Relative Efficiency of two Bottom Trawls in Catching Juvenile and Commercial-sized Flatfishes in the Gulf of St. Lawrence

The relative efficiencies of a No. 36 Yankee shrimp trawl and a No. 41.5 Yankee otter trawl in catching three species of flatfishes (witch flounder, American plaice and Greenland halibut) were compared from data collected during research-vessel surveys of the northeastern Gulf of St. Lawrence. The shrimp trawl outfished the otter trawl in catching juveniles «30 ern) of the three species, the greatest differences being for witch flounder and American plaice. The performance of the shrimp trawl, without and with a tickler chain attached to the footrope, in catching juvenile and commercial-sized (~30 ern) flatfishes was evaluated from a series of replicate tows. Marked increases in the catches of juveniles were observed for witch flounder and American plaice but not for Greenland halibut with the use of a tickler chain.