Discarding of Commercial Groundfish Species in the Gulf of Maine Shrimp Fishery

Abstract The objective of the research was to quantify discards of American plaice Hippoglossoides platessoides, witch flounder Glyptocephalus cynoglossus, yellowtail flounder Pleuronectes ferrugineus, winter flounder Pleuronectes americanus, goosefish Lophius americanus, silver hake Merluccius bilinearis, and Atlantic cod Gadus morhua in the Gulf of Maine shrimp fishery. Data were obtained from 50 tows made by commercial trawlers fishing in the southwestern Gulf of Maine, Mean discard percentages (100 × fish discarded/fish caught) per tow, on a weight basis, were 93% for silver hake, 81% for American plaice, 76% for witch flounder, 56% for Atlantic cod, 41 % for goosefish, 20% for yellowtail flounder, and 11% for winter flounder. Mean discard percentages per tow on a numerical basis were slightly higher. Neither catch condition nor tow duration affected discard percentage, but discard percentage decreased with increasing depth for American plaice.