Does the Water Temperature of the Environment Have an Effect on Fish?

The ecosystem is a complex relation of interconnected physical, chemical and biological processes. This can affect marine life in the ocean causing fish undue stress. Although it is hard to separate individual processes in the oceans ecosystem -- one thing is sure -- temperature does have an effect. It is the key element in maintaining the stability of the oceans' ecosystem, as well as marine life.

Dissolved Oxygen

• Marine life thrives on oxygen, be it fish, insects, algae or plankton. Chemical reactions within the water increase as the temperature goes up, multiplying biological activity in that area. With greater activity -- oxygen is used more rapidly -- creating a decrease in surplus, due to an increased number of organisms using it. The problem is that warm water holds less oxygen, creating a shortage.

Density and Viscosity

• Density is weight and viscosity is how fast it flows. As the temperature goes up, density and viscosity go down. This decrease causes an increase in the speed at which suspended food and sediment particles settle to the bottom. Bottom sediment can kill fish eggs, slow burrowing activities and trap emerging young. With less food in the water, smaller microbial life becomes stressed putting a strain on the food chain.

Toxin Exposure

• Fish metabolism rises with temperature. With increased metabolism, there is a greater need for oxygen, causing faster gill ventilation. Higher levels of toxins within the water are filtered through the fish. The problem is two-fold -- as increased temperature increases the water's ability to absorb chemical pollutants. The resulting effect can lower the fish's ability to tolerate higher temperatures -- reducing its resistance to disease.

Stress

• Stress is a physiological response from the fish caused by the inability to maintain its relationship between the changed environment and ecosystem. The central nervous system of the stressed fish triggers a release of stress hormones, changing the blood chemistry. Their altered metabolism results in a loss of electrolytes. This changes their behavior, growth and spawning ability -- as well as incidence of disease. Temperature does affect the oceans ecosystem and the fish that life within it.