Spawning of Atlantic cod ( Gadus morhua ) in the northern Gulf of St. Lawrence: a study of adult and egg distributions and characteristics

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Ouellet, P, Lambert, Y, Castonguay, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1997
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Cabot; atlantic cod; Gadus morhua
• Online Access: http://dx.doi.org/10.1139/f96-259; http://www.nrcresearchpress.com/doi/pdf/10.1139/f96-259

From 1993 to 1995, Atlantic cod (Gadus morhua) egg abundance and distribution, fisheries acoustic surveys, and analysis of trawl catches provided evidence of spawning for the northern Gulf of St. Lawrence cod stock at the same location off Newfoundland's west coast. From the relative proportion of spent fish and various developmental stages of cod eggs, spawning could not have started before the end of March or early April. Spawning started while cod were in dense shoals following a prespawning migration from Cabot Strait. Larger cod started to spawn earlier than smaller cod. In May 1994, cod dispersed soon after spawning began, and most of the spawning activity probably occurred as the fish migrated and scattered within the northern Gulf. Stage I cod eggs were distributed throughout the water column but higher concentrations were observed within the cold (<0°C) layer of the Gulf each year. We propose that water temperature could have a dominant influence on determination of year-class strength in the northern Gulf via its effect on egg development and survival.