CONDITION AND ENERGY RESERVES OF ATLANTIC COD (GADUS-MORHUA) DURING THE COLLAPSE OF THE NORTHERN GULF OF ST. LAWRENCE STOCK

Interannual variations and seasonal cycles in condition and energy res erves were investigated for the northern Gulf of St. Lawrence cod (Gad us morhua) before and during the collapse of the stock. Significant de creases in cod condition between the late 1980s and the early 1990s co incided with the reduction in biomass. Cod exhibited clear seasonal va riations in condition factor (Fulton's K), energy reserves, and tissue composition. Maximum K (0.87-0.91) and highest hepatosomatic index (H SI; 4.3-5.7%) occurred during the autumn while minimum levels occurred in spring. In May, the levels of condition (K, 0.69-0.74; HSI, 2.2-3. 0) were below those reported for other stocks. In spring during spawni ng, a proportion of the wild cod had condition and energy reserves tha t were within the range that resulted in mortality among unfed fish he ld in the laboratory. Feeding experiments also indicate that the condi tion of wild cod in fall was lower than that observed for well-fed fis h held in the laboratory. The decline in the condition and energy rese rves of cod during several consecutive years may have lowered the prod uctivity of the northern Gulf of St. Lawrence stock. This, along with overfishing, could have contributed to the collapse of this stock.