GEF

Unit 5  |  The Importance of Biodiversity 114 5.4  The Biodiversity Crisis: Tropical Forests and Oceans Currently, human activity is rapidly eroding biodiversity. Growing human populations and economies are fueling the conversion of natural habitats into agricultural land, animal pasture, and cities. Logging, mining, overfishing, and illegal hunting are further threatening the ecological wealth of the planet. Present rates of species extinction are hundreds of times faster than what scientists consider the normal rate. Some researchers consider the present crisis to represent a human-caused mass extinction, comparable in scale to the last mass extinction 65 million years ago that killed off the dinosaurs and many other species. EXTINCTION The end of a species on Earth. SUSTAINABILITY CONCEPTS Biodiversity hotspots, such as the Great Barrier Reef, Madagascar, and Costa Rica, are important destinations for ecotourism. It is unlikely that these locations would receive a large economic benefit from tourism without their high levels of biodiversity. The Great Barrier Reef off the coast of Australia is a unique ecosystem that is home to many valuable species.