Resource Ecology & Ecosystem Modeling (REEM) Program
Fish Stomach Collection and Lab Analysis
Laboratory analysis was performed on 2,470 groundfish stomachs from the eastern Bering Sea and on 386 groundfish stomachs from the Gulf of Alaska. A total of 2,265 Bering Sea samples and 69 Gulf of Alaska samples were collected by fisheries observers; 9,666 records were added to the groundfish food habits database.
By Troy Buckley, Geoff Lang, and Mei-Sun Yang
Multispecies and Ecosystem Modeling
Dr. Ivonne Ortiz successfully defended her University of Washington doctoral dissertation entitled “Ecosystem Dynamics of the Aleutian Islands.” This work combines substantial historical information of human interactions with the Aleutian Islands ecosystem with ecosystem-level and fine-scale modeling of ecosystem processes in the fisheries management region, building towards the development of a fisheries ecosystem plan (FEP).
The work completes a “three region” comparative picture of the food webs of the Bering Sea, Gulf of Alaska, and Aleutian Islands ecosystems which has been developed by the Resource Ecology & Ecosystem Modeling (REEM) Program over the last several years.
Figure 1. Relative total consumption of major prey types in three Alaskan marine ecosystems. From left to right: Aleutian Islands (AI), eastern Bering Sea (EBS), and Gulf of Alaska (GOA).
The completion of this work will allow the comparison of processes between ecosystems (Fig. 1 above) as well as allowing detailed examination of processes occurring within the Aleutian Islands archipelago (see Fig. 2).
By Ivonne Ortiz and Kerim Aydin
Ecosystem Assessment
REEM scientists participated in a multi-agency collaboration to compile, edit, and present a working draft Aleutian Islands Fishery Ecosystem Plan (FEP) (http://www.fakr.noaa.gov/npfmc/current_issues/ecosystem/AIEFP307.pdf) to the North Pacific Fishery Management Council (NPFMC) at its February and March/April 2007 meetings.
The full Aleutian Islands FEP team includes participants from the AFSC’s Status of Stocks & Multispecies Assessment (SSMA) Program, the NMFS Alaska Regional Office, NOAA’s Pacific Marine Environmental Lab, the Alaska Department of Fish and Game (ADF&G), the U.S. Fish and Wildlife Service, the North Pacific Research Board (NPRB), and NPFMC staff. In addition, the dissertation research by Dr. Ivonne Ortiz on spatial food webs in the Aleutian Islands played a central role in FEP development.
The draft Aleutian Islands FEP describes the ecosystem in terms of historical, physical, biological, socio-economic, and management relationships, and uses the description of these relationships to identify key interactions in the ecosystem. Examples include the interaction of water temperature with biological processes, the interaction of fisheries with predator-prey relationships, and the interaction of international shipping with local ecology. For each interaction, a set of ecosystem indicators was identified to evaluate whether the interaction was changing relative to our current knowledge of the ecosystem.
Some ecosystem indicators already exist for the Aleutian Islands, but others identified by the team still need to be developed. The FEP team evaluated the relative probability of each interaction occurring and what type of ecological and economic impacts might arise from each interaction within a qualitative risk assessment framework.
The results of this exercise are currently being refined by the FEP team so that interactions identified as both high probability and high risk can be brought to the attention of the Council to provide context for their fishery management decision making process. The team envisions that ecosystem indicators developed for the Aleutian Islands might be incorporated within the Ecosystem Considerations section of the Stock Assessment and Fishery Evaluation (SAFE) report to be annually reviewed by the Council.
At present, the team is working to provide advice to the Council on how to incorporate the ecosystem level advice compiled in the FEP within fishery management in the Aleutian Islands. The Council is scheduled to review a complete document at its June 2007 meeting.
