Analysis of American Plaice, Cod and Yellowtail Flounder Catches in Research Vessel Surveys on the Tail of the Grand Bank, 1971-89

Abstract

Catches of American plaice (Hippoglossoides platessoides), yellowtail flounder (Limanda ferruginea) and cod (Gadus morhua) were examined from stratified-random research vessel surveys on the Tail of the Grand Bank from 1971 to 1989 to determine the relative proportion of these species present within and outside the Canadian 200-mile fishing boundary. For American plaice and yellowtail flounder, the relative abundance on either side of the 200-mile boundary changed as commercial catches increased outside 200 miles in the mid-1980s. For cod, the relative changes in abundance coincided with the declaration of the 200-mile boundary in 1977 and the subsequent restrictions placed on non-Canadian fisheries. Line transect surveys designed to further examine the spatial distribution of these species were conducted in 1986 and 1987. Larger catches were noted of all three species in most areas inside the 200-mile boundary compared to areas outside 200 miles. Comparison of these results with those from the stratified-random surveys indicated that these proportions of relative abundance were not always present.