Large-scale threats to toothed whales include hunting, incidental entanglement, habitat destruction, and pollution. Though there is valid concern for several whale species, not all whale populations are endangered or threatened. Killer whales are not endangered. Though hundreds of dolphins and porpoises still drown in fishing nets, the impact on most populations appears to be minimal. However, if recent trends in human impact continue, even these relatively stable populations may begin to lose ground.
Preservation is priority.
In 1986, the IWC declared a moratorium on commercial whaling, hoping to allow whale populations to recover. The IWC has no means by which to enforce the moratorium, however, and whaling nations sometimes threaten to disregard it. The main objective of the MMPA is to maintain the stability of marine mammal populations and marine ecosystems. See Whale Species Populations and Status table. Zoological parks respond.