Stock Effect of Bio-Economic Indicators in an Over- exploited Fishery of the Gulf of Mexico

The main bio-economic indicators of a pelagic fishery of the Northern Gulf of México (the Gulf Menhaden Brevoortia patronus Goode), was examined to understand their 8 performance as a result of simulated trials of the age of first catch and the fishing mortality. First, the validity of simulation was tested rebuilding numerically the performance of biological data and catch over time. A simple approach was made assigning economic value to the catch per-kg and the cost of fishing, so the output of biological variables could be linked to their corresponding economic performance, under the dynamics of the exploited stock, before adding value to the catch. As a part of results, the historical trend of a declining yield, suggests that the fishery has been over exploiting the juveniles, and even tough this condition has been sustained for more than forty years, this process produces nearly 400 thousand t, while it could yield more than one million t if it exploits only adult fish. On testing the economic indicators of the stock response as effect of the age of first catch, it is evident that the current yield is well below the Maximum Sustainable Yield, which might be higher if only adult fish are the targets of the fishery. The same occurs with the Maximum Economic Yield. The Benefit/Cost displays an inverse relationship with the Cost per t. It was found that the fishery could profit more than three hundred million USD if the age of first catch is re-addressed to get only adults as fisheries target. It is clear that this approach could be adopted as useful tool for decision-making and fisheries management.