Characterization of King Mackerel and Spanish Mackerel Bycatches of South Carolina Shrimp Trawlers

Abstract

Abstract Juvenile king mackerel Scomberomorus cavalla and Spanish mackerel S. maculatus are caught by commercial shrimp trawlers in South Carolina. Our study documented the extent and duration of this bycatch during the commercial shrimp trawling season in South Carolina waters. Sampling was conducted onboard commercial shrimp vessels based in McClellanville, South Carolina, during 1991 and on vessels based in McClellanville, Charleston, and Beaufort in 1992. Eight vessels and 137 trawl tows (mean tow duration, 2.88 h) were sampled; 81 king and 257 Spanish mackerel were collected. The mean annual sample catch per unit effort (CPUE) of king mackerel was 0.244 fish/h; adjusted for trawl footrope length in meters, the mean annual total CPUE was 0.038 fish/(h·m). King mackerel were found in only 21% of the tow samples, and peak catches occurred in October 1991 and September 1992. The mean annual sample CPUE for Spanish mackerel was 0.701 fish/h, and the mean annual total CPUE was 0.109 fish/(h·m). Spanish mac...