SPAWNING OF ATLANTIC-COD (GADUS-MORHUA) IN THE NORTHERN GULF-OF-ST-LAWRENCE - A STUDY OF ADULT AND EGG DISTRIBUTIONS AND CHARACTERISTICS

From 1993 to 1995, Atlantic cod (Gadus morhua) egg abundance and distr ibution, fisheries acoustic surveys, and analysis of trawl catches pro vided evidence of spawning for the northern Gulf of St. Lawrence cod s tock at the same location off Newfoundland's west coast. From the rela tive 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 pr espawning migration from Cabot Strait. Larger cod started to spawn ear lier 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 wer e distributed throughout the water column but higher concentrations we re observed within the cold (<0 degrees 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 eff ect on egg development and survival.