Marine mammals are mammals that rely on the ocean to survive. They include whales, dolphins, porpoises, seals, sea lions, walruses, polar bears, sea otters, manatees, and dugongs. Some are fully aquatic, such as whales and dolphins. Others, such as seals and sea lions, spend most of their time in water but return to land or ice for activities such as resting or giving birth. Marine mammals are vital to the balance of marine ecosystems and are key indicators of the overall health of the ocean.
All marine mammals are protected under the Marine Mammal Protection Act. Some are also protected under the Endangered Species Act and the Convention on International Trade in Endangered Species of Wild Fauna and Flora.
With some exceptions, the MMPA prohibits the “take” of marine mammals—including harassment, hunting, capturing, collecting, or killing—in U.S. waters and by U.S. citizens on the high seas. The act also makes it illegal to import marine mammals and marine mammal products into the United States without a permit. Learn more about the MMPA.
Our work to protect and conserve marine mammal species includes:
Managing the take of marine mammals through permits and authorizations (sections 101 and 104 of the MMPA).
Investigating and prosecuting violations of the MMPA (section 107).
Partnering with other nations to make sure they hold international fishing to our standards according to the MMPA (section 108).
Evaluating the status of marine mammals to determine whether they should be designated as depleted and developing conservation plans for depleted species or stocks (section 115).
Developing stock assessment reports—with scientific information on a species' or stock’s geographic range, population structure, abundance, and threats—to evaluate stock status (section 117).
Managing incidental marine mammal interactions with commercial fisheries through authorization and reporting, by assessing the level of mortality and injury in commercial fisheries, and by developing take reduction plans (section 118).
Collaborating with Alaska Native organizations to conserve marine mammal populations in Alaska (section 119).
Coordinating a national network to respond to marine mammal strandings (section 403).
Investigating and responding to marine mammal unusual mortality events (section 404).
All marine mammal species found in U.S. waters are protected under the Marine Mammal Protection Act, as well as marine mammals listed as endangered or threatened under the Endangered Species Act worldwide. The MMPA prohibits, with certain exceptions, the "take" of marine mammals in U.S. waters and by U.S. citizens on the high seas, and the importation of marine mammals and marine mammal products into the United States.
NOAA Fisheries is charged with protecting whales, dolphins, porpoises, seals, and sea lions. Walrus, manatees, sea otters, and polar bears are protected by the U.S. Fish and Wildlife Service. The Marine Mammal Commission provides independent, science-based oversight of federal agencies’ policies and actions addressing human impacts on marine mammals and their ecosystems. Additionally, the Animal and Plant Health Inspection Service, under the Department of Agriculture, is responsible for regulations managing marine mammals in captivity under the Animal Welfare Act.
NOAA Fisheries scientists collect and analyze data on the marine mammal populations we manage. We gather information on a species' or stock’s population structure, life history characteristics and productivity rates, abundance, and threats—particularly those caused by human activities. We publish this information, and our analyses, in annual stock assessment reports.
Find marine mammal stock assessment reports
The MMPA generally prohibits the "take" of marine mammals (e.g., harassment, hunting, capturing, collecting, or killing). The act also makes it illegal to import or export marine mammals and marine mammal products into or out of the United States without a permit or other applicable authorization. NOAA Fisheries authorizes take for certain activities, for example, scientific research, commercial and educational photography, and incidental take during commercial fishing operations and other non-fishery commercial activities like construction projects.
Learn more about permits and authorizations
Fisheries bycatch is the greatest direct cause of marine mammal death and injury. To address this threat, NOAA Fisheries develops and implements take reduction plans—plans to mitigate marine mammal death and serious injury in commercial fisheries to help stocks recover. Teams of scientists, members of the fishing industry, representatives of environmental groups, and resource managers work together to develop these plans. The teams design each plan to reduce bycatch within a specific timeframe through a combination of voluntary and regulatory measures.
Learn more about take reduction planning
The MMPA prohibits killing or injuring marine mammals, except under certain circumstances. This program provides an annual exemption for the incidental mortality or injury of marine mammals that occurs during commercial fishing. This exemption does not include marine mammal stocks listed as endangered or threatened under the Endangered Species Act—incidental take of these species must be permitted separately.
Learn more about the Marine Mammal Authorization Program
Sometimes marine mammals are found in distress—sick, injured, or dead. The cause is often unknown, but sometimes it is shown to be disease, ship strikes, entanglements in marine debris or fishing gear, harmful algal blooms, pollution exposure, or other trauma. NOAA Fisheries works with trained partners in every coastal state to respond to reports of marine mammals in distress, assess the animals’ condition, and (in certain cases) try to rehabilitate or move them. If a marine mammal is dead, responders may perform a necropsy—an animal autopsy—to learn more. The valuable biological information collected during stranding responses helps us make better management decisions for marine mammal conservation. Marine mammals are mammals like us, and several species live in coastal waters that people use, and forage on some of the same fish that people consume. As such, they can help serve as indicators of ocean health, giving insight into larger environmental issues, which may also have implications for human health and welfare.
Learn more about the Marine Mammal Health and Stranding Response Program
When marine mammal stranding rates are higher than usual, the MMPA sets out a process to evaluate strandings and determine whether they should be designated as unusual mortality events, which triggers a specific investigative response. UMEs can be caused by either natural or human factors, such as disease outbreaks, biotoxins from harmful algal blooms, oceanographic events, pollution, vessel strikes, and entanglement in fishing gear or marine debris.
Learn more about unusual mortality events
Learn how NOAA Fisheries protects all marine mammals under the Marine Mammal Protection Act.