Humans have affected populations of all species, from American crocs in South Florida to saltwater crocs in Australia, the smaller caimans of Central and South America, and everything in between. The two primary threats to crocodilians from humans are habitat loss and unsustainable use. Adult American Crocodile in the Florida Keys Juvenile American Croc Humans are consumers, and the consumption of wildlife in one form or another is a common characteristic that all cultures share. In a world currently supporting six billion people, much of our consumption has become unsustainable, however. At its simplest, an action is sustainable if it can be continued indefinitely.
Crocodilians provide excellent examples of both unsustainable and sustainable use.
Decades of commercial overexploitation, combined with the destruction of wetland habitats, brought several species to the brink of extinction. Although a great deal of research still needs to be conducted on sustainable use of crocs and other herps, many biologists believe that the commercial use of some species can be compatible with healthy, sustainable populations. For example, the commercial use of some crocodile species provides financial incentives for people to ensure that both the crocodile population and the habitat it depends on remain in good condition.