Was it a shark? This is how experts identify shark bites

Tess Sheets | Treasure Coast Newspapers

Show Caption Hide Caption Vero Beach expert, Grant Gilmore, helps identify shark bites Grant Gilmore, senior scientist for Estuarine, Coastal and Ocean Science in Vero Beach, talks about the different types of sharks that inhabit Florida's coastline and the distinguishing bite marks and shapes.

A Saturday afternoon surfing session with friends turned grisly for 14-year-old Kaia Anderson in November, when what felt like a tug on her leg landed her in the hospital with three torn tendons in her Achilles heel.

July 12 was special for the teen. Eight months after what was believed to be a shark clamped down on the girl's foot, her father, Randall Anderson, let her go surfing again.

"She grew up on the beach. She knows the whole circle of life," he said. "She knows sharks do what they do and we do what we do. We’re in their backyard and that’s how it is.”

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The injury likely was caused by a bull or spinner shark that mistook the Melbourne Beach girl's foot for bait fish. The creature moved on after biting Kaia, but left her with 100 stitches.

It’s frequently surfers who fall victim to the mistaken identity. But that’s just because they're the ones most often swimming with the toothy culprit.

An appendage gets mistaken for a fish and — CHOMP! The International Shark Attack File reported 37 unprovoked shark attacks in Florida in 2017, seven of which were in Brevard County and four on the Treasure Coast. No fatalities were reported in the United States, according to researchers.

“If sharks depended on humans for food, they would have starved to death a long time ago,” said Grant Gilmore, senior scientist for Estuarine, Coastal and Ocean Science in Vero Beach. “They’re after their prey."

Still, accidental bites can cause serious damage.

Injuries could range from small cuts, “to complex wounds involving tendons, nerves, blood vessels and bones,” said Dr. Daniel Segina, orthopedic surgeon with Health First Medical Group.

What bit me?

Some fish attacks, like those of a barracuda or bluefish, have occasionally been misidentified as shark bites. Distinct features of the wound can not only help experts distinguish a shark from another creature, but determine the species and size.

Bites from a barracuda or bluefish appear as a slicing laceration, according to Gilmore. The bluefish bite is distinct in its small, cutting wounds.

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Though these critters don’t make a habit of attacking humans, it can happen accidentally, such as when a person walks into a fish feeding frenzy, Gilmore said.

But more often than not, if you think it’s a shark bite, it “almost always” is, Segina said.

“Sea creature bites are, overall, very uncommon with the overwhelming majority of bites on humans being attributed to sharks,” he said.

“Shark bites usually have a distinctive crescent pattern of cuts or puncture wounds. Often there can be significant damage to tissue and sometimes even teeth are left behind in the wound.”

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Correctly identifying the species of shark can help experts better understand its role in its ecosystem and how they influence others around them.

“All these top predators structure all the ecosystems below them,” Gilmore said. “You take them out, and you create imbalance in the ocean and in the lagoon here.

When you look at the whole bait fish, and what’s swimming out there that they’re eating, you find what role they’re playing.”

Though most bites are accidental, serious injuries could require surgery, and recovery times could range from weeks to months.

Cody High of San Angelo, Texas, thought his older brother was pulling a joke soon after a family photo in the shallow waters off of Cocoa Beach in May. It was only the second time in his life that the 15-year-old had been in the ocean.

What felt "like a hand" slapping the back of his leg was actually an elusive creature that onlookers described as a 6-foot bull shark.

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“When I saw blood, that’s when everything started getting serious,” Cody said. “I didn’t look at the leg until I saw my dad. He tried to stay calm but I’m pretty sure he wasn’t calm considering a part of my leg was practically gone. I could feel a part of my left leg just hanging.”

The teen was treated by a surgeon at Arnold Palmer Children's Hospital in Orlando.

Now donning a bite-sized scar, Cody is anxious for his next venture into the ocean.

“I honestly want to go back as quick as possible,” he said.

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Muddled migration

A recent study by researchers at Florida Atlantic University discovered a decline in black tip shark migration to South Florida as waters warm. This snow-bird like migration pattern that takes place each summer is the largest in U.S. coastal waters.

Instead, the creatures are stopping in Central Florida and north to the Carolinas, where the water is murkier than crystal clear South Florida beaches, but just as warm.

This puts those wading in inlet waters filled with bait fish at a greater risk for bites, as sharks can more easily mistake a limb for prey.

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Two shark bites were reported less than 2 miles from one another at Fernandina Beach in North Florida on July 13. The scene prompted a shut down of the beach that day. Both people sustained non-life threatening injuries.

“All shark bites, even ones that appear minor, should be evaluated by a physician,” Segina said. “Even if the bite appears minor, more serious injuries may be present. There is always a significant risk of infection and frequently antibiotics are prescribed.”

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What was that?

Sharks inhabiting our beaches are each identifiable to experts by distinct teeth markings and shapes. Here are some of the most common culprits and the gnarly evidence they leave behind.

Black tip shark: The most common bite on the east Central Florida coast comes from a shark that’s pretty easy to spot.

The black tip shark has a bite distinct in its numerous small teeth punctures, which differ from a bluefish's cutting wounds. The creature— its protruding fin a vision of its namesake— likes to linger about 100 to 200 feet from shore and forage on small fish.

Nurse shark: With tiny teeth used to crush their prey, nurse sharks also gobble on small fish, including lobster. The nurse shark's small, turf-like teeth wouldn't produce a cutting wound, but the creature has been reported to attack humans if provoked.

Sand tiger shark: Sand tiger sharks also feed on small fish, using their pointed, fish-hook-like teeth to hold and swallow their prey whole. They are not a dangerous shark, even though it looks like it would be.

A bite from a sand tiger shark, which is uncommon, would produce small puncture wounds from the top and bottom jaw.

Crikey! Alligator eats bonnethead shark in South Carolina An alligator eats a bonnethead shark on Hilton Head Island, South Carolina, in this video provided by Chris Cox.

Bull shark: Known to be more aggressive, the bull shark has a jaw distinct in its broad, cutting upper teeth and pointed lower teeth. That is for holding prey... coming down and cutting.

If this shark bit someone, it would produce puncture wounds on one side of the bite, cutting on the other.

Tiger shark: Sharp, cutting teeth, similar to those of a bluefish, but bigger, characterize the tiger shark. Their wide jaws allow them to eat sea turtles, which are more abundant on the Treasure Coast than any other area in the western hemisphere.

Their unique jaw produces cutting wounds on the upper and lower portion of the bite.

A bite by a tiger shark is also distinguishable in its saw-like appearance. Once it has latched onto its prey, a tiger shark shakes its head back and forth.

SOURCE: Grant Gilmore, senior scientist for Estuarine, Coastal and Ocean Science in Vero Beach

Reporter Wayne Price contributed to this story.

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2017 Video: Heather Orr, shark bite victim Heather Orr of Palm Bay talks about being bitten in the hand by a shark while swimming at Ocean Ave. Posted April 2017