link to AFSC home page

link to AFSC home page link to NMFS home page link to NOAA home page

Resource Ecology & Fisheries Management (REFM) Division

AFSC Quarterly
Research Reports
Apr-May-June 2010
ABL Reports
FMA Reports
NMML Reports
RACE Reports
REFM Reports
All Reports (.pdf)
Quarterly Index
Quarterly Home

Status of Stocks & Multispecies Assessment

ICES, PICES, and FAO International Symposium  (abstracts)

  • Scenario-based Models for Predicting Stakeholder Responses to a Changing Climate: A Case Study for the Eastern Bering Sea
    Anne B. Hollowed1, Nicholas A. Bond2, Alan Haynie1, James N. Ianelli1 and Franz J. Mueter3;
    1 AFSC, Seattle, WA; 2 University of Washington, Joint Institute for the Study of Atmosphere and Ocean, Seattle, WA; 3 University of Alaska, School of Fisheries and Ocean Sciences, Juneau, AK

    The North Pacific Research Board and the National Science Foundation are funding a large interdisciplinary research program to provide forecasts of the impacts of climate change on the eastern Bering Sea ecosystem. These forecasts require scenarios of future stakeholder engagement and decision rules to simulate how stakeholders will respond to a changing environment. A retrospective analysis is conducted to explore how fishers and policy makers shifted their strategies in response to past changes in climate and societal pressures. Three factors emerged as the key drivers influencing stakeholders and managers: changes in socioeconomic conditions, changes in fisheries management, and changes in scientific understanding. Stakeholder decision rules are developed to predict responses to legal or economic constraints governing commercial fishing in the region. Ecosystem scenarios are derived by statistical downscaling climate/ocean forcing for the region from Intergovernmental Panel on Climate Change (IPCC) model output. The scenarios of stakeholder responses are developed for the following stressors: a) changes in the demand for seafood, b) increasing fuel prices, and c) resource partitioning due to species interactions, fisheries interactions, or Marine Spatial Planning. Scenarios of shifting ecosystem conditions will include: a) shifting zoogeographic boundaries due to climate change, and b) shifting reproductive potential due to changing climate. The trade-offs and risks associated with each stakeholder scenario are discussed. The decision rule approach provides a foundation for communicating with stakeholders and attempts to initiate discussions of more complex adaptive and holistic management and modeling approaches.

  • The Challenges of Developing Fisheries Stock Assessment Approaches, Harvest Control Rules, and Management Strategies to Satisfy and Adapt to Increasingly Complex Management Objectives in a Changing Environment
    James N. Ianelli; AFSC, Seattle, WA

    The task of applying the best available information for fisheries management advice is growing rapidly as the number of stocks or stock components considered increases. Stock assessments are highly uncertain; adding links through consumption observations and environmental parameters generally inflates the uncertainty on stock dynamics. From the fisheries harvest side, transparency of activities is generally better, but there remain serious information gaps for managers (e.g., lack of observer data, information on costs, fishery responses to different types of regulations, etc.). Adding nonstationary dynamics to both of these sets of processes (at the ecosystem and fisheries management levels) further complicates predictions beyond near-term trends. Forecast methods exist that distill complex adaptations and interactions and perform well in predictive tests. However, these methods generally ignore processes typical in annual fisheries decision making including how broad-reaching management systems respond to new information. In this paper, we propose a fisheries management scenario where routine assessments are tested periodically for productivity changes that may affect estimated stock "target" levels. This provides a way for managers to evaluate the consequences of applying periodic adjustments to such reference points. We contrast this with typical stock assessment models (which use up-to-date "best available" data) linked to management control rules (for setting quotas) that are revised periodically based on extensive management strategy evaluations that typically ignore productivity changes.

  • Incorporating Climate Variability Into the Assessment of Gulf of Alaska Pacific Cod
    Z. Teresa A’mar1, André E. Punt2 and Grant G. Thompson11AFSC, Seattle, WA, 2University of Washington, School of Aquatic and Fishery Sciences, Seattle, WA

    The exploration of the relationships between environmental forcing and recruitment and representing them within an operating model is a key component in the development of a management strategy evaluation framework which incorporates climate variability. The management strategy for the fishery for Pacific cod, Gadus macrocephalus, in the Gulf of Alaska (GOA) consists of an age-structured stock assessment model and a harvest control rule. The relationships between age-0 abundance and climate indices and the uncertainty associated with these relationships were characterized within a statistical catch-at-age population dynamics operating model similar in structure to the stock assessment model for GOA Pacific cod. The operating model incorporated region-specific historical climate indices and was fitted to the data used for the stock assessment for GOA Pacific cod. The results from the operating model were compared with those from the 2009 stock assessment with respect to recruitment, stock status, and management measures. This comparison allowed for quantifying how the inclusion of climate data affected estimation precision, error, and bias.

By Anne Hollowed

<<< previous

next >>>

            Home | FOIA | Privacy | | Accessibility      doc logo