The rate of shark attacks in Hawaii has been trending upward in recent years, but the risk of getting bitten by one of the feared ocean predators in isle waters remains extremely low: roughly 5-in-1 million, according to new research that examined 55 years of shark attack data from around the globe.
The study published this week in the PLoS ONE scientific journal spotlights seven world regions, including Hawaii, with analysis showing that shark attacks everywhere are highly variable from year to year, but in some locations the rates have increased over recent decades.
Hawaii’s shark attack rate per 1 million population was the highest of all the regions but is still minuscule, according to Steve Midway, assistant professor in the Department of Oceanography and Coastal Sciences at Louisiana State University in Baton Rouge and co-author of the “Trends in global shark attacks” study.
The new research reveals the U.S. Atlantic Coast/Gulf of Mexico and Southern Australia regions also showed noticeable increases in shark attack rates — a doubling in the past 20 years.
Each of the three trending regions has its own dominant shark species: bull sharks off the Atlantic and Gulf coasts, white sharks in Southern Australia and tiger sharks in Hawaii.
Midway said that because complete data were not available for all the locations studied, the shark attack rates were calculated using only the resident human population. Visitor counts — a significant segment of ocean users in Hawaii, Florida, Australia and other areas where shark attacks are more common — were not considered.
With Hawaii’s surging visitor arrivals — nearly 10 million in 2018 — the rates of shark attacks here are even lower than reported in the study, Midway said.
“It’s not a new message in terms of the big picture: The risk is low and that’s been known,” he said. “What we did that was new and a little bit different was look at the place and time globally over more than 50 years,” providing a historical context that might contribute to a better understanding of the risk.
The study authors also hope the information will temper the hysteria that often accompanies shark attacks and “contribute to a more scientifically grounded discussion of sharks and their management and conservation.”
A closer look
From 1960 to 2015 there were 1,215 reported “unprovoked” shark attacks in the U.S., most resulting in minor skin injuries. Twenty-four, or roughly 2 percent, were fatal over the 55-year period. Of the 133 documented shark incidents in Hawaii waters from 1970 to 2015, only seven, or 5 percent, were fatal. (Researchers used the shorter time period in their analysis of some of the regional data.)
Midway, who specializes in fish ecology, said he was intrigued by a spate of seven shark attacks off North Carolina in the summer of 2015 and contacted George Burgess at the International Shark Attack File at the University of Florida in Gainesville, a recognized clearinghouse for shark attack reports worldwide.
“We did this to exhale and take a step back when shark attacks happen, and look at it from the big picture,” Midway said. “It’s not meant to be predictive or to tell you how to reduce your chances of getting bitten by a shark. It was designed to provide context to what, relatively speaking, is really a trivial occurrence in just about any one of the regions.”
Burgess said the study, also co-authored by Tyler Wagner of the U.S. Geological Survey, provides “good statistical oomph” to the notion the shark attack risk is slight, with far more people killed or injured by jellyfish, stingrays, sunburn, sand hole collapses, surf accidents and car crashes on the way to the beach.
“What we’ve learned is that the year-to-year variation is not something we get excited about. The real trend is that in certain areas of the world, the attack rate has gone up higher in the last 20 years or so, and other areas did not show that pattern,” Burgess said.
“Of interest is the pattern of increases in areas that have sharks in abundance and humans in some abundance.”
The growing popularity of ocean recreation, especially surfing, is likely one reason for the increase in human- shark interactions and for more diverse areas not historically known for shark attacks emerging in the data. It’s also no coincidence the same regions with increasing shark attack rates also have high rates of technology use, including smartphones, email and the internet, which makes it easier to document and share news of shark attacks, he said.
For those same reasons, the ISAF has become better at developing international contacts to facilitate reporting, according to Burgess.
“I don’t believe the increases we’ve seen are because sharks are suddenly hungry for humans, but are due to changes in the behavior patterns of humans, and the ability to report has increased,” he said.
Midway, who taught summer marine science classes for high school students in Hawaii in 2005 and 2006, said less known factors may be at play as well, including coastal development, environmental conditions and changes in the annual cycles of prey fish that draw sharks to nearshore waters.
“Data on how many sharks are in the water and how many people are in the water are not widely available, and we don’t monitor shark population dynamics well,” he said. “There are a lot of lower-level things going on that we don’t fully understand.”
The study’s findings may be of little comfort to the rare few who beat the odds.
A harrowing account
Of the untold millions of people who entered the ocean in Hawaii last year, Juliun Perkins was one of three who were mauled by a shark. It happened Sept. 8 as he was sitting on his surfboard about a half-mile off Pounders in Laie.
Nearly six months later the 24-year-old Kailua Realtor is still undergoing therapy to recover full use of his right arm, which was mangled by a 10- to 12-foot tiger shark. The incident hasn’t kept Perkins from returning to the waves, although he admits he hasn’t been back to the scene of his terrifying encounter.
“There are sharks everywhere. You just gotta be careful, making sure you’re with people when you surf,” he said. “It all comes back to knowing that’s their territory and we’re visitors to their home.”
During that morning surf session outside Pounders, Perkins was sitting on his board, looking left at others catching waves.
“It snuck up on the other side of me or underneath; I didn’t see it at all beforehand,” he said. “It grabbed onto me, and I knew straight away what was happening. I saw the shark on my arm and remember very clearly that I was surprised it didn’t go for my legs. It almost jumped out of the water.
“I saw its head and eyes, and I could tell it was a tiger shark by the structure of its head,” said Perkins, referring to the species’ characteristic broad, blunt snout.
“It thrashed around; its tail splashed back and forth. I don’t really know why it let go; I’m just grateful it did.”
But that wasn’t the scariest part of his ordeal. His right arm shredded and bleeding profusely, Perkins was still a half-mile from shore and vulnerable in the 6- to 8-foot surf, with occasional 10-footers.
“I had to somehow get in with one arm and avoid these big waves,” he said. “I started paddling and yelling, ‘Shark! Shark! Shark!’ I didn’t think anyone knew I had been bitten at the time, so I was raising my arm in the air so people could see that I was hurt.
“Then a big wave came through and crashed right on me, and I went over the falls. My leash came off, and I was treading water out there with one arm and trying to stay afloat, trying to stay calm, trying not to use energy and trying to get away from the shark and the waves.”
A friend, Mitchell Hashimoto, was farther in and retrieved Perkins’ board, bringing it back to him and then quickly paddling to shore to call 911. Other surfers — Jesse King, Bret Marumoto, Flynn Novak, Drew Wilkinson, Jose Gomez and Ryan Hailstones — came to his aid in the water and on the beach, using their surfboard leashes as tourniquets and rendering first aid.
“They were there the whole time, making sure I was OK. It felt so good to have those six guys with me. Just a few moments before when the wave crashed on me, I thought I was gonna die, so to have them appear made me feel so loved and happy they came.”
When he went into emergency surgery at The Queen’s Medical Center, doctors were uncertain whether they could save his arm.
“I still have some nightmares, or when I’m in the water I think I see shadows moving, but it’s not anything at all,” Perkins said. “But I’ve grown up in the ocean my whole life, and I’m not going to let the fear stop me from doing what I love.”
Perkins’ harrowing account makes it easy to see why shark attacks elicit a visceral reaction in the public. But his experience also underscores another of the study’s messages, that “ultimately, all shark attacks are local,” with the risk best assessed at individual beach or surf spots, depending on the day’s conditions and activities.
“Be careful when you hear about numbers of whatever going up or down, keeping in mind that whether it’s car accidents or falling coconuts to the head or shark bites, each situation is unique as far of causative factors,” Burgess said. “You have to look carefully at what both participants were doing and don’t just fall for the numbers. You have to be skeptical about what might have influenced it.”
ISAF tips for lessening the risk of encountering a shark include staying in groups and not wandering far to keep from becoming isolated in the water; not wearing shiny jewelry that resembles fish scales when reflecting light or brightly colored clothing, since sharks see contrast particularly well; and avoiding murky and contaminated waters and areas being used by fisherman, especially if there are signs of bait fish or feeding activity.
REDUCE YOUR RISK
>> Stay in groups and don’t wander too far, since sharks are more likely to attack a solitary individual.
>> Avoid the water during darkness and twilight hours when sharks are most active and have a competitive sensory advantage.
>> Do not enter the water if bleeding from an open wound, and enter with caution if menstruating; a shark’s olfactory ability is acute.
>> Wearing shiny jewelry is discouraged because the reflected light resembles the sheen of fish scales.
>> Avoid waters with known effluents or sewage and those being used by fishermen, especially if there are signs of bait fishes or feeding activity.
>> The presence of dolphins does not indicate the absence of sharks; both often eat the same food items.
>> Use extra caution in murky water and avoid uneven tanning and brightly colored clothing, as sharks see contrast particularly well.
>> Refrain from excess splashing, and do not allow pets in the water because of their erratic movements.
>> Be wary in the area between sandbars or near steep drop-offs, as these are favorite hangouts for sharks.
Source: International Shark Attack File
IN THE WATER
What victims of shark attacks worldwide were doing when they were bitten:
53% >> Surfing/board sports
30% >> Swimming/wading
6% >> Snorkeling/free diving
5% >> Scuba diving
3% >> Body surfing/horseplay
3% >> Other shallow-water activities
Source: International Shark Attack File
ATTACKS IN U.S.
Of the 66 unprovoked shark attacks worldwide last year, 32 were in the United States. Of those, 16 were in Florida, three were in Hawaii and one was in Massachusetts, where the victim was killed.
International Shark Attack File
AROUND THE ISLES
Recent shark bite incidents in Hawaii
>> Feb. 4, 2019: Hanalei Bay, Kauai. Surfer injured on left leg by tiger shark.
>> Sept. 8, 2018: Pounders, Laie, Oahu. Surfer (Perkins) bitten on right forearm.
>> April 19, 2018: Shipwreck Beach, Poipu, Kauai. Bodyboarder bitten on inner right thigh by tiger shark.
>> March 31, 2018: Kukio Beach, North Kona, Hawaii island. Stand-up paddleboarder suffers severe wounds on right arm and leg from tiger shark.
Source: State Department of Land and Natural Resources