# Presentation: 516817

**Steller Sea Lion Research: **
**Background**

## Distribution of Steller Sea Lions (from North Pacific 

- Distribution of Steller Sea Lions (from North Pacific
- Universities Marine Mammal Research Consortium website)

## Steller Sea Lion Population Trends

## Counts of adult and juvenile Steller sea lions (trend sites)

## Ultimate Cause(s) of Decline

- Entanglement in marine debris
- Pup/subsistence harvest
- Pollution
- Harassment
- Increased predation
- Disease
- Oceanographic changes
- Indirect effects of fisheries

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- Not likely causes of the decline

_**Hypotheses**_**:**  **Decline is caused by reduced prey availability caused by oceanographic changes or indirect effects of fisheries**

**}**

- Not likely causes of the decline; may now be exacerbating the decline

## Slide 6

## Conference Report (HR106-1033) (15 December 2000) referenced in Commerce Appropriations Bill (HR5548)(15 December 2000

*Section 208*
- $10,000,000 “shall be available only for research regarding litigation concerning the Alaska Steller sea lion and Bering Sea/Gulf of Alaska groundfish fisheries of which...”
- $6,000,000 ~ OAR – “to study the impact of ocean climate shifts on the North Pacific and Bering Sea fish and marine mammal species composition”
- $2,000,000 ~ NOS – “to study predator/prey relationships as they relate to the decline of the western population of Steller sea lions”
- $2,000,000 ~ NPFMC – “for an independent analysis of Steller sea lion science and other work related to such litigation”

## Preliminary 3-Year (FY00-02) Research Plan

- Objectives:
- To understand the current decline in abundance of the western stock of Steller sea lions
- To evaluate the extent to which commercial fisheries are contributing to this decline

## PMEL Research Plan ($3.4M)

- Goal: To understand the relationship between the changes in the physical environment and the current decline in abundance of the western stock of Steller sea lions
- Retrospective and Modeling
- Argo Drifters
- Aleutian Study
- Kodiak Study

## Studies must be designed to differentiate between changes in marine mammal populations due to the environment and changes resulting from fisheries
Need to gather data on the appropriate scale to determine. . . 
Cumulative ecosystem impacts
Indirect effects of fisheries on Steller sea lions

- Need to gather data on the appropriate scale to determine. . .
- Cumulative ecosystem impacts
- Indirect effects of fisheries on Steller sea lions

**Research Challenges**

*Photo by NASA/SeaWIFs*

## Slide 11

## Determining the influence of climate change on the ecosystem

**“*****to study the impact of ocean climate shifts on North Pacific and Bering Sea fish and marine mammal species composition”***
-  Basin scale
-  Regional scale (**Alaskan Stream and subarctic gyre**)
-  Local scale (**Aleutian Passes and Kodiak Island rookeries**)

## Critical habitat for Steller sea lions is the coastal regions of the Bering Sea, Aleutian Islands and the Gulf of Alaska.

## Basin-scale climate variability

**The Pacific Decadal Oscillation (PDO) is an index of climate variability derived from sea surface temperature anomalies.  **
** ****Arrows indicate the mean circulation patterns that respond to climate change.**

*Basin Scale*

_**Basin-scale climate variability**_

## Modeling

** ****Model domain (yellow) includes critical Steller sea lion habitat (red)**
** ****Models enable examination of climate change on ecosystems associated with sea lions**

_**Modeling**_

*Basin Scale*

## Collaboration:  Existing GLOBEC models

*Basin Scale*

## Collaboration

**Floats will be deployed in 2001 (black dots).  **
** ****Conduct temperature and salinity profiles**
** ****Transmit data to shore**
** ****Provide information on vertical structure and its spatial variability**
** ****Furnish input for models**
** ****Last four years**

*Basin Scale*

## We will extend the grid in the N. Pacific into the Bering Sea.

*Basin Scale*

## Collaboration

_**Collaboration**_
**In 2001, biophysical moorings will be deployed in the Bering Sea and North Pacific by GLOBEC, SEBSCC and FOCI.  These programs also will conduct inter-disciplinary cruises.**

*Regional Scale*

## Moored Observations

_**Moored Observations**_
**PMEL has deployed bio-physical moorings since 1991 in the northern Gulf of Alaska and Bering Sea.  **
**Biological and physical sensors **
** ****measure critical aspects of the ecosystem**
** ****provide necessary time series to examine temporal variability of ecosystem.**

## Temperature and Fluorescence

_**Temperature **__**and **__**Fluorescence**_
**The first five years at Site 2 on the Bering Sea middle shelf **
**  ****Evolution of the water column structure**
**  ****Timing of spring bloom and its  association with ice (subsurface temperatures <1****o****C)**
**  ****Impact of summer storms on primary production**

## PMEL will deploy biophysical moorings in the N. Pacific.  

*Local Scale                                               Regional Scale                                                Basin Scale                *

## Aleutian Islands  

**We propose a study of climate impact on the local ecosystem of the Aleutian Islands.  **

*Local Scale*

## Unimak Pass flow is driven by along shore wind

## Aleutian Islands Study Participants

**Atka mackerel  (NMFS; L. Fritz)**
**Orca whales (NMML, S. Moore )**
**Steller sea lions (NMML; T. Loughlin)**
**Physical and nutrients (PMEL; P. Stabeno)**
**Primary production, zooplankton and seabirds**

## Kodiak Island

*Local Scale*

_**Kodiak Island**_
-   **We propose a study of climate impact on the local ecosystem around the Kodiak Island.  **

## Kodiak Island Study Participants

**Pollock  (NMFS; A. Hollowed)**
**Steller sea lions (NMML; T. Loughlin)**
**Physical and nutrients (PMEL; P. Stabeno)**
**Primary production and zooplankton will be made nearby as part of GLOBEC.  **

## Integrated Observational Network

**The integrated North Pacific observational grid consists of moored biophysical platforms (triangles) and Argo floats (circles).  Sites to be added by our proposed research (pink) will relate climate change to Steller sea lion ecology.**

## Current Lines of Research (FY00)

- Non-pup counts and pup counts (NMFS, ADFG)
- Food habits, nutrition, energetics, and foraging behavior (NMFS, ADFG, UofA-Sea Grant, NPUMMRC, ASLC, TAMU
- Predation on Stellers- killer whales (NPUMMRC, NMFS)
- Ecosystem change (NMFS, NPUMMRC)
- Disease/health condition/contaminants (NMFS, NPUMMRC, ADFG, ASLC)

## Current Lines of Research (FY00)-cont.

- Satellite tagging/other tagging (NMFS, ADFG, NPUMMRC, ASLC)
- Remote sensing (NMFS, UofA,NPUMMRC)
- Pup branding and tagging (NMFS, ADFG)
- Competition with Fisheries (NMFS, NPUMMRC)
- Reproduction (ASLC, NMFS)

## Fishery Management under ESA, MSFCMA, and NEPA

- Fishery management measures under the MSFCMA are implemented as amendments to existing Fishery Management Plans (FMP)
- Amendments often necessitate statutory requirements under the ESA (e.g., Biological Opinion) and NEPA (e.g., Environmental Assessment, Environmental Impact Statement)

## Fishery Management under ESA, MSFCMA, and NEPA- cont.

- April 1990, by emergency rule, SSL listed as threatened under the ESA, monitoring of incidental take required, establishment of Recovery Team for SSL
- Jan 1991, seasonal restrictions for pollock required
- June 1991, spatial restrictions for pollock required, prohibition on trawling within 10 nm of 14 rookeries

## Jeopardy- 

- Jeopardy-

## }

- Entanglement in debris
- Subsistence harvest
- Pollution
- Harassment
- Increased predation
- Disease
- Oceanographic changes
- Indirect effects of fisheries

_***CAUSES OF DECLINE***_

- STELLER SEA LION- FISHERY INTERACTIONS SUMMARY

**}**

**}**

- POSSIBLE FACTORS

- LIKELY FACTORS

_***LEGAL CHALLENGES***_

- 8 Aug 2000 – Injunction against all trawling in Critical Habitat
- Remand to prepare comprehensive Biol. Opinion
- Remand to prepare Suppl. Env. Impact Statement
- Programmatic SEIS – due late Jan 2001
- 30 Nov 2000 – BiOp completed; injunction lifted
- Special North Pacific Council meeting in Jan 2001
- Comments from all parties to judge on 2 February 2001

- _ALASKA FISHERIES SCIENCE CENTER – 19 Jan 2001_

**}**

- UNLIKELY
- FACTORS

## Temporal Variability

_**Temporal Variability**_
**Time history of PDO index (below) and associated changes in biological populations (right)**

*Basin Scale*