Swimmers warned of sharks off SoCal coast By The Associated Press Wednesday, June 30, 2010 at 6:19 p.m. VENTURA, Calif. â Federal wildlife officials are warning swimmers to enter the water at their own risk after great white sharks were spotted feasting on sea lions around the Channel Islands. The National Park Service says there have been three attacks on California sea lions in the past few months near Santa Barbara Island. There have been no attacks on humans but because of the potential risk a warning was instituted Wednesday and will remain in effect until further notice. Officials say great white sightings in Southern California are rare. Migrating sharks usually pass through without stopping for meals.