Reduction of Atlantic Salmon (Salmo salar) Catches in Canada Attributed to the Greenland Fishery

Abstract

Recaptures of Atlantic salmon (Salmo salar) tagged as smolts show that substantial numbers of those produced in the Maritimes are caught in Greenland waters. Percentage recoveries in the home-river system show a significant inverse correlation with levels of catches in Greenland. Analyses of detailed data collected since 1950 indicate that the Greenland fishery has caused serious reduction of Miramichi stocks of 2-sea-winter salmon and will affect the future long-term production of Atlantic salmon in Canada.Total landings have risen higher per million smolts produced in the Miramichi system since the Greenland fishery began. The escapement from fisheries and the potential spawning stock per given numbers of smolts has dropped correspondingly. Lowered escapement has been followed by lowered abundance of progeny as reflected by density of young in nursery stream areas. Significantly, recruitment as measured in numbers of underyearlings depends more crucially on numbers of salmon escaping the fishery than on numbers of grilse. As shown by this statistical analysis, the Greenland fishery has had a direct adverse effect on the numbers of salmon surviving to enter their spawning river. Consequently, the abundant smolt runs in 1964, 1965, and 1968 produced by good escapement some 4 yr earlier failed to maintain adequate levels of recruitment and have instead been followed by all-time low commercial catches and recruitment of young in rivers.