Habitat loss occurs when an ecosystem has been negatively impacted by human activities or natural disasters. Three major types of habitat loss are destruction, fragmentation and degradation.
Habitat Destruction: The harvesting and exploitation of the earth's natural resources by man is the leading cause of habitat destruction. Human activities such as commercial development, clearing land for agriculture, drilling for oil and gas exploration have wreaked havoc on our ecosystems. The majority of deforestation can be directly attributed to agricultural expansion. The world's growing need for food has resulted in the increased conversion of natural habitats into agricultural lands. During the 1990s about 94 million hectares of the earth's forests were cleared and 70 percent of that land was converted for agriculture use. Habitat destruction is not limited to terrestrial habitats. In the ocean, destructive commercial fishing activities such as trawling and dynamiting reefs have been responsible for the loss of entire coral reefs.
Habitat Fragmentation: Urban growth and expansion has led to a need for transportation routes. The development of roadways often cuts directly through habitats, creating fragmented sections of land that are not large or well-connected enough to support the species living there. Animals inhabiting these areas are often left isolated and unable to reach other suitable areas to feed or find mates. Animals that attempt to reach other habitats by crossing roads and highways may be killed or injured by cars. Aquatic animals can be affected by habitat fragmentation as well. The damming and rerouting of rivers may cause certain areas such as swamps and riverbeds to shrink or completely dry up. This poses a serious problem for the wildlife such as fish, turtles and alligators that rely on these wetland habitats.
Habitat Degradation: This occurs when there is a disruption to an ecosystem that leaves it unable to support the species that inhabit it. Pollution, climate change, invasive species and occurrences such as fires can lead to habitat degradation. Pollution is a major cause of this type of habitat loss, and freshwater wildlife is usually the most affected. For example, water runoff from agricultural areas often carries excess nutrients and fertilizers and can cause harmful algae blooms, which can deprive fish of oxygen and block sunlight necessary for the growth of coral.
Other factors such as global climate change/? can attribute to extreme habitat degradation for coral reef ecosystems. For example, even slight increases in water temperature can lead to "coral bleaching," which can wipe out entire reef systems. In 2002, the Great Barrier Reef in Australia, suffered from a severe instance of coral bleaching, in which 60 percent of the reef was affected. It is estimated that all of the world's reefs can be gone by the year 2050 if the rate of climate change doesn't decrease. Unfortunately, if the reef ecosystems die, so do many of the species that rely on them.
Many of the habitats that wildlife call home are rapidly disappearing due to all of these factors. According to the IUCN's Red List, 85 percent of all the world's wildlife is threatened by habitat loss. The shrinking of living space can lead to several problems, including competition for resources such as food and shelter, and can threaten the biodiversity of the species. Habitat loss is currently the leading cause of species extinction throughout the world.
For more information on conservation organizations that work to protect and conserve our natural habitats, check out these sites:
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