Evaluating the effects of angler behavior on the efficacy of harvest regulations in recreational fisheries

A computer-implemented simulation model was modified to compare various regulation schemes and determine how they are affected by angler non-compliance and voluntary catch-and release fishing. Combinations of three creel limits and five length limits were simulated. Scenarios for no regulations and catch-and-release were also simulated. Angler noncompliance varied from 0% to 50% and voluntary release included rates of 20%, 50%, and 80%. Based on catch, harvest, yield, and PSD, the ranking of specific regulations changed little among levels of angler non-compliance and voluntary release. All four decision variables were most influenced by regulations when angler compliance was high and voluntary release was low. Further, for a fishery with a high degree of voluntary release, and relatively high angler compliance, regulations did not produce any discernible benefits in the fishery.

The model was demonstrated with data on a smallmouth bass, Micropterus dolomieu, fishery for the upper and lower James River, Virginia. Simulated regulations were assessed based on adjustments to angler non-compliance, which averaged based on adjustments to angler non-compliance, which averaged 17 percent, and voluntary release, which averaged 90 percent. Model results indicate that more restrictive regulations improved PSD and catch, whereas numerical harvest and yield in weight benefitted from liberal regulations. Variability among the 81 regulations was low, suggesting that voluntary release (90% average) is a dominant control in the James River smallmouth bass fishery. From a management standpoint, these findings also suggest that, where appropriate, management strategies should focus on increasing voluntary release and rely on regulations only in certain fisheries.