Can bycatch in a flatfish gillnet fishery be reduced with rectangular mesh?

Abstract

Gillnets fished in North Carolina, USA, estuaries have high rates of bycatch relative to the target catch of southern flounder, Paralichthys lethostigma Jordan & Gilbert. This study tested whether rectangular-mesh gillnets would maintain catch rates of southern flounder and reduce fish bycatch relative to conventional diamond-mesh gillnets in two North Carolina estuaries. In the Neuse River estuary, catch rates of legal southern flounder were not different between the two mesh shapes, but the bycatch of red drum, Sciaenops ocellatus (Linnaeus) and other fish species was reduced with rectangular-mesh net. In the Newport River estuary, southern flounder and red drum catches were reduced in rectangular-mesh net, but the decrease was greater for red drum. Catches of sublegal southern flounder were reduced in the rectangular-mesh net in both estuaries. Reduced catch rates of sublegal southern flounder and bycatch species suggest rectangular mesh may help manage stocks of estuarine fish species in areas where gillnets are used to target flatfishes.