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Using a management strategy evaluation approach, we compare a range of new and established management procedures (MPs) for setting catch-limits in fisheries. Performance is evaluated with respect to fish life history type, level of stock depletion, data quality, and autocorrelation in recruitment strength. We quantify the robustness of each MP with respect to the various observation processes. Methods using observations of absolute biomass or stock depletion offer the best overall performance and this is consistent across life history types, data qualities, and stock depletion levels. Simple MPs can outperform conventional data-limited methods and data-rich assessments that use time-series of catch and effort data. MP performance is most sensitive to biases in catch data. Our results indicate that often tuning MPs for specific stocks is important, though this may not be viable in data-poor assessment scenarios because of insufficient data and analysis resources. [ABSTRACT FROM AUTHOR]

Robert, M., Faraj, A., McAllister, M. K., and Rivot, E. 2010. Bayesian state-space modelling of the De Lury depletion model: strengths and limitations of the method, and application to the Moroccan octopus fishery. – ICES Journal of Marine Science, 67: 1272–1290.The strengths and limitations of a Bayesian state-space modelling framework are investigated for a De Lury depletion model that accommodates two recruitment pulses per year. The framework was applied to the Moroccan fishery for common octopus (Octopus vulgaris) between 1982 and 2002. To allow identifiability, natural mortality (M) and the recruitment rhythm were fixed, and the variance of both process and observation errors were assumed to be equal. A simulation–estimation (SE) approach was derived to test the performance of the method. If the data showed responses to harvest, the estimates of the most important figures, i.e. the initial abundance and the second recruitment pulse, were accurate, with relatively small bias. Results confirm that greater depletion yields smaller bias and uncertainty and that inferences are sensitive to the mis-specification of M. The 21 depletion series in the Moroccan dataset were jointly treated in a hierarchical model including random walk to capture the systematic fluctuations in estimates of catchability and initial abundance. The model provides estimates of the annual recruitment and monthly octopus population size. The recruitment estimates could be used to investigate the link between recruitment variability and the coastal North African upwelling regime to improve understanding of the dynamics and management of octopus stocks. [ABSTRACT FROM PUBLISHER]

Clarke, S. C., McAllister, M. K., and Kirkpatrick, R. C. 2009. Estimating legal and illegal catches of Russian sockeye salmon from trade and market data. – ICES Journal of Marine Science, 66: 532–545.To address concerns about the conservation of Russian sockeye salmon (Oncorhynchus nerka) in the face of potentially large-scale illegal, unreported, and unregulated (IUU) fishing activities, we estimated the quantities of sockeye caught in eastern Russia based on trade data from Japan, China, and Korea. In addition to being a fishery-independent estimate, our approach avoids reliance on Russian customs documentation that may not capture quantities of fish transhipped at sea. Using a Bayesian statistical model, we estimate quantities imported and traded in municipal markets as two separate estimates of the actual Russian sockeye catch. To estimate the “excess” catch deriving from IUU fishing operations, these trade-based estimates of catch are compared with official Russian catch figures. The results support (posterior probabilities 0.72 to >0.99) the hypothesis that there are substantial quantities of excess catch of Russian sockeye making their way to East Asian markets. In the years 2003–2005, the median quantities of annual excess catch were estimated to range from 8000 to 15 000 t, representing a value of US$40–74 million and demonstrating that actual catches are 60–90% above reported levels. [ABSTRACT FROM PUBLISHER]

Although much work has been done developing system-level indicators for ecosystem-based fishery management (EBFM), few of those proposed include a spatial component. Even in single-species management, time and area closures have been applied without a clear understanding of what their effect might be on identifying overfishing thresholds and other reference points. For EBFM, spatial zoning of the marine environment, including no-take marine reserves and areas where destructive fishing gears are prohibited, may become a prime management tool. Therefore, indicators of the effectiveness of spatial management will be required, along with an understanding of how indicators related to other objectives will be influenced. We review single-species models that have been used to model spatial zoning, including potential bias in assessment and current work on effort reallocation after area closure, as well as available ecosystem-based models and metrics and how they might account for spatial management. Metrics that can be derived from explicitly spatial approaches such as GIS-based ecosystem and fishery evaluations are also discussed. [Copyright &y& Elsevier]