Shark Attacks may Increase: Experts Warn in U.S.

Shark attacks in California's beaches during the Memorial Day weekend.

Corona Del Mar State Beach: A woman was found bleeding profusely Sunday about 100 yards off the shore. Large bite marks on her upper torso and shoulder were reported by the Associated Press. The Newport Beach, Calif. shoreline were shut down through Monday.

Neptune Beach, Florida: The same day, a 13-year-old boy was bitten on the calf by a nearly 6-foot-long shark while he was wading in waist-high water in the beach which is about 17 miles east of Jacksonville. Though he suffered severe lacerations, he was in stable condition at UF Health Jacksonville on Monday.

"[May is] when our sharks become more abundant in our local waters ... and the animals peak in abundance around June and July," Jim Gelsleichter, a shark expert at the University of North Florida told WJXT.

"These are entirely predictable things just as you can predict drownings or car accidents as a result of this being a huge holiday weekend," George Burgess, director of the International Shark Attack File at the University of Florida, told Reuters about the weekend's incidents.

Reason of the attacks: Increasing population of people and sharks.

A 2015 study by the NOAA Fisheries Service found that shark populations have been increasing on the East Coast, an ongoing trend.

"We've seen an increase in the number of sharks in every survey since 2001; that reflects management efforts to conserve the populations of various shark species," Lisa Natanson, the scientist at the Narragansett Laboratory of NOAA Fisheries' Northeast Fisheries Science Center who led the survey, said in a press release. The survey samples coastal waters from Florida to Maryland and Delaware, where migratory sharks concentrate as the waters warm in the spring and summer.

The last survey, in 2012, found 1,831 sharks. The 2015 survey found 2,835, which is a 55 percent increase.