Officials in Huntington Beach postponed a major surf contest Thursday after spotting an aggressive 10-foot shark in the ocean. Authorities monitored the waters and gave the “all clear” to reopen the area Friday afternoon.

The 8th annual Vans Jack’s Surfboards Pro, a World Surf League Qualifying Series 4,000-level event, draws a large crowd of spectators and surf enthusiasts to the five-day competition and festival.

On Thursday, after the event ended for the day, a shark was spotted off lifeguard tower No. 3, located on the southern-most edge of the beach, said Trevor McDonald, Marine Safety Division Chief for the Huntington Beach Fire Department.

“When you have that combination where you have a larger shark, and you observe aggressive behavior, we take precaution and implemented a 24-hour water closure,” McDonald said.

The species of the shark was unknown. Aggressive shark behavior includes circling and charging in the water.

“The safety of our surfers and staff is our top priority, and in accordance with Huntington Beach City Protocol, the event will remain on hold for 24 hours,” Brian Robbins, World Surf League Tour Manager, said Thursday. “Competition will resume once the water safety team and local authorities confirm the competition area is clear.”

With the competition cleared to resume, the next call for surfers will be Saturday at 6:30 a.m., with a possible 7 a.m. start.

The city’s Marine Safety Division had staff on jet skis and lifeguard boats to help secure the water and monitor for more shark activity during the closure, McDonald said.

“We also have drones that we’ve been able to put up in the air to have an aerial view, and we’re working with our Huntington Beach Police Department and their police helicopter so we can continue with monitoring the area,” he said.

Spotting the 10-foot shark isn’t a typical sighting for the local Marine Safety Division.

“We do sometimes see smaller juvenile sharks, and when you just have a small juvenile shark under 8 feet that’s not showing any type of aggressive behavior, that doesn’t trigger a close like this,” McDonald said. “We only have the closures triggered when we see above 8 feet combined with that aggressive behavior.”

This sighting is on par with what Long Beach Shark Lab Director Chris Lowe predicted would be a “very sharky summer,” caused by a shift in warmer temperatures that start much earlier in the year.

In March, an 8-foot great white was spotted circling a surfer in Newport Beach, which prompted an immediate shutdown of the shoreline.

Another sighting and shark rescue occurred in April when a fisherman in Hermosa Beach freed a juvenile great white caught on a fishing line.