Biological characteristics of a resident population of Atlantic cod (Gadus morhua L.) in southern Labrador

• Published in: ICES Journal of Marine Science
• Main Authors: Morris, Corey J., Green, John M.
• Format: Text
• Language: English
• Published: Oxford University Press 2002
• Subjects: Regular Articles; Newfoundland; Gilbert Bay; atlantic cod; Gadus morhua
• Online Access: http://icesjms.oxfordjournals.org/cgi/content/short/59/4/666; https://doi.org/10.1006/jmsc.2002.1228

The growth, length at age, time of spawning, food, and movements of the genetically distinct, resident northern Atlantic cod ( Gadus morhua L.) in Gilbert Bay, Labrador, were studied over four consecutive years (1998–2001). Angling and plankton nets were used to sample all stages of the life history. During the study, 2453 cod were tagged with Floy t-bar tags, but none were recaptured outside the bay. Length-at-age is smaller than those of other Atlantic cod off Newfoundland and Labrador. Males mature at 31.0–35.5 cm total length (TL) and 4–6 years of age, and females at 31.4–42.1 cm, 4–8 years of age. Spawning starts shortly after ice retreats from the bay, usually in mid-May, and lasts for ∼3 weeks, a much shorter duration than reported for other northern cod. Timing appears critical to the retention of spawning products in the bay. Stomach contents indicated a wide range of benthic prey but that food availability may be low, contributing to the slow growth rate, individual cod targeting a small number of prey types. Gilbert Bay cod could be threatened if they continue to be managed as part of the Newfoundland–Labrador northern cod stock.