Marine Mammal Protection Act

The Marine Mammal Protection Act of 1972 was enacted in response to increasing concerns among scientists and the public that significant declines in some species of marine mammals were caused by human activities. The Act established a national policy to prevent marine mammal species and population stocks from declining beyond the point where they ceased to be significant functioning elements of the ecosystems of which they are a part. Nowhere else in the world had a government made the conservation of healthy and stable ecosystems as important as the conservation of individual species.

The Department of Commerce through the National Marine Fisheries Service is charged with protecting whales, dolphins, porpoises, seals, and seal lions. Walrus, manatees, otters, and polar bears are protected by the Department of the Interior through the U.S. Fish and Wildlife Service. The Animal and Plant Health Inspection Service, a part of the Department of Agriculture, is responsible for regulations managing marine mammals in captivity.

Innovative Features

In addition to shifting the focus of conservation from species to ecosystems, the Act contains many innovative features never before established in legislation. It:


The MMPA established a moratorium on the taking of marine mammals in U.S. waters. It defines “take” to mean “to hunt harass, capture, or kill” any marine mammal or attempt to do so. The inclusion of harassment in the definition was a groundbreaking action by Congress. Exceptions to the moratorium can be made through permitting actions for take incidental to commercial fishing and other nonfishing activities; for scientific research; and for public display at licensed institutions such as aquaria and science centers. The moratorium generally does not apply to Alaska natives who live on the Alaskan coast. The MMPA contains provisions allowing for take for subsistence use or to create and sell “authentic articles of handicrafts and clothing” without permits or authorizations. The taking must not be “accomplished in a wasteful manner,” and the Secretaries of Commerce and the Interior may regulate the taking of a depleted species or stock, regardless of the purpose for which it is taken.

What You Can Do

People can positively affect changes in our ecosystems and help protect marine species by learning about the issues and changing behaviors. You can make a difference. Learn more