Recent great white shark sightings prompted the Huntington Beach Police Department to issue an advisory for Orange County beaches Friday.
There have been several sightings during the past week off the coast of Sunset Beach and Seal Beach, according to the advisory.
"Shark Advisory" signs have been posted along the entire Sunset Beach surf line and are expected to remain through the holiday weekend, according to the Police Department.
Lifeguards also posted the advisory signs along the northern section of Bolsa Chica State Beach.
As of Friday morning there were no warnings to stay out of the water, but officials advised swimmers not to provoke or interfere with the sharks.
The sharks, which are juvenile and feed on stingrays, are not known to attack humans, according to the advisory.
The sightings are not unusual, but have shifted areas, the Police Department stated.
A local expert said the sightings were not worrisome.
The area from Santa Barbara to San Diego is a "nursery" for baby sharks, according to Chris Lowe, director of the Cal State Long Beach Shark Lab.
"There have been hundreds of these little sharks out there for years, and thousands of people going in the water every day," Lowe said. "These little sharks swim right by them and nobody seems to be bothered."
It is unusual to see babies beginning in February, which has happened this year. Typically they're seen later in spring, he said.
Lifeguards were expected to work with a Cal State Fullerton marine biology professor Friday to tag and track the shark patterns.
Anyone who sees a shark can report it to the nearest lifeguards, according to the advisory.
KTLA's Melissa Pamer contributed to this article.