F ish and shellfish respond directly to climate fluctuations. The responses are species dependent and can include noticeable changes in growth and reproduction of individual fish, as well as the distribution and abundance of fish populations. Warmer temperatures lead to faster growth rates. In the Northwest Atlantic, the largest cod are found on Georges Bank with a 4-year old fish being, on average, five times bigger than one off Labrador and Newfoundland.
Temperature also affects the reproductive cycle of fish and shellfish.
These fish reside in warm offshore waters and move onto St. Pierre Bank prior to spawning. Temperature is one of the primary factors, together with food availability and suitable spawning grounds, in determining the large-scale distribution pattern of fish and shellfish. This recent shift appears to be part of a larger scale ecosystem change. Recruitment is a measure of how many young survive long enough to potentially enter the fishery. Understanding recruitment variability has been the number one issue in fisheries science this century.