Sea Lion Q&A

Get to know the California sea lions:

California sea lions have always frequented the San Francisco Bay, especially during the winter months when herring spawn in the bay. The Marine Mammal Center’s biologists believe that the sea lions have chosen to haul out at PIER 39’s K-Dock because there’s plenty of food nearby in the bay and ocean, their natural predators (white sharks and orcas) do not typically feed in the bay and there is plenty of space. Also, the docks are easier to haul out on, more comfortable and more protected from storms than a rocky beach. As the tide goes in and out, the floating docks move up and down on the water, so the sea lions just keep sleeping rather then having to scramble up and down rocks with the tide.

Yes. When the first sea lions arrived, the dock was filled with boats and overnight guest docking. The boat owners were not too happy about having to avoid sea lions in order to reach their boats. Initially there was some discussion about how to get rid of the animals and the PIER 39 Marina contacted The Marine Mammal Center to guide their decisions. Ultimately, for the safety of the boat owners, it was decided to leave the dock to the sea lions. Boat owners who owned dock slips were relocated elsewhere in the PIER 39 Marina. The weight of the sea lions–often thousands of pounds–caused K-Dock to submerge, become waterlogged and eventually fall apart. In an attempt to repair K-Dock, PIER 39 built twelve 10′ x 12′ floats which were placed between the fingers of K-Dock. In the summer of 1995, the original K-Dock was removed and more floats were moved in to replace the dock.

Yes and no. From late summer (late July) to late spring (mid May), there are typically hundreds of sea lions hauled out at K-Dock (ranging from 150 to 600+). In June and July, most of the sea lions head south to breeding grounds on the Channel Islands, although a handful to a few dozen have remained throughout the summer in recent years. In late July, non-breeding sub-adult males and juvenile females begin to migrate north again. Other breeding males travel north later, and some males migrate as far north as Alaska and British Columbia, Canada.

It is illegal in the U.S. to feed, harm or harass wild marine mammals, including sea lions. PIER 39 Marina staff hose down the docks when needed (usually weekly during warm weather when there are lots of sea lions), so that the smell of the sea lions does not drive away the tourists and neighboring boat owners. To do this, they use a boat pulling a small raft equipped with a compressor that pumps bay water to be sprayed on the docks. Additionally, The Marine Mammal Center monitors sick and injured animals, rescuing them when possible.