A new study published Tuesday indicates a “dramatic increase” in the number of great white sharks swimming in Monterey Bay in recent years.
The study finds that water temperatures have warmed in the region since 2014. Therefore, juvenile great white sharks -between 5 and 9 feet long- that traditionally concentrated in warm waters in Southern California are moving north to Monterey Bay.
There was a time were no juvenile white sharks could be seen in the ocean between Manresa State Beach in Aptos and New Brighton State Beach in Capitola. Recently, there are dozens spotted every year, according to research from scientists at the Monterey Bay Aquarium, Duke University, and California State University Long Beach. The sharks patrol the waters in groups between April and October, sometimes within a few yards of the shoreline. The sharks are photographed regularly swimming near people, who often have no clue that the sharks are so close by.
“I’ve seen sharks right under surfers — just a few feet away,” Chris Gularte tells Mercury News, chief pilot with Specialized Helicopters, a tour company in Watsonville that regularly flies over the area. “When the water is warm and they come in the bay, you can see them swim near people all day long. Standup paddlers and kayakers will go right up to them and not realize they are there.”
However, Gularte claims he has not seen sharks from his helicopter in more famous Santa Cruz surfing spots such as Steamer Lane in Santa Cruz or Pleasure Point near Capitola. He also witnesses increasing numbers of sharks off the Salinas River mouth and in San Francisco Bay.
In one tragic interaction last May, surfer Ben Kelly, 26, of Santa Cruz, was bitten about 100 yards from shore at Manresa State Beach in Aptos. A shark bit his right knee, hit an artery and he bled to death. Investigators found that the shark was at least 10 feet long, bigger than the juveniles that have mostly congregated a few miles north.
“What’s been going on here has been really strange and different and unusual and not what we are used to,” said Kyle van Houtan, chief scientist at the Monterey Bay Aquarium. “Monterey Bay is famous for cold water, kelp, otters, anchovies, and whales. One thing that hasn’t been here are juvenile white sharks. But in the past five years or so that has totally changed.”
Southern California has a system to adapt to the influx of juvenile great white sharks. Last year, scientists tagged 53 juvenile great white sharks with transmitters, said Chris Lowe, a marine biologist with Cal State Long Beach. The tags send a signal when the sharks swim close to four special buoys off Santa Barbara, Huntington Beach, Long Beach, and San Clemente. Lifeguards on the beach receive a text alerting them that sharks are in the area.
Credit: Elias Levy.
Lowe is working with officials from the Monterey Bay National Marine Sanctuary to establish a similar system from Seacliff State Beach to New Brighton State Beach, an area locals call “Shark Park.”
Great white sharks generally avoid people, and when they do bite somebody, it’s almost never a sustained attack. It’s a one-time bite, and then they leave.
“We really don’t know the motivations of the sharks when these things happen,” Lowe said. “At best we think the shark made a mistake — they thought they were going after a fish or a seal.”
Sal Jorgensen, a marine researcher with UC Santa Cruz and co-author of the study, explains that newly born great white sharks stay in warm waters close to shore to feed on fish, rays, and squid.
After two or three years in warm water, the sharks grow larger than 10 feet long and swim out to deeper, colder waters. Their teeth widen and become more serrated. Next, the sharks reach sizes of 17 to 19 feet long and eat sea lions and other marine mammals, usually in colder waters in places such as the Farallon Islands.
The “shark nurseries” where they grow have typically been south of Santa Barbara County. But after the Pacific Ocean off the West Coast warmed considerably in an event known as “the Blob” in 2014, warmer conditions have moved northward, the scientists found. The warm conditions endured through El Niño events in 2015-16 and 2018-19 and continue today.
Credit: Elias Levy.
Tyler Fox, a pro surfer who has surfed in the Aptos area for years, said he has noticed a change.
“People are spotting them more and more in the water there,” said Fox, publisher of Santa Cruz Waves magazine. “A couple of my buddies had one swim within 10 feet. The frequency of encounters has definitely increased.”
Fox said surfers he knows did not go back to the area off Manresa Beach after Kelly’s death. But now, particularly in the colder months when the sharks aren’t believed to be around, surfers have returned. He said he surfed there Sunday.
“There are always fluke situations, but I believe in that particular zone, they are cruising around, hanging out, and getting warm,” he said. “They are not in hunting mode. They are not coming at you as you see in Jaws with a fin coming straight at you. I think it’s fairly safe.”