Retrospective Analyses of Commercial Trip Limit Efficacy in the Southeastern USA

Abstract

Trip limits are frequently used as a management measure to control or reduce harvest by restricting harvest to a maximum amount. The goal of trip limits is often to lengthen the fishing season relative to the annual catch limit by slowing the landings rate or incentivizing fishers to target another species. Two recent commercial trip limits implemented in the southeastern USA were examined to determine the accuracy of the predicted changes in harvest. For South Atlantic Snowy Grouper Hyporthodus niveatus, analysts accurately predicted the change in landings (weight) that could be expected per trip in response to a trip limit increase but did not account for an increased number of trips early in the fishing season. An increased number of trips resulted in higher landings causing Snowy Grouper to reach the quota and close earlier than desired. For Gulf of Mexico Gray Triggerfish Balistes capriscus, analysts underestimated the predicted change in landings per trip that could be realized from implementing a trip limit (numbers of fish). The Gray Triggerfish analysis failed to account for fishers retaining larger individual fish on average after the trip limit was implemented, resulting in higher landings than predicted. When examining per-fish trip limits, it is recommended that other potential changes in fishing behavior, such as changes in the mean weight of fish being retained or increased effort, be considered. The results of this study could be used to improve the effectiveness of trip limits as a management tool.