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U.S. Marine Mammal Protection Act Marks Four Decades of Success
May 10, 2012

May 9,  2012

Sea lions
Sea lions congregate on docks in San Francisco, a popular “haul-out” site.

Populations of oceangoing mammals are rebounding in U.S. waters and beyond, thanks to a federal law enacted nearly 40 years ago.

In 2012, the United States celebrates the 40th anniversary of the Marine Mammal Protection Act, one of the nation’s most important conservation laws, according to the Department of the Interior. The groundbreaking legislation, enacted October 21, 1972, helps conserve marine mammals such as polar bears, sea otters, walruses and manatees, as well as the ocean ecosystems that support them.

Under the law’s protections, populations of formerly declining species such as the West Indian manatee, the California sea lion, the Pacific harbor seal and the elephant seal have steadily increased. The law also has played a key role in reducing conflicts between polar bears and humans in Alaska.

Wildlife conservation has a long history in the United States, and the United States is a leader in international efforts to protect wildlife.

In the late 19th century, when U.S. expansion reached its westward limit, Americans gradually recognized environmental changes and took steps to protect their precious natural heritage. The conservation movement, which included President Theodore Roosevelt among its supporters, advanced private and public initiatives to protect endangered species.

A series of progressively more protective statutes were passed from 1900 onward as the nation sought to preserve and manage its rich biodiversity.

The 1966 Endangered Species Preservation Act directed the Department of the Interior to create a list of endangered U.S. wildlife and allocated up to $15 million each year to buy and preserve their habitats. As a result of growing public pressure to save whales, the act was revised in 1969 to allow listing of foreign species and prohibit imports of products made from those species.

A stronger act, the Endangered Species Act, was passed in 1973, in part to settle legal wrangling between the departments of Interior and Defense over the U.S. Navy’s use of sperm-whale oil in submarines.

But the Marine Mammal Protection Act already had raised a broad protective umbrella over all marine mammals — those that spend much or all of their lives in or on the ocean.

Some marine mammals — those determined to be at risk of extinction — also are protected under the Endangered Species Act and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).


The U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric Administration share authority for implementing and enforcing the Marine Mammal Protection Act, a law that complements the Endangered Species Act but is uniquely focused on protecting marine mammals.

The protection of marine mammals and their ecosystems is especially important in the face of climate uncertainty and multiple threats to the marine environment. Additionally, conservation of these iconic species and their habitats helps support livelihoods, such as subsistence use, ecotourism and fisheries, in many coastal communities.

The law prohibits, with certain exceptions, “take” (hunting or capturing) of marine mammals in U.S. waters and by U.S. citizens on the high seas, as well as the importation of marine mammals and marine mammal products into the United States.

It also prohibits possession, transport, export or offer to purchase, sell or export marine mammals or products created from them. In addition, the law established the Marine Mammal Commission, an independent governmental entity charged with providing oversight of marine mammal conservation policies and programs being carried out by federal regulatory agencies.

The service’s National Wildlife Refuge System plays an important role in protecting marine mammals:

• The Arctic National Wildlife Refuge protects vital polar bear denning areas.

• The Hawaiian Islands and Midway Atoll refuges conserve breeding habitat for the critically endangered Hawaiian monk seal.

• The Crystal River refuge in Florida was established in 1983 specifically for the protection of the endangered West Indian manatee.

• The Monomoy refuge south of Cape Cod is the largest “haul-out” site (or coastal assembly point) for gray seals on the Atlantic seaboard, with approximately 5,000 seals.