Management Performance of Ecological Indicators Using Threshold-Based Fishery Control Rules

Thresholds in the response of ecosystem indicators to fishing and environmental drivers have been suggested as reference points for implementing ecosystem based fisheries management, though their efficacy for management largely remains untested. We used an end-to-end ecosystem model for the Northeast US continental shelf marine ecosystem to evaluate the performance of fishery control rules that included empirically defined thresholds in ecological indicators. We tested alternative methods for incorporating these thresholds into fisheries management strategies, and compared the results to those from approaches that did not use ecosystem indicator thresholds. We found that control rules using indicator thresholds were able to perform well against several management objectives in some cases, but that the method for selecting and including thresholds associated with good performance depended on the management objective. The ability to quantify tradeoffs among both economic and ecological management objectives associated with alternative fisheries management strategies enables a broader consideration of the value of ecosystem indicators as management tools. It is suggested that while threshold responses in indicators can be useful for management, in some instances they are difficult to identify and alternative management options may be sufficient to achieve objectives.