World Sea Lion Day Date in the current year: May 30, 2025

Sea lions, along with fur seals, make up the Otariidae family. Until recently, sea lions were grouped in the subfamily Otariinae, but more recent taxonomies do not group them in a single subfamily. However, all sea lions share certain characteristics that distinguish them from fur seals, such as greater bulk, shorter and coarser fur, and larger prey.

Sea lions are found in both the northern and southern hemispheres, from subarctic to tropical regions, with the exception of the northern Atlantic Ocean. Known for their external ear flaps, long front flippers, ability to walk on all fours, and strong swimming and diving abilities, sea lions are highly agile both in the water and on land. They feed primarily on fish, squid, and other small marine animals, using their sensitive whiskers to detect prey underwater.

Sea lions are social animals that often congregate in large colonies on beaches or rocky shores, where they engage in vocal communication, especially during the breeding season. They are intelligent, curious and playful and are often seen interacting with people and boats. Because of their trainability, they are often used in marine parks and even by the military for underwater detection tasks.

There are six living species of sea lion (Steller sea lion, Australian sea lion, South American sea lion, New Zealand sea lion, California sea lion, Galapagos sea lion) and one extinct species, the Japanese sea lion. The International Union for Conservation of Nature lists three sea lion species (Australian, New Zealand, and Galapagos) as endangered.

Major threats to sea lions include illegal shooting, bycatch in commercial fisheries, habitat loss, climate change, pollution, disease, noise, oil spills, and long nursing periods that make pups vulnerable to predators such as killer whales and sharks. Conservation measures include protection of breeding habitat, captive breeding programs, fisheries management, and awareness campaigns to reduce danger from human contact.

World Sea Lion Day was created by Ocean Connections, a nonprofit organization dedicated to raising awareness of ocean conservation through education. The date, May 30, was chosen to commemorate the birthday of Slick, a California sea lion from the Milwaukee County Zoo who was born on this day in 1986. While the life expectancy for California sea lions in the wild is 8-12 years, Slick lived for 30 years, passing away two and a half months shy of his 31st birthday.

You can get involved with World Sea Lion Day by learning fun facts about these amazing marine mammals and sharing what you’ve learned with others, seeing lions at your local zoo or aquarium if it has any, donating to a conservation organization that focuses on sea lions specifically or marine mammals in general, and spreading the word on social media using the hashtag #WorldSeaLionDay.