USA Today NetworkCheri Carlson, Ventura County (Calif.) Star Published 4:48 p.m. ET July 24, 2017 | Updated 5:05 p.m. ET July 24, 2017

For the past 10 years, researchers have tagged juvenile white sharks off Southern California. They found a half dozen hot spots for shark nurseries just off the coast. Cheri Carlson/The Star

Chris Loeb of the California State University-Long Beach Shark Lab releases a juvenile white shark off the coast of Southern California(Photo: Shark Lab at California State University-Long Beach)

VENTURA, Calif. A nursery for great white sharks sits just off Ventura and Oxnard two of a half dozen hot spots along the Southern California coast.

Chris Lowe, a professor at California State University-Long Beach, and his team at the university's Shark Lab searched through close to 100 years of fishery records and identified hot spots for the juvenile sharks. The state started keeping shark records long before the Discovery Channel's Shark Week, which began in 1988 and is having its 30th anniversary this week, had its debut.

About 10 years ago, they began taggingyoung white sharks along the coast to try to confirm those findings. They did.

With the acoustic transmitters that we implant in the sharks, they have to swim within 300 yards of one of our underwater receivers, Lowe said. We have those all along the coast in the Southern California.

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What they found was that the young white sharks stayed in the areas Dana Point, Huntington Beach, Oxnard, Santa Monica Bay and Ventura over the summerbefore working their way down the coast and heading to the Baja Peninsula for the winter.

After the winter, some of those young sharks head back to Southern California the next summer. Some do it over and over again, Lowe said.

Weve seen the number of babies in Southern California steadily increase over the last 10 years. Thats a sign that ... our coastal ocean is getting healthier.

"The sharks that we tag tend to hang out mainly at those hot spot areas during their first few summers," he said.They are safer areas for the juveniles ones away from predators and full of easy-to-catch sting rays.

While the young sharks come back to Southern California, they don't always pick the same spot.Why they pick one over another is one of the questions Lowe would like to answer.

It's still too early in the season to say whether they will hang out off the Ventura County coast this year, but in the past month people have seen them.

In June, state lifeguards posted signs along the beach after authorities confirmed a sighting of a juvenile shark near Ventura Pier.

The beach wasn't closed, which follows a protocol used throughout the area. The signs just acted as an advisory, said Tyson Butzke, Ventura sector supervisor for California State Parks.

The shark, about 6 to 8 feet long,didn't show any aggressive behavior, and the advisory was lifted the next day.

For 20 years, Ventura Harbormaster John Higgins said he hadn't seen any sharks close to shore in the area.

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Then in 2015, surfers, harbor patrol and others saw them regularly just off the coast.

"I could go there almost every day and see them," Higgins said of a spot just south of the harbor beaches.

Beach-goers enjoy a warm day near the Ventura Harbor South Jetty in Ventura, Calif.(Photo: Chuck Kirman, Ventura County (Calif.) Star)

Since then, "we have been kind of invested in knowing about these sharks," he said.

Higgins and others have worked with Lowe to learn more about the sharks and helped set up receivers to help track the tagged sharks.

Now, harbor patrol officers specifically look for the juvenile sharks, and agencies have worked together to share information.

"They are just juvenile white sharks. They're not the great white shark that you see on 'Jaws' or as part of Shark Week," Higgins said.

A newborn great white shark measures 4 to 5 feet long. They grow about a foot annually for the first three or four years.

Weve seen the number of babies in Southern California steadily increase over the last 10 years, Lowe said.Thats a sign that were doing some things right and that our coastal ocean is getting healthier."

Most of the sharks along the beaches in Ventura and Oxnard are between a few weeks and a few years old.

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They tend to stay closer to shore, eating stingrays and fish along the bottom of the ocean.

Aggressive behavior is rare, but people should leave them alone, Lowe said. Like any wild animal, they will defend themselves if threatened.

Follow Cheri Carlson on Twitter:@vcCheri

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