Destruction of Habitats

Destruction and alteration of habitat are recognized as the greatest threat to biodiversity. Marine scientists looking at the problems of oceans and coastal areas at the start of the new millennium declared: "Habitats, of course, have changed naturally since long before the appearance of humanity, but the sheer scale of the present onslaught is unprecedented."

The destruction comes from physical alterations, pollution, and invasions of alien species as well as other biological threats such as eutrophication and red tides. Some phenomena are natural events. But many result from human activities, and most impacts are from land-based activities.