Maximum Sustainable Yield and Bycatch Minimization “to the Extent Practicable”

Two goals of marine fisheries management in the USA are (1) to achieve maximum sustainable yield (MSY) and (2) to minimize bycatch “to the extent practicable.” However, the determination of MSY is contingent on the selectivity of the various fisheries involved and the mix of these fisheries that managers desire. I compare several methods of computing MSY and associated parameters that involve alternative assumptions about the balance between target and bycatch fisheries. These methods were evaluated using a deterministic population simulation model. Additionally, biological risk was evaluated by computing relative spawning levels in the presence and absence of bycatch. While the choice of the method will largely be driven by socioeconomic factors, some implications for management are discussed. Before analysts can calculate MSY and associated parameters, managers must determine their desired mix of fishing and the definition of “to the extent practicable.”