The importance of environmental factors in the design of management procedures

The effects on recruitment of environmental factors such as temperature have been studied for decades. Correlations between environmental and biological indices have arisen, but have then broken down. In some cases, mechanisms that explain a strong correlation have been identified and management procedures to account for them have been developed. There are more such examples in crustacean and pelagic fisheries than in demersal fisheries. In this study, a Monte Carlo simulation approach to explore the implications of ignoring the effect of environmental Factors on recruitment and on setting fishing mortality reference points is described. A gadoid-like example, with three levels of strength of interaction between the environmental factor and recruitment, is considered. In these examples, there is no gain (in terms of either conservation or average yield) when an environmental factor is incorporated in the short-term prediction of recruitment. Changes in fishing mortality reference points only lead to gains when the environmental factor can be well predicted. The importance of simulation studies in exploring the likely benefits and feasibility of incorporating environmental factors in management procedures is emphasized.