Sea Lions' Role in the Local Ecosystem
Like us, California sea lions are predators and enjoy variety in their diet. They feed on squid, octopus, herring, rockfish, salmon, anchovies and more. They are considered “opportunistic feeders,” eating available prey rather than focusing on one species. As sea lions travel the coast between the Channel Islands in Southern California, north to British Columbia, they learn where prey is abundant and find safe places like PIER 39 to haul out or rest. Just like we frequent a good restaurant and return to a favorite vacation destination, sea lions return to the same places to find food and a safe haven. Instead of flight schedules and traffic, they must be wary of white sharks and killer whales (orcas). Sea lions are an important link in the local marine food web that connects plants to animals through what they eat.
The San Francisco Bay-Delta is an important estuary where fresh and ocean water mix, providing vital habitats for many species of plants and animals. Humans (and sea lions) have depended on the food sources and enjoyed the protected waters for hundreds of years. Unfortunately, years of development and reckless waste management practices damaged the Bay-Delta ecosystem. Overfishing and dumping also contributed to the habitat destruction. Recently, municipalities all around the Bay-Delta have improved waste management, restored wetlands and passed laws that decreased the amount of pollution entering the water and controlled development. Water quality has improved, bringing back salmon, large flocks of birds, sea lions and harbor porpoises.