Seals and sea lions belong to a group of marine mammals called pinnipeds, which means fin or flipper-footed. These animals live in the ocean, but are able to come on land for long periods of time. Some species have evolved the ability to hold their breath for up to two hours and dive to depths of more than 6,500 feet when looking for food.
There are two families of pinnipeds: Phocids and Otariids. Phocids are also known as earless seals or “true” seals. They have ear holes, but no external ear flaps. They also have small front flippers and move on land by flopping along on their bellies. At sea, these seals move their rear flippers back and forth like a fish's tail to propel themselves through the water. Phocids include the harbor seal and Hawaiian monk seal.
Otariids, also known as eared seals, include sea lions and fur seals such as the Steller sea lion and the northern fur seal. Unlike true seals, they have external ear flaps. Their front flippers are large, and on land, they are able to bring all four flippers underneath their bodies and walk on them. Otariids propel themselves in the water by paddling their front flippers and using their rear flippers to steer.
All seals and sea lions are protected under the Marine Mammal Protection Act, and some are also listed under the Endangered Species Act. Together with our partners, we work to study, protect, and conserve these unique marine mammals and their habitats.
Species News
![Two stranding responders carry a stranded harbor porpoise away from some rocks](/s3/styles/inline_field_thumbnail/s3/2024-04/harbor-porpoise-Seacoast-Science-Center.jpg?h=29c30e7b&itok=hUr5qItv)
![Spotted, gray harp seal on sandy shore moving towards the ocean water.](/s3/styles/inline_field_thumbnail/s3/2023-03/4496x3000-harp-seal-Seuss-release-MysticAquarium.jpg?h=d5895ce4&itok=RcIxliRC)
![A mother Hawaiian monk seal and her pup lay side by side on a sandy beach.](/s3/styles/inline_field_thumbnail/s3/2024-03/750x500-Hawaiian-monk-seal-and-pup-napping-HMAR.png?h=3dbd9eac&itok=ANfNiVBs)
![Aerial view of Bogoslof Island in June 2022 showing the impact of the volcanic eruption from 2019](/s3/styles/inline_field_thumbnail/s3/2024-03/750x500-bogoslof-2022-afsc.png?h=9e499333&itok=yASL2jA3)
Multimedia
![Cape Shirreff field camp against a backdrop of mountains in Antarctica. Credit: NOAA Fisheries](/s3/styles/inline_field_thumbnail/s3/2024-04/capeshirreff17.jpg?h=6925e8ec&itok=YSv_o0VF)
![A Hawaiian monk seal pup lays in the sand](/s3/styles/inline_field_thumbnail/s3/2024-03/PM6-Kalaupapa-2017-Noaa-16632-02.jpg?h=94b28deb&itok=FMvjKh6o)
Research
Publications by Northeast Passive Acoustics Branch Staff
We regularly publish their findings in scientific journals and Center-produced documents.
Sea Lion Removals Annual Summary
NOAA Fisheries has authorized Washington, Oregon, and Idaho to lethally remove individually identifiable, predatory California Sea Lions in the vicinity of Bonneville Dam that are having a negative impact on the recovery of salmon and steelhead.
Cape Shirreff Situation Reports 2023-2024
These reports highlight science activities and events from the U.S. Antarctic Marine Living Resources Program Field Camp at Cape Shirreff, Livingston Island, part of the South Shetland Islands of Antarctica
Marine Protected Species of the Hawaiian Islands
Pacific Islands species lists under NOAA Fisheries jurisdiction from the Hawaiian Islands.
Viewing Marine Life
Watching marine animals in their natural habitat can be a positive way to promote conservation and respect for animals and their environment.
![On Shipwreck Beach on the south coast of Kauai, Hawaii, an endangered Hawaiian monk seal takes a nap on the beach. The sign in the foreground instructs people to walk around the seal.](/s3/styles/original/s3/dam-migration/750x500-monk-seal-on-beach-istock.jpg?itok=oBg0FhOi)