Seasonal Movement Patterns of Cobia in the Western Gulf of Mexico

Cobia (Rachycentron canadum) is a coastal migratory pelagic species that supports a popular recreational fishery (>90% of landings) but is also captured in commercial fisheries and as bycatch in shrimp fisheries along the U.S. Atlantic coast and throughout the Gulf of Mexico (Gulf; SEDAR 2013). Cobia are managed as separate Atlantic and Gulf migratory stocks by the Atlantic States Marine Fisheries Commission and the Gulf of Mexico Fishery Management Council.

Despite the species’ popularity as a sportfish, few stock assessments have been conducted, and only recently has cobia been assessed through the Southeast Data, Assessment, and Review (SEDAR) process. The most recent assessment for cobia in the Gulf migratory group was conducted in 2012 (SEDAR 28). Although this assessment did not suggest overfished status or that overfishing was occurring, confidence in the assessment was low, and management advice was greatly hindered by severe data gaps (SEDAR 2013). In particular, deficiencies regarding stock structure, life history, movement patterns, and post-release survival contributed toward high uncertainty in the stock assessment. For example, the southern boundary of the Gulf stock, particularly with respect to Mexico and Texas waters, is unknown (SEDAR 2018).

Recreational guides and private anglers fishing for Gulf cobia have sent clear messages through public testimony in recent Gulf Council meetings expressing dire concerns about the condition of the stock. The Gulf Council has been proactive in addressing these concerns, with an increased minimum size limit recently implemented (GMFMC 2019). This precautionary measure will likely benefit the stock; however, there remains a substantial need to better understand the stock structure and how seasonal movements may influence how fishing effort and mortality are distributed, which is critical to inform future management.

Marine scientists and researchers from the Center for Sportfish Science and Conservation will use tracking data from satellite- and acoustically-tagged cobia to meet the specific objectives of this project:

1. Examine seasonal movement patterns of cobia and evaluate the degree of mixing between sub-regions in the Gulf of Mexico.
2. Examine fine-scale coastal movement, site fidelity, and habitat use patterns of cobia along the Texas Coast.

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GMFMC. 2019. Framework Amendment 7 to the Fishery Management Plan for Coastal Migratory Pelagic Resources in the Gulf of Mexico and Atlantic Region – Modifications to Gulf of Mexico migratory group cobia size and possession limits. GMFMC, Tampa, FL.

SEDAR. 2013. SEDAR 28 – Gulf of Mexico Cobia Stock Assessment Report. SEDAR, North Charleston, SC.

SEDAR. 2018. SEDAR 58 – Cobia Stock ID Process Report Compilation. SEDAR, North Charleston, SC.