How to survive if you encounter a shark

If you've ever been in the ocean you've probably been close to a shark. Most of the time they do not bother humans except for rare instances of mistaken identity. But this summer there's been a frightening spate of shark attacks along the Atlantic coast, with at least nine people getting bitten in the waters off the Carolinas in recent weeks.

Should you be unlucky enough to encounter a shark in the water, what should you do? Although advice abounds for how to win in one-on-one combat with a shark, David Shiffman, a Ph.D. candidate at the University of Miami who studies shark biology and conservation, told CBS News that fighting back is highly improbable and unlikely. "The overwhelming majority of attacks are hit-and-run style attacks," he said. "The shark bites you and is gone before you even know it."

However, there is anecdotal evidence about ways to thwart a shark attack -- assuming, of course, that you are able to spot a shark before it spots you. Andrew Nosal, Ph.D., a marine biologist at the Scripps Institution of Oceanography advises, "If you have any object with you like a boogie board or selfie stick, you can use that to ward off the shark or strike it if it approaches."

The thinking goes that getting hit or poked by an object would surprise a shark, which is used to dealing with species that don't have appendages like arms and legs that can punch or kick. "Sharks back away because they've never experienced it before," Chris Brewster, president of the United States Lifesaving Association, told CBS News. "You want to help the shark understand that you were misidentified."

A commonly-repeated piece of advice is to punch the shark in the nose, but some experts were skeptical. "Have you ever tried punching underwater?" Shiffman asked. "You don't move very quickly."

Shiffman said that he is hesitant about giving any advice for how to deal with shark attacks because it is so unlikely to occur. "More people are bitten by other people in New York City than are bitten by sharks," he told CBS News.

According to the Florida Museum of Natural History, divers who are confronted by sharks acting aggressively -- swimming in zigzag motions or in an up and down course -- should back up against any available structure in the water such as a reef or pile to limit the angles from which the shark can approach. Divers that are in open water are advised to stand back to back with a fellow diver and gradually rise to the surface.

For everyone else, Shiffman believes that people should bring their focus outside of the water when it comes to avoiding shark encounters. Beach-goers should ensure that they are in an area where lifeguards are present because lifeguards are in a physical position to notice any sharks swimming in the area. Drones are also being used along the coast in Southern California to help spot sharks in the water.

Nosal says it is important to remember that there is no such thing as shark-infested waters. "The sharks live there and cannot infest their own home," he told CBS News in an email. "If anything, the waters are infested with humans. We share that space with the sharks and must remember and respect that."

How a surgeon tends to a shark bite

Dr. Daniel Kapp, a plastic surgeon in Jupiter, Florida, who also treats patients at Jupiter Medical Center's Wound Care Center, has tended to a number of patients with shark bites. "Shark attacks are common in Palm Beach County," he told CBS News. "We get 5-10 shark bites a year."

Sharks can do a lot of damage to the human body. Their teeth are serrated like a shredder to cut prey into smaller portions. If a shark bites a human limb it shreds the layers of skin and tissue, making a bite difficult to repair.

Shark teeth also carry a lot of bacteria that is unknown to researchers. In 2013, researchers in Florida swabbed the mouths of sharks to identify the bacteria present to help doctors prescribe more appropriate antibiotics. The research focused on blacktip sharks and recommended the two best antibiotics to treat their bites.

The environment also plays a role in the level of injuries. "Salt water is filled with bacteria that tends to be aggressive in wounds," Kapp said.

If a shark bites you, call for help and leave the water immediately. If a limb has been torn off and it is within reach, it can be taken to the shore and wrapped in a cool towel for the doctors to try to use later when repairing the wounds.

Once out of the water, apply a tourniquet to the wound area to staunch the bleeding and wait for emergency medical responders. If your body starts to go into shock or becomes extremely cold, wrap yourself in a towel while you wait for help. Do not move around as this can lead to sand getting into the wound or increase blood loss.

Once in the hospital, trauma surgeons and plastic surgeons manage bite wounds. Patients have the level of damage assessed for repair, and they are treated with broad-spectrum antibiotics to reduce the likelihood of infection. Kapp said that doctors also spend a lot of time washing sand out of wounds. From there, patients may need extended wound care depending on the severity of their bite.

The greatest piece of advice Kapp has to offer with regards to avoiding sharks is not to swim at dusk or dawn, because that's when sharks feed. "Every bite I've taken care of occured at dusk or dawn," he told CBS News.