Scenario Barents Sea: A tool for evaluating fisheries management regimes

The issues of scenario modelling in general are discussed. A scenario model for the Barents Sea fisheries is presented, with VPA based management for cod and herring, and capelin management based on the CapTool procedure.

Probing scenarios are used to investigate specific questions, and simulations describing selected issues connected to the management procedures are presented.

Uncertainty scenarios are used to evaluate one management procedure, or to compare several, and issues of robustness and efficiency are central to the analysis of simulation results. An uncertainty experiment, with scenarios chosen purely for demonstration, is simulated, and the main results are presented. With mean yearly catches as the only response, the best management strategy is found to be a combination of F high for cod, a spawning target of 500 000 tonnes for capelin, and a constant nominal fishing mortality rate of F=0.20 for herring. When considering biomass variables as additional performance measures, it is found that the 500 000 tonnes spawning target still is the best for capelin, but the cod procedure should rather be F med than F high and the herring procedure should be the yield-per-recruit based strategy F 0.3.