Global warming is being offered as one theory to explain the increase in shark attacks off the North Carolina coast.  The color of summer's bathing suits could  be another theory.

People surround and attend to a 68-year-old man that was bit by a shark in waist-deep water off Ocracoke Island, N.C (Laura I. Hefty via AP)

George H. Burgess, the director of the International Shark Attack File at the Florida Museum of Natural History, believes a "perfect storm" of conditions are coming together to create ideal conditions that attract sharks according to National Geographic.

One of those conditions is the warmer water he says that is created by global warming. “Clearly global climate change is a reality and it has resulted in warmer temperatures in certain places at certain times,” says Burgess. Ocean temperatures reached 80 degrees earlier than usual this year, reports National Geographic, which brought more people to the beach and into the water.

Another condition is a drought in North Carolina which has made the water saltier, another preference of sharks. A small bait fish called menhaden that sharks like have been in plentiful supply off the North Carolina coast.

Burgess says that based on the the bites he has seen bull or tiger sharks are to blame for the recent attacks.

A shark biologist, meanwhile, says brightly colored bathing suits attract sharks as well. "There is a color, almost a fluorescent greenish or yellow that you see on a lot of equipment, which was once called by the U.S. Navy 'yum yum yellow' because it was the one color that sharks would come over and investigate and bite down on. It's only because it's so bright and contrasts with darker colors," Dr. Robert Hueter is a shark biologist at the Mote Marine Laboratory in Sarasota, Fla. tells NBC Charlotte.

Hueter also advises to not wear shiny jewelry into the water as it looks like a fishing lure.

A shark bit a 68-year-old man several times Wednesday in waist-deep water off North Carolina's Outer Banks, officials said, the seventh in a record-breaking year of shark attacks for the state's coastal waters.

A spokeswoman at the Greenville, North Carolina, hospital where he was taken said Wednesday night that the man, Andrew Costello, was in fair condition. Costello is a former editor for the Boston Herald.

He suffered wounds to his ribcage, lower leg, hip and both hands as he tried to fight off the animal, said Justin Gibbs, the director of emergency services in Hyde County. The attack happened around noon on a beach on Ocracoke Island, right in front of a lifeguard tower, he said.