Article written by Kylie Marozsan.
The people of Monterey are no stranger to wildlife. From deer on their lawns to harbor seals near their beaches and brown pelicans flying overhead, wildlife is extremely abundant near and in the Monterey Bay National Marine Sanctuary (MBNMS). Last year, around mid-August, San Carlos Beach, a popular scuba dive and beach spot, was shut down on August 19th due to hundreds of California sea lions (Zalophus californianus) congregating there. This year, the sea lions returned in June, more than two months earlier than in 2024.
California sea lions on San Carlos Beach. Photo: Kylie Marozsan, MBNMS Hollings Intern.
California sea lions are protected by the Marine Mammal Protection Act (1972) which prohibits the harassing, hurting, collecting, capturing, and killing of marine mammals. San Carlos Beach was closed at the beginning of June, to ensure the safety of the community and the sea lions; it is encouraged to watch the sea lions from a safe distance of at least 150 feet away. Male sea lions are larger than females, weighing up to 700 pounds in adulthood and reaching about seven and a half feet long. Adult males are also easily identifiable due to their pronounced and lighter colored foreheads. These are called sagittal crests. On San Carlos Beach, just about all of the sea lions were males, or sub-adult males.
Male sea lion barking. Photo: Kylie Marozsan, MBNMS Hollings Intern.
The sea lions stayed for about a month at San Carlos beach, while they stocked up on some of their favorite foods, such as rockfish, squid, and sardines. It seems that these sea lions stop in Monterey before continuing their migration because of the rich productivity that is found in the Bay. They reside in Channel Islands while they breed, and then head north, toward British Colombia. Sea lions can be seen exhibiting a variety of behaviors, such as resting, defending territory, nursing, barking, and rafting. Rafting is a behavior where sea lions enter the water with their flipper out, in order to warm themselves up.
Sea lions rafting. Photo: Kylie Marozsan, MBNMS Hollings Intern.
The abundance of California sea lions on San Carlos Beach is an indicator of the rich biodiversity of Monterey Bay National Marine Sanctuary. Their presence invites us to watch, learn, and protect the ecosystems that support them.
Click here to learn more about California sea lions.