California Sea Lion | NOAA Fisheries

Skip to main content Species Directory California Sea Lion Overview Conservation & Management Science Resources California sea lions are "eared seals" native to the West Coast of North America. They live in coastal waters and on beaches, docks, buoys, and jetties. Learn more about California sea lions.

California Sea Lion

Zalophus californianus

Protected Status

MMPA Protected Throughout Its Range

Quick Facts

Weight 240 pounds (females) to 700 pounds (males) Length 6 feet (females) to 7.5 feet (males) Lifespan 20 to 30 years Threats Biotoxins resulting from harmful algal blooms, Disease, Entanglement in fishing gear, Human-caused injuries Region West Coast Adult California sea lion. Credit: NOAA Fisheries

Adult California sea lion. Credit: NOAA Fisheries

About the Species

Adult California sea lion. Credit: NOAA Fisheries

Adult California sea lion. Credit: NOAA Fisheries

California sea lions are “eared seals” native to the West Coast of North America. They live in coastal waters and on beaches, docks, buoys, and jetties. They are easily trained and intelligent and are commonly seen in zoos and aquariums. California sea lions are playful, intelligent, and very vocal (sounding like barking dogs).

Like all marine mammals, they are protected under the Marine Mammal Protection Act. Their population has been increasing since at least 1975, after protections were put in place under the MMPA.

NOAA Fisheries helps conserve the California sea lion through collaborative management, integrated science, partnerships, and outreach. Our scientists use innovative techniques to study, protect, and rescue California sea lions in distress—for example, stranded or caught in nets. Our work helps reduce harm from human activities (such as fishing and pollution) through management based on sound science, public input, and public outreach.

Population Status

NOAA Fisheries estimates population size for the U.S. stock of California sea lions in our stock assessment report. From 1975 to 2014, the maximum population growth rate of the U.S. stock of California sea lions was 7 percent per year.

Appearance

Adult females and juveniles are slender-bodied and are blonde to tan in color. Adult males are generally larger than females and are mostly dark brown to black in color. Pups are dark brown at birth and weigh about 16 pounds. When pups are 4 to 5 months old, they molt their dark brown coats for light brown or silver coats.

California sea lions have broad front flippers and long, narrow snouts. Subadult and adult males have pronounced forehead crests crowned with tufts of blonde or lighter hair. California sea lions have visible ear flaps, and three to five claws on their hind flippers.

Behavior and Diet

California sea lions feed mainly offshore in coastal areas. They eat a variety of prey—such as squid, anchovies, mackerel, rockfish, and sardines—found in upwelling areas. They also may take fish from commercial fishing gear, sport fishing lines, and fish passage facilities at dams and rivers.

California sea lions are very social on land and in the water, but during the breeding season the males aggressively defend their territories and females fight other females to protect their pups. While on the breeding islands, California sea lions are very skittish around humans and will run into the water if they see or smell people.

California sea lion males bark like dogs to communicate with other males and females. Females and pups communicate using vocalizations that are unique to the female and pup. Each pup and female has a unique scent that also identifies them. A female can locate her pup among hundreds of others by her pup’s vocalization. When she finds her pup, she smells it as a final check.

One common behavior—called “rafting”—can make a sea lion look like it’s caught in a net. A rafting sea lion holds its flippers above the water for a long time, motionless, to rest and regulate its body temperature. If you cannot see a buoy or net gear, the seal is most likely rafting.

Where They Live

California sea lions live in the shallow waters of the eastern North Pacific Ocean. They prefer sandy beaches or rocky coves for breeding and haul-out sites. Along the West Coast, they also haul out on marina docks as well as jetties and buoys. California sea lions range from southeast Alaska to the Pacific coast of central Mexico. Their primary breeding range is from the Channel Islands in southern California to central Mexico. NOAA Fisheries divides the California sea lion population into three stocks (United States, western Baja California, and Gulf of California) based on the location of major rookeries and the international border. The U.S. stock waters ranges from the U.S./Mexico border to Canada. In normal years, male California sea lions migrate during the winter to feeding areas off California, Oregon, Washington, British Columbia, Canada, and southeast Alaska but females and pups stay near the breeding colonies until the pups are weaned. In warm water (El Niño) years, some females are found as far north as Washington and Oregon, presumably following prey.

World map providing approximate representation of the California sea lion’s range.

Lifespan & Reproduction

Males are polygamous, establishing breeding territories that may include up to 14 females. They defend their territories with aggressive physical displays and vocalization. Sea lions reach sexual maturity at 4 to 5 years old, but do not become socially mature until much older—they begin holding territories at around 9 to 12 years old. Breeding season lasts from late June to early August; most pups are born from May through June. Three to four weeks after giving birth, females are ready to mate again.

California sea lions separate their nursing and feeding activities. A mother sea lion nurses her pup for 1 to 2 days, then leaves the pup ashore while she travels to feeding areas at sea. She spends 2 to 5 days feeding, then returns to nurse. During the mother's absence, the pup doesn’t eat. Females continue a pattern of going to sea for several days and nursing ashore for several days until they wean their pups. This takes almost a year. If you see a pup on the shore, please leave it be. If it looks to be in distress, call your local marine mammal stranding network member.

Threats

Entanglement

One of the main threats to California sea lions is getting caught in fishing gear. They can become entangled in many different gear types, including traps, pots, or gillnets. Once entangled, they may drag and swim with attached gear for long distances, ultimately resulting in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success and death.

Biotoxins from Harmful Algal Blooms

Under the right conditions, algae can grow out of control. Some algae “blooms” produce toxins that can kill fish, mammals, and birds, and may sicken or even kill humans in extreme cases. California sea lions are top predators, which means these toxins can build up in their bodies, possibly leading to seizures or death from domoic acid poisoning.

Human-Caused Injuries and Mortalities

California sea lions are easy to view in the wild, but this puts them at higher risk of human-related injuries and death. Feeding or trying to feed them is harmful and illegal, because it changes their natural behaviors and makes them less wary of people and vessels. They learn to associate humans with an easy meal and change their natural hunting practices—for example, they take bait catch directly off fishing gear. Sometimes they fall victim to retaliation (such as shooting) by frustrated boaters and fishermen.

They may also be disturbed or harassed by the presence of humans and watercraft. Harassment happens when any act of pursuit, torment, or annoyance might injure them or disrupt their behaviors—and it’s illegal. Remember to share the shore with California sea lions, for their safety and yours.

Scientific Classification

Kingdom	Animalia
Phylum	Chordata
Class	Mammalia
Order	Carnivora
Family	Otariidae
Genus	Zalophus
Species	californianus

Last updated by NOAA Fisheries on 04/07/2025

What We Do

Conservation & Management

All California sea lions are protected under the MMPA. Our work supports protection and conservation by:

• Reducing interactions with commercial fishing gear
• Minimizing harassment and illegal feeding
• Responding to dead, injured, or entangled sea lions
• Encouraging responsible viewing of wild sea lions
• Minimizing the effects of vessel disturbance and other types of human impacts

Learn more about our conservation efforts

Science

Our research has found new aspects of California sea lion biology, behavior, and ecology and helped us understand the challenges that sea lions face. It is especially important in conservation and management—as the population recovers, more sea lions come into contact with people and other protected resources.

Our research includes:

• Assessing abundance, survival, and birth rates and how they change over time as the population grows
• Monitoring food habits and foraging ecology to understand the role of sea lions in the coastal and offshore marine ecosystem under different environmental conditions
• Describing disease ecology and human sources of death and the role they play in the population’s health

Learn more about our research

How You Can Help

Keep Your Distance

Be responsible when viewing marine life in the wild. Observe all seals and sea lions from a safe distance of at least 50 yards and limit your time spent observing to 30 minutes or less.

Learn more about our marine life viewing guidelines

Report Marine Life in Distress

Report a sick, injured, entangled, stranded, or dead animal to make sure professional responders and scientists know about it and can take appropriate action. Numerous organizations around the country are trained and ready to respond. Never approach or try to save an injured or entangled animal yourself—it can be dangerous to both the animal and you.

Learn who you should contact when you encounter a stranded or injured marine animal

Report a Violation

Call the NOAA Fisheries Enforcement Hotline at (800) 853-1964 to report a federal marine resource violation. This hotline is available 24 hours a day, 7 days a week for anyone in the United States.

You may also contact your closest NOAA Office of Law Enforcement field office during regular business hours.

Featured News

Channel Islands Marine & Wildlife Institute staff measure the thickness of the sea lion's blubber in preparation for an x-ray. Photo courtesy Channel Islands Marine & Wildlife Institute Feature Story

California Man Sentenced to 3 Years in Prison for Sea Lion Beating

West Coast A sea lion with domoic acid poisoning experiencing involuntary muscle spasms. Credit: Channel Islands Marine & Wildlife Institute Feature Story

Early Bloom of Toxic Algae off Southern California Sickens Hundreds of Sea Lions and Dolphins

West Coast The California sea lion was estimated at about 2 years old when it was found shot in the back at Bolsa Chica State Beach August 7, 2024. Feature Story

Reward Offered for Information on Shooting of Sea Lion Found Alive on Bolsa Chica State Beach

West Coast At first glance, seals (true or “earless seals”) and sea lions look fairly similar. Taking a closer look, these are some of the general differences to tell these animals, such as on the harbor seal (left) and California sea lion (right) pictured above. Feature Story

Is It a Seal or a Sea Lion?

Alaska New England/Mid-Atlantic Pacific Islands West Coast National View More News

Related Species

Steller Sea Lion

Northern Fur Seal

Guadalupe Fur Seal

Management Overview

The California sea lion is protected throughout its range under the Marine Mammal Protection Act.

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Conservation Efforts

Minimizing Harassment and Illegal Feeding

As humans interact more with seals and sea lions, they risk disturbing or injuring these animals. Learn more about how to safely and responsibly view seals and sea lions.

Learn more about the rules on feeding and harassing marine mammals in the wild

Reducing Interactions with Fishing Gear

California sea lions can get entangled in fishing gear, causing injury and possibly death. NOAA Fisheries is working to better understand and characterize the frequency, geographic extent, and magnitude of these interactions. We are also working with researchers to find and study ways to safely and effectively make these interactions less likely.

Learn more about bycatch and fisheries interactions

Overseeing Marine Mammal Health and Stranding Response

We work with volunteer networks in all coastal states to respond to marine mammal strandings including all pinnipeds. When stranded animals are found alive, NOAA Fisheries and our partners assess the animal’s health and determine the best course of action. When stranded animals are found dead, our scientists work to understand and investigate the cause of death. Although the cause often remains unknown, scientists can sometimes attribute strandings to disease, harmful algal blooms, vessel strikes, fishing gear entanglements, pollution exposure, and underwater noise. Some strandings can serve as indicators of ocean health, giving insight into larger environmental issues that may also have implications for human health and welfare.

Learn more about the Marine Mammal Health and Stranding Response Program

Marine Mammal Unusual Mortality Events

California Sea Lions have been part of declared unusual mortality events in the past. Under the Marine Mammal Protection Act, an unusual mortality event is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." To understand the health of marine mammal populations, scientists study unusual mortality events.

Get information on active and past UMEs

Get an overview of marine mammal UMEs

Regulatory History

This species is protected under the Marine Mammal Protection Act of 1972, as amended.

Key Actions and Documents

Incidental Take

Incidental Take Authorization: City & Borough of Yakutat, Alaska's Yakutat Small Boat Harbor Replacement Project in Yakutat, Alaska

Incidental Take Authorization: City & Borough of Yakutat, Alaska's Yakutat Small Boat Harbor Replacement Project in Yakutat, Alaska

• Notice of Final IHA
• Notice of Proposed IHA

Notice, Alaska Effective 08/01/2026

Incidental Take Authorization: Oregon Department of Transportation’s Yaquina Bay Dolphin Replacement Project in Newport, Oregon

Incidental Take Authorization: Oregon Department of Transportation’s Yaquina Bay Dolphin Replacement Project in Newport, Oregon

• Notice of Final IHA
• Notice of Proposed IHA

Notice, West Coast Effective 11/01/2025

Incidental Take Authorization: Scripps Institution of Oceanography's Geophysical Surveys in the Cascadia Subduction Zone of the Northeast Pacific

Incidental Take Authorization: Scripps Institution of Oceanography's Geophysical Surveys in the Cascadia Subduction Zone of the Northeast Pacific Ocean

• Notice of Final IHA
• Notice of Proposed IHA

Notice, West Coast Effective 09/02/2025

Incidental Take Authorization: Washington Department of Transportation's Mukilteo Wingwalls Repair Project in Puget Sound, Washington

Incidental Take Authorization: Washington Department of Transportation's Mukilteo Wingwalls Repair Project in Puget Sound, Washington

• Notice of Final IHA
• Notice of Proposed IHA

Notice, West Coast Effective 01/05/2026

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More Information

• Marine Mammal Protection
• Marine Mammal Permits and Authorizations

Last updated by NOAA Fisheries on 04/07/2025

Science Overview

NOAA Fisheries researches the biology, behavior, and ecology of the California sea lion. We use the results to inform management decisions and recovery efforts for this depleted species.

Stock Assessments

Determining the number of California sea lions in each population—and whether a stock is growing or shrinking over time—helps resource managers assess the success of conservation measures. Our scientists collect information and present these data in annual stock assessment reports.

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Additional Research

NOAA scientists conduct wide-ranging research on the biology, life history, and health of California sea lions including:

• Diet/foraging ecology
• Distribution and migration
• Threats such as disease, contaminants, and entanglement
• Genetics

Learn more about what our scientists are working on

Research & Data

California Current Marine Mammal Assessment Program

We assess the population status of marine mammals in the California Current. West Coast

California Sea Lion Research

California sea lion research in California, Oregon and Alaska. Alaska

Investigations of Peritoneal and Intestinal Infections of Adult Hookworms in Northern Fur Seal and California Sea Lion Pups on San Miguel Island, California

A study of hookworms and their effects on northern fur seal and California sea lion health. February 24, 2011 - Peer-Reviewed Research , Alaska View More

More Information

• Marine Mammal Permits and Authorizations
• Population Assessments

Recent Science Blogs

Survey

Studying Fur Seal and Sea Lion Populations in Sunny Southern California – Blog Post 3

Survey Surfing California sea lions. Credit: NOAA Fisheries/Tony Orr under NMFS Research Permits #22678 and #23283. Survey

Studying Fur Seal and Sea Lion Populations in Sunny Southern California – Blog Post 2

Survey California sea lion pup. Credit: NOAA Fisheries / Tony Orr UAS under NMFS Research Permits #22678 and #23283. Research

Studying Fur Seal and Sea Lion Populations in Sunny Southern California - Blog Post 1

Research Intern Chris Moon searching for marked California sea lions on San Miguel Island. Credit: NOAA Fisheries / Sharon Melin. View More

Last updated by NOAA Fisheries on 04/07/2025

Documents

Document

Final Report: Willamette Falls Pinniped-Fishery Interaction Task Force, Marine Mammal Protection Act, Section 120

Summary of Task Force recommendations

West Coast Document

Final Report and Recommendations of the Bonneville Pinniped-Fishery Interaction Task Force

Marine Mammal Protection Act, Section 120

West Coast Document

West Coast Pinniped Program Investigations on California Sea Lion and Pacific Harbor Seal Impacts on Salmonids and Other Fishery Resources

Results of the West Coast Pinniped Program

West Coast Document

Domoic Acid Toxicity in California Sea Lions (Zalophus californianus) Stranded Along the Central California Coast, May-October 1998

NOAA Technical Memorandum NMFS-OPR- 17

National More Documents

Research

California Current Marine Mammal Assessment Program

We assess the population status of marine mammals in the California Current.

West Coast

California Sea Lion Research

California sea lion research in California, Oregon and Alaska.

Alaska Peer-Reviewed Research

Investigations of Peritoneal and Intestinal Infections of Adult Hookworms in Northern Fur Seal and California Sea Lion Pups on San Miguel Island, California

A study of hookworms and their effects on northern fur seal and California sea lion health.

Alaska More Research

Outreach & Education

Outreach Materials

Fishermen: Do Not Shoot Seals and Sea Lions Video

Don't harm your fishery for all. Shooting seals and sea lions is against the law unless you are an…

Alaska More Outreach Materials More Educational Materials

Last updated by NOAA Fisheries on 04/07/2025