26-08-2017, 12:55 PM
Thermal pollution is the degradation of water quality by any process that changes the temperature of the ambient water. A common cause of thermal pollution is the use of water as a refrigerant by power plants and industrial manufacturers. When the water used as refrigerant is returned to the natural environment at a higher temperature, the sudden change in temperature decreases the oxygen supply and affects the composition of the ecosystem. Fish and other organisms adapted to a particular temperature range can be destroyed by an abrupt change in water temperature (either a rapid increase or decrease) known as a "heat shock".
The elevated temperature typically lowers the dissolved oxygen level of the water, since the gases are less soluble in warmer liquids. This can damage aquatic animals such as fish, amphibians and other aquatic organisms. Thermal pollution can also increase the metabolic rate of aquatic animals, such as enzymatic activity, resulting in these organisms that consume more food in a shorter time than if their environment have not changed. An increase in the metabolic rate can result in fewer resources; The more adapted organisms that move in may have an advantage over organisms that are not used at the hottest temperature. As a result, food chains in old and new environments may be compromised. Some species of fish will avoid stream segments or coastal areas adjacent to a thermal discharge. Biodiversity can decrease as a result.
The high temperature limits the dispersion of oxygen in deeper waters, contributing to the anaerobic conditions. This can lead to increased levels of bacteria when there is sufficient food supply. Many aquatic species will not reproduce at elevated temperatures.
Primary producers (eg, plants, cyanobacteria) are affected by hot water because the higher water temperature increases plant growth rates, resulting in shorter life and overpopulation of species. This can cause a bloom of algae that reduces oxygen levels.
Changes in temperature even one to two degrees Celsius can cause significant changes in body metabolism and other adverse effects in cell biology. The main adverse changes may include making the cell walls less permeable to the necessary osmosis, coagulation of cellular proteins and alteration of enzymatic metabolism. These cell-level effects may adversely affect mortality and reproduction.
A large increase in temperature can lead to the denaturation of life-sustaining enzymes by breaking the hydrogen and disulfide bonds within the quaternary structure of the enzymes. Decreased enzyme activity in aquatic organisms can cause problems such as inability to break down lipids, leading to malnutrition.
In limited cases, temperate water has little deleterious effect and may even lead to improved function of the receiving aquatic ecosystem. This phenomenon is observed especially in the seasonal waters and is known as thermal enrichment. An extreme case stems from the aggregation habits of the manatee, which often uses power plant discharge plants during the winter. Projections indicate that manatee populations would decrease with the elimination of these discharges.
The elevated temperature typically lowers the dissolved oxygen level of the water, since the gases are less soluble in warmer liquids. This can damage aquatic animals such as fish, amphibians and other aquatic organisms. Thermal pollution can also increase the metabolic rate of aquatic animals, such as enzymatic activity, resulting in these organisms that consume more food in a shorter time than if their environment have not changed. An increase in the metabolic rate can result in fewer resources; The more adapted organisms that move in may have an advantage over organisms that are not used at the hottest temperature. As a result, food chains in old and new environments may be compromised. Some species of fish will avoid stream segments or coastal areas adjacent to a thermal discharge. Biodiversity can decrease as a result.
The high temperature limits the dispersion of oxygen in deeper waters, contributing to the anaerobic conditions. This can lead to increased levels of bacteria when there is sufficient food supply. Many aquatic species will not reproduce at elevated temperatures.
Primary producers (eg, plants, cyanobacteria) are affected by hot water because the higher water temperature increases plant growth rates, resulting in shorter life and overpopulation of species. This can cause a bloom of algae that reduces oxygen levels.
Changes in temperature even one to two degrees Celsius can cause significant changes in body metabolism and other adverse effects in cell biology. The main adverse changes may include making the cell walls less permeable to the necessary osmosis, coagulation of cellular proteins and alteration of enzymatic metabolism. These cell-level effects may adversely affect mortality and reproduction.
A large increase in temperature can lead to the denaturation of life-sustaining enzymes by breaking the hydrogen and disulfide bonds within the quaternary structure of the enzymes. Decreased enzyme activity in aquatic organisms can cause problems such as inability to break down lipids, leading to malnutrition.
In limited cases, temperate water has little deleterious effect and may even lead to improved function of the receiving aquatic ecosystem. This phenomenon is observed especially in the seasonal waters and is known as thermal enrichment. An extreme case stems from the aggregation habits of the manatee, which often uses power plant discharge plants during the winter. Projections indicate that manatee populations would decrease with the elimination of these discharges.