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. A few examples are provided below. 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. In very cold years on the Bank, they appear to delay migration onto the Bank thereby remaining in the warm offshore waters longer, resulting in faster gonad development and an earlier readiness to spawn. 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.