A shark advisory was issued at Coronado's Silver Strand State Beach Thursday after two surfers spotted a shark.
The men, members of the military, were paddling out at around 8:30 a.m. when they saw an 8-foot-long shark, possibly a great white. Lifeguards are working to determine if it was, in fact, a great white shark.
The men were uninjured in the encounter with the non-aggressive shark.
They reported the sighting to lifeguards, who issued a shark advisory, effective through 8:15 a.m. Friday. People were warned to enter the water at their own risk.
But signs posted on the beach did not deter some beachgoers from entering the water Thursday afternoon.
No other sharks have been spotted in the area since that encounter.
Juvenile great whites, typically under 8 feet, are common along Southern California, where they feed on small fish. As they get larger, white sharks start feeding on bigger marine mammals, a factor lifeguards use to consider closures.
According to Christopher G. Lowe, Ph.D., Professor of Marine Biology at California State University Long Beach and Director of the Cal State Long Beach Shark Lab, shark sightings may be high this year because of several factors, including increased great white shark and marine mammal populations.
Lowe said weather patterns like El Nino tend to change migration patterns and said Southern California is considered a great white shark “nursery.” Rising sea temperatures may also contribute to an increase in shark sightings.
The advisory comes more than a month after a woman swimming off the coast of San Onofre State Beach, at a favorite surf spot, was attacked by a 10-foot white shark.