The shark was spotted around 1 p.m., according to the San Diego Fire-Rescue Department's Lifeguard Division.
Lifeguards received a report that the shark was showing aggressive behavior to a group of swimmers and kayakers. The swimmers climbed onboard kayaks and safely arrived at shore. The shark reportedly followed the kayakers to the beach.
The shark was last seen just beyond the surf line at the end of Avenida De La Playa at the south end of La Jolla Shores.
After deciding there was a threat to public safety. lifeguards evacuated the waters between La Jolla Cove and Scripps Pier. They will be closed for 24 hours.