Mercury in Cobia from Estuarine and Offshore Waters of the Southeastern United States: Fisheries Implications

Abstract

AbstractIn marine ecosystems, upper‐trophic‐level pelagic fish often contain high concentrations of mercury. Individuals of several frequently landed marine fish species bioaccumulate mercury at concentrations linked directly to effects on fish physiology and human health risks. Knowledge of mercury in Cobias Rachycentron canadum has been limited. With this study, I addressed that problem by providing a comprehensive assessment of mercury in muscle taken from Cobia specimens within a range of size‐ and age‐classes representative of those targeted by the recreational and commercial fisheries operating in the southeastern United States (Atlantic Ocean and eastern Gulf of Mexico). Total mercury concentration (THg) in muscle ranged from 0.025 to 3.9 mg/kg (wet weight), with a mean of 0.743 mg/kg (SD = 0.609). In approximately 95% of all legal‐size Cobias (≥838.2 mm FL), THg exceeded 0.3 mg/kg (i.e., the U.S. Environmental Protection Agency's human health screening value for mercury). Proposed and recent increases in size limits for Cobias in some waters of the southeastern United States would further increase this percentage. The present results for Cobias from the western Atlantic and Gulf of Mexico further substantiate current fish consumption advisories and provide guidance for new or revised advisories in other regions.