Diving and snorkling have had to give way to reading and writing, but she has discovered spring and definite changes in seasons. Carol also works as a volunteer interpreter and newsletter editor for the Oregon Coast Aquarium and has worked in wild bird rehabilitation. The behavior and physiology of fishes is often greatly modified by changes in temperature. Because most fishes are ectotherms, their body temperature rapidly equilibrates to the surrounding water temperature. This is especially true for small-bodied juveniles.
Warmer temperatures tend to accelerate many physiological processes, such as metabolism and growth.
If temperature conditions change, fish can exhibit a simple bioenergetic response, with behavior corresponding to internal shifts in physiological rates. In this case, general swimming activity would be expected to increase as water temperature rises and decrease as temperature falls. Alternatively, fish can respond to temperature changes by showing avoidance behavior. In this case, swimming activity would be expected to increase with either a rise or fall in temperature as fish attempt to move out of the undesirable temperatures. These two mechanisms, passive bioenergetic response or active avoidance, were tested with juvenile sablefish and walleye pollock in a series of experiments.