Estimation of marine exploitation rates on Atlantic salmon (Salmo salar L.) stocks in Newfoundland, Canada

Marine exploitation rates were estimated For nine Newfoundland Atlantic sal mon (Salmo salar L.) populations, separately For small and large salmon siz e components. Estimates were derived using counts of salmon returning to fi sh counting facilities rather than from tagging studies and thus adjustment s were not required to account for tag loss. handling or tagging mortality, or tag reporting rates. For all stocks combined, the overall marine exploi tation rate during the period 1984-1991 averaged 45.3%(29.6-57.1%) on small salmon and 74.2%(57.7-83.7%) on large salmon. These estimates are consider ed minimum values. Concerns related to declining salmon abundance resulted in the closure of the Newfoundland commercial salmon fishery in 1992. Resul ts are discussed in relation to previous estimates derived from tagging, an d highlight the importance of accounting for marine exploitation when exami ning trends in salmon survival and return data even when commercial fisheri es have been closed.