Lunar cycles, water temps, bait fish signal return of sharks

By on July 1, 2015

Bull sharks commonly feed in shallow water.

Experts say the recent spate of shark bites off North Carolina all come down to warm water and plentiful bait — and lots of people getting into the mix.

An attack Wednesday and two last week on swimmers along the Outer Banks followed incidents earlier this month off the southern coast of North Carolina.

The three on the Outer Banks involved a 68-year-old man on Ocracoke Island, a 17-year-old boy at Rodanthe and a 47-year-old man in Avon.

“They were at the wrong place at the right time,” said Frank Schwartz, a marine zoology professor at the University of North Carolina’s Institute of Marine Sciences in Morehead City. “A lot of things came together at the same time. It was a kind of perfect storm for shark attacks.”

Schwartz, who has studied sharks for 48 years in North Carolina, and 13 years prior in Maryland, said the long, cold winter delayed the arrival of warmer water and the summer sharks. With the recent spike in temperatures, the sharks — which like 80-degree water — have converged on the coast at about the same time as throngs of beachgoers.

Temperatures at the Avon Fishing Pier — near where one attack happened — have been hovering between 80 and 82 degrees for most of the month of June.

Sharks are not seeking out people, Schwartz said, but the warm water combined with chasing baitfish can make them aggressive toward an unfortunate swimmer caught in their path.

“They might be following the food or ripples in the ocean,” Schwartz said.

When the ocean dips to 70 degrees or below in September, the sharks will depart quickly.

“The water temperature determines when they’ll be here,” Schwartz said, “or when they won’t be here.”

Here’s what the National Park Service advises:
• Don’t swim too far from shore
• Stay in groups
• Avoid swimming near fishermen or in the vicinity of other aquatic activity like birds diving for fish or bait fish in the water
• Avoid swimming near fishing piers
• Avoid being in the water at twilight or during the night time hours
• Don’t go into the water if bleeding from a wound
• Leave jewelry and shining objects at home

Although he can’t be certain, the professor said he guessed the culprits were bull, spinner or tiger sharks.
For the time being, Schwartz suggested, bathers should stay away from a rough ocean during new and full moons, and “don’t go splashing around too much.”

There are no plans to close the beaches on Cape Hatteras National Seashore, said Cyndy Holda, spokeswoman for the National Park Service Outer Banks Group.

Swimmers, she said, are advised to take precautions and not swim near piers or at dusk when sharks are most likely to feed.

“People should be alert,” Holda said.

Lee Nettles, director of the Outer Banks Visitors Bureau, said his office has been getting calls from worried vacationers. Nettles said visitors are given assurances that there are several lifeguarded beaches and that shark attacks are rare.

But even for those who may be nervous about going into the water, he said, there are many other activities to enjoy on the Outer Banks.

“When it comes down to it, there’s 100 miles of shoreline, and it’s a wild environment,” he said. “It’s like going into the forest. It can be very beautiful, but you might see a bear . . .

“Usually, nature is our strongest calling card. But now it’s giving us pause.”

Still, not everyone is alarmed at the prospect of encountering the master predator during their dip in the sea.

“Yeah, no big deal,” said Scott Ruszkowski, from South Bend, Indiana, as he was leaving Coquina Beach, across the road from the Bodie Island Lighthouse. “We had all the kids out there. We took precautions so as not to look like a baby seal.”

Ruszkowski, who was part of a group of two couples, three other adults and six children, said he has been visiting the Outer Banks for close to 20 years.

One of the girls in his group, Emily Mast, 12, said her mother told her she shouldn’t be too worried because the attacks happened further south.

“I wasn’t that scared,” she said, “but I was still thinking about it.”

Lifeguards on duty have been peppered with questions from beachgoers, said Katherine Walton, a lifeguard with Duck Surf Rescue, which is contracted by the Park Service.

“The most common questions are ‘Have you seen any sharks?’ and ‘Are there sharks out there?’ ” she said, chatting while sitting atop the lifeguard stand at Coquina.

“I say, ‘It’s the Atlantic Ocean, that’s where sharks live,’ ” Walton said with a smile, adding she understands why people are uneasy.

“I think people are spooked about getting in the water.”

But Walton said there have been no issues at Coquina, and while she agrees it is smart to be aware and cautious, she said she would not let fear of sharks affect her vacation.

Still, some would-be swimmers would rather not give any shark the benefit of the doubt.

“We’re not going to go in,” said Cherry Raleigh, who was visiting Coquina with her family from Colerain, N.C. “We’re just going to go to the edge.”

Her 21-year-old daughter Jenna Raleigh, however, wasn’t too worried, although she said she paid more mind to sharks since the attacks were so recent.

“It’s so rare, but people freak out about it,” she said. “I usually go in kind of far. I probably still will. They don’t really bother you. They’re looking for fish.”

Boone Vandzurra, National Park Service acting chief ranger, said in an e-mail that sharks were seen in the area of both Hatteras Island incidents. People at the beach reported seeing the dorsal fin, and specifically in Avon, he said, folks had called out ‘Shark!’

The hands of the boy in the Waves incident were injured fighting off the shark, he said.

Vandzurra said that, based on eyewitness accounts, authorities agree that sharks caused the multiple injuries suffered by both swimmers. But the Park Service is not calling them shark attacks, he added.

George Burgess, director of the shark research program at the Florida Museum of Natural History and the curator of the International Shark Attack File, said that the water is not only warm, it is also saltier than usual, another shark preference. Plus, he said he understands that there are about twice the number of sea turtle nests up and down the coast, providing lots of food moving from ocean to beach for sharks to follow.

Biologists in Cape Hatteras National Seashore report that the seashore is headed for a record-breaking turtle-nesting season.

And to top off the food offerings, Burgess said, there are also big schools of oily menhaden — a prime baitfish for sharks and lesser predators that sharks will also gladly eat.

Add to that sweltering people swarming to the beach with their just-out-of-school children.

“Lots of people,” Burgess said. “Lots of sharks and a lot of food. And that’s a formula for shark attacks.”

The fact that the recent attacks happened earlier in the day than the deadly dusk feeding hour people are warned about is not particularly unusual, Burgess said.

“Sharks move into shallow water all the time,” he said. “They tend to be more active between dusk and dawn.”

In fact, it was around 4 p.m., he said, when one Outer Banks attack and the two serious attacks on the southern beaches happened. That’s about the same time, he said, that sea turtles in the ocean start heading toward the beach.

Burgess said that probably more than one species was involved in the attacks. No doubt the larger sharks would have been either a bull or tiger shark, which go after larger prey.

“No shark focuses on humans because we’re not part of the sea and we’re not on the menu, so to speak,” he said. “When we get bit, it’s either mistaken identity or an exception to the rule.”

“The conditions now are a little different than usual. We’re the ones blessed with the brain; the sharks are the ones with the teeth.”

Despite the recent string of attacks, he said the year will likely end up with an average number.

Burgess’ advice: Stay away from inlets, fishing piers, channels and troughs between sand bars in the surf zone — all favorite shark cruising grounds. Watch for diving seabirds and big schools of baitfish – both indicators of shark food, literally. Be smart about where you choose to go in the ocean.

“The sea is not a backyard pool,” he said. “It’s a wilderness. We’re eco-tourists.”

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