Guest commentary: What you might not know about La Jolla’s sea lions and how to watch them

La Jolla is a wildlife jewel with nesting birds, sea lions, seals, leopard sharks and more. For at least the past decade, sea lions have chosen La Jolla to rest, give birth, nurse their young and mate.

These highly intelligent mammals delight tourists and locals with their vocalizations and playfulness in and out of the water. So why did sea lions choose La Jolla as a year-round residence, making it the only sea lion rookery on California’s coast?

Though no research has been done, it is thought that this rookery was established when sea lions washed ashore from the Channel Islands, the main breeding area, possibly during a storm. Sea lions chose to stay in La Jolla because they prefer rocky ledges and sandy beaches. La Jolla also has easy access to food, with its deep canyon just offshore giving nursing moms a food source nearby.

Now, with over 50 births recorded annually for several years on Point La Jolla and Boomer Beach just west of The Cove, it qualifies the area as a rookery, according to the definition by the National Oceanic and Atmospheric Administration.

Do they stay all year? Yes! Mother sea lions nurse their pups for up to 11 months, according to a study that found that most weaning of sea lion pups takes place at the end of April and May. This is a lot longer than seals, whose pups are weaned within six to eight weeks. Most male sea lions, juveniles and non-birthing females migrate out of the area during winter. The rookery also is a resting station for migrating sea lions coming from Mexico, so sometimes you may see a lot more sea lions than at other times.

How do they use the area? Sea lions give birth, nurse their young and mate on Boomer Beach and Point La Jolla. As pups develop, they practice their swimming skills in the relative safety of the shallower beach waters and in the rocky crevices on Point La Jolla. Visitors often spend hours watching the pups play and swim. During mating season, males weighing up to 800 pounds establish territories on the beach, rocks and cliff, making it dangerous for people to be in the area. There are regularly over 50 sea lions and pups resting on Boomer Beach.

How do sea lions affect the marine ecology? Sea lions contribute to the ecosystem through their waste material, according to a study by Tiffanie Nelson of the Australian Institute of Marine Science. The guts of sea lions contain bacteria that metabolize iron and phosphorus, important elements for growth of the first tier in the marine food chain — phytoplankton. Hence, sea lions contribute to species productivity and diversity.

What’s the best way to view the sea lions? La Jolla is privileged to have the only rookery on California’s coast where you can see sea lions up close in their natural habitat. Viewing from the sidewalk or by following NOAA’s recommended distance of 50 yards ensures your safety and the best chance for the pups’ survival. If a sea lion approaches you, it is establishing territory and not asking to be in your photo. Preserving their environment and closing their breeding area on Boomer Beach and Point La Jolla ensures that everyone can enjoy watching these playful marine mammals like nowhere else in the world.

Viewing tips

• Watch quietly from the sidewalk and keep your voice low.

• Move slowly so as not to scare the sea lions.

• Never get within 50 yards of sea lions (NOAA recommendation).

• Do not touch or pet sea lions.

• Do not feed sea lions.

• Never throw anything at sea lions.

• Be respectful of sea lions and their habitat.

• It is a violation of the federal Marine Mammal Protection Act to disturb sea lions’ natural behavior by getting close to them. Be a good sea lion visitor!

Robyn Davidoff is a docent with the Sierra Club Seal Society. ◆