should be developed and/or revised to minimize 

potential impacts of human activities. Buffer zones may be the best waly to limit disturbance 

around rookeries and major haulouts. Major feeding areas at sea may also need to be protected 

from humail disturbance through the prohibition or control of certain activities (e.g., shooting). 

Specific guidelines or regulations should address disturbance that may be caused by vessels 

(commercial and sport fishing, tourist, research, and recreational), aircraft (private, charter, and 

military), and activity on the ground (tourislts, researchers, motorized vehicles,, and industrial 

activities). The Steller sea lion recovery coordinator (Section 71) should take a lead role iin 

developing and working to assure implementation of the necessary regulation:;. 

15. Identify and designate "Critical Habitat" ,areas 

All rookeries, major haulout sites, and important feeding areas identified in Sections 11 1, 

112, and 113 should be considered for designation as "critical habitat." When areas are designated, 

they should be large enough to ensure that potential impacts can be controlled and minimized. 

The seasonal nature of use patterns (Section 12) should, if applicable, be documented when critical 

habitat designation is made. 

2. Identifi management stocks 

Steller sea lions are widely distributed and recent population changes have been different in 

various parts of the species' range. Causes of the decline and measures necessary to halt it and 

start population recovery may vary from location to location. If it is possible to identify more than 

one stock of sea lions within the overall range, then management actions will have to consider 

differences in abundance and status of each s8tock. Even if biologically discrete stocks do not occur, 

it may be desirable to designate management units in order to facilitate development and 
application of conservation measures. 

Existing data from tagged animals suggest that a considerable am0un.t of movement occurs, 

both among areas within Alaska, and bemeen Alaska and regions to the south. Studies should be 

done to delineate home ranges, fidelity to rookeries and haulouts, amount of population 

interchange between prospective management units, and predominant activities within units. 

These aspects should be examined with regard to sex, age, and reprodluctive status of sea lions. 

This section describes use of visual marking/tagging and analysis of biological parameters 

to identi@ management stocks. Telemetry studies such as that described in Section 613 can 

provide detailed information on movement: patterns. However, such information usually covers a 

relatively short time span because of limitations of battery life and transmitter attachments. A 

telemetry study is not recommended specifically in this Section because short-term movements are 

of lesser iimportance when considering stock discreetness. However, information that is collected 

in telemetry studies should also be considered in the designation of m~anageiment units. 

21. Conduct visual mar kind tag gin^: studie: 

Shce 1975, several thousand Steller sea lions have been marked with brands antl tags. 

Since these marks may persist for many years, they can give an indication of' the long-term rate of 

interchange of animals among areas, as w~ell as the degree of fidelity to particular locations such as 

rookeries. Such studies are limited because they provide information only on marking and 

resighting locations and not on where mairked animals have been in the interim. Also, the activity 

involved in marking large numbers of animals is intrusive and will cause some disturbance to 

rookeries. Nonetheless, when done in corljunction with other activities (e.g., Section 44) valuable 

information may be obtained without creating an unacceptable impact. Stuldies may be required to 

evaluate the effectiveness and impacts of various marking and tagging methods, as well as to test 

new techniques such as use of passive integrated transponder chips. 

21 1. -and brand pups on selected rookeries 

Using appropriate techniques, pups should be tagged and branded at selected rookeries in 

the western Gulf of Alaska (e.g., Marmot antl Sugarloaf islands), eastern Aleutians (e.g., Bogoslof 

and Uganlak islands), central and western Aleutians (e.g., Seguam and Kiska islands), and 

southeast Alaska (Forrester Island). These are areas experiencing different levels of population 

decline. Factors that should be considered when planning and conducting I-agging and branding 

studies are tag loss, legibility of tags or brands, injury and mortality possibky associated with 

branding, disturbance effects to rookeries during branding or tagging, and procedures for 

mitigating disturbance. This study should1 be done in conjunction with studlies described in Section 

44. 

212. &litor rookeries for occurrence of marked animals 

Monitoring for marked animals should be done throughout the species' range in 

conjunction with studies described in Sections 12, 322, 33, 342, and 44. Special effort should be 

given to monitoring in the central Gulf of' Alaska to obtain information from sea lions that were 

branded in 1975 and 1976 and will soon no longer be part of the reproductive population, and 

from ani~nals branded in 1987 and 1988 that are now approaching reproductive age. 
22. &:rmine if biolonical parameters indicate different stocks of sea lions_ 

'The degree of genetic interchange among animals in different regions is the most important 

factor in stock identification. Morphometric and genetic comparisons can give an indication of 

stock discreetness, which can then be used as a basis for delineating or adjusting management 

units. Limited studies of genetic variatioln in Steller sea lions that have been conducted do not 

conclusively show whether or not there is more than one population or stock (Lidicker et al., 

1981). 

Techniques that show promise foir identifying management stocks include morphometric 

analyses, protein electrophoresis, DNA analyses, and analyses for regionally varying trace 

chemicals. Additional techniques may betcome available in the future. Materials (e.g., blood, skin, 

liver, or other tissues) and data required for these analyses may be obtained from existing 

collectiolils (see Section 45) or from sampling programs described in Sections 41, 42, 43, 443, and 

61. Although these sources are expected to provide adequate sample sizes for most analyses, it is 

possible that additional sampling programs will have to be developed. Those sampling programs, if 

needed, should conform to the criteria set forth in Sections 42 and 43. 

23. Corn~~ile and analyze data 

Data should be analyzed to detem~ine whether or not management (stocks can be identified, 

Stock boundaries should be described, if possible, and the degree of interch.ange with other stocks 

should be quantified. When analyzing movement data, consideration should be given to sex, age, 

and reproductive condition of the marked animals. 

This Section refers only to data analysis relating to the identificatiorn of management stocks. 

Other specific data analyses are identified in Sections 47 and 615. It should be noted, however, 

that the compilation, evaluation, and dissemination of data generated by efforts described in this 

plan shou~ld not be overly compartmentalized. The task of facilitating analysis, presentation, and 

distribution of data should be a responsibility of the Steller sea lion Recove~y Plan coorciinator 

(Section 71). 

3. Monitor status and trend of sea lions 

Cu~rrently, the status and trend of Steller sea lions is monitored using two primary 

methods: aerial photographic surveys of large segments of the population or1 rookeries and 

haulouts, and pup counts at selected rookeries. 

Aerial surveys are conducted by flying over each rookery or haulout and photogr,aphing 

the animals present. The surveys are timed to coincide with seasonal and daily periods when 

high numbers of animals are on shore, i.e., during the breeding season in mid June/early July 

and between 10:OO a.m. and 4:00 p.m. Aerial surveys have been limited to one-time counts of 

the hauled1 out population. The counts do not enumerate those animals which were at sea 

during the survey, or provide a measure of variability which is required for statistical analysis of 

the data. However, this survey method provides a useful index of abundance, and the results 

can be compared over time to evaluate population trend. 
In addition to aerial surveys, pup counts have been conducted at rookeries in late June 

and early July. Adults go to the water teinporarily while people are ton the rookery counting 

pups. Although small numbers of pups may be missed (including those not yet born and those 

already able to accompany adults into the water), this type of count is treated as a total count. 

Pup counts are used to measure productivity because they reflect the total number of parturient 

females. However, caution must be exercised when generalizing about population trends based 

solely on pup counts. A declining number of pups in the population could be indicative of a 

declining total population, a decline in fecundity, a decline in the number of reproductively 

active females, or a combination of' these and other factors. 

Both the pup counts and aerial surveys should be continued in order to monitor status 

and trend of sea lions throughout their range. In addition, a method shoul~d be developed that 

will allow abundance and trend in specific areas to be measured with statistical confidence. 

31. Devellop statisticallv valid survey proc~edures 

A single count, even when made dluring the most stable attendance period, only produces 

an estimate of the number of animals present at a given time and does not provide any measure 

of variability. Repeated counts of the sanne area are needed to provide a basis for calculating 

variances and confidence intervals. This type of data is particularly necessary in order to 

quantify population trend (i.e., the rate at which numbers are declining or increasing). 

Repetitive count data are now available for some locations. These data should be analyzed to 

provide a1 preliminary assessment of the survey design requirements. Repeated surveys should 

then be conducted daily over a broad area (e.g., a portion of southea~st Alaska). The study 

design should account for tidal stage and other factors that may affect hauling out behavior. 

Once statistically valid survey methods ar~e developed, they should be incorporated into the 

monitoring program in addition to methods presently in use. 

32. Conduct Alaska statewide survev every year 

Alaska is the center of distribution and abundance for Steller sea lions, and counts made 

in Alaska have been used as an index of the overall status of the species. Numbers have not 

declined in southeast Alaska, but have declined in most of the remainder of the state. Frequent 

monitorii~g of the distribution and number of Steller sea lions throughout Alaska is required to 

maintain a current knowledge of the population trend in various regions. It is particularly 

important to monitor carefully the Prince William Sound area, since it appears that the decline 

may recently have spread to that area. 

321. &Induct aerial survev of adults and juveniles at all rookeries aind major haulouts 

All rookeries and major haulout sites from Forrester Island to at least Agattu Island 

should ble surveyed using established methodology (i.e., flying at approximately 500-800 feet 

altitude, 0.25 miles offshore, and 80 knots air speed). Surveys should be flown between 

10:OO a.m. and about 4:00 p.m., from about June 10-30. The number of animals present should 

be estimated and photographs taken for subsequent counting in the laborattory. New techniques 

(e.g., high resolution video cameras) shoiuld be evaluated to improve1 methods. 

A.t least two survey crews will be required, one for southeast Alaska and Prince William 
Sound, and another for areas to the wes:t of Prince William Sound. Within the region from the 

Kenai P~eninsula to Kiska Island, special effort should be made to ensure that counts are 

obtained at all trend count sites identified in Appendix A. 

322. Conduct pup counts at selected rookeries 

Pup counts are an important measure of the status and trend of the population-but they 

are relatively difficult to obtain. Counts from aerial or vessel surveys are riot reliable because 

pups frequently are under boulders or cliffs, or are obscured by other animals. The most 

reliable counts of pups are obtained fronn land, usually by slowly walking through the rookery 

which causes the adults to move toward the water while the pups remain lhigher on the beach. 

At some sites, reliable counts can be obtained by looking down on the rookery from cliffs or 

bluffs. Optimal dates to count are from about the last week of June through the first week of 

July. Access to the sites must be by ship, helicopter, or in a few casles, float plane. 

F'up counts should be conducted at selected sites in Alaska in order to maintain a current 

level of lknowledge on status and trends (of sea lions for management and research plarming. 

The Team recommends doing pup counts; at each rookery only every other year to miniunize 

disturbance. During even numbered years pup counts should be done at Seal Rocks, Sugarloaf 

Island, C'howiet Island, Chernabura Island, Clubbing Rocks, Ugamak Island, and Akutan Island. 

During odd numbered years, counts should be done at Outer Island, Marmot Island, ChJrikof 

Island, Atkins Island, Pinnacle Rock, Akun Island, Bogoslof Island, and all rookeries in southeast 

Alaska (see Appendix B). These sites may be visited by helicopter or ship. Because of cost and 

difficulty of access, we do not recommend biennial pup counts at rookeries in the central and 

western Aleutian Islands. Pup counts in those areas would be made every 15 years as part of the 

range-wide survey (Section 34). Additional pup counts could be made in those areas i11 the 

course of other activities, such as those described in Section 44. 

33. Conduct surveys of pups and non-pups at rookeries in California and Oregon every other 

year 

The number of Steller sea lions in parts of California has declined greatly. In Oregon, 

sea lion numbers have fluctuated but shown no strong trend. Since human activities may be 

affecting animals in California and Oregon, and because factors responsible for population 

changes may be different than in Alaska, complete surveys of pups and non-pups should be 

conducteid at least every other year. 

Some rookeries are currently being surveyed more or less regularly by various personnel 

and agencies. There is a need, however, to coordinate surveys so that they include all rookeries 

in California (Aiio Nuevo Island, Farallon Islands, Cape Mendocino, and St. George Reef) and 

Oregon (:Rogue Reef and Orford Reef). Methods used should be designed to give data ithat are 

comparable to that described in Sections 327. and 322. However, techniques may have to vary 

somewhat due to specific conditions (e.g., topography and access limitation:^) at each location, 

and to fit the characteristics of existing programs. 

34. Conduct range-wide survey every 5 years 

Information on status and trend of' the entire population is needed to guide changes in 
listing categories, to facilitate area management, and to help establish research priorities. 

Because animals may move from one area. to another, results from surveys done in separate 

parts of the range during different years can not necessarily be combined. Therefore, in order 

to monitor the status and trend of the population as a whole it is necessary to conduct surveys 

throughout the entire range of the species during the same year. This has been attempted only 

once, in 1989, when all areas except British Columbia and California were counted. Conducting 

a range-vride survey is an international effort and will require cooperation and support of 

investiga1:ors and agencies in the United Stat:es, Canada, and Russia. 

341. mlduct aerial survey of adults and juveniles at all rookeries and mailor haulouts 

Surveys should be conducted using the methods described in Sections 321 and 33. 

Because of the large area to be covered, six separate survey crews will be required as follows: 

(1) California, Oregon, and Washington; (2) British Columbia, southeast Alaska, and eastern 

Gulf of Alaska; (3) central and western Gulf of Alaska, and eastern Aleutian Islands; (4) central 

and western Aleutian Islands; (5) Kamchatka; and (6) Kuril Islands. Rookeries in the Okhotsk 

Sea and Commander Islands (and perhaps Kamchatka and the Kurils) may ineed to be surveyed 

by land or ship because of the difficulties in obtaining aircraft for swrveys in Russia. 

342. Conduct pup counts at selected rookeries 

Counts should be conducted using the methods described in Sections 322 and 33. 

Important index rookeries that should be counted are listed below, by region (see also Appendix 

B) . 

Califolnia, Oregon, and Washington ---all known rookeries 

British Clolumbia ..................... all known rookeries 

southeast Alaska ..................... all known rookeries 

eastern Gulf of Alaska -------------- Seal Rocks 

central Grulf of Alaska -------------- Outer Island, Sugarloaf Island, Ma~mot Island, Chirikof Island, 

Chowie~t Island 

western Gulf of Alaska ------------- Atkins lisland, Chernabura Island, Pinnacle Rock, Clubbing 

Rocks 

eastern fdeutian Islands ------------ Ugamak Island, Akun Island, Akutan Islaind, Bogoslof' Island 

central Aleutian Islands ------------ Yunaska Island, Seguam Island, Ulak Island, Kiska Island 

western .Aleutian Islands ----------- Buldir [sland, Agattu Island 

Bering Siea Walrus Island 

Russia all sites that can be visited by ship 

The selection of these rookeries is; preliminary and should be changed if other sites are 

determined to be more important. Because of the alternate year counting schedule for index 

rookeries described in Section 322, some sites will not be counted in the year of the range-wide 

survey (see Appendix B). For those rookeries, data from the previous year should be used in 

compiling an estimate of range-wide pup production. 
4. mlitor health, condition, and vital parameters 

The health and condition of individual Steller sea lions may be one of the most 

important factors to monitor in relation to the population decline and recovery. Condition of 

individuals will affect their survival and reproductive output (i.e., vital parameters) which in 

turn will influence population status artd trend. Initial efforts to develop life tables (Calkins and 

Pitcher, 1982; York, in preparation) should be continued and expanded. Successful and 

accurate assessment of the factors contributing to the population decline requires good life-table 

data to provide quantitative measures olf the impact of a given factor on productivity and 

mortality. Likewise, the degree of success of management efforts is ultimately assesseld by the 

effect c)n mortality and productivity. Previous studies have collected a variety of mea.; urements 

and sa~nples that can be used in this ev,aluation (e.g., Calkins and Goodwin, 1988). Additional 

data antd samples should be collected in conjunction with other programs to address s,pecific 

researcih needs. Standardized protocols should be used for collection and storage of specimens, 

and materials should be archived for fuihre analyses. New techniques should be developed, 

evaluated, and applied as appropriate. 

41. &mine and sample dead animals from rookeries, incidental take, subsistence harvests, and 

those located by stranding networks and carcass surveys 

'The various programs that will be conducted to evaluate rates and causes of mortality 

(Sectiori 51) will provide access to dead sea lions for examination and sampling. Dead pups 

should lbe collected at intensive study sites established under Section 44 whenever this is 

possible without disturbance to normal irookery activities. Carcasses opportunistically recovered 

should be examined and sampled to the maximum extent possible. Animals taken incidentally 

in comn~ercial fisheries and by subsistence hunters can be sampled when very fresh, and efforts 

should be made to seek the cooperation of fishermen and subsistence hunters in gaining quick 

access to dead animals. People collecting specimens should be trained, and should be provided 

with necessary protocols. 

Measurements, teeth, reproductive tracts, and tissue samples made available by studies 

described in Sections 22, 432, 445, 46, 611, and 621 should be collected and analyzed to assess 

and monitor general condition and reprclductive status. Collection and analysis of reproductive 

tracts from female sea lions is particularly important for monitoring critical vital parameters. 

Standard techniques (Pitcher and Calkin:;, 1981) should be used to determine reproductive 

status of each individual. Data should be used to determine ovulation rates, pregnancy rates, 

and age of sexual maturity. Whenever possible, blood and tissue samples should be collected 

for use in studies of disease, contaminants? and DNA analysis for stock identification (see 

Sections 22 and 46). 

42. m.ct and sample animals 

Given the rapidity of population decline in some areas and the threatened status of the 

species, lethal collection of sea lions to obtain samples or data is not desirable. Limited lethal 

collectiol~s may, however, be deemed necessary at some future time for the acquisition of certain 

kinds of crucial data that may not be obtainable from other techniques. Careful consideration 

of the question of lethal collection is particularly relevant in the case of the Steller sea lion 

because some of the most significant data concerning the decline of the species and the possible 
causes of the decline came from aiumals collected in the late 1970s and early 1980s. For 

example, the report from the April, 1990 U.S.-U.S.S.R workshop on Steller sea lions states: "... 

some of the most enlightening information on the possible causes of the decline, and how the 

decline is affecting population structure, came from collections of animals in the 1970s and 

1980s by the ADFG. In those studies, changes in physical size of individua~ls of known age and 

possible changes in age distribution and pregnancy rates were observed. These types of data are 

important in considerations of the factor:; affecting the population and its irelative health. 

Collecticlns may be required in the future if adequate samples cannot be obtained from1 

commercial fisheries observer programs or through other sources." (Anonymous, 1990, p. 9). 

C)ecisions to employ lethal sampling techniques should address the possible impact of 

sampling on the local population, the deficiencies of any alternative non-lethal collecting 

techniques, and the significance of the data to be derived from the collection. 

43. m.10~ methods for non-lethal sampling 

VVhenever possible, non-lethal sa~npling should be used to monitor health, condition, and 

vital parameters. In addition to existing methods, efforts should be made to develop or adapt 

techniques not yet tried on Steller sea lions. It is recognized that some techniques (e.g., 

chemical immobilization) may pose a risk of mortality. Such incidental mortality must be 

accepted under the same criteria set forth for lethal sampling: the potential cost of the 

technique should not exceed the anticipated benefit to the species from knowledge derived from 

the sampling technique. 

PL variety of studies require temporary restraint of animals. The large size and vigilance 

of Steller sea lions may limit the usefulness of some capture and restraint techniques developed 

for smalller or more approachable pinnipeds. Although few Steller s~ea lions are currently 

maintained in captivity, the possibility of research with captive animals should also be 

considerled. 

The increasing use of telemetry djevices and other techniques to sannple free-ranging 

individuisls should be given high priority,, because these techniques minimize potentially 

disturbing interactions with the animals ;and provide data from animals under the most "natural" 

conditio~ns possible. 

431. melop and evaluate capture techniques 

In recent years, there has been a great deal of work done on techniques for capturing 

and imrr~obilizing marine mammals. Techniques for chemical immobilizati~on of Steller sea lions 

and closely related otariids have been investigated (Loughlin and Spraker, 1989; Boyd et al., 

1990). ]However, some mortality does occur even with the best methods currently available, so 

efforts to improve techniques should be continued. Emphasis on improving techniques should 

not be taken to imply that special studies need to be conducted for that specific purpose. It 

should ble possible to do most development and evaluation of new techniques during research 

conducted for other purposes (e.g., Section 613). 
432. welop indices of condition 

Various measurements may be used singly and in combinatioin to evaluate the physical 

conditior~ of individual sea lions. Methocls currently in use include body weight (comp,ared to 

age or length), length/girth ratios, and directly measured blubber thjickness (Calkins an.d 

Goodwin, 1988). In addition, there are rlecently developed techniques for assessing condition 

that may be more suitable for some situations or that can provide measures particularly sensitive 

to certain aspects of condition not reflected by body size and subcutaneous fat stores (e.g., 

Huntley et al., 1987). These include, but are not limited to, isotopic tracer techniques for 

assessing body composition and metabolism, ultrasound and electricad conductivity measures of 

body fat, measures of lactation energy exchange, and a variety of blood chemistry measures 

associated with specific aspects of condition (e.g., anemia, immune response, ketone bodies, 

humoral enzyme levels). Expert advice on this field should be solicited and a complete plan for 

condition assessment should be developed based on multiple indices of condition. Data on 

condition indices will most likely be collected at intensive study sites described in Section 44. 

Samples from dead animals will be obtained by activities described in Section 41. 

44. Cond-uct studies on rookeries 

Observational studies of sea lions Ion land can yield a wealth of data that can be used to 

evaluate status and condition. Data shou:ld be collected as part of a complete program at 

selected intensive study sites. The 1progra:m at intensive study sites sh~ould iinclude population 

monitoring efforts (Sections 441 and 442:1, monitoring of mortality specified in Section 51, 

sampling from dead animals described in Section 41, and collections of stomach contents and 

scats described in Section 611. In addition, observations of certain behaviors on the rookery can 

also serve as indices of health, condition, and vital parameters. For example, copulatior~s over 

the course of the breeding season can indicate the relative proportion of nulliparous females 

being reclruited into the local breeding population because these females tend to copulate early 

in the breeding season (Gisiner, 1985). Average tenures of territorial males may be reduced in 

comparison to other years or other areas if males are in poor condition, since males rely on 

stored fat reserves while on a territory. Other observational data which are relatively easy and 

inexpensive to obtain might serve as an index of individual or population condition values that 

are difficult to measure directly because they require lethal collection or handling of 1ar;ge 

numbers of animals. 

Intensive studies should be undertaken each year for the next 5 years at sites in Oregon 

(Rogue Rleef), southeast Alaska (Forrester Island), the Gulf of Alaska (Manr~ot Island anid 

Chirikof Iisland), and the eastern Aleutians; (IJgamak Island). Because of the expense and 

logistic difficulties of transporting and maintaining camps in the central and western Aleutians, 

intensive :studies for this area should be conducted every 3 years (perhaps 11992 and 1995). 

Suggested. study sites in the central and western Aleutians should include at least two of the 

following:: Seguam Island, Kiska Island, Buldir Island, and Agattu Island. Choice of specific sites 

will depend on a number of variables, incl.uding, but not limited to, access tlo adequate numbers 

of animals, year-to-year stability of the site, potential for disturbance to animals or disru~ption of 

other research activities, and requirements of data comparability between sites or between years. 

Selection of specific sites should therefore be done by qualified persons who are familiar with 

the sites and other relevant factors. 
441. Determine sex and age classes of animals on shore 

Daily or weekly counts broken dovvn into age/sex classes sho~ild be made by experienced 

observers at selected index sites during the summer breeding season (approximately mid-May to 

mid-August). If field camps are maintained outside the breeding season, counts should continue 

to be macle to provide information on seasonal variation in use of sites. Frehquent counts by 

experienced observers approach the accuracy of aerial photographs. Such counts have been 

used to verify aerial counts and as a source of data if aerial counts are not feasible. The 

age/sex composition of groups on the study site provide site-to-site and beh~een-year 

comparative data on ma1e:female ratio?, fema1e:pup ratios, and fema1e:juvenile ratios. These 

data serve as indicators of possible changes in individual condition, sex-related differences in 

survival, fecundity, and other life history parameters. More intensive follow-up studies can then 

be focused on potential problems revealed by the dynamics of age/sex classes at intensive study 

sites. 

Observations of mother-pup attendance patterns should also be conducted. Fem*ale 

attendance patterns in closely related otaniids have been shown to be correlated with female 

condition and food availability. For example, during the 1983 El Niiio climatic disturbances, 

female attendance patterns and pup condition in California sea lions and Gailapagos fur seals 

were altered by climatically induced food shortages (Trillrnich et al., 1986; Ono et al., 1987). 

Data on attendance patterns may also be obtained from telemetry packages placed on breeding 

females (see Section 613). 

Data on mother-pup attendance patterns should be combined with lactation energetics 

data (Section 445) to provide a more complete picture of the foraging ecology of reprod.uctive 

females. These data are important for datia compilations and models (of foraging ecology in 

Sections 6'12, 614, and 62. 

442. Deteirmine rates of pup production artd mortality 

Currently, counts made by researchers walking through rookeries and displacing the 

adults are probably the best measure of pup production. Such counts are us,ually very accurate 

and may yield numbers of pups 30% or more higher than counts made with adults present. The 

activity results in some disturbance and potential pup mortality, and for that reason this type of 

pup count is done infrequently at a limited number of sample sites. Some counts may be 

conducted in conjunction with pup tagging or marking efforts that may also temporarily 

displace adults. 

Section 322 describes a coordinated program of alternate-year pup counts at selected 

sites in Alisska. The sites listed for regular, biennial pup counts include the htensive study sites; 

activities at the intensive study sites should therefore be coordinated with the needs of Slection 

322. Additionally, at intensive study sites, repeated counts of pups should be conducted without 

disturbing the animals, as part of the daily or weekly counts described in Section 441. Such 

counts, made over the duration of the breeding season, may approach the accuracy of single 

counts with adults removed, although it might be desirable in the early year:; of this plan to 

perform comparison of the two counting methods at some intensive study sites. 

Pulp mortality (see Section 5'12) also can be most accurately and easily monitored by a 
shore-based observer who examines the rookery daily or weekly throughout the seasoil. 

443. Tag and brand pups and adult females 

Section 21 also recommends taggindmarking efforts to determine dispersal and seasonal 

movement patterns of animals from different management units. Thus should not be taken to 

imply &.at there should be two separate, mutually exclusive tagginglmarking programs; Sections 

21 and 443 simply emphasize different dlata aspects of a single taggindmarking program. Any 

taggingl'marking proposal should be considered in light of its ability to be coordinatedl with 

other activities (e.g., pup counts and field physiology studies requiring animal capture and 

restraint); its probability of being followed by studies that can make use of the potenbial data 

yielded Iby animals marked to reveal age,, sex, place of birth, and individual identity (the types of 

activities proposed in Sections 2 and 4 of this plan); and the potential impacts of disturbance 

resulting from taggindmarking activities. 

Pups may be tagged in conjunction with counts (see Sections 322, 33, and 342). 

Females immobilized for attachment of telemetry equipment or other experimental procedures 

should allso be tagged (Sections 415 and 613). There are limitations to the benefits derived 

from tagging. It is usually difficult, if nclt impossible, to re-tag anhnals older than pups. Tag 

loss and abrasion of identification numbers over time can therefore serious;ly reduce the effective 

number of individually identifiable animals. In addition, most tags are difficult to read under 

normal field conditions, even if they are still in place and possess legible markings. 

Nevertheless, tags are inexpensive and easy to put on. Color-coded tags can provide data on the 

rookery of origin of animals sighted at various locations even after the tag markings are worn 

off. The accumulated tag sighting data can provide information on the extent of dispersion 

from various sites, the seasonal movements of individuals from a given site, and the relative 

amount of immigration from one site to (other intensive study sites. Such information :should be 

useful in determining stock identity (Secf on 2) and seasonal use patterns (Section 12). 

Elranding is more expensive, the equipment is more cumbersome, and marking (does not 

proceed as quickly or easily as tagging. Nevertheless, branding or some other means of 

producir~g long-lasting, easily read individual identification should be considered as a means of 

providin,g much needed life table data on recruitment and age-specific reproductive rates. 

Branding pups to indicate rookery and year of birth has produced valuable information even 

though the branded animals were not intlividually identified (Calkins and Pitcher, 1982). Pups 

were branded with individual identification marks in 1987 and 1988 on two beaches at Marmot 

Island, but one of the beaches was later abandoned by the sea lions as the population declined 

(Anonymous, 1990) and the marked animals apparently dispersed (a1thoug;h surviving animals 

may still return to the branding site or oiher monitored sites as they come of breeding age). 

444. Monitor status of tagged anim-i 

Long-term studies of tagged, branded, or naturally marked animals can be used to 

estimate such vital parameters as age of first reproduction, age specific pup production, site 

fidelity, ontogeny of male temtory acquisition, cohort survivorship, non-breeding range of 

individuals, and others. It should be noted, however, that some of these studies may require 

sample sizes larger than can be practically attained. 
Prolonged follow-up studies are required to develop life table data for long-lived species 

with low fecundity such as the Steller sea lion. In addition, public reporting of sightings of 

marked animals should be encouraged through public education and informational programs 

(see Section 75). 

445. Obtain measurements and samples using non-lethal techniques 

Techniques developed and evaluated in Section 43 should be applied at the intensive 

study sites, in coordination with other activities. Programs that have potential for disturbance 

may need to be conducted away from sites being monitored for regular counts or being used for 

ongoing behavioral studies. Measurements and samples required by other programs should be 

collected in conjunction with the activities planned in this Section in order to reduce the 

number (of capture efforts required to fulfill all research and monitoring goals (e.g., tissue 

sampling; for Section 22 studies, tagging (and branding for Section 21 and 4143 studies, 

attachment of radio-tags for Section 613 studies, and food habits sampling in Section 611 could 

all be performed during captures for condition assessment and energetics studies under this 

Section). 

45. -pile a catalo~ of all tissues and otther samples 

Previous research has resulted in the collection of a considerable number of tissues and 

other sa~nples from Steller sea lions. Most of this material is currently held by ADFG or NMML. 

Some, but not all, of this material has been analyzed. All of the existing material should be 

centrally cataloged so that it may be available for completion of ongoing ainalyses or for 

additional analyses that are required later. The catalog should include the location of samples, 

their condition, and whether or not any analysis has been conducted on them. Documentation 

should indicate the protocols used in malting collections. To this catalog will be added the 

samples <generated by efforts described in Sections 22, 41, 445, 511, 611, and 612. Steps should 

be taken to ensure that samples are being pxoperly archived. 

46. -duct laboratow analyses of samples for diseases and parasites, contaminant levels, and 

nutritional status 

Arrangements should be made wii5 appropriate laboratories that can provide reliable, 

timely, and cost-effective analyses of samples. In many cases, the data collection procetdure, 

sampling, and analysis may be canied out by a single agency or contractor. Criteria should be 

established for prioritizing samples for analysis. The types of analyses to be performed wiU be 

determined by the needs of programs instituted under Sections 41, 42, 445, 51, and 61. 

47. mile and analyze data 

Dlata collected in current and future research should be analyzed and reported in a 

timely manner. Reports should be thoroughly referenced and follow standards of organization 

to facilitate comparison with existing reports. As much as possible, data should be presented in 

peer-reviewed periodicals and other open publications to ensure that research program:; benefit 

from regular peer commentary. 

To the maximum extent possible, current and future research effort; should collect data 
in such a way that they can be co~nparedl with historical data. Studies may need to be 

conducted to calibrate results from newljr developed techniques with those obtained by previous 

methods. Data analyses should examine trends over time and attempt to clorrelate observed 

changes with physical, biological, or human induced changes in the environment. 

Analyses of data should also emp'hasize correlations between regional differences in sea 

lion population trends with regional differences in other factors, such as physical oceanography, 

food resources, human activities (fishing, tourist activities, etc.). Factors that are correlated 

with declining regional populations can help identify the causes of declines, which in turn will 

lead to nnore effective management efforl-s. 

5. Assess and minimize causes of mortality 

R-egardless of the causal factors o:F the current decline, the gola1 of population recovery 

requires a major effort to decrease mortality wherever possible. Furthermore, the decline in 

Steller sea lion numbers must eventually be traced to specific source:; of mortality and/or 

reductions in productivity; this can only be done by quantitative assessments of the causes of 

mortality. 

51. -mine causes of mortality and their relative contributions to total mortality 

51 1. Implement/expand strand in^ networks 

Nlarine mammal stranding networks have provided valuable data on mortality for several 

marine mammal and bird species. Examples include episodic outbreaks of lleptospirosis and San 

Miguel sea lion virus in California sea lions and gillnet mortality of seabirds and harbor 

porpoises in central California. As illustrated by these examples, stranding networks may be 

valuable for determining causes of illness, injury, or death within an area as well as year-to-year 

changes in the number or location of affected animals. Data from stranding networks are 

usually not used to determine the relative contribution of a specific agent olf mortality to total 

population mortality because some agent:; may be more Likely than others to produce st-randings 

and subsequent recovery of animals by stranding networks. Also, because of the large size and 

relative inaccessibility of much of the SteiUer sea lion range, and the relative rarity of Steller sea 

lion strandings, information derived from stranding networks may not be very extensive for this 

species. 

Existing organizations and individuals should be informed that Steller sea lion strandings 

are of particular significance. Data that are obtained should be cataloged and maintained by a 

central agency, and should be kept up to date through annual or semi-annual mailings to 

stranding; networks, state fish and game agencies, etc. A possible approach would be to request 

that stranding networks notlfy a designatled office (e.g., the regional stranding program 

coordinator), and a trained group of people who might respond to strandings. 

Personnel examining stranded animals should endeavor to determin'e the cause of death 

or injury, and look especially for evidence of interactions with humans (e.g., bullet wounds or 

net marks). Besides indicating the presence of potential agents of mortality, the opportunity to 

examine sick or injured animals may lead to better field diagnosis of sick or injured animals that 
are not stranded. Maintaining stranded individuals in captivity for filrther :study or treatment 

may be practical only for younger, smaller individuals. Rehabi1itatio:n and :release may be of 

value in the recovery of very small populations, but it is not likely that such an effort would 

make a significant contribution considering the current numbers of Steller sea lions. 

Dead animals, even those that are decomposed, can be valuable sources of data. High 

priority should be attached to the reporting of stranded sea lions regardless of conditioin. A 

priority list for observations, measurements, and specimens to be collected :should be made 

available to state fish and game agencies, Federal research and manalgemen~teams, and other 

appropriate groups and individuals within the Steller sea lion range. 

512. w~ev selected areas for dead animals 

During studies at selected index sites (see Section 44), persorlnel should have the 

materials and training to: (1) determine approximate age/sex and location of all dead animals 

observed; (2) perform field necropsies to determine causes of pup mortality on the rookeries 

and collect tissue samples needed for other studies (Sections 22 and 41); aind (3) properly store 

and transport collected materials for laboratory analysis (Section 46). Undler some 

circumstances it is recognized that the cost of recovery may exceed the value of potential data 

from the dead animal; for example, dead pups should be counted and sampled during pup 

counts when pups have been separated from adults, but rookeries should not be disturl~ed solely 

to recover dead pups (see Section 442 for discussion of methods for determining pup mortality). 

Efforts should also be made to identify sites where there is an high probability of being 

able to locate and sample dead animals. This effort will need to be coordinated with activities 

of stranding networks (Section 511), aerial survey crews (Sections 32, 33, innd 34), field 

enforcement (Section 76), and other field activities. If identified sites are not visited regularly 

as part of the activities listed above, it may be desirable to conduct special field efforts to 

examine and sample dead animals. 

513. Monitor incidental take in comnmercj.al fisheries 

The mechanisms for reporting incidental takes and ensuring compliance are provided in 

the MMF'A and NMFS regulations. Additional effort should be devoted to emphasizing the 

significance of these data for Steller sea lions. Specific methods for <assurinlg maximum 

complia~lice in reporting, and for proper sampling of animals and storage of specimens should be 

developed. To increase their cooperation and compliance fishermen shoulcl be encouraged to 

take an interactive role in developing strategies for reporting takes. Educational programs 

aimed at fishing organizations and communities (see Section 75) would be a particularly useful 

forum for developing workable monitoring procedures. 

Current observations of sea lions at sea and on land indicate that entanglement in debris 

is infrequent. There should be a continued effort to estimate the relative number of entangled 

animals :in stranding data, by observers aboard vessels at sea, and during field research activities 

such as pup counts (Sections 322, 33, and 342) and observations at intensive study sites 

(Section 44). When possible, the entangling material should be identified as this may provide 
clues about the circumstances under which sea lions become entangled. Literature surveys 

should be conducted regularly to update information on related marine mammal and bird 

entanglement incidents, and surveys of occurrence of entangling materials (packing bands, net 

fragments, etc.) at sea. Data should be usled to support efforts to mitigate mortality (see Section 

523). 

515. -mine and monitor level of subsistence take in Alaska 

Available data on subsistence take of sea lions in Alaska has recently been summarized 

(Haynes and Mishler, 1991). A statewide subsistence harvest survey should be conducted to 

provide more current and accurate estimatles of regional and total harvest levels. Subseqluently, 

annual monitoring should be done at locations where substantial numbers of sea lions are being 

taken. Oblservers should determine the numbers and age/sex of animals taken, numbers killed 

or injured but not recovered, methods used to take, etc. In addition to monitoring activities, 

personnel interacting with subsistence hunters should seek cooperation in obtaining 

measurem~ents and samples required by Sections 22, 41, and 611. 

516. Evalu.ate causes and extent of other deliberate killing 

Enforcement programs (Section 76) and educational programs (Section 75) shoulld yield 

information about specific instances of deliberate killing not associated with subsistence 

hunting. 1;ollow-up on reports of deliberate killing are needed to determine the causes of such 

mortality (:see Section 41) and how prevalent such incidents are. Once sources of deliberate 

killing are identified, programs should be developed to eliminate this source of mortality,. 

51 7. Evaluate mortality caused by non-human predators 

Known marine predators of Steller sea lions include killer whales and sharks. 

Observations of predation have been sporadic and opportunistic. Rookeries (lo not appear to be 

regularly patrolled by killer whales. It would therefore be difficult to develo]:, a reliable estimate 

of predation for a specific location or rookery., Even at sites where marine predators (white 

sharks and killer whales) are easily sighted from shore, such as the Fairallon Islands in 

California, it has not been possible to devellop quantitative assessments of the extent of 

predation or its possible impact on pinnipeld populations (D. Ainley, personal communication). 

Potential terrestrial predators include brown and black bears, and to a lesser degree 

foxes, bald eagles, ravens, and gulls (the latter four probably prey only on injured or abandoned 

pups that would likely die anyway). There is no record of bears contributing regularly or 

substantially to sea lion mortality. 

Du~ing the current population decline reports of predation have not increased, and it is 

therefore unlikely that predation has contributed substantially to the problem. Nonetheless, 

opportunistic observations of predation can and should be made in conjuncti~on with intensive 

study programs (Section 44) and other field activities. 
52. Minimize iniury and mortality 

It is clear that human activities hav~e caused injury to and mortality of many thousands 

of Steller sea lions (e.g., Perez and Loughlin, 1990). Steps should be taken to improve the data 

base in this area, and at the same bine reduce all human-related mortality and trauma to the 

maximum extent possible. 

At present, the causes and extent of natural mortality are not known. As research 

outlined in this plan progresses, data may ireveal agents of natural mortality (e.g., disease) that 

could be controlled to facilitate population recovery. Currently, however, no programs for 

attempting to reduce natural mortality are identified. 

521. Develop and implement methods to reduce incidental take 

Gear modification programs should be considered for fisheries where the incidental take 

of sea lions can be identified with specific gear types. Current data, however, tend to indicate 

that sea lion mortality in fishing gear is more a function of area and fleeding activity than it is of 

the gear itself. For example, incidental tak;e is higher when fishing is conducted at night: 

(Loughlin and Nelson, 1986). 

Particular attention should be paid to the timing and location of fisheries where :sea lion 

mortality is known to occur. Fishery mana~gement regulations may be able tlo shift the location 

or timing of those fisheries to reduce the incidental take of sea lions, with little or no impact on 

the overalll commercial catches of fish. Ch,anges in regulations to alteir the time and area where 

fish may be taken may, however, impact current and traditional fishing patterns and could affect 

the econolnic return from the fisheries. 

Available data should be reviewed <annually to determine where the likelihood of 

incidental take is greatest, and to identify alternative areas or times where those fisheries could 

operate. If necessary, new regulations or modifications to existing regylations should be 

developed and implemented. Educational programs (Section 75) should include active 

involvement of fishermen in development of techniques to reduce and eliminate incidental takes. 

522. Develop non-harmful deterrents for use bv commercial fishermen: 

Existing regulations prohibit fishermen from shooting at or near sea lions to keep them 

away from their gear or catch. Alternative methods for displacing pinnipeds, such as seal 

bombs, killer whale sounds, and taste aversion, have been tried, but they have generally not 

been very successful (e.g., see Mate and H,arvey, 1987). Fishermen are therefore left wit* the 

very real problem of sea lions damaging their gear and catch, and little or nothing they {can 

legally do. Some additional effort should therefore be devoted to finding new non-harmful 

means of lkeeping sea lions away from fishing operations, perhaps with support providecl by the 

fishing industry. For example, Sasakawa (1989) reportedly was able to keep Steller sea lions 

away from submerged setnets by using explosive sounds. However, Sasakawa did not describe 

the possible physical effects of the explosions on sea lions, and that is a factor that must- be 

considered before such techniques can be used. 

Part of the current problem is that some fisheries, for example the pollock roe fishery, 
produce large amounts of readily available fish (target species, bycatch, and waste) that provide 

an easy food source attractive to sea lions. Aversive techniques intended to deter sea lions from 

coming near boats and gear must therefore overcome the positive relinforcement supplied by the 

readily available fish. Continued attentioln should be given to procetlures that will reduce this 

attractant. 

It should also be recognized that one of the possible causes olf the current decline of 

Steller sea lion numbers is poor individual condition leading to increased mortality and reduced 

pup production. It may therefore impede recovery of the population if sea lions are kept away 

from food resources because those resources are also being harvested by a lcommercial fishery. 

It may be more appropriate to consider other management techniques (e.g., Section 52'1) to 

mitigate incidental takes and gear damage rather than using methodis that drive sea lions away 

from food sources. 

523. Improve and continue prowarns to nninirnize marine debris 

While entanglement in debris has not been shown to be a major factor in sea lion 

mortality, some animals do become entangled in net fragments and packing bands. The 

educational program within the fishing inldustry, including all suppol-t units, to totally eliminate 

the at-sea discard of materials that may cisuse marine mammal entanglement should be 

continued. Entanglement of fur seals in net fragments is decreasing (Fowler and Ragen, 1990), 

but efforts to further reduce or eliminate this problem should be continued. Foreign fishing and 

support vessels may be major sources of packing bands and scraps of netting. Efforts slzould be 

made to lhave input at the international level through the International Convention for the 

Prevention of Pollution from Ships (MARIPOL) and related organizations, through the NMFS 

Marine Entanglement Research Program. Educational programs (Section 75) should stress the 

harmful effects of marine debris. 

524. &:lop methods to reduce loss rate in subsistence harvests 

Not all sea lions killed or injured in subsistence hunts are recovered. Changes in capture 

methods, areas, or timing may reduce the loss rate (and disturbance rto rookeries and haulouts 

that may result from hunting). A progrann to work with one or more of the) major subsistence 

communities should be developed to explore solutions. 

53. Review and revise recommendations flor maximum allowable levels of lethal take 

Maximum allowable levels of lethal take should take into consideration subsisteince, 

commercial fisheries, research, and other human-related sources of killing. Current information 

indicates that commercial fisheries and subsistence hunters take the vast maljority of animals. 

Allowable levels of take should be established based on abundance and trend (determhed and 

monitored as described in Section 3) in appropriate management units (identified in Section 2). 

If necessary, mechanisms should be developed to allocate portions of the tortal allowable take 

among various general categories (e.g., incidental take, subsistence, research). 

The maximum legal incidental take of Steller sea lions under Ithe MMPA as amended in 

1988 was set at 1,350 animals annually. 'The Emergency Interim Rule listing sea lions as 

threatened reduced the allowable incidental take to 675 in the area west of 141" west longitude. 
No specific rationale was given for either number. Although percentage of' the index count 

apparently was not the basis for setting and modifying incidental take limits, the allowable level 

amounted to about 2.2%-2.7%. NMFS is currently working on an overall plan for semhg 

allowable levels of incidental take for marine mammals that will apply to ad species including 

Steller sea lions, and a draft regime has been proposed (NMFS, 199'1). This proposal dl be 

revised and submitted to Congress for their consideration during MMPA reauthorization in 

1993. If necessary, takes in fisheries should be divided by region, season, and gear type to 

prevent Ihigh takes in one fishery or region from overburdening or cllosing (other fisheries. 

The ESA allows the continued subsistence harvest of threatened or endangered species 

by Alaska Natives, but such taking may be regulated if it negatively affects the species. Levels 

of subsistence harvests (documented in Section 515) should be evaluated in relation to1 the 

current condition of the stock (Sections 2 and 3). If regulation of the harvest is deemed 

necessary, the communities taking Steller sea lions should be included in the process of setting 

the 0veri3ll harvest limits and the clistribu~tion among villages (as is clone with bowhead whales 

by NMF!; and the Alaska Eskimo Whaling Commission). Animals killled and lost should be 

included in any limit set on subsistence take. 

Because there is no sustainable yield from a depleted, declining population, there is no 

biologically defensible basis for estimating maximum allowable removals for regions where sea 

lions are declining. Since sea lions are declining in the area from the cenbral Gulf of Alaska 

through the Aleutian Islands, efforts should be made to minimize all sources of mortality in this 

region until such time as population recovery begins. Efforts should also be made to slee that, 

whenever possible, any allowed lethal talkes provide information that will aid in recovery of the 

population. In areas where sea lion num.bers are stable or increasing, allo~~able removals can 

be calcullated based on biological factors such as abundance and pro~ductiwity. 

6. Investigate feeding ecolow and factors affecting energetic status 

PJthough the sea lion diet as a wlhole is diverse, in particular areas a single species may 

comprise: as much as 50% of their food for certain periods. Such species are usually locally 

concentrated or form schools or aggregations in particular areas at certain times. Exannples 

include herring, walleye pollock, hake, and rockfish. 

Many of the prey eaten by Steller sea lions are species that also are taken in commercial 

fisheries., It is unclear at present whether and how particular fisheries may affect the ability of 

sea lions to obtain an adequate supply of food. Fluctuations in abundance of fish and shellfish 

stocks in Alaska have been well documented in recent years (e.g., Naumenko et. al., 1990; 

Megrey and Wespestad, 1990). However, the influences of predators, commercial harvests, and 

environmental factors on fish stock abundance are poorly understood. Sea lions may be able to 

alter the mix of prey in their diet in response to changes in prey abundance, but the degree to 

which th~ey can switch, and the possible costs of such switching, are unknolwn. 

C:orrelations of sea lion population changes with gross estimates of fish catches have not 

provided. much insight into sea lion-fishery interactions (Loughlin and Merrick, 1989). 

Comparisons of the condition of sea lions collected in the Gulf of Alaska in the mid-1970s and 

the mid-1980s suggested that animals collected in the latter period were nutritionally stressed 
(Calkins and Goodwin, 1988), but the data do not allow the identification of specific problems. 

Nonetheless, it is obvious that rapid recovery of the sea lion population will require that animals 

have optimal feeding conditions. 

It may be necessary to implement management actions to ensure that food supplies, 

especiallly in critical areas and times, are adequate to stop the decline and then support a 

growing sea lion population. In many cases, additional information will be needed to design 

properly focused and effective management measures. The actions tlhat must be taken to obtain 

the necessary information and to implement appropriate measures are described below. 

61. Investigate sea lion feeding ecoh 

One of the principal reasons for investigating sea lion feeding ecology is to understand 

the interaction between food availability ,and the status and trend of the sea lion population. 

Additional information is needed on the sea lions' nutritional requirements, and on hovv much 

prey is available seasonally and spatially to meet those requirements. Correlation of changes in 

feeding h~abits with population changes in specific areas can be informative, but will require 

long-term studies. Comparisons of feeding habits among areas where sea lion populations are 

showing different trends may be particularly valuable. 

Tlze existing data on sea lion feeding ecology are largely restricted to a description of the 

diet. This description has resulted mostly from the examination of stomach contents of animals 

collected for scientific purposes, and from stranded animals. Considering the current status of 

the sea lijon population, it is unlikely that large scientific collections can be justified in imost 

areas at this time. Therefore, it is essential that alternative methods of describing and 

monitoring changes in the sea lion diet be developed. 

Uinderstanding the interactions between sea lions and their food resources requires 

additional information beyond a description of characteristics of prey being eaten. Recently 

developed techniques that allow the investigation of energetics and nutritional physiology of 

free ranging animals should be applied to sea lions where possible. 'Telemetry and other devices 

should be used to describe diving behavior and characteristics of feeding cycles, and to identify 

feeding areas. Models need to be developed to integrate information on sea lion feeding and 

energetics with factors that may influence prey populations. Such models can be used to 

identify areas of significant interaction and to evaluate the possible effectiveness of potential 

management actions. 

61 1. Describe foods eaten bv sea lions 

To provide direction for ecological and process studies, it is necessary to know what 

foods are being consumed by sea lions. 1x1 addition to the specific identity of prey, the size (or 

age) classes that are being eaten must be determined. Ideally, such data should be obtained for 

all age/sex classes of sea lions in all areas and seasons. The data should be used to compare 

prey utilization among different regions aind to monitor changes from year to year in a 

particular area. To evaluate differences between age classes, areas, seasons, or years, sa~mpling 

and analysis must allow statistical testing. 
61 11. Collect and analyze stomach contents 

Stomach contents should be collected from dead sea lions whenever possible (see 

Section 4.1). Potential sources of n1ateria:l include beachcast carcasses, animals incidentally 

taken in commercial fisheries, and animals taken by Alaska Natives. Animals taken in 

cornmerc:ial fisheries are of particular interest, since it is likely that their stolmachs will contain 

fresh foo'd remains, and the location wheire they were feeding will be: known. However, sea 

lions caught by fisheries may be more likely to have been feeding on the target species, and this 

bias must be taken into account during analysis of results. 

The entire stomach contents shoulld be collected from every animal incidentally taken in 

commercial fisheries as part of observer programs. Intestinal contents should also be collected 

and examined for prey remains. Samples collected from these sources may not reflect the exact 

diversity or relative proportions of prey species eaten by the sea lion population, and srnall 

sample sizes may preclude statistical treatment of the data. They may nonetheless be useful for 

comparisons among areas and over time. While other methods (e.g., Section 6112) may 

produce larger sample sizes, analysis of stomach contents will give data that are the most 

comparable with data collected in previous years. 

Obtaining samples of stomach contents from live sea lions by gastric lavage (putting 

fluid into the stomach and pumping it out) would require animals to be anaesthetized. The 

technique could be tested on sea lions that are anaesthetized for other purposes (Sections 445 

and 613)1. However, the drug levels currently used when animals are handled for attaching 

telemetqr equipment are too low to allour them to be lavaged. Higher drug levels result in an 

increased chance of death, which rnay preclude use of lavage techniques uriless alternative 

immobilization methods are developed (see Section 431). 

Sample analysis should determine the identity of prey and thleir relative importance in 

the sample (by number, weight, and/or volume). Diagnostic hard parts should be used for 

identification of contents where necessary. Original sizes of prey co~nsumetl should be 

determined by measuring intact organisms and appropriate hard pants such as otoliths. 

6112. Qllect and analyze scats 

Hard parts of prey may pass through the gastrointestinal tract and appear in scats. 

Although there are biases associated with differential digestion and passage and it is u:jually not 

possible to determine which individual piroduced a particular scat, valuable informati011 on diet 

composilion can be obtained from scat ainalysis (e.g., Olesiuk et al., 1990). Physical 

characteristics of the substrate may preclude scat collection in some locatiolns, but some specific 

areas may be suitable for sampling. Relatively large sample sizes can be obtained and used to 

monitor changes or trends in prey utilization. Scat collecting should generally be done in 

conjunction with other activities (e.g., Sections 322, 33, 342, and 443) in order to minimize 

potential disturbance. 

Scat analysis requires careful separation of the hard parts of prey from non-dia,gnostic 

material in the feces (Bigg and Olesiuk, 1990). Once separated, hard parts should be identified 

and measured in the same manner as those obtained from stomach contents. 
612. Determine food and enerw requirements 

For the Steller sea lion population to recover, the proper amounts and types of food 

must be available to individuals during critical periods. A large combined biomass of assorted 

prey speciies does not necessarily indicate an adequate food supply, since some of the species 

may be nutritionally poor at times or energetically costly to catch. To ensure a food supply of 

adequate quantity ahd composition, it is necessary to know the sea lions' nutritional 

requirements and their costs of obtaining prey. Isotopic studies and other techniques sh.ould be 

used to measure the food intake and energy expenditure of free-ranging animals (see Section 

432). Such studies may be conducted in conjunction with intensive om-site study programs 

(Section 414). Studies of captive anxmals may be useful to develop and validate techniques, as 

well as to provide a more detailed picture of nutritional requirements for solme age/sex classes. 

Results from captive studies must be used with caution since they may overestimate nuhitional 

requirements (Innes et al., 1987). 

Foraging costs will vary with location (due to transit times anti prey dispersion) and 

with the Type of prey (due to differences in difficulty of capture). Therefore, whenever possible, 

energetics studies should be done in conjunction with programs at intensive study sites (Section 

44), studies on feeding areas and diving behavior (Section 613), diet compo:sition (Section 611)' 

and prey availability (Section 6141). Animals that have been injected with isotopes can be 

studied with satellite telemetry to measure the costs of foraging under different cir~umst~ances. 

This infonnation on the dietary needs and energetics of the sea lions should then be compared 

to the abundance, nutritional characteristics, and distributions of various prey species 

throughout the year (Section 614). 

It would be desirable to collect baseline data on food and energy requirements for all 

age and sex classes at a variety of locations throughout the year. Initial emphasis should be put 

on juveniles (especially pups after weaning) and adult females. If other agel'sex classes ;Ire 

determined to be experiencing nutritional stress, then foraging studies should emphasize those 

groups. Studies should be designed to detect changes in foraging effort over time, as well as to 

allow com~parisons of areas with different population status (Section 3) and patterns of prey 

availability (Section 6141). 

613. Determine feeding areas and feed in^ sitratenies 

Determining the locations, time of clay, and depths at which sea lions feed will enhance 

efforts to assess and monitor the abundance and composition of their prey resources. When 

coupled with simultaneous studies of prey distribution and abundance (Section 6141), it will 

also help determine the degree and type of competition between sea lions anld commercial 

fisheries and to identlfy which areas and depths constitute critical foraging habitat (see Sections 

112 and 15). Continued monitoring will reveal how variable these feeding areas are and may 

provide an indication of the species' ability to change location or depth in response to ch<anging 

prey availability. 

6131. wify feeding areas 

It will be difficult to identify the areas used by Steller sea lions for feeding. 

Observations of sea lions feeding at sea can pinpoint feeding locations and, when made from 
boats, sarnpling of the prey is also possiblle. However, such data have an inherent bias 

associated with the activities of the observation platform (e.g., salmoin fishing boats are very 

likely to encounter sea lions feeding on sa~lrnon). Aerial or shipboard surve:ys of standairdized 

tracks avoid this bias but may have a much lower probability of encounteIing sea lions. 

Another approach that has been used with pinnipeds is to track individuals by using satellite, 

radio, or sonic tags. While these methods are expensive, labor intensive, and cause somle 

disturbance to the animals, they provide the most accurate and detailed information about 

feeding areas and transit routes. 

For wide-ranging species such as Steller sea lions, satellite telemetry is the most 

appropriate technique currently available for identifying feeding areas. Satellite tags should be 

applied to an adequate sample of animals at selected locations throughout their range. Because 

of the limited duration of tag function, it will be necessary to apply them at different times of 

year in order to obtain coverage for all seasons. Satellite tags will also provide data that will be 

useful for studies described in Sections 1 ,and 2. 

6132. mestigate diving behavior and feeding cycles 

Sea lions alternate feeding trips at sea with stays on land. The timing and durabion of 

these cyc:les can vary with age, reproductive status, time of year, and food availability. 

Observations of changes in feeding cycle characteristics among sea lions of a given age or 

reproductive status may therefore provide an indication of changes in food availability. 

Characteristics of dives can be detcemined by using devices that record time and depth. 

In situations where animals may easily be captured and handled, relatively iinexpensive timedepth recorders can be deployed and recovered. However, considering the problems with 

handling Steller sea lions, incorporation of time-depth measurements in satellite packages 

appears to be the most appropriate method currently available. 

Satellite tags allow very precise m~onitoring of feeding cycles because the likelihood of 

overlooking animals when they are ashore is minimal. However, they are expensive and 

potentiallly can affect the feeding patterns of the animals to which they are applied. Because 

large sample sizes are usually required to detect changes in feeding cycle patterns, naturally 

scarred, branded, and flipper tagged animals should be monitored in addition to those with 

radio or satellite tags (in conjunction with Section 44). Because animals are not always seen 

when they first come ashore, attendance pattern data from telemetry and direct observations are 

not entirely comparable (e.g., observational studies tend to give longer at-sea times) but 

information from both sources can be useful. Because lactating females return to land 

frequently to nurse their pups, their attendance patterns on the rookeries can be relatively easily 

monitored, especially if some animals are marked (see Section 443). 

Measurement of time on shore and at sea should be compared among areas and years. 

Because foraging effort may vary in addition to the amount of time at sea, (energetics studies 

(Section 612) should be conducted concurrently with studies of feeding cycle patterns. Changes 

in feeding cycle patterns should be analyzed for correlations with commerciial fisheries catches 

and with rates of abortion, mortality, and copulation (Section 44). 
614. &ss sidcance of various prey 

Determination of the sigruficance of a particular food to sea lions requires more than 

simply knowing its relative contribution to the diet. Certain prey may occur in particular 

circumstances in which they can be captured efficiently with little cost. It is likely that the 

caloric value of prey varies with age, sex, and season of the year. These factors may interact to 

make the availability of particular prey items of critical importance for sea lion nutrition at 

certain times and places. Additional data are needed to address the significance of individual 

prey species. 

6141. Characterize xeonaphic and seasonal patterns of prey availability andl utilization bv sea 

lions 

Sampling programs should be based on the analysis of existing diet information (Section 

615) and additional information on seasonal prey use that is obtained from studies described in 

Section 61.1. Potential prey availability should be estimated in areas where animals are known 

to be feeding (Section 6131) by using hydroacoustics, nets, underwater cameras, or other 

appropriate techniques. Sampling should lbe designed to give estimates of prey availability in 

actual feeding areas, as opposed to broad geographic regions. Annuall patterns of prey 

availability should be determined using these data. In addition, measurements of param~eters 

such as density and depth of prey, and distance from the rookery or hauloui, are necessary to 

evaluate foraging costs. Prey sampling in areas adjacent to identified feeding areas woulld help 

determine why animals feed in certain locations and not in others. 

While some of the information described in this Section may be obtained during 

standard PIJMFS resource assessment cruises, adjustments will have to Ibe made to techniques and 

the distrib-ution of effort to satisfy the data requirements for sea lions. 

6142. Determine nutritional value of prey 

The nutritional value of a particular type of prey can be vieweti as the net energy 

obtained by its capture and assimilation. An assessment of net nutritional value requires the 

integration, of costs of swimming to and from feeding areas and diving to capture prey (Sections 

612 and 613), with information on the amounts and characteristics of prey ciaught on a feeding 

trip. 

Ma:ny marine organisms show large variations in caloric content and essential nutrients, 

often associated with maturation and production of eggs. For example, adult: females just prior 

to spawning may have a very high caloric value, while spent (post-spawning) individuals 

contain much less energy. Where not already known, patterns of caloric and nutrient va~iation 

should be documented for major sea lion prey species that are identified in Section 611, using 

specimens (obtained in Section 6141. 

Digestibility influences assimilation efficiency and can therefore affect the actual 

nutritional value of prey. Available data indicate that pinnipeds in general have high 

assimilation efficiencies, and additional investigation of this factor may not be necessary for 
Steller se!a lions. If further studies are necessary they will probably require the use of captive 

animals. 

615. mnvile and analyze data 

The information that is generally available on sea lion feeding ecology is contained in a 

number (of published papers and agency reports (e.g., Pitcher, 1981; Ca1kin.s and Goodwin, 

1988). A considerable amount of information exists that has been only partially analyced and 

has not been reported. All available information, including that frorn Russia and Canada, 

should be reviewed, analyzed, and presented in a comprehensive report. R-esults of that report 

should be used to assess the current state of knowledge about sea lion feeding habits, (and to 

guide the design of future research. 

Ei thorough analysis of existing data is required to identlfy all the areas that are 

appropriate for comparisons over he. 'The review of historical data on sea Lion feeding should 

compare regions of differing population status and trend, where possible. Comparisons of 

current and historical data will need to a,llow for ecosystem changes that may have occurred 

over time. 

It is unlikely that the existing data base will allow definitive comparisons to be made. 

Future collections and analyses should take advantage of the variations in population status and 

trend throughout the sea lion range in order to gain insight into the interactions between 

feeding and population parameters. To the maximum extent possible, current and fumre 

research efforts should collect data on sea lion feeding in a way that it can be compared with 

historical data. 

62. bestinate interrelationships between prey abundance and sea lion mowth and ~roductivity 

While the dynamics of the Steller sea lion population may be affected by a variety of 

factors, growth of individuals and productivity of the population are likely to be limited by food 

availability at some point. Field studies have demonstrated the role of food in regulating 

population productivity in many terrestrial ecosystems (e.g., McCullough, 1979; SkogLand, 

1985). However, marine mammals foraging in complex marine ecosystems pose tremendous 

problems for such studies. El Niiio events have provided some insight into the role of food in 

limiting pinniped productivity (Ono et al., 1987). 

A variety of techniques are available for assessing the abundance of marine fishes and 

invertebrates. However, these techniques have been developed by fishery managers to assess 

overall stock sizes, and may not measure prey abundance in the areas and times of importance 

to sea lions. Existing data sets should be examined for information. on local prey abundance. 

Future data collection efforts and analyses may need to be designed specifically to address 

questions of relevance to Steller sea lion feeding ecology. 

621. M~asure growth and productivity in areas with different food availability 

Once analyzed, existing data on sea lion biology and the distribution and abundance of 

fish stocks should be used to select stud,y areas (e.g., Ugamak Island, Marmot Island, Forrester 

Island, and Rogue Reef). Variables other than food availability must be considered in area 
selection and evaluation of results (e.g., predation, disease, and migration costs). A variety of 

parameters, including pup production andl survival (Sections 3 and M2), sex/age class 

distribution (Section 441), and individual size and condition (Sections 432 and 445), should be 

measured in these areas. Satellite telemetry should be used to define the areas used for feeding 

(Section tj13), and data should be collected on foods being consumed (Section 611). Standard 

resource assessment techniques, modified as necessary, should be used to monitor the 

abundance and characteristics of prey in the feeding areas (Sections 6141 and 6142). 

As an alternative to, or in addition to, use of study areas with natural variations in prey 

resource characteristics, fisheries could be regulated as a means to manipulate food availability 

(see Section 64). Design of such a manipulative study should take into account information on 

prey identity (Section 61 I), feeding areas (Section 6131), and food requirements (Section 612). 

It would be necessary to monitor the aburtdance of prey in the study area (Section 6141) in 

order to measure the actual effect of regulations on prey resource availability. 

622. &lop models for individual and population energetics, nowth, and ~roductivity 

One or more models will be required to integrate the information described under 

Section 621 and related Sections. A model or models should be developed to help assess the 

energetic needs of sea lions, and how variiltions in availability of food as a whole, and of 

individual prey species, may affect nutritional status of individuals. The influence of nuitritional 

status on growth, condition, reproductive performance, and survival should be modelled. As a 

final step, models sihould be used to help assess how variations in individual parameters may 

affect population status and trend. 

Models should be designed so that they not only integrate existing data but can also be 

used in a predictive mode to project how variations in prey availability may <affecthe status and 

trend of sea lions in various areas. 

63. Deternline effects of fisheries on sea lion prey 

The abundance of commercially hairvested fish stocks is known to fluctuate, sometimes 

declining drastically. In most cases the role of fishery removals in such stock: declines is unclear. 

However, jit is clear that some stock fluctuations have been due to 0verfishin;g (Pruter, 1976; 

Megrey and Wespestad, 1990). 

In addition to gross changes in long-term overall abundance, fisheries may affect sea lion 

food availatbility by changing small scale distribution, abundance, and behavior of prey. 

Intensive pulse fisheries clearly reduce the density of fish in specific areas. The activities of 

boats and gear may cause changes in the blehavior and characteristics of prey aggregations. 

Subtle ecosystem changes may accompany llarge human-induced removals of major species. 

631. Detennine effects of fisheries on sea lion prey 

Tra'ditional fishery assessments usually attempt to gather broad scale information on 

stock abundance. Data are gathered at the times and areas when sampling can be conducted 
most efficiently. Results of such assessments may be used to track overall changes in stock 

sizes, but they are of limited value for assessing changes in prey availability in sea lion feeding 

areas. Data that have been and are being collected using hydroacoustics may be very useful for 

identifying localized concentrations of fis:h that can serve as sea lion prey. 

The influence of fisheries on prey in the actual areas used by sea lions for feeding can be 

addressed in two ways. Detailed assessments of short- and long-term effects can be conducted 

in feeding areas before, during, and after fishing activities occur (feeding areas will be identified 

by studies described in Section 613). Altlernatively, comparisons can be made of prey stock 

charactelistics in similar areas that are artd are not fished (see Section 621). Some of the data 

required for these comparisons may be collected in studies described in Section 6141. However, 

additional sampling (e.g., time series that span the course of fishing activity) will be necessary 

to assess changes in prey stocks that may be specifically attributable to fishery removals. Special 

attention, should be given to the depth distribution of the species and size classes of prey needed 

by sensitive age/sex classes of sea lions (e.g., juveniles). 

632. me1 effects of fishing on prev composition, distribution, abundance,, and behavia 

Models may prove useful for evaluating the possible effects of fishing on prey 

availability. Current models used :for stock assessment should be applied to specific areas to 

look at how removals affect abundance of various age classes of prey. Data from field studies 

will be needed for the development and testing of models that describe effects on prey 

distribution, abundance, and behavior. FAodels should be designed so that they can be used to 

predict how various levels and types of fishing may influence availability of prey for sea lions. 

64. -.re adequate food availability in :Feeding areas 

For the Steller sea lion populatioin to grow (i.e., recover), measures must be taken to 

ensure that food availability is not limiting. Fish stocks must be assessed and monitored on a 

local basis along with certain parameters of the sea lion population. Where prey abundance is 

low, or where the sea lions show signs of nutritional stress, prey availability must be increased, 

if possible. The types of prey available and the energetic cost of obtaining the prey should be 

acceptable in all critical feeding areas. 1:F a fishery is having detrimental effects on prey 

availability, either through removals of t<arget species or bycatch, additionall regulation of the 

fishery rnay be necessary. Coordination among agencies and organizations involved in 

developinent of necessary regulations should be provided by the Steller sea lion Recovery Plan 

Coordinator (Section 71). 

641. bwlate fishing areas, seaso:ns, ancl types of operations 

In some instances, it may be possiible to reduce competition between commercial fisheries 

and sea lions by changing fishing areas, seasons, time of day, and types of operations. Studies 

should be initiated on the amount and species of fish, including bycatch, taken by fisheries 

under visrious conditions. These results should be compared to studies of sea lion feeding 

ecology (Sections 611, 612, and 613) to determine the extent of overlap, especially foir any 

age/sex classes that are likely to be foodl limited (e.g., weaned pups or lactating females). 

Where alterations in operations can reduce competition, appropriate changes should be initiated 

and the sea lions monitored for responses (see Section 621). 
642. Repplate fishery catches 

Development of fishery managemlent policies and plans must take into account the types 

and amounts of food needed to support a recovering sea lion population. 'The mechanism by 

which sea lion food requirements are accounted for in the calculation of acceptable commercial 

harvest levels should be explicitly described. Where appropriate, a specific portion of the 

acceptable biological catch should be set aside for sea lion consumption. AJternatively, natural 

mortality estimates used in models should be modified to ensure that predator consumption is 

adequately provided for. If there are signs that prey availability is being reduced by a fishery 

such that it is a limiting factor in the recovery of the sea lion population, then restrictions 

should be placed upon the commercial fisheries' allowable catches to the extent necessary to 

ensure adequate prey. Quotas for catches should be set on a regional and seasonal basis for 

each stock of each prey species identified as important (Section 614). If certain age/sex classes 

of sea lions are found to be especially food limited, then special effoi-ts shoiuld be made to 

regulate total allowable catches in their feeding areas. 

In addition to regulatory needs described above, it may be desirable to manipulate 

fisheries iss part of experiments to determine the influence of food supply on sea lion growth 

and productivity. Studies of this type are discussed in Section 621. 

7. Implement Recovery Plan and coordinate recovery activities 

The principal responsibility for implementation of the Steller Sea Lion Recovery Plan lies 

with the lVMFS Office of Protected Resources. Recovery actions will need to be coordinated 

with the IVMFS regional offices and other involved resource management agencies and user 

groups. The Steller Sea Lion Recovery Team should be used to evaluate the ongoing recovery 

program, and to recommend changes including updates to the recoveq plan. International 

coordination may also be necessary in order to implement an effective recovery program.. 

Education and enforcement are critical cornponents of the overall recovery effort. 

71. Establish a Steller sea lion Recovery Pl.an Coordinator staff position 

NMFS should hire a full-time person to coordinate recovery efforts for Steller sea lions. 

Duties of the Steller sea lion Recovery Plan Coordinator should include: 

a. Coordinate all aspects of NMFS sea lion recovery efforts, such as evaluation and development 

of regulations, designation of critical habitat, and Section 7 consultations; 

b. Provide liaison with regional Fishery Management Councils, state fishery managers, FWS 

wildlife refuge managers, enforcement agencies, researchers, and other interested parties; 

c. Publish annual activity reports and work plans; 

d. Facilitate and coordinate research activities, including development of scopes of work for 

conuacts; 

e. Coordinate data management and assist- with data analysis and distribution. 
72. Maint'ain the Steller Sea Lion Recovenr Team 

NMFS should continue to fund the costs for operation of the !;teller Sea Lion Recovery 

Team. The Team should conduct an annual review of information from research and 

monitoring programs and recommend chainges in research programs and management strategies, 

where necessary. The annual review should be completed in time to make recommendations for 

research 2nd management for the followin~g year. The Steller Sea Lion Recovery Plan 

Coordinator and other management agency representatives should attend T~!am meetings to 

provide coordination and agency input. The Team should revise and update the recoveIy plan 

at appropriate intervals. 

73. Monitor Section 7 ESA requests for consultation 

Existing personnel in NMFS who deal with ESA Section 7 requests slhould also deal with 

consultations relative to Steller sea lions. This should be done in collaboration with the Steller 

sea lion Recovery Plan Coordinator., 

74. Develop mechanisms for international conservation efforts 

The United States, Canada, and Russia have a particular interest in c:onservation of 

Steller sea lions since virtually all rookeries occur within their territorial seas. Because :sea lions 

move freely across the boundaries separating these nations, conservation efforts put in place by 

each nation should be closely coordinated. Conservation measures may be of some significance 

to other nations (e.g., Japan, Taiwan, Poland, Peoples Republic of China, and North anti South 

Korea) that conduct commercial fisheries or other activities in areas where sea lions occur. 

Those nations should be made aware of Ineasures that are in place, and the need to ensure that 

their citizens act accordingly. Where appropriate (e.g., during range-wide surveys), clos8e 

coordination of research activities is also desirable. 

741. wibute Recoverv Plan to other involved nations 

Copies of the approved Steller Sea Lion Recovery Plan, and other information such as 

implementation plans, should be sent to appropriate agencies and organizations in the Soviet 

Union, Canada, Japan, Taiwan, Poland, Peoples Republic of China, and North and South Korea. 

742. &lop bilateral or multilateral conservation ameements 

NMFS should work with the Department of State to develop and implement agreements 

with Russia and Canada to coordinate conservation efforts for Steller sea lions. Joint research 

programs to look at interchange of animals between areas, and for comparison of biological 

characteristics and population parameters among regions are needed. Some of the management 

issues that should be considered include adequacy of protective regulations, and mechanisms for 

allocating allowable take of sea lions between jurisdictions. 
75. Conduct information and educational pronams 

Many of the regulations that are put into place to protect Steller sea Lions will apply to 

all members of the public. Public affairs personnel in responsible agencies should plan and 

implement well-rounded public awareness programs that describe the status of sea lions and the 

protective regulations that are in place. 'The public should be made aware that they can aid in 

the recovery effort by reporting violations of regulations, injured or stranded animals, and other 

relevant information. Types of coverage that might be effective include news releases, mailouts, signs, public service announcements, interpretive programs, fhs, and environmental 

educatioin lesson plans featuring sea lions, 

Since fishermen in many areas maly interact with Steller sea lions or1 a regular basis, it is 

particula.rly important that they be made aware of and kept informed about sea lion 

conservation efforts. Information can be distributed as part of ongoing regulatory programs 

(e.g., in logbooks and regulation books), as well as through media directed specifically at the 

fishing industry (e.g., trade magazines). Mail-outs to permit holders and signs posted in boat 

harbors nnay also be effective. Materials and trained personnel should be m~ade available to 

assist industry in developing its own additional educational programs. Fishermen and their 

representatives should be encouraged to Elecome involved in the development, evaluation, and 

implementation of sea lion conservation measures. 

76. Enforce remlations 

R~!gulations that are currently in place and that may be developed have a great potential 

for assisting in the recovery of the Steller :sea lion population. The prohibition on shooting at 

or near sea lions, if enforced, could greatly reduce the number of anirnals lost to the population 

each year due to human-related factors. Elimination of this unnecessary and avoidable source 

of mortality should be given very high priority. 

Members of the Recovery Team did not have the expertise to consider the mechanisms 

and costs of enforcement programs m detail. Although enforcement of wildlife regulations in 

vast regions, such as the waters off Alaska, is a very difficult task, existing personnel and 

programs could, if properly directed, provide significant benefits for sea lions. It is clear that 

enforcement of sea lion regulations and conservation measures would benefit greatly by 

increased cooperation and coordination amlong various agencies, including NMFS, the State of 

Alaska Fish and Wildlife Protection, and the USCG. In order to emphasize the importance of 

this item, the Recovery Team is specifically recommending that funds be provided for a person 

to coordinate Steller sea lion enforcement efforts. 

761. Devellop and improve systems for reporting violations 

In addition to its role in directly protecting animals, enforcement of regulations is 

important as an educational tool. For example, if sea lions can be shot or harassed with 

impunity, an educational program is not likely to reach the offenders who are the major source 

of shooting mortality. Successful enforcement of regulations is greatly dependent on 

information derived from the public. A toll-free telephone number for reporting violations is 

useful, as is a guarantee of anonymity to informants if they so desire. A reward system far 

informatior1 leading to successful prosecution of offenders has been used by tlne State of Alaska 
for fish and wildlife violations and has been quite successful (project Safeguard). All field 

personnel associated with Federal, state, and local resource management and enforcement 

agencies should be made aware of regulations and procedures for reporting violations. Trained 

observers should be placed in areas wheire people are most likely to interact with sea lions. 

762. &vide adequate and effective field. enforcement proarams 

Effective enforcement of regulations requires extensive field work and is expensive. In 

areas where fisheries are thought to pose significant problems, field camps; ashore might be the 

most effective enforcement technique. Such camps would have to be within sight and sound of 

fishing operations, and equipped with tlne means to get to offenders rapid1.y. There is a history 

of harassment and deliberate shooting in certain fisheries that take place near important sea 

lion hau~louts. 

Control of human activity within prohibited areas around breeding grounds and haulouts 

is necessary and will take extensive patrol work. Care must be taken that the patrols themselves 

are not disruptive to sea lion breeding and feeding patterns. Careful coordination of 

enforcement efforts between Federal, state, and local authorities is ]necessary, as are educational 

programs within the agencies to overcorne differences in approach and, in some areas, the lack 

of understanding of the seriousness of the sea lion population decline. Enforcement agents of 

all the agencies involved with the fisheries should be knowledgeable enough about the 

population status and the laws protecting sea lions to be able to work with and advise the 

industry, and to recognize and report violations. 

'When information is gathered that is likely to result in successful prosecution isnd 

conviction of violators, such cases should be given high priority by NMFS enforcement. It is 

essential that violators are prosecuted ir~ a timely fashion so that the seriousness of regulations 

and the effectiveness of enforcement are made evident. 

G. Implementation Schedule 

As recovery plans are developed for each species, specific recovery tasks are identified and 

prioritized. As new information warrants, these plans, including tasks and priorities, will be 

reviewed and revised. In addition, funding and implementation of the tasks identified in recovery 

plans will be tracked in order to aid in effective management of specific recovery programs. 

NMFS believes that periodic review and updating of plans and tracking of recovery. efforts are 

important elements of a successful recov~ery program. Information from tracking and implementing 

recovery actions and other sources will be used to review plans anti revise them as necessary. 

Recovery tasks within the Steller Sea Lion Recovery Plan are prioritized 1-3. Tlhe Recovery 

Team has deemed that a Priority 1 ranking is given to the highest priority tasks within this plan, 

and is given to those actions necessary to monitor the decline of, or to prevent the Steller sea lion, 

a species facing a high and continued magnitude of threat, from further declining. Within this 

recovely plan, Priority 1 tasks are characterized as being either administrative (A), management (MI 

or research (R). 


2. APPENDICES 

APPENDIX A. List of rookeries and haulouts to be counted annually 

and used in analysis of Steller sea lion population trend 

(see Sections 1I.B and E.32!1) (from Memck et al., 1991). 

Trend Count Site Rookery Haulout 

Central Gulf of Alaska 

S. Ushagat I. 

N. Ugashat I. 

Ugashat I.-rocks to south 

Sugarloaf I. 

Latax Rocks 

Sea Lion Rocks 

Long I. 

Ma.rrnot I. 

Kodiak I.-Cape Chiniak 

Kodiak I.-Cape Barnabas 

Two-headed I. 

Sitl~ak I.-Cape Sitkinak 

Chirikof I. 

Chowiet I. 

Ugaiushak I. 

Sutwik I. 

Western Gulf of Alaska 

Spiltz I. 

Bird I. 

Clubbing Rocks 

Pininacle Rock 

Sea Lion Rocks 

Nagai I. 

Chernabura I. 

Atluins I. 

Castle Rock 
APPESNDIX A (Cont.). List of rookeriles and haulouts to be counted 

annually and used in analysis of Steller sea lion 

population trend (see Sections 1II.B and E.321) 

(from Menick et al., 1991). 

Trenjd Count Site Rookery IHaulout 

Eastern Aleutian Islands 

Amak I. 

Sea Lion Rocks 

Amak I.-offshore rocks 

Ugamak I. 

Round I. 

Akutan I.-Cape Morgan 

Akutan I.-Reef Point 

Akun I. 

Bogoslof I. 

Umnak I. 

Adugak I 

Vsevidof I. 

Ogchul I. 

Cenhral Aleutian Islands 

Chuginadak I. 

HerbertI. 

Carlisle I. 

Kag;amil I. 

Yunaska I. 

Chagulak I. 

Amutka I. 

Seguam I.-Saddleridge 

Seguam I.-Other 

Agl-igadak I. 

Tan.adak1. 

SagigikI. 

Amlia I.-East Cape 

Amlia I.-West Cape 

Atk,a I.-Cape Korovin 

Atk.a I.-North Cape 

Salt- I. 

Kasatochi I. 

Ikiginak I. 
APPENDIX A (Cont.). List of rookeries and haulouts to be counted 

annually and used in analysis of Steller sea lion 

population trend (see Sections 1II.B and E.321) 

(from Merrick et al.,, 1991). 

Trend Count Site Rookery Haulout 

Ce:ntral Aleutian Islands (cont.) 

Anagaksik I. 

Little Tanaga I.-SE Point 

Little Tanaga I.-Straits 

Adak I.-Cape Moffet 

Adak I.-Argonne Point 

Adak-Lake Point 

Gramp Rock 

Ulak I. 

Amatignak 

Dinkum Rocks 

Unalga I. 

Kavalga I. 

S kagul I. 

Tag I. 

Ugidak I. 

Amchitka I.-Ivakin Point 

Amchitka I.-East Cape 

Ayugadak I. 

Kiska I.-Cape St. Stephens 

Kiska I.-Lief Cove 
Appendix B: List of selected rookeries and schedule for conduct of Steller sea lion pup 

counts (:see Sections E.322, 33, and 342). Sites to be included for monitoring trend in pup 

production in the Kenai-Kiska region are indicated by an asterisk. 

Rookery 31991 1992 1993 1994 1995 

Californjb 

all roolkeries 

Oregon 

all roo:keries 

British C:olumbia 

all roo:keries 

Southea,st Alaska 

all rookeries 

Eastern Gulf of Alaska 

Seal Rocks 

Central {Gulf of Alaska 

Outer :Island* 

Marmot Island* 

Chirikof Island* 

Sugarlloaf Island* 

Chowi'et Island* 

Western Gulf of Alaska 

Atkins Island* 

Pinnacle Rock" 

Chernabura Island* 

Clubbing Rocks* 

Eastern Aleutian Islands 

Akun Island* 

Bogosllof Island* 

Ugamak Island* 

Akutan Island* 
Appendix B (cont): List of selected rook~eries and schedule for conduct of Steller sea lion pup 

counts (see Sections E.322, 33, and 342. Sites to be included for monitorhng trend in pup 

production in the Kenai-Kiska region are indicated by an asterisk. 

Central Aleutian Islands 

Yunask,a Island 

Seguarrl Island 

Ulak Island 

Kiska Island 

Western Aleutian Islands 

Buldir Islands 

Agattu Island 

Bering Sea 

Walrus Island 

Russia 

all rookeries 

*U.S. GOVEMENT PRIMING OFFICE: 1994-300-631/12671 

92