Incorporating Ecosystem Dynamics in Fishery Stock Assessments and Management: Case Studies from the North Pacific Fishery Management Council

With the acceptance the ecosystem based fishery management (EBFM) approach, stock assessment scientists are exploring techniques to incorporate ecosystem dynamics into their models to address both tactical and strategic management issues.  Tactical issues facing assessment scientists responsible for advising the North Pacific Fisheries Management Council (NPFMC) include the evaluation of environmental impacts on: vital rates (reproductive potential, natural mortality and growth); fishery or survey catchabilty or selectivity; incidental catch; and temporal periods of stock productivity used to set time frames for setting biological reference points.  Strategic issues facing the NPFMC include estimation of single species and multi-species harvest control rules as strategies for managing multi-species technical interactions. To address both tactical and strategic issues, analysts commonly simulate the implications of alternative management strategies within a management strategy evaluation framework.  To prepare for the implications of climate change, scientists have formed an interdisciplinary research team to develop multi-model projection scenarios necessary to understand the dual impacts of fishing and climate change on marine ecosystems. This talk will review case studies of each of the approaches noted above as well as the challenges and key research needed to address the EBFM.