Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term applies to natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks and other wildlife.
Atlantic cod stocks were severely overexploited in the 1970s and 1980s, leading to their abrupt collapse in 1992.
When the giant flightless birds called moa were overexploited to the point of extinction, the giant Haast's eagle that preyed on them also became extinct.
Cows on Selsley Common. The tragedy of the commons is a useful parable for understanding how overexploitation can occur.
The Atlantic bluefin tuna is currently overexploited. Scientists say 7,500 tons annually is the sustainable limit, yet the fishing industry continue to harvest 60,000 tons.
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, invasive species, and climate change. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration.
Golden lion tamarin, an endemic and one of the endangered species saved from extinction in Brazil
The California condor is a critically endangered species. Note the wing tags used for population monitoring.
Photo of Pusa hispida saimensis, also known as Saimaa ringed seal, from 1956. Living only in Lake Saimaa, Finland, Saimaa ringed seals are among the most endangered seals in the world, having a total population of only about 400 individuals.