The effect of stock abundance on range contraction of yellowtail flounder ( Pleuronectes ferruginea) on the Grand Bank of Newfoundland in the Northwest Atlantic from 1975 to 1995

Abstract

Research vessel surveys showed that yellowtail flounder ( Pleuronectes ferruginea) on the Grand Bank, off New-foundland in the Northwest Atlantic, declined in abundance between the 1970s and the mid 1990s. The northern limit of distribution decreased substantially in the late 1980s and early 1990s, coincident with large declines in population abundance and a decrease in bottom water temperatures. This range contraction continued into the mid 1990s, despite a stabilization of the population size and a reversal of the cooling trend. In 1995, this species was rarely found on the northern Grand Bank. The area west of the Southeast Shoal on the southern Grand Bank had relatively high densities of yellowtail flounder throughout the period studied. The area occupied by the stock was positively correlated with stock abundance from surveys, but not with bottom temperatures from these same surveys. We conclude that the contraction in the area of distribution for this stock to the preferred habitat around the Southeast Shoal is primarily a function of low stock size, which resulted from increased fishing activity in the mid to late 1980s.