Causes include overfishing, pollution and ocean acidification. Fishing has declined due to habitat degradation, overfishing, trawling, bycatch and climate change. Severe environmental problems include deforestation, soil erosion, overgrazing, and overfishing. Issues with wild fisheries are overfishing and pollution. Such overfishing has severely damaged bluefin stocks. Overfishing and pollution from gold mine tailings resulted in the decline of the fishery. Aquatic animals are subject to pressure from overfishing, destructive fishing, marine pollution and climate change. Lamprey distribution may be adversely affected by overfishing and pollution. As ecosystems, estuaries are under threat from human activities such as pollution and overfishing. Examples of tragedies of the commons are overfishing and overgrazing. American paddlefish populations have declined dramatically, primarily as a result of overfishing and habitat destruction. Seahorse populations are thought to be endangered as a result of overfishing and habitat destruction. Around year 2000, owing to overfishing and high demand, lobster aquaculture expanded. The sea is in danger of becoming barren due to overfishing and pollution. The major threats are from overfishing and habitat change.