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The 2014 ICES ECOKNOWS Symposium

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The International Council for the Exploration of the Sea (ICES) held the  symposium “The Ecological Basis of Risk Analysis for Marine Ecosystems” on 2 – 4 June 2014 in Porvoo, Finland. Other sponsors of the symposium included the North Pacific Marine Science Organization (PICES) and the European Commission’s Community Research and Development Information Service (CORDIS) Seventh Framework Programme (FP7). The symposium was organized in close collaboration with the FP7 ECOKNOWS project ( for improving fisheries science and management by integrating new sources of biological and environmental knowledge with respect to implementing an ecosystem approach to fisheries management.

The goal of the symposium was to review, discuss, and assess methodological approaches, case studies, and outcomes relevant to effective and efficient interdisciplinary marine ecosystems risk analysis, particularly in relation to resource use and risks of overexploitation. By comparing the different scientific fields focusing on marine risks, the symposium explored how science can identify and quantify uncertainty and develop processes that allow better interpretation of uncertainty estimates, leading to management that more effectively and efficiently meets objectives. The themes of the symposium included  fisheries management under uncertainty, decision modeling in fisheries management, probabilistic fish stock assessment, oil spill and eutrophication risk analysis, environmental risk assessment for marine areas, and risk analysis in aquaculture. The keynote speakers included Samu Mäntyniemi (FI), Robert Stephenson (CA), and Tony Smith (AU).

There were several talks which mentioned Bayesian approaches, "data poor" methods, and how to communicate risk and uncertainty to stakeholders. Samu Mäntyniemi (FI) talked about the development of a general population dynamics model and case studies were presented in other talks. Anna Kuparinen (FI) has several recent papers in The ICES Journal of Marine Science on Allee effects and environmental influences on recruitment. There were comments about model averaging and data weighting; Ian Stewart (US) suggested decreasing the importance of model weighting, as picking the "best" model out of a set of models puts all of the weight on one model implicitly. There were also comments about asking stakeholder groups and decision makers about which tables and figures they find useful. John Mumford's (UK) talk dealt specifically with risk, visualization, and communication; he raised the issues of risk assessment vs. risk perception, how risk changes over time (spatial, temporal, cumulative), and how to express and incorporate uncertainty in the management goals and objectives. Diedre Duggan (UK) talked about developing indicators with stakeholders, and combining indicators and signal detection theory into a tool for decision making. Andrew Edwards (CA) talked about Awatea (software developed by Allan Hicks and Ray Hilborn) and its associated R package, PBSawatea. Javier Ruiz (ES) described a model with finer time scales for environmental influences on early life history stages and coarser time scales for the fishery. Finlay Scott (IT) presented a framework, a4a (assessment for all), for “data moderate” stocks which can run several thousand versions of simple stock assessment models incorporating model and biological uncertainty and alternate hypotheses, and referenced Millar et al. 2014 ICES J Mar Sci for model averaging techniques. Sakari Kuikka (FI) commented that there were few papers on Bayesian economic or bio-economic models and that this may be a deficit when moving towards ecosystem-based fisheries management or integrative modeling and management.

AFSC scientist Teresa A’mar attended the symposium, along with Wesley Patrick (NOAA Fisheries, Office of Sustainable Fisheries), Ian Stewart (International Pacific Halibut Commission), and more than 70 other researchers, primarily from Europe and Canada. In the “Fisheries management under uncertainty” session, Teresa presented the results of the study “The impact of changes in natural mortality on the performance of management strategies for the Gulf of Alaska walleye pollock (Gadus chalcogrammus) fishery”, which she co-authored with the stock assessment author Martin Dorn. Management strategy evaluation was used to examine the impact of changes over time in natural mortality on the performance of the current management strategy for the Gulf of Alaska walleye pollock fishery. Changes and trends in natural mortality-at-age are a proxy for changes in predation impacts. While the biomass of several walleye pollock predators has been stable or decreasing since the 1970s, arrowtooth flounder biomass has increased significantly. Arrowtooth flounder predation on walleye pollock is predominantly on smaller fish, thus impacting recruitment. The current management strategy was evaluated under several scenarios of changes over time in natural mortality-at-age for young fish. The results suggest that stock size and the associated acceptable biological catch (ABC) may be positively biased (i.e., overestimated) if the true natural mortality-at-age for young fish differs appreciably from the values assumed in the current management strategy.

Select symposium papers will be published in The ICES Journal of Marine Science within approximately 18 months after the symposium.

By Teresa A’mar


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