How Does Thermal Pollution Affect Ecosystems?
Pollution is simply the act of introducing something potentially harmful into the ecosystem. The site where the polluting occurs often determines the degree of the pollution and whether or not the agent is indeed a pollutant. For example, applying pesticide to a garden or farm field may not be pollution, but if that same pesticide enters a stream, it then becomes pollution. Many types of pollution, such as littering and factory emissions, are readily identifiable. Pollution, however, also can be caused by an unnatural warming of waterways. This act is defined as thermal pollution.
Other People Are Reading
-
Definition
-
Surface water, whether it is a lake or a stream, tends to stay relatively stable in terms of temperatures. Seasonal changes bring about slow changes in temperatures that the waterway's plant and animal life can tolerate. A common practice among industries is to use nearby water resources as cooling water, discharging warmed water back into the ecosystem. This action creates an unnatural and oftentimes a far too rapid shift in the water's temperature.
Effects
-
A quick change in water temperature can have profound effects on the fish and other organisms that live in waterways impacted by thermal pollution. Changes in water temperature can alter fish metabolism. For example, during the colder times of the year, a fish's metabolism slows, and food resources are limited. If the water is suddenly warmed, the fish's metabolism increases. With limited food available, however, the fish is likely to die.
-
Water Chemistry
-
The impacts on water chemistry are complex. First, as temperatures rise, the amount of dissolved oxygen available to plants and animals decreases. For cold water fish such as trout, this change can lead to fish kill. If the change occurs too quickly, fish become stressed and vulnerable to disease. Second, if great numbers of fish die, the water chemistry is altered because the ammonia and nitrite levels increase. If left unchecked, the water becomes an ecological dead zone, unable to support any life.
Sources
-
Thermal pollution is caused by several types of industry. Cooling waters are often needed for electricity generation and nuclear power. Other industries, such as paper mills, also rely on cooling waters to conduct their manufacturing processes.
Other Effects
-
Discharge waters from factories can have other detrimental effects on the ecosystem. If water flow is strong, it can introduce sediment into the water and cause soil erosion along the shorelines. The resulting cloudy water can block light, impairing plants' ability to carry out photosynthesis. Photosynthesis is the process by which plants make food. If a plant cannot make food or produce energy, it will die, further impacting the water quality.
-
References
Resources
- Photo Credit factory image by Zbigniew Nowak from Fotolia.com
