A seal catches a salmon off the coast of Washington State. Scientists are working to determine how much salmon the seals eat.

Salmon in the Pacific Northwest Are Facing a New Threat: Booming Populations of Seals and Sea Lions

The mammals’ return to the region represented a conservation success story, but their appetite for endangered fish is upsetting the balance of a delicate ecosystem

Ronan the California sea lion sits in front of a pool at UC Santa Cruz’s Long Marine Laboratory.

This Sea Lion Can Headbang Better Than You—Watch Her Out-Perform Humans at Keeping a Beat

A new study of Ronan, a sea lion famous for her dancing skills, challenges the idea that only vocal learners can match a tempo

Volunteers with the Channel Islands Marine & Wildlife Institute in Santa Barbara, California, rescue a sick sea lion that's likely suffering from domoic acid poisoning.

Sea Lion Bites Surfer Amid One of the Worst Outbreaks of Domoic Acid Poisoning That California Wildlife Rescuers Can Remember

Sea lions, dolphins and birds are sick and dying because of a toxic algae bloom in Southern California—and animal care organizations are overwhelmed by the scale

At dawn, a woman and her dog walk along a serene shore in the Corona Del Mar area of Newport Beach as gentle waves greet them.

Smithsonian Photo Contest Galleries

See 15 Stunning Photos of California That Showcase the Golden State’s Majestic Beauty

California offers lovely beaches, forests, deserts, mountains and more!

Hundreds of sea lions have inundated a beach in central California.

See Hundreds of Sea Lions Take Over a Popular California Beach

The pinnipeds are resting on San Carlos Beach as part of their annual northward journey from the Channel Islands, prompting officials to close it down

An Australian sea lion captures video while swimming through an invertebrate reef habitat.

Scientists Enlist the Help of Sea Lions to Reveal a Unique View of the Ocean Floor

Australian researchers glued satellite-linked GPS cameras to the animals’ backs to capture footage that could be vital to marine conservation efforts

More than 1,000 sea lions gathered at San Francisco's Pier 39 last week, marking the largest congregation of the marine mammals at the city's Fisherman's Wharf in about 15 years.

More Than 1,000 Sea Lions Gather at San Francisco’s Pier 39, the Largest Group in 15 Years

The pinnipeds came to the area to feed on anchovies and herring as they prepare for breeding season

An elephant seal pup on South Georgia Island

Why Did Seals and Sea Lions Never Commit to a Life Fully at Sea?

While whales moved from living on land to an existence immersed in water, pinnipeds embraced an amphibious lifestyle

Sea lions breed and give birth at Point La Jolla in San Diego.

San Diego Closes Popular Beach for Seven Years to Protect Sea Lions

Visitors have been getting too close to the marine mammals—taking selfies and even harassing them—as they rear their pups

A sea lion receiving care at the Pacific Marine Mammal Center in Laguna Beach, California, shows signs of domoic acid poisoning.

Algae Is Making Sea Lions More Aggressive in California

A toxin present in algal blooms is moving through the food chain, leading to the deaths of sea lions and dolphins