Natural mortality of cod (Gadus morhua) in the Southern Gulf of St Lawrence

• Published in: ICES Journal of Marine Science
• Main Author: Sinclair, A. F.
• Format: Text
• Language: English
• Published: Oxford University Press 2001
• Subjects: Regular Articles; Gadus morhua
• Online Access: http://icesjms.oxfordjournals.org/cgi/content/short/58/1/1; https://doi.org/10.1006/jmsc.1999.0490

The closure of the cod fishery in Canada's southern Gulf of St Lawrence, and the existence of a reliable research vessel (RV) survey of the stock, has provided a unique opportunity to directly estimate the instantaneous rate of natural mortality (M) of a commercial cod stock. The results indicate that M is currently in the range of 0.4, which is higher than the value of 0.2 assumed in the past. An M of 0.4 is not inconsistent with the observed age range of cod in commercial catches and with recent growth characteristics of the stock. There is evidence that M may have increased in the early 1980s.