Post-release Mortality and Movement Patterns of Cobia in the Gulf of Mexico

The Cobia (Rachycentron canadum) is a highly prized coastal migratory pelagic species supporting popular recreational fisheries along the U.S. Atlantic coast and throughout the Gulf of Mexico (GOM). The most recent stock assessment for the Gulf Stock indicated that overfishing was occurring, and the stock was at risk of becoming overfished in the near future with spawning stock biomass at reduced levels. Confidence in the update assessment remained low and management advice was greatly hindered by severe data gaps that this proposal directly addresses. Deficiencies regarding post-release mortality, life history, and stock structure contributed toward high uncertainty in the stock assessment.

Furthermore, stakeholders fishing for Gulf Cobia have sent clear messages through public testimony in recent years expressing dire concerns about the condition of the stock. The Gulf of Mexico Fishery Management Council (GMFMC) has been proactive in addressing these concerns by increasing the minimum size limit in March 2020 – prior to results from the SEDAR 28 update assessment – and decreasing the daily bag and vessel limits in November 2022. These regulatory actions will likely benefit the stock; however, a better understanding of the post-release fate of fish released in the recreational fishery is critical to inform future management, especially considering regulatory discards will increase with this larger size limit and decreased bag and vessel limits.

Given these data needs, the overarching goal of this project is to estimate the post-release mortality rate of Cobia captured in the GOM recreational fishery while providing key information on stock structure using advanced electronic tagging. To achieve this goal, we will build on our strong preliminary data by using well-established relationships between PIs and anglers to tag 50Cobia with pop-up satellite archival tags (PSATs) aboard multiple vessels across the GOM.

The rationale for this project is that once we estimate the post-release mortality rate of regulatory discards, managers will be better able to predict how the stock will respond to new regulations, reduce uncertainty in the stock assessment, and make more informed decisions regarding the management of Gulf Cobia.