NOAA Technical Memorandum NMFS-AFSC-129

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Marine Fisheries Service

Alaska Fisheries Science Center

June 2002

by

R. C. Ferrero and L. W. Fritz

Steller Sea Lion Research and

Coordination: A Brief History and

Summary of Recent Progress
NOAA Technical Memorandum NMFS

The National Marine Fisheries Service's Alaska Fisheries Science Center

uses the NOAA Technical Memorandum series to issue informal scientific

and technical publications when complete formal review and editorial

processing are not appropriate or feasible. Documents within this series

reflect sound professional work and may be referenced in the formal scientific

and technical literature.

The NMFS-AFSC Technical Memorandum series of the Alaska Fisheries

Science Center continues the NMFS-F/NWC series established in 1970 by

the Northwest Fisheries Center. The new NMFS-NWFSC series will be used

by the Northwest Fisheries Science Center.

This document should be cited as follows:

Ferrero, R. C., and L. W. Fritz. 2002. Steller sea lion research

coordination: a brief history and summary of recent progress. U.S.

Dep. Commer., NOAA Tech. Memo. NMFS-AFSC-129, 34 p.

 

Reference in this document to trade names does not imply endorsement by

the National Marine Fisheries Service, NOAA.
June 2002

NOAA Technical Memorandum NMFS-AFSC-129

by

R. C. Ferrero and L. W. Fritz

Steller Sea Lion Research and

Coordination: A Brief History and

Summary of Recent Progress

Alaska Fisheries Science Center

7600 Sand Point Way N.E.

Seattle, WA 98115

www.afsc.noaa.gov

U.S. DEPARTMENT OF COMMERCE

Donald L. Evans, Secretary

National Oceanic and Atmospheric Administration

Scott B. Gudes, Acting Under Secretary and Administrator

National Marine Fisheries Service

William T. Hogarth, Assistant Administrator for Fisheries
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iii

Abstract

The Steller sea lion (Eumetopias jubatus), first listed under the Endangered Species Act

(ESA) in 1990, has been the subject of intensive scientific research since a steep population

decline was identified in the late 1980s. Research efforts during most of the 1990s were guided

by recommendations contained in the Steller Sea Lion Recovery Plan. Research funding for

federal agencies during this period was <$1 million (M) annually, of which over half was required

for population monitoring surveys. During the late 1990s, Steller sea lion research activities were

intensified as recent scientific findings, litigation, and new legislation focused increasing attention

on the ongoing decline and concern over possible impacts by commercial fisheries in Alaskan

waters. This renewed attention was manifest in a seven-fold increase in funding between 2000

and 2001, with over 125 individual projects planned or implemented. A wide spectrum of

research entities were engaged in these studies, including federal and state agencies, universities

and non-governmental research organizations. In cooperation with the entities that received

federal funding, the National Marine Fisheries Service developed a research coordination

framework to clarify the context of individual research projects, to show their relationships to

each other and to link them to the underlying hypotheses that might explain the continued

decline of Steller sea lions. This paper summarizes the evolution of Steller sea lion research over

the past two decades and describes the development of a comprehensive and coordinated

program that responds to Congressional intent.
v

Contents

Abstract............................................................................................................................................... iii

Introduction ....................................................................................................................................... 1

Steller Sea Lion Research in the 1970s, 1980s, and 1990s .............................................................. 2

Renewed Research Emphasis in the Late 1990s and Early 2002s .................................................. 4

NMFS Response to the FY01 Congressional Appropriations Language ...................................... 10

Coordination ...................................................................................................................................... 13

Steller Sea Lion Research Framework ............................................................................................. 13

Comprehensiveness .......................................................................................................................... 19

Summary and Conclusions ............................................................................................................... 19

Citations ............................................................................................................................................. 21
Introduction

In 1990, the western stock of Steller sea lion (Eumetopias jubatus) was listed as

threatened under the U.S. Endangered Species Act of 1973 (ESA) after a steep decline in the

population (>15% per year) was observed in the late 1980s. After seven more years of continued

decline, the western stock was re-listed as endangered in 1997. Despite research and

management efforts to bring about recovery, the population has continued to decline (Fig. 1). 

The underlying causes of the steep decline in the 1980s are uncertain, while the factors underlying

the protracted slide since then are equally enigmatic. The pace at which scientific information has

become available to provide guidance to management has been slow, due largely to constraints

on the resources available to fund research, but also due to the difficulties associated with

designing and conducting studies of Steller sea lions in their natural habitat. 

Compounding the research problem, several of the largest U.S. fisheries operate within

the range of the Steller sea lion and their role, if any, in the decline or failure to recover remains

both a topic of debate (National Research Council 1996, NMFS 1998a, NMFS 1999, NMFS 2000)

and a significant issue for ongoing litigation (Greenpeace et al. v NMFS and At-Sea Processors et

al., Civ. No. C98-0492-C). On the one hand, if fisheries play a significant part in the continued

decline and lack of recovery, then actions should be taken to avoid those effects. On the other

hand, if fisheries do not impede recovery, then the economic viability of those fisheries should

not be unnecessarily compromised. In either case, scientific information is critical to the future of

both the Steller sea lion population and U.S. fisheries in Alaska.

While frustrating, these circumstances do not imply that the past 20 years of research on

Steller sea lions have been fruitless. On the contrary, this record underscores the reality and

complexity of the problem facing resource managers: the Steller sea lion occupies expansive,

remote, and rugged habitat across the North Pacific Ocean (Fig. 2); simple solutions explaining

the decline do not exist, and our understanding of marine ecosystems and the factors that impact

Steller sea lion population trends is rudimentary at best. The development and implementation of

broad scale, comprehensive scientific investigations needed to address an issue of this magnitude

and complexity are enormous and costly undertakings. Therefore, it should not be unreasonable

to expect scientific progress to be tempered by both the availability of research funds and the

intricacy of the studied ecosystem and research questions. However, unlike most of the period

since the 1980s, the current level of research funding offers renewed opportunities to understand

the Steller sea lion decline and to promote its recovery (Table 1).

The objectives of this paper are two-fold. First, we trace the progress of Steller sea lion

research as it evolved from a modestly funded protected resource issue in the 1980s to its present

form: one of the largest single-species research efforts in U.S. history. Second, we describe the

research framework developed by the National Marine Fisheries Service (NMFS) as an

organizational tool to guide the development of a comprehensive and coordinated program in

keeping with Congressional intent. We explain how the framework can clarify the context of

individual research projects as well as their relationships to each other and the underlying

hypotheses that might explain the continued decline of the western stock of Steller sea lions. 
2

Steller Sea Lion Research in the 1970s, 1980s, and 1990s

Despite being the most abundant sea lion in North America at the time, research on

Steller sea lions prior to the 1970s principally involved studies of its population status and

distribution (Kenyon and Rice 1961, Mathisen and Lopp 1963), or brief descriptions of their diet

(Imler and Sarber 1947, Mathisen et al. 1962, Thorsteinson and Lensink 1962). In the 1970s and

early 1980s, potential exploration of Alaska’s continental shelf for oil and gas prompted baseline

research on growth, reproduction, and other aspects of their life history, along with continued

monitoring of the Steller sea lion population (Pitcher 1981, Pitcher and Calkins 1981, Calkins and

Pitcher 1982, Loughlin et al. 1984, Calkins and Goodwin 1988). At this time, the decline in the

Steller sea lion population in Alaska was first noted by Braham et al. (1980) after surveys

conducted in the eastern Aleutian Islands in 1975-77. It was evident from these surveys and

others that the population of Steller sea lions in the eastern Aleutians had begun to decline in the

1960s. By 1989, significant declines ranging from 33% to 87% had been observed in most

segments of its range, including Russia, the Bering Sea, Aleutian Islands, western and central

Gulf of Alaska, and Oregon/California. (Loughlin et al. 1990, 1992). These significant and steep

(particularly in the late 1980s) decreases in the size of the Steller sea lion population resulted in

NMFS being petitioned to list the species under the ESA, and which prompted NMFS to list it as

threatened in 1990.

Section 4(f) of the ESA requires that recovery plans be developed for listed species unless the

appropriate Secretary (of the Department of Commerce or Interior) finds that such a plan will not

promote conservation of the species. NMFS appointed a Steller Sea Lion Recovery Team

(SSLRT) in 1990 to draft a plan, which it completed in December 1992 (NMFS 1992). Recovery

Plans must incorporate a) site-specific management actions that are considered necessary to

achieve conservation goals and survival of the species, b) objective and measurable criteria to

determine when a species will no longer need protection under the ESA, and c) estimates of the

time and costs associated with plan recommendations. When the SSLRT drafted the plan, it was

not able to make recommendations on site-specific management actions because the factors that

caused the decline in Steller sea lion abundance were poorly known. Therefore, the plan focused

primarily on recommendations for research essential to determine population (and recovery)

status and immediate, tangible actions such as reducing direct mortality from shooting and

incidental takes in fisheries that could help arrest the population decline. The plan also identified

other research needs relating to both natural and human-related factors that could be affecting the

population. This discussion of research needs provided most of the initial guidance for the

development of subsequent plans and projects conducted from 1993 to 1998. Funding for

research by federal agencies during this period was <$1 million (M) annually, of which over half

was required for population monitoring surveys (Table 1).

Baseline and monitoring studies included identification of management stocks or units

through tagging/branding and genetic investigations, and monitoring the status and trend of sea

lion populations through adult/juvenile surveys and pup counts. As a result, extensive branding
3

and brand resight efforts were re-initiated in the mid-1990s, and aerial survey protocols were

standardized between the principal agencies conducting baseline studies: the Alaska Department

of Fish and Game (ADF&G) and NMFS’ National Marine Mammal Laboratory (NMML). 

Genetic studies of pup mtDNA (which reflect matrilineage or the distribution and movement of

reproductive females) conducted in the early 1990s indicated that Steller sea lions have at least

two distinct population segments (DPSs): the western DPS which breeds on rookeries in Russia

and Alaska west of 144/W (Cape Suckling east of Prince William Sound), and the eastern DPS

which breeds on rookeries in southeast Alaska, British Columbia, Oregon and California (Fig. 2;

Bickham et al. 1996, Loughlin 1997). Genetic differences, along with differences in their

population status and trend, led to separate listings under the ESA in 1997, with the western DPS

reclassified as endangered and the eastern DPS remaining threatened (62 FR 30772).

Natural factors discussed in the recovery plan that could have contributed to the

population decline were parasitism and disease, environmental changes, and predation (Table 2).

The SSLRT recognized that the effects of disease agents and environmental changes on Steller

sea lions were largely unknown. As such, compilation and examination of tissue samples for

diseases were identified as research needs in the plan, but little progress was made throughout the

1990s in determining the role that diseases or parasites had played in the continuing decline

(NMFS 2000). Furthermore, while the SSLRT did not include studies of environmental change

on their list of recommended research, numerous reports were written in the 1990s on the

“regime shift” of 1976-77 and its effect on climate, oceanographic conditions, and the fish

community structure in the North Pacific Ocean (Hollowed and Wooster 1992, Beamish 1993,

Francis and Hare 1994, Hollowed and Wooster 1995, Francis et al. 1998, Anderson and Piatt

1999, Shima et al. 2000). How such changes relate to the decline in abundance of Steller sea lions

is still largely uncertain. The SSLRT dismissed increased predator activity as a significant factor

in the decline, but recommended research to evaluate the current magnitude of killer whale or

shark predation. The potential for killer whale predation having an impact on Steller sea lion

populations was later underscored by the discovery of 14 flipper tags (which had been applied to

sea lion pups in 1987-88) in the stomach of a beached killer whale in 1992. This observation,

along with the results of a killer whale-sea lion predation model (Barrett-Lennard et al. 1995), has

led to renewed interest in predation as a factor in at least the sea lion population’s lack of

recovery, if not the continued decline observed since 1990.

Human-related factors discussed in the recovery plan that may have contributed to the

population decline of sea lions were residual effects of the commercial harvest of pups and adult

males from 1959 to1972, the ongoing subsistence harvest by Alaska natives, incidental take by

fisheries, intentional killing, entanglement in debris, toxic substances (contaminants), disturbance,

and competition for food (with fisheries; Table 2). Each of these factors were considered by the

SSLRT, and for each except for entanglement and effects of commercial harvests, the SSLRT

concluded that there was insufficient information to determine its role in the decline. The plan

contains recommendations to estimate and reduce rates of mortality due to incidental take,

intentional killing, and struck and loss rate by subsistence hunters, as well as the development of

non-harmful methods of deterrence for fishers and programs to minimize marine debris. Much
4

of this work was begun or was continued in the 1990s by ADF&G and NMFS through increased

monitoring of subsistence hunts, partnerships with native organizations, or through fishery

observer programs (Wolfe and Mishler 1993, Angliss et al. 2001). In part due to inadequate

funding, little progress has been made on assessing the impact of contaminants despite the

recommendations in the plan, and the effects of disturbance have largely been ignored. While

considerable attention has been focused on competition with fisheries for food in scientific

reviews (National Research Council 1996), litigation (Greenpeace et al. v NMFS and At-Sea

Processors et al., Civ. No. C98-0492-C) and official government documents (NMFS 1998a,

NMFS 1999, NMFS 2000), there has been little progress on the scientific front in assessing the

mechanisms or magnitude of such interactions until recently (i.e., 2001). 

Renewed Research Emphasis in the Late 1990s and Early 2000s

By the late 1990s, interest in Steller sea lion research was renewed due to a combination

of several factors, including recent scientific findings, litigation, and legislation. NMFS reinitiated

formal ESA consultations on specific groundfish fisheries (Atka mackerel (Pleurogrammus

monopterygius) and walleye pollock (Theragra chalcogramma) based on information and

analyses that showed the potential for competitive overlap between them and sea lions. This new

information consisted primarily of

• Steller sea lion food habits.

• Depths, locations, and size ranges of fish targeted by groundfish fisheries.

• Disproportionate rates of harvest in sea lion foraging habitats.

• Potential localized depletions of prey.

The food habits information revealed strong prevalences of Atka mackerel, walleye

pollock, and Pacific cod (Gadus macrocephalus), all of which are targeted by groundfish

fisheries, in the diet of Steller sea lions. The size ranges of fish consumed by sea lions and those

targeted by fisheries overlapped considerably, as did the depths and geographic locations used by

both fisheries and sea lions. While these data in and of themselves suggested the potential for

competitive overlap, further analyses of the distribution of the Atka mackerel and walleye pollock

fisheries indicated that there was likelihood they could affect survival and recovery of Steller sea

lions. Survey and fishery data suggest that harvest rates in some of the areas utilized by the Atka

mackerel and walleye pollock fisheries are greater than the target rate on the stock as a whole

(Fritz 1995, NMFS 1998b, NMFS 1999, Fritz 2002). This could reduce the availability of prey in

areas used by the fishery, many of which are within areas designated as Steller sea lion critical

habitat. 

Because of these concerns, NMFS and the NPFMC took actions in 1998 which spatially

and temporally dispersed the Atka mackerel fishery and reduced effort in Steller sea lion critical

habitat in the Aleutian Islands. Efforts to restructure the pollock fisheries in the North Pacific to

address Steller sea lion concerns have been more protracted. The conclusions of a NMFS
5

biological opinion on the effects of the proposed 1999 walleye pollock fishery on Steller sea lions

(NMFS 1998a) were that it was likely to jeopardize their continued existence and adversely

modify Steller sea lion critical habitat. This was based on an analysis of the information

described above which suggested that fisheries could reduce the prey availability for Steller sea

lions in important foraging habitats. Consequently, NMFS and the NPFMC modified the fishery

(in a reasonable and prudent alternative, or RPA, to the fishery as originally proposed) to spatially

and temporally disperse effort as well as reduce catches within critical habitat. However,

considerable scientific uncertainty existed regarding the effects of fisheries on Steller sea lions as

well as the efficacy of the management measures proposed to mitigate them. While NMFS gave

the “benefit of the doubt” to the sea lion in its conclusions regarding the effects of the walleye

pollock fishery, NMFS could not convince the U.S. Western District Court and the Honorable

Thomas S. Zilly how the RPA avoided jeopardy to the continued existence of Steller sea lions

and avoided adversely modifying their critical habitat. As a result, the RPA was remanded back

to NMFS, which produced a revised final RPA under which the walleye pollock fishery operated

through 2000. 

The U.S. Western District Court also required NMFS to write a biological opinion

analyzing the combined and cumulative effects of all the groundfish fisheries as managed under

the fishery management plans. This document (NMFS 2000), finalized in November 2000,

concluded that the BSAI and GOA groundfish fisheries were likely to jeopardize Steller sea lions

and adversely modify their critical habitat because effects would likely occur at three scales: 

local, regional, and global. Much of the evidence for the local and regional fishery effects came

from analyses of Steller sea lion food habits and fishery data as described above. However, new

information on the potential impacts at the global, or ecosystem, scale of the overall target fishing

rates supported, according to NMFS, the conclusion of jeopardy and adverse modification. The

RPA developed in the November 2000 Biological Opinion, however, was controversial because

of the magnitude of perceived impacts to the fishing industry. Again, this stemmed largely from

the lack of firm evidence and considerable scientific uncertainty on the magnitude of fishery

effects on Steller sea lions and the efficacy of the proposed measures in mitigating these effects. 

The growing concern over the Steller sea lion decline and the possibility that the decline

may be related to uncertain but adverse interactions with the Alaskan groundfish fisheries

surfaced on the national scene during Congressional appropriations hearings in summer 2000. 

While the House Report on appropriations for the Departments of Commerce, Justice, and State

(CJS)(H.R. 106-680) did not mention the Steller sea lion issue, the Senate Report on CJS

appropriations (S. Rept 106-404) addressed the issue in detail. The differing responses were

likely due, at least in part, to the composition of the two Appropriations Committees, with the

Senate side being chaired by Senator Ted Stevens of Alaska. The subsection outlining the NMFS

budget contained the following paragraph:

“The Committee is greatly concerned by the administration’s proposed reduction of funding

for Steller sea lion recovery off Alaska. The cause of the Steller sea lion decline is still

unknown, and the costly limitations which could seriously impede the Nation’s most
6

productive fisheries are being implemented. Lawsuits are being filed which challenge the

agency’s data on the Steller sea lion, and more resources are needed to enable the agency to

produce the science and data to keep these fisheries open while protecting the sea lion

population. The Committee, therefore, has provided a total of $12,300,000 including

$7,000,000 for the National Marine Fisheries Service; $2,500,000 for the State of Alaska;

$1,000,000 for the Alaska SeaLife Center; $1,000,000 for the Gulf Apex Predator study at the

University of Alaska; and, $800,000 for the North Pacific Marine Mammal Consortium, to

address this pressing concern.”

Clearly the need for better scientific data was recognized both as a means of clarifying the

relationship between Steller sea lions and commercial fisheries to promote recovery, and as a

stimulus for a more thorough investigation of factors besides fisheries that might actually be

driving the decline. It is also worth noting that the initial Senate plan gave the majority of the

funds to the NMFS as the agency mandated with management authority for Steller sea lions

under ESA and the Marine Mammal Protection Act (MMPA) , and the remainder to the State of

Alaska and other non-governmental research organizations that were already involved with

Steller sea lion research. At this point, the proposed changes in funding were almost $7.6 M

more than the total research funds appropriated in FY00.

The existence of disparate versions of the CJS appropriations bills on the House and

Senate side followed a typical pattern in the Congressional Budget process and a Conference

Committee was established to draft a final, compromise version of the bill. The Conference

Committee met in the fall, and their report (H. Rept. 106-1005) was issued on 25 October 2000. 

The proposed funding for Steller sea lions specified in the Senate Report (106-404): 

“The conference agreement includes $12,300,000 for Steller sea lion recovery, to be allocated

according to the direction of the Senate report. Senate language regarding the

Administration’s reduction of funding for Steller sea lion recovery is included by reference.”

In addition to the $12.3 M, the conference language contained an additional allocation

under the heading of Fisheries Management Programs:

“...to provide increases for data collection on fishery management programs, including..., and

$10,000,000 for research regarding the Alaska Steller sea lion and pollock lawsuit”.

Whereas the appropriations contained in a conference report are normally the same as

those that appear in the final bill, the process by which the Department of Commerce (and so the

National Marine Fisheries Service) funding was determined for FY01 took a different route. Up

to this point, the process was on track with all three committee reports tiering off of the original

CJS appropriations bill (H.R. 4690). That bill was replaced in December by a version that

referenced a conference report containing additional, even more specific language regarding

Steller sea lions and the disposition of the Alaskan groundfish fisheries. To understand these

events, it is important to remember that NMFS was in the process of redrafting the
7

SSL/groundfish fishery Biological Opinion (hereafter referred to as the November 2000

Biological Opinion), and when its contents were made public on 30 November 2000, a suite of

restrictive measures to promote Steller sea lion protection were included. 

In a speech on the Senate floor on 14 December, Senator Ted Stevens (Alaska), Senate

Appropriations Committee Chairman, reacted to the November 2000 Biological Opinion and the

course of action NMFS was recommending. He stated, “I have made the statement that I will not

sign this conference report if it does not adequately restore this fishery”(i.e. the conference report

on the bill that would ultimately contain the Commerce Department’s appropriations). The final

package of FY01 appropriations passed after language was added to conference report H.R.106-

1033 (on H.R. 4577) (also referred to as the “Steven’s Rider”). Of that language, Sections 206

and 209 are relevant to Steller sea lion research funding. 

 SEC. 206. The Departments of Commerce, Justice, and State, the Judiciary, and Related

Agencies Appropriations Act, 2001, as enacted by section 1(a)(2) of the Act entitled ``An Act

making appropriations for the government of the District of Columbia and other activities

chargeable in whole or in part against revenues of said District for the fiscal year ending

September 30, 2001, and for other purposes'' is amended by inserting before the period at

the end of the paragraph under the heading ``National Oceanic and Atmospheric

Administration, Operations, Research, and Facilities'' the following new proviso: ``: Provided

further, That, of the amounts made available for the National Marine Fisheries Service under

this heading, $10,000,000 shall be available only for research regarding litigation concerning

the Alaska Steller sea lion and Bering Sea/Aleutian Islands and Gulf of Alaska groundfish

fisheries, of which $6,000,000 shall be available only for the Office of Oceanic and

Atmospheric Research to study the impact of ocean climate shifts on the North Pacific and

Bering Sea fish and marine mammal species composition, of which $2,000,000 shall be

available only for the National Ocean Service to study predator/prey relationships as they

relate to the decline of the western population of Steller sea lions, and of which $2,000,000

shall be available only for the North Pacific Fishery Management Council for an independent

analysis of Steller sea lion science and other work related to such litigation.

In essence, the new proviso contained in Section 206 reallocated the $10 M “for research

regarding the Alaska Steller sea lion and pollock lawsuit” in the NMFS budget as specified by the

25 October CJS conference report to non-NMFS entities. Given the ire that the November 2000

Biological Opinion had caused because of its focus on avoiding potential adverse impacts by the

Alaskan groundfish fisheries, it appears that this change in language represented Congressional

intent to investigate a broader range of possible factors explaining the decline (i.e., climate change

and increased predation by killer whales and sharks). Further, the appropriation of $2 M to the

NPFMC to review the science underlying the November 2000 Biological Opinion also signaled

discomfort with the NMFS position to further restrict certain fisheries based on the scientific

information available at the time. However, independent of the funding distribution, this $10 M,

over and above the $12.3 M already identified, substantially increased the potential breadth of

future Steller sea lion research. 
8

Section 209 provided further guidance, with language that superseded the RPAs

contained in the November 2000 Biological Opinion (sub-section c), the appropriation of still

more funds for Steller sea lion research (sub-section d) and a directive for a National Academy of

Science review of the basis for the NMFS conclusions in the November 2000 Biological Opinion

(sub-section b):

 SEC. 209. IMPLEMENTATION OF STELLER SEA LION PROTECTIVE MEASURES.--

 (a) FINDINGS.--The Congress finds that-- 

 (1) the western population of Steller sea lions has substantially declined over the last

twenty-five years.

 (2) scientists should closely research and analyze all possible factors relating to such

decline, including the possible interactions between commercial fishing and Steller sea lions

and the localized depletion hypothesis;

 (3) the authority to manage commercial fishing in federal waters lies with the regional

councils and the Secretary of Commerce (hereafter in this section ``Secretary'') pursuant to the

Magnuson-Stevens Fishery Conservation and Management Act (hereafter in this section

``Magnuson-Stevens Act''); and 

 (4) the Secretary of Commerce shall comply with the Magnuson-Stevens Act when using

fishery management plans and regulations to implement the decisions made pursuant to

findings under the Endangered Species Act, and shall utilize the processes and procedures of

the regional fishery management councils as required by the Magnuson-Stevens Act.

 (b) INDEPENDENT SCIENTIFIC REVIEW.--The North Pacific Fishery Management Council

(hereafter in this section ``North Pacific Council) shall utilize the expertise of the National

Academy of Sciences to conduct an independent scientific review of the November 30, 2000

Biological Opinion for the Bering Sea/Aleutian Islands and Gulf of Alaska groundfish fisheries

(hereafter in this section ``Biological Opinion''), its underlying hypothesis, and the Reasonable

and Prudent Alternatives (hereafter in this section ``Alternatives'') contained therein. The

Secretary shall cooperate with the independent scientific review, and the National Academy of

Sciences is requested to give its highest priority to this review. 

 (c) PREPARATION OF FISHERY MANAGEMENT PLANS AND REGULATIONS TO

IMPLEMENT PROTECTIVE MEASURES IN THE NOVEMBER 30, 2000 BIOLOGICAL

OPINION.-- 

 (1) The Secretary of Commerce shall submit to the North Pacific Council proposed

conservation and management measures to implement the Alternatives contained in the

November 30, 2000 Biological Opinion for the Bering Sea/Aleutian Islands and Gulf of Alaska
9

groundfish fisheries. The North Pacific Council shall prepare and transmit to the Secretary a

fishery management plan amendment or amendments to implement such Alternatives

that are consistent with the Magnuson-Stevens Act (including requirements in such Act

relating to best available science, bycatch reduction, impacting on fishing communities, the

safety of life at sea, and public comment and hearings.)

 (2) The Bering Sea/Aleutian Islands and Gulf of Alaska groundfish fisheries shall be

managed in a manner consistent with the Alternatives contained in the Biological Opinion,

except as otherwise provided in this section. The Alternatives shall become fully effective no

later than January 1, 2002, as revised if necessary and appropriate based on the independent

scientific review referred to in subsection (b) and other new information, and shall be phased

in in 2001 as described in paragraph (3). 

 (3) The 2001 Bering Sea/Aleutian Islands and Gulf of Alaska groundfish fisheries shall be

managed in accordance with the fishery management plan and federal regulations in effect for

such fisheries prior to July 15, 2000, including--

 (A) conservative total allowable catch levels; 

 (B) no entry zones within three miles of rookeries; 

 (C) restricted harvest levels near rookeries and haul-outs; 

 (D) federally-trained observers; 

 (E) spatial and temporal harvest restrictions; 

 (F) federally-mandated bycatch reduction programs; and 

 (G) additional conservation benefits provided through cooperative fishing arrangements,

and said regulations are hereby restored to full force and effect.

 (4) The Secretary shall amend these regulations by January 20, 2001, after consultation with

the North Pacific Council and in a manner consistent with all law, including the

Magnuson-Stevens Act, and consistent with the Alternatives to the maximum extent

practicable, subject to the other provisions of this subsection.

 (5) The harvest reduction requirement (``Global Control Rule'') shall take effect immediately

in any 2001 groundfish fishery in which it applies, but shall not cause a reduction in the total

allowable catch of any fishery of more than ten percent.

 (6) In enforcing regulations for the 2001 fisheries, the Secretary, upon recommendation of

the North Pacific Council, may open critical habitat where needed, adjust seasonal catch

levels, and take other measures as needed to ensure that harvest levels are sufficient to provide

income from these fisheries for small boats and Alaskan on-shore processors that is no less

than in 1999.

 
10

 (7) The regulations that are promulgated pursuant to paragraph (4) shall not be modified in

any way other than upon recommendation of the North Pacific Council, before March 15,

2001.

 (d) SEA LION PROTECTION MEASURES.--$20,000,000 is hereby appropriated to the

Secretary of Commerce to remain available until expended to develop and implement a

coordinated, comprehensive research and recovery program for the Steller sea lion, which

shall be designed to study-- 

 (1) available prey species; 

 (2) predator/prey relationships;

 (3) predation by other marine mammals;

 (4) interactions between fisheries and Steller sea lions, including the localized depletion

theory; 

 (5) regime shift, climate change, and other impacts associated with changing environmental

conditions in the North Pacific and Bering Sea;

 (6) disease;

 (7) juvenile and pup survival rates; 

 (8) population counts; 

 (9) nutritional stress; 

 (10) foreign commercial harvest of sealions outside the exclusive economic zone; 

 (11) the residual impacts of former government-authorized Steller sea lion eradication

bounty programs; and

 (12) the residual impacts of intentional lethal takes of Steller sea lions. 

Within available funds the Secretary shall implement on a pilot basis innovative

non-lethal measures to protect Steller sea lions from marine mammal predators including killer

whales,...

Focusing on Section 209(d), the most specific expression of Congressional intent for the

Steller sea lion research objectives is readily apparent. Not only would an additional $20 M be

made available, but it was to be spent on investigations or activities related to a list of 13 topics

representing the full range of possible factors underlying the Steller sea lion decline and failure to

recover. Of the $20 M, $5 M was earmarked for the Alaska Sea Life Center elsewhere in the

Congressional Record. Subsequent clarification of Congressional intent for the use of the

remaining $15 M indicated that the funds were to be used by non-federal parties. This further

suggests another expression of Congressional interest in widening the range of Steller sea lion

related research, inclusion of participants from diverse academic backgrounds, and enhanced

attention to non-fishery related factors. 
11

NMFS Response to the FY2001 Congressional Appropriations Language

Recapping the Congressional actions during 2000, the FY01 appropriations language

identified a total of $43.15 M in the NOAA budget for the implementation of Steller sea lion

protective measures. Congress directed that a broad research program be conducted to examine

all possible factors relating to the Steller sea lion decline, including interactions with commercial

fishing and further investigation of alternative hypotheses. The FY01 appropriations represented

an increase of $38.43 M in research funding over the previous year. Further, the funds were

directed to several organizations, both federal and non-federal, that are involved in Steller sea lion

research. This group of FY01 directly funded entities included:

• NOAA-Fisheries (National Marine Fisheries Service: NMFS)

• NOAA-Office of Oceanic and Atmospheric Research (OAR)

• NOAA-National Ocean Service (NOS)

• North Pacific Fishery Management Council (NPFMC)

• Alaska Department of Fish and Game (ADF&G)

• University of Alaska (UAF)

• Alaska Sea Life Center (ASLC)

• North Pacific Universities Marine Mammal Research Consortium (NPUMMRC). 

The intended scope of this research effort was far broader and more robust than

previously available resources could have allowed. Thus, the challenge in January 2001 was to

marshal the collective resources and expertise of the entities that had received funding and to

develop a coherent and calculated approach to the expanded investigations. Two issues were

immediately apparent; first, many Steller sea lion research projects begin in winter so there was

little time to waste in getting new or expanded projects up and running. Second, Congress

succeeded in spreading out the research funding and involving many new parties, but ultimately,

management responsibility for Steller sea lions still rested with NMFS. Thus, the subsequent

actions by NMFS represented an effort to encourage and support the efforts of all involved while

maintaining its management role and providing guidance during the process of program

development.

With large-scale increases in funding, a broadened base of participating parties and the

consequent proliferation of individual investigations, the appropriations language references to

coordination and comprehensiveness were interpreted by NMFS’ Alaska Fisheries Science

Center (AFSC) as the fundamental requirements of the Steller sea lion research program as a

whole.

The following discussion summarizes NMFS activities in support of the Steller sea lion

research program development during FY01 and assesses the level of coordination and

comprehensiveness achieved thus far. For brevity, actions of parties other than the AFSC are not

fully discussed. We note, however, that their contributions to the overall program are substantial. 

Additional details can be found at the web-sites of the Cooperative Institute for Arctic Science
12

(CIFAR) (www.cifar.uaf.edu), PMEL ( www.pmel.noaa.gov), ADF&G (www.state.ak.us/adfg),

ASLC (www.alaskasealife.org), NPUMMRC (www.marinemammal.org), and UAF

(www.sfos.uaf.edu/npmr/projects/mammals).

Although all of the $43.15 M FY01 Steller sea lion appropriations were included in the

NMFS budget, the total available to support NMFS-sponsored activities totaled $22.85 M; the

remainder was earmarked for non-NMFS parties (Table 1; Fig. 4 showing how FY01 funds were

distributed). The NMFS funds appeared in three allocations: $0.85 M for Steller sea lion

recovery, $7.0 M for expanded Steller sea lion research and $15.0 M initially assigned to the

Secretary of Commerce for unspecified Steller sea lion research.

 The first two allocations, totaling $7.85 M, were used by AFSC to support and expand ongoing

Steller sea lion and related Alaska groundfish/fishery investigations. Changes in the program

were based on guidance in the appropriations language. Of note, new programs were designed to

investigate fisheries effects and the efficacy of management measures (e.g., no-trawl zones),

expand sea lion branding, tagging, and scat collection efforts, study shark and killer whale

predation, survey groundfish and forage fish populations in sea lion habitats, and examine the

effects of diseases and contaminants on Steller sea lions. An approximate breakdown of AFSC

funding allocation included:

• Fisheries effects $1.0M

• Sea lion biology and ecology $5.0M

• Shark and killer whale predation $0.6M

• Groundfish and forage fish surveys $1.0M

• Diseases and contaminants $0.2M

The $15 M allocation was used to fund a competitive grants process (the Steller Sea Lion

Research Initiative (SSLRI)), administered through the NMFS’ Alaska Regional Office with

technical support from the AFSC. This program was designed to draw upon non-NMFS

expertise by soliciting proposals that addressed any of the 13 areas of research emphasis listed in

the appropriations language (Sec 209(d) above). While federal entities could not compete

directly for these funds, they could be identified as collaborative partners where their support was

critical to the study. 

The research areas named in Sec 209(d) included both general hypotheses as well as

specific lines of investigation relevant to many hypotheses which complicated project

organization. Therefore, the list was distilled into six principal hypotheses or factors contributing

to, or causing, the decline that more closely tracked the logic and terminology familiar to the

Steller sea lion research community:

• Fisheries effects.

• Environmental change.

• Other anthropogenic effects.
13

• Predation.

• Disease.

• Contaminants.

A total of 31 research proposals were funded under the SSLRI. Selected projects

addressed five of the six research hypotheses (no disease studies were proposed) and all but two

of the research areas from the appropriations language (i.e., disease and the non-lethal deterrence

of killer whales). The SSRLI-funded research project themes included baseline collection of sea

lion vital rates (population counts and assessment of reproductive rates), development of new

tools and techniques to understand sea lion foraging ecology, improved and expanded collection

of data on prey distribution and abundance, and construction of new mathematical bioenergetic

models that will attempt to synthesize a multitude of physical and biological interactions. 

Coordination 

Progress toward achieving a coordinated approach for committing research resources to

the various appropriations language directives is most evident in the chronology of meetings and

production of planning documents between January and September 2001. It is important to

recognize, however, that although the Steller sea lion research program was greatly enlarged and

much attention given to naming areas of study in the appropriations language, the coordination

aspect was addressed by Congress in only the most generic of terms. Further, the purposeful

dispersion of funding to more fully involve non-NMFS participants initially confounded efforts

to guide overall program design and development. Not surprisingly, given fiscal timing and

logistical constraints, attention to coordination largely took a back seat to each party’s need to

rapidly enhance or establish projects in the face of field season startups only 2 months away. 

Nonetheless, by September, significant progress had been made, highlighted by three research

planning meetings held in January, July, and September 2001. One of the principal goals of the

planning meetings was to jointly develop a research framework.

Steller Sea Lion Research Framework

Representatives from each of the 2001 funded entities reviewed and finalized a Steller sea

lion research framework based on a NMFS-AFSC concept. This framework (Fig. 3) was

developed to

• Facilitate the exchange of information, ideas, and support among individual investigators

doing similar or related research in the same geographic area (identify linkages).

• Assist in the research planning process to identify major research areas that are lacking in

effort or are saturated (identify gaps).

• Ensure that each project is addressing one or more of the hypotheses related to one or

more factors causing or contributing to the decline or lack of recovery of Steller sea lions.
14

Ultimately, there are only three reasons why a population of animals declines: decreased

survival of one or more age classes, decreased numbers of births, or increased emigration from

the area. In the case of the western stock of Steller sea lions, both of the first two reasons are

likely operating, but increased emigration is probably not likely (NMFS 1992). While these may

be the reasons that the population is declining, NMFS identified at least 6 factors that could be 

causing or contributing to decreased survival or numbers of births (see above). Each of these

factors could affect sea lions through one or more mechanisms:

• Nutritional stress, including cumulative impacts resulting from increasing exposure to

other factors.

• Direct mortality.

• Reduction in individual fitness, which increases exposure to other factors.

In addition, each factor can have more than one type of effect on sea lions or their

environment, each of which forms the basis for a specific hypothesis or question (Table 3). 

The research framework developed by the coordination group organizes projects from

two perspectives. The first is termed “top-down” since the main criterion is the factor causing the

decline that the project is studying. In this approach, the results of each study will be used to

address one or more hypotheses for the decline (Table 3). The other organizational perspective

may be more functional for the individual researcher since it is based on the type of research

being conducted, or research theme. This is termed the “bottom-up” perspective since similar

tools or disciplines of study are grouped. 

“Top-Down” Perspective: Factors Causing or Contributing to the Decline

Indirect effects of fisheries - Three categories of indirect fishery effects were identified: removal

of prey, disturbance, and changes to fish community structure (Fig. 4). Effects of prey removals

could be manifested at either large scales (on the order of ecosystems or fishery management

units such as the Gulf of Alaska) or local scales (such as the eastside of Kodiak Island or the

Unimak Pass area). Included at the local scale is the impact of prey removals as a function of

fishing patterns (e.g., timing and location). 

Fisheries disturb the marine environment in at least three ways that could affect sea lions. 

Two involve changes in prey and prey patch distribution, while the third addresses simple

competitive spatial disturbance, or interference competition. Disturbances of prey could change

patch structure in at least two ways: by reducing the density of individual patches (dispersion) or

by changing the distribution, size, or number of patches in space (e.g., deeper, more dispersed,

smaller, fewer). These are complex research questions which involve sea lion foraging behavior

and how fish respond to fishing gear.
15

Changes in the composition of the fish community can result from fisheries targeting

particular species, which could affect sea lions: 

• By reducing the amount, availability, or quality of prey available to sea lions. These

effects would flow from changes in the composition of the fish community as a result of

the history of fishing on one or more species in the North Pacific Ocean, including whales

(e.g. “trophic cascade hypothesis”).

• By increasing the rates of predation on sea lions due to prey switching by sea lion

predators. This could occur if the population size of a preferred prey of a sea lion

predator (e.g., shark) were depleted as a result of fisheries and the predator switched to

eating more sea lions.

• By increasing the level of competition between sea lions and other groundfish consumers

for a preferred sea lion prey.

This research hypothesis is well-covered by projects administered principally by NMFSAFSC, UA, NPUMMRC, and ADF&G. Research runs the gamut from field examination

of small-scale effects of fisheries on prey distribution and abundance to retrospective

studies of data collected by fisheries observers and during fishery-independent groundfish

surveys. The AFSC used a portion of its additional funds to conduct expanded surveys

of the fish community in Steller sea lion critical habitat. Given the large number of

projects that will directly or indirectly contribute to our understanding of fisheries effects

(including baseline studies of Steller sea lion biology) and the high cost of ship time for

fish surveys, this area (i.e., indirect effect of fisheries) has the largest funding total ($20-25

M).

Environmental changes - As with indirect fisheries effects, three types of effects from changes in

the environment were identified: decreased production, altered prey patch distribution, and

changes to the structure or distribution of biological communities (Fig. 5). Each could reduce the

environmental carrying capacity for sea lions, resulting in decreased survival or births through

nutritional stress or direct mortality. Decreased production (primary and secondary) from

environmental change would reduce the amount of prey available on either large or local scales. 

Similar to question F2, the local scale production hypothesis (E2) also addresses the issue of

changes in the timing of local production as a result of changes in the environment and how this

could affect sea lions. Environmental changes can alter the distribution of prey patches (i.e., with

depth) making fish less available to sea lions. Structural and distributional responses of biological

communities to environmental changes also include reductions in the amount, availability or

quality of sea lion prey, or increased predation on or competition with sea lions.

Research into the possible effects of environmental change on Steller sea lions was

initiated primarily by OAR and NOS through the CIFAR’s proposal solicitation process and by

OAR’s Pacific Marine Environmental Laboratory (PMEL). However, several cross-cutting

projects (funded by CIFAR, SSLRI, NPUMMRC, and AFSC) will attempt to produce models
16

that synthesize results from new oceanographic projects and a broad range of biological and

physical data to examine relative impacts on Steller sea lion bioenergetics and survival. New

funds allocated to NOS and OAR in FY01 totaled $8M, while similar projects conducted by

others (particularly modeling efforts) boosted the funding in this area to $10-12M.

Direct anthropogenic effects - Subsistence hunting, intentional shooting, incidental take in

fisheries, and residual effects of legal harvests or bounties are all examples of direct

anthropogenic effects that could decrease survival or births of sea lions through direct mortality

(Table 3).

Projects funded under this category will examine a wide variety of human-related

activities that lead to sea lion mortality, including subsistence hunting, illegal shooting, incidental

take in fisheries, and killing of sea lions outside of U.S. waters. Other effects, such as those

resulting from discontinued pups harvests and bounty programs, are also considered here,

primarily in modeling projects. Prior to FY01, ADF&G, AFSC and AKR conducted all of these

research and monitoring activities, while modeling work was done at these institutions and at

NPUMMRC. New funds allocated in FY01 permitted expansion of these existing programs and

initiation of community-based research and monitoring of local sea lion rookeries and haulouts

by native organizations in Alaska (funded through SSLRI). Some of these new communitybased efforts are in collaboration with scientists at UA and environmental consulting firms. 

Approximately $1M was spent in FY01 on these research activities.

Predation - Predation by both killer whales and sharks could be a factor in both the original

decline and the lack of recovery of Steller sea lion populations in Alaska. Predation effects could

be manifested in one of two ways (Table 3): 

• The number of sea lions killed by predators has increased due to increases in killer whale

or shark populations or their per capita rate of predation (prey switching). 

• The number of sea lions killed by predators has remained relatively constant but it has an

increased impact on the population because of low sea lion population size.

While killer whale and shark research and monitoring activities were already underway

(primarily at AFSC and NPUMMRC), expanded funding in FY01 permitted the initiation of

programs at UA and ASLC, as well as with the aforementioned groups. Shark biology

investigations (e.g., tagging, food habits and movement), along with expanded killer whale

monitoring, characterization (e.g., transient vs. resident), and population assessment were among

the projects funded. In addition, mathematical models that incorporate the effects of predation

along with other factors on the Steller sea lion population will be developed. Funding for these

research activities totaled $2-3 M. 

Disease - The effects of diseases (either novel epidemic or increased incidence of endemic

diseases) could decrease survival or births of sea lions through direct mortality of individuals or
17

through a reduction in individual fitness, which would increase their vulnerability to other factors

(Table 3).

While routine monitoring for known diseases had been part of ongoing biological work at

AFSC and ADF&G, new funding allowed for considerable expansion of these efforts. New, 

more comprehensive disease and parasite assessments will also begin at the ASLC. Funding

totaled approximately $1 M.

Contaminants - Similar to the effects of disease, the effects of organic and inorganic

contaminants could decrease survival or births of sea lions through direct mortality of individuals 

or through a reduction in individual fitness, which would increase their vulnerability to other

factors (Table 3).

Prior to FY01, sea lion blubber and tissue samples were collected and analyzed for metals

and organic pollutants by both the AFSC and ADF&G. However, no research program existed

with the sole purpose of examining the role of contaminants in the decline of Steller sea lions. 

New research programs funded under SSLRI (at Yale University) and initiated at ASLC, along

with continued funding of the work at AFSC and ADF&G, will develop tools to assess the threat

posed by pollutants and provide for field data collection. FY01 funds spent on contaminant

research totaled approximately $1M.

Synergies - A frequent topic of discussion among the funded entities when the framework was

being developed was that each factor was considered in isolation, when in reality, more than one

of them could be in effect now or in the past. Several of the projects, particularly those that have

a modeling component, specifically address how fisheries and environmental effects could

combine in an unpredictable manner to reduce prey availability, abundance, or quality to sea

lions. All possible combinations of effects were addressed in a single question, S1 (Table 3).

“Bottom-Up” Perspective: Research Themes

The Abottom-up@ perspective for organizing research projects is the one that is probably

most familiar to both researchers and the public. This is because it reflects the type of research

being conducted. Just as it is possible for research conducted under a single theme to address

several questions, it is also possible for a series of projects that each attempt to answer a single

question to use different tools or techniques, or be responsive to different themes. The 11 themes

identified were as follows: 

Life History - Investigations of the life history of Steller sea lions, including all aspects of

ontogenetic development (e.g., weaning process, molt), growth, and reproduction. Behavioral

studies are included as a sub-theme since the age and sex of the studied individuals are central to

their behavior.
18

Foraging - Studies of the foraging ecology of Steller sea lion juveniles and adults. This includes

all aspects of foraging, including what is eaten (food habits and diet), the costs incurred in

locating and obtaining prey (bioenergetics), and differences in habitat use by juveniles and adults

(habitat use).

Vital Rates - All studies related to population assessment (both counting of animals and

assessment of their condition), reproductive rates, and survival/mortality rates (e.g. branding

studies). Modeling studies, such as the creation of a new life table, would also fall under this

theme. Many of these studies supply baseline information necessary to address all of the

hypotheses/questions. 

Fish Assessment and Fisheries - Prey or fish surveys, along with any studies of the impacts of

fisheries on either large or small spatial/temporal scales.

Ecosystems - Any study dealing with bottom-up processes in the ocean and how changes in

them might affect the prey field for Steller sea lions. As with the Fish Assessment and Fisheries

theme, there are two sub-themes (local/regional and global) depending on the scale of the

ecosystem study.

Other Anthropogenic Effects - Any studies of the effects or quantification of subsistence

hunting, intentional shooting, incidental take, or the residual effect of harvests and bounties on

the Steller sea lion population. This theme, along with the following three, directly corresponds

with one of factors causing or contributing to the decline.

Predation - Killer whale and shark predation are sub-themes under this general research theme,

which would include all studies whose primary focus is addressing questions P1-P4.

Disease - Studies of sea lion diseases (including parasites) are included in one of two sub-themes:

1) assessment of the effects of diseases on the health of individuals, and 2) assessment of the

population-level impact of diseases.

Contaminants - Similar to sea lion disease studies, contaminant studies were also placed into one

of two sub-themes depending on the scale at which contaminant effects were analyzed: 1)

assessment of the effects of contaminants on the health of individuals, and 2) assessment of the

effects of contaminants on sea lion habitats (environmental-level effects), and how this could

reduce sea lion survival or births.

Management - Projects under this theme involve funding for meetings to implement regulations

(e.g., NPFMC), for independent reviews of the scientific and legal basis for actions, and for

analysis of impacts of actions (particularly economic). Reviews address the information available

and required to answer some or all of the questions posed, while other projects inform decisions

made by managers.
19

Communications - Communication of ideas and information both among researchers

(coordination) and between researchers and the interested public (outreach) are the principal

goals of projects under this theme. Forms of communication considered include symposia,

publishing of scientific literature, and web-based content.

Comprehensiveness

Major strides have been made in achieving a comprehensive research program to

investigate the factors responsible for the Steller sea lion decline. Most of the research areas

identified in the Stevens Rider have projects oriented to them and over 150 individual research

projects are underway. The expansion not only addresses a broader series of plausible

hypotheses for the Steller sea lion decline, but also enables a much more thorough, integrated

investigation of each. However, whether the current mix of projects constitutes a fully

responsive, comprehensive program is yet to be determined. Gaps, overlaps, efficiencies, and

potential synergies will be monitored as the program unfolds. AFSC intends to provide oversight

and coordination for the ongoing program. As results accumulate and concepts arise from the

work now underway, our sense of the degree to which the program is responding will evolve. 

Through its coordination and leadership efforts, the AFSC will place a high priority on assuring

that this diverse research program stays integrated and on track. A key component of this effort

will be the timely reporting of results to all constituent groups that express interest.

The efforts to expand the Steller sea lion research capabilities both inside NMFS and

among our new partners have largely met the initial objectives noted above, especially in light of

practical expectations for a program of this magnitude and complexity. While results from the

majority of studies were not available prior to the completion of FY02 field studies and analyses 

(many of which are multi-year projects with starting dates in FY02), much of the planning and

organizing apparatus necessary to provide direction for them has seen significant progress. In

essence, aside from ongoing Steller sea lion studies, FY01, and to a certain degree, FY02, served

as periods of preparation during which new projects were designed, funds were distributed, and

communications links among key participants receiving earmarks were solidified. With respect to

responsiveness to the 13 areas of research emphasis, all but one is addressed and in most cases

by a variety of complementary studies. With a core group of contacts representing each of the

endowed parties now established, we are also in position to monitor progress and identify both

opportunities for coordination and gaps in need of attention. Whether the current suite of studies

constitutes a comprehensive and coordinated program depends on the success of individual

projects, but with the aid of a research framework, we now have a means of evaluation that has

been jointly developed and accepted by the participating parties. 
20

Summary and Conclusion

The current outlook for Steller sea lion research suggests promise for future science-based

management efforts. The complexity and scope of research, and the communication and

coordination among the participants are considerably enhanced relative to the program

capabilities of the past two decades. However, expectations for meaningful progress toward

identification of key factors for the recovery of Steller sea lions should be tempered by two

realities. 

First, few, if any of the ongoing studies are likely to yield conclusive results regarding the

underlying constraints on Steller sea lion recovery in the short term. That is, most efforts involve

multi-year studies, ranging from 2 to 10 years, designed to provide insights and inferences on

various facets of the issue. A realistic expectation is for new information to coalesce over time

and provide the basis for more refined or targeted questions centered on those aspects that have

shown particular promise. Likewise, progress will be evident as the new information points out

the factors less likely to play important roles and so are de-emphasized in future work. The

underlying assumption for the entire research effort, however, is that sufficient funding levels

persist long enough for the ongoing suite of studies to produce meaningful results, and to allow

those results to form the basis for more refined investigations. 

Second, our understanding of ecosystem processes is limited and marine science is more

likely to produce glimpses of the underlying mechanics rather than an overall picture of its

dynamics for many years to come. As such, while the Steller sea lion research efforts are very

likely to greatly enhance our knowledge base, they should not be expected to either prove causal

relationships or produce tools for predicting ecosystem function. Rather, we should consider the

real value of the new information as ever improving the scientific foundations for management

decisions, which in turn, must still rely on the application of conservation principles in the face of

uncertainty. 
21

Citations

Anderson, P. J., and J. F. Piatt. 1999. Community reorganization in the Gulf of Alaska following

ocean climate regime shift. Marine Ecol. Progr. Series 189: 117-123.

Angliss, R.P., D.P. DeMaster, and A.L. Lopez. 2001. Alaska marine mammal stock assessments,

2001. U.S. Dep. Comer., NOAA Tech. Memo. NMFS-AFSC-124, 203 p.

Barrett-Lennard, L.G., K. Heise, E.Saulitis, G. Ellis, and C. Matkin. 1995. The impact of killer

whale predation on Steller sea lion populations in British Columbia and Alaska. 

University of British Columbia, Fisheries Centre, 2204 Main Mall, Vancouver, B.C. V6T

1Z4. 71 p.

Beamish, R. J. 1993. Climate and exceptional fish production off the west coast of North

America. Can. J. Fish. Aquat. Sci. 50: 2270-2291.

Bickham, J. W., J. C. Patton, and T. R. Loughlin. 1996. High variability for control-region

sequences in a marine mammal: Implications for conservation and biogeography of

Steller sea lions (Eumetopias jubatus). J. Mammal. 77: 95-108.

Braham, H. W., R. D. Everitt, and D. J. Rugh. 1980. Northern sea lion decline in the eastern

Aleutian Islands. J. Wildl. Manage. 44: 25-33.

Calkins, D., and E. Goodwin. 1988. Investigations of the declining sea lion population in the

Gulf of Alaska. Alaska Dept. Fish and Game, 333 Raspberry Road, Anchorage, AK

99518. 76 p.

Calkins, D., and K. Pitcher. 1982. Population assessment, ecology, and trophic relationships of

Steller sea lions in the Gulf of Alaska. U.S. Dep. Commer., NOAA Outer Continental

Shelf Environmental Assessment Program Final Report 19 (1983), p. 445-546.

Francis, R. C., and S. R. Hare. 1994. Decadal scale regime shifts in the large marine ecosystem

of the northeast Pacific: A case for historical science. Fish. Oceanogr. 3: 279-291.

Francis, R. C., S. R. Hare, A. B. Hollowed, and W. S. Wooster. 1998. Effect of interdecadal

climate variability on the oceanic ecosystems of the NE Pacific. Fish. Oceanogr. 7: 1-21.

Fritz, L. W. 1995. Effects of the Catcher Vessel Operational Area on walleye pollock fisheries

and marine mammals in the eastern Bering Sea, 1990-94. U.S. Dep. Commer. NMFSAFSC Processed Rep. 95-04, 114 p. Alaska Fish. Sci. Cent., Natl. Mar. Fish. Serv.,

NOAA, 7600 Sand Point Way NE, Seattle WA 98115.
22

Fritz, L. W. 2002. Do trawl fisheries off Alaska create localized depletions of Atka mackerel

(Pleurogrammus monopterygius)? Unpublished manuscript, 27 p. Alaska Fisheries

Science Center, 7600 Sand Point Way NE, Seattle, WA 98115.,

Hollowed, A. B., and W. S. Wooster. 1992. Variability in winter ocean conditions and strong

year-classes of northeast Pacific groundfish. ICES Mar. Sci. Symp. 195: 433-444. 

Hollowed, A. B., and W. S. Wooster. 1995. Decadal-scale variations in the eastern Subarctic

Pacific: II. Response of northeast Pacific fish stocks. In Climate Change and Northern

Fish Populations. Can. Spec. Pub. Fish. Aquat. Sci. 121: 373-385. 

Imler, R. H., and H. R. Sarber. 1947. Harbor seals and sea lions in Alaska. U.S. Dept. Interior,

Fish Wildl. Serv., Spec. Sci. Rept. 28, 23 p.

Kenyon, K. W., and D. W. Rice. 1961. Abundance and distribution of the Steller sea lion. J.

Mammal. 42: 223-234.

Loughlin, T. R. 1997. Using the phylogeographic method to identify Steller sea lion stocks. 

Molecular Genetics of Marine Mammals, Spec. Pub. 3: 159-171.

Loughlin, T. R., A. S. Perlov, and V. A. Vladimirov. 1990. Survey of northern sea lions

(Eumetopias jubatus) in the Gulf of Alaska and Aleutian Islands during June 1989. U.S.

Dep. Commer., NOAA Tech. Memo. NMFS F/NWC-176, 26 p.

Loughlin, T. R., A. S. Perlov, and V. A. Vladimirov. 1992. Range-wide survey and estimation of

total number of Steller sea lions in 1989. Mar. Mammal Sci. 8: 220-239.

Loughlin, T. R., D. J. Rugh, and C. H. Fiscus. 1984. Northern sea lion distribution and

abundance: 1956-1980. J. Wildl. Manage. 48: 729-740.

Mathisen, O. A., and R. J. Lopp. 1963. Photographic census of the Steller sea lion herd in

Alaska, 1956-58. U.S. Dept. Interior, Fish Wildl.Serv., Spec. Sci. Rept. 424, 20 p.

Mathisen, O. A., R. T. Baade, and R. J. Lopp. 1962. Breeding habits, growth and stomach

contents of the Steller sea lion in Alaska. J. Mammal. 43: 469-477.

National Marine Fisheries Service. 1992. Recovery plan for the Steller sea lion (Eumetopias

jubatus). Prepared by the Steller sea lion recovery team for the National Marine Fisheries

Service, Silver Spring MD. 92 p. Available from the NMFS Office of Protected

Resources 1315 East-West Highway, Silver Spring MD 20910.
23

National Marine Fisheries Service. 1998a. Section 7 consultation on the (1) Authorization of the

Bering Sea and Aleutian Islands groundfish fishery for walleye pollock under the Bering

Sea and Aleutian Islands Groundfish Fishery Management Plan, (2) Authorization of the

Bering Sea and Aleutian Islands groundfish fishery for Atka mackerel under the Bering

Sea and Aleutian Islands Groundfish Fishery Management Plan, and (3) Authorization of

the Gulf of Alaska groundfish fishery for walleye pollock under the Gulf of Alaska

Groundfish Fishery Management Plan, between 1999 and 2002. Office of Protected

Resources, NMFS, Silver Spring, MD.

National Marine Fisheries Service. 1998b. Environmental Assessment/Regulatory Impact

Review/Initial Regulatory Flexibility Analysis for an amendment to the Bering

Sea/Aleutian Islands Groundfish Fishery Management Plan to reapportion total allowable

catch of Atka mackerel and reduce fishery effects on Steller sea lions. Alaska Regional

Office and Alaska Fisheries Science Center, Juneau, AK.

National Marine Fisheries Service. 1999. Environmental Assessment/Regulatory Impact

Review/Initial Regulatory Flexibility Analysis for an amendment to the Bering

Sea/Aleutian Islands and Gulf of Alaska Groundfish Fishery Management Plans to reduce

effects of the fishery for walleye pollock on Steller sea lions. Alaska Regional Office and

Alaska Fisheries Science Center, Juneau, AK.

National Marine Fisheries Service. 2000. Section 7 consultation on the (1) Authorization of

Bering Sea/Aleutian Islands groundfish fisheries based on the Fishery Management Plan

for the Bering Sea/Aleutian Islands Groundfish, and (2) Authorization of Gulf of Alaska

groundfish fisheries based on the Fishery Management Plan for Groundfish of the Gulf of

Alaska. Office of Protected Resources, NMFS, Silver Spring MD.

National Research Council. 1996. The Bering Sea Ecosystem. National Academy Press,

Washington, D.C. 307 p.

Pitcher, K. 1981. Prey of Steller sea lions, Eumetopias jubatus, in the Gulf of Alaska. Fish. Bull.,

U.S. 79: 467-472.

Pitcher, K., and D. Calkins. 1981. Reproductive biology of Steller sea lions in the Gulf of Alaska. 

J. Mammal. 62: 599-605.

Shima, M., A. B. Hollowed, and G. R. Van Blaricom. 2000. Response of pinniped populations

to directed harvest, climate variability, and commercial fishery activity: a comparative

analysis. Rev. Fish. Sci. 8: 89-124.

Thorsteinson, F. V., and C. J. Lensink. 1962. Biological observations of Steller sea lions taken

during an experimental harvest. J. Wildl. Manage. 26: 353-359.
24

Wolfe, R. J., and C. Mishler. 1993. The subsistence harvest of harbor seal and sea lion by Alaska

natives in 1992. Technical Paper No. 229, Alaska Dep. Fish and Game, Division of

Subsistence, P.O. Box 25526, Juneau, AK 99802-5526. 443 p.
25

1NOAA Office of Oceanic and Atmospheric Research and National Ocean Service

2Alaska SeaLife Center, Alaska Department of Fish and Game, North Pacific Universities Marine

 Mammal Research Consortium, North Pacific Fishery Management Council, University of Alaska, and

 Alaska Fisheries Development Foundation

3

Includes funds for the Steller Sea Lion Research Initiative (SSLRI)

Table 1. -- Federal funding ($1,000s) for Steller sea lion research in fiscal years (FY) 1982

- 2000 available to NMFS and other federal agencies1, and to other research

organizations2.

FY Federal 

Agencies

Non-Federal

Research

Organizations

Total

1982 50 50

1983 50 50

1984 50 50

1985 200 200

1986 100 100

1987 300 300

1988 200 200

1989 200 200

1990 600 600

1991 559 559

1992 676 750 1,426

1993 517 728 1,245

1994 584 708 1,292

1995 645 708 1,353

1996 831 1,005 1,836

1997 867 1,022 1,889

1998 978 2,043 3,021

1999 1,653 1,863 3,516

2000 2,110 2,610 4,720

2001 15,850 27,3003 43,150

2002 25,650 14,495 40,145
26

Table 2. -- Summary of the potential factors contributing to the decline of Steller sea lions

identified by the Steller Sea Lion Recovery Team’s (SSLRT) recovery plan

(NMFS 1992), their research recommendations, and progress made in the

1990s in evaluating the contribution of each factor in the continued decline.

Source Factor in Steller Sea

Lion Decline

SSLRT Research

Recommendation

Progress in the 1990s in

Evaluating Contribution of 

Factor in Recent Decline

Natural

Parasitism and disease Increase monitoring Little

Environmental change None Re-emergence as factor 

Predation Evaluate Re-emergence as factor

Human

Commercial harvest None Much; not considered a

factor

Subsistence harvest Monitor Much; better estimates and

mortality rate reduced 

Incidental take Monitor Much; not considered a

factor

Intentional killing Evaluate and educate Little

Entanglement Evaluate and educate Much; not considered a

factor

Toxic substances Increase monitoring Little

Disturbance None Little

Competition for food Determine effects of

fisheries on prey

Little
27

Table 3.-- Structure of specific hypotheses for each factor causing or contributing to the

decline of Steller sea lions. 

A. Indirect Fisheries Effects. Read each hypothesis (F1-F8) as:

Has [General Effect][Specific Effect] resulting in [Reason for the Decline] through [Mechanism]

Code General

Effect Specific Effect Reason for the Decline Mechanism

F1 Prey

removal by

fisheries

Reduced ecosystem-wide

prey abundance or

availability

Decreased survival or

births of sea lions

Nutritional

stress

F2 Reduced local prey

abundance or availability

F3

Prey

disturbance

by fisheries

Reduced density of

individual prey patches

F4

Changed distribution and

reduced size or number of

prey patches

F5

Competitive

interaction

with

fisheries

Reduced prey availability

F6

Fish

community

changes

from fishing

Reduced abundance,

availability, or quality of

prey

F7 Increased predation on sea

lions

Decreased survival of

sea lions

Direct

mortality

F8 Increased competition for

prey with sea lions

Decreased survival or

births of sea lions

Nutritional

stress
28

B. Environmental Changes: Read each hypothesis (E1-E6) as:

Has [General Effect][Specific Effect] resulting in [Reason for the Decline] through [Mechanism]

Code General

Effect Specific Effect Reason for the Decline Mechanism

E1

Decreased

production

from

environmental

change

Reduced ecosystemwide prey abundance or

availability

Decreased survival or

births of sea lions

Nutritional

stress

E2 Reduced local prey

abundance or availability

E3 Environmental

change

Altered distribution and

availability of prey

patches

E4

Environmental

change altered

composition of

biological

communities

Reducing abundance,

availability, or quality of

prey

E5 Increasing predation on

sea lions

Decreased survival of

sea lions

Direct

mortality

E6 Increasing competition

for prey with sea lions

Decreased survival or

births of sea lions

Nutritional

stress

C. Direct Anthropogenic Effects: Read each hypothesis (A1-A4) as:

Has [Specific Effect] resulted in [Reason for the Decline] through [Mechanism]

Code Specific

Effect Reason for the Decline Mechanism

A1 Subsistence hunting

Decreased survival of sea lions Direct mortality

A2 Intentional shooting

A3 Incidental take in

fisheries

A4 Residual effect of

legal harvests
29

D. Predation: Read hypotheses (P1-P4) as:

Have [Specific Effect] of [Predator] resulted in [Reason for the Decline] through [Mechanism]

Code Specific Effect Predator Reason for the Decline Mechanism

P1

Increases in

the population

Killer whales

Decreased survival of

sea lions

Direct

mortality

P2

Increases in

per capita

predation rates

P3 Increases in

the population

Sharks

P4

Increases in

per capita

predation rates

E. Diseases: Read hypotheses (D1-D2) as:

Have [Specific Effect] resulted in [Reason for the Decline] through [Mechanism]

Code Specific Effect Reason for the Decline Mechanism

D1

A single or

combination of

endemic or new

diseases

Decreased survival or births of sea

lions

Direct mortality

D2 Reduction in

individual fitness

F. Contaminants: Read hypotheses (C1-C2) as:

Have [Specific Effect] resulted in [Reason for the Decline] through [Mechanism]

Code Specific Effect Reason for the Decline Mechanism

C1

A single or suite of

organic or inorganic

contaminants, either

persistent or acute

Decreased survival or births of sea

lions

Direct mortality

C2 Reduction in

individual fitness

G. Synergisms (S1): Have two or more of the above factors combined to decrease survival or

births of sea lions through nutritional stress, direct mortality, or a reduction in individual fitness?
30

Figure 1. -- Estimated number of Steller sea lions in the western population in Alaska, 1970-2000.
Figure 2 -- Range of the Steller sea lion (Eumetopias jubatus) in the North Pacific Ocean. Rookeries are terrestrial breeding locations.

31
32

Reasons why population is declining

Factors causing or contributing to the decline

Mechanisms 

Hypotheses/Questions

Projects

Research Themes

Project Types

Framework structure

Figure 3. -- Generalized structure of Steller sea lion research framework.
33

Factors: 1. Indirect effects of fisheries

Large scale

F1

Small spatial or

temporal scale

F2

Removal of Prey

Reduced prey

patch density

F3

Changed distribution,

size, or number of

prey patches

F4

Increased competitive

spatial disturbance

F5

Disturbance

Reduction in amount,

availability or quality

of prey

F6

Increased

predation

F7

Increased

competition

F8

Changes to

Fish Community

Top- Down Approach

Figure 4.-- Organization of hypotheses and questions related to the possible indirect effects of

 fisheries on the decline of Steller sea lions. F1 through F8 refer to the hypotheses

 listed in Table 3.
34

Factors: 2. Environmental changes

Large scale

E1

Small spatial or

temporal scale

E2

Decreased production Altered patch distribution

E3

Reduction in amount,

availability or quality

of prey

E4

Increased

predation

E5

Increased

competition

E6

Changes to structure

or distribution of

biological communities

Top- Down Approach

Figure 5.-- Organization of hypotheses and questions related to the possible effects of

 environmental changes on the decline of Steller sea lions. E1 through E6 refer to the

 hypotheses listed in Table 3.
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AFSC128 WEINBERG, K.L., M. E. WILKINS, F. R. SHAW, and M. ZIMMERMANN. 2002. The 2001 Pacific west

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age composition, 140 p. + Appendices. NTIS number pending.

127 MARQUETTE, W. M. 2002. Annotated bibliography of the bowhead whale, Balaena mysticetus, 1767-

1983, 325 p. NTIS number pending.

126 HONKALEHTO, T., W. PATTON, S. DE BLOIS, and N. WILLIAMSON. 2002. Echo integration-trawl

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125 HONKALEHTO, T., N. WILLIAMSON, and S. DE BLOIS. 2002. Echo integration-trawl survey results

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77 p. NTIS number pending.

124 ANGLISS, R. P., D. P. DEMASTER, and A. L. LOPEZ. 2001. Alaska marine mammal stock

assessments, 2001, 203 p. NTIS number pending.

123 ROBSON , B. W. (editor). 2001. Fur seal investigations, 1999, 52 p. NTIS No. PB2002-100418.

122 SEASE, J. L., W. P. TAYLOR, T. R. LOUGHLIN, and K. W. PITCHER. 2001. Aerial and land-based

surveys of Steller sea lions (Eumetopias jubatus) in Alaska, June and July 1999 and 2000, 52 p. NTIS

No. PB2001-107277.

121 BRITT, L. L., and M. H. MARTIN. 2001. Data report: 1999 Gulf of Alaska bottom trawl survey, 249 p.

NTIS No. PB2001-105324

120 LAUTH, R. R. 2001. The 2000 Pacific west coast upper continental slope trawl survey of groundfish

resources off Washington, Oregon, and California: Estimates of distribution, abundance, and length

composition, 284 p. NTIS No. PB2001-105327.

119 FERRERO, R. C., HILL, D. P. DEMASTER, P. S. HILL, M. M. MUTO, and A. L. LOPEZ. 2000. Alaska

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118 WILSON, C. D., M. A. GUTTORMSEN, K. COOKE, M. W. SAUNDERS, and R. KIESER. 2000. Echo

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117 ORR, J. W., M. A. BROWN, and D. C. BAKER. 2000. Guide to rockfishes (Scorpaenidae) of the

genera Sebastes, Sebastolobus, and Adelosebastes of the northeast Pacific Ocean, second edition,

47 p. NTIS No. PB2001-100757.

116 WION, D. A., and R. A. MCCONNAUGHEY (editors). 2000. Mobile fishing gear effects on benthic

habitats: A bibliography, 163 p. NTIS No. PB2000-108106.

115 LAUTH, R. R. 2000. The 1999 Pacific west coast upper continental slope trawl survey of groundfish 

resources off Washington, Oregon, and California: Estimates of distribution, abundance, and length 

composition, 287 p. NTIS No. PB2000-106004.