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Robustness of both short-term stock biomass recovery and longer-term sustainable management strategies to different plausible climatic change scenarios were evaluated for North Sea cod (Gadus morhua), where climate was assumed to impact growth and recruitment. In the short term, climate change had little effect on stock recovery, which depends instead upon reducing fishing effort to allow existing year classes to survive to maturity. In the longer term, climate change has greater effects on stock status, but higher yields and biomass can be expected if fishing mortality is reduced. Incorporating environmental covariates in stock assessment predictions will not achieve sustainable resource use. The implications of climate change for biological reference points depend upon the mechanism through which temperature acts on recruitment, i.e. on juvenile survival or carrying capacity. It is not possible to distinguish between these processes with stock assessment data sets alone. However, this study indicates that reference points based on fishing mortality appear more robust to uncertainty than those based on biomass. Ideally, simpler management procedures are required that meet pre-agreed management objectives and are robust to uncertainty about the true dynamics. [Copyright &y& Elsevier]

The bluefish Pomatomus saltatrix and the striped weakfish Cynoscion guatucupa are two of the most important commercially exploited species in southern Brazil. These species overlap spatially and temporally in southern Brazil and are exploited by a multi-purpose fleet. We analyse the consequences of different management options in terms of the bio-economy of the gillnet and purse-seine fisheries by considering P. saltatrix and C. guatucupa as the main targets. Development of the bio-economic model was based upon multi-fleet, single species models for P. saltatrix and C. guatucupa. The results are compared at the medium-term forecast level from stochastic simulations, and the technical interactions between the fleets that exploit the bluefish and striped weakfish are also addressed. The purse-seine fishery has a strong impact on the gillnet fishery. A management plan, which allocates moderate levels of effort for all co-existing fleets and interacting species, seems efficient, but effort should be controlled for P. saltatrix (for both fleets) and, for the gillnet fleet, relatively more trips should be allocated for C. guatucupa. For P. saltatrix, the best management relies upon the scenarios harvesting the oldest individuals. [Copyright &y& Elsevier]

Herring caught in the Thames Estuary sustain a small local commercial fishery (peak catch of 606 t during the 1972–1973 fishing season). Loss of local consumers'' interest in the herring product has resulted in a gradual decline in catches and fishing effort for the stock. The stock is assessed using an age-structured model that relies on the information provided by a scientific trawl survey, and management advice is provided before the fishing season starts in October. Given its current low economic value, managers have requested evaluation of options for multi-annual Total Allowable Catches (TACs) in an attempt to reduce the frequency (and costs) of assessment and associated management advice. A tentative relationship between sea surface temperature and recruitment is used to predict the impact of increasing sea temperatures on future recruitment in the context of global warming. Hypotheses of auto-correlation and of an environmental effect on recruitment, together with trends in weight-at-age and the overestimation of spawning-stock biomass, form the basis for sensitivity tests of the management options considered. Implementation of a 3-year fixed TAC with 40% constraint in TAC variability and a slight reduction in target F would seem appropriate for the stock, given that it is within safe biological limits and compares well in terms of yield and risk with the current approach of annual TAC revision. [Copyright &y& Elsevier]