Shark attacks decrease worldwide; is COVID/climate change to blame?
Shark bites appear lower worldwide in 2020 compared to 2019, but researchers don't know whether COVID, climate change, coincidence or something else were factors.
They do know the coronavirus pandemic made it more difficult to get information from hospitals, so while they think their numbers are correct, they couldn't get enough background information to know all the circumstances around the incidents.
There were 129 shark interactions reported in 2020 compared to 140 in 2019. Of those, researchers classified 57 as unprovoked, compared to 64 in 2019, which was fewer than the five-year average of 80 from 2015-19.
Researchers' investigations classified the rest as:
- 39: Provoked
- 16: Unconfirmed
- 6: Attacks on boats
- 6: Not enough information to classify
- 3: Doubtful
- 1: At a public aquarium
- 1: During scavenging
"After the pandemic hit in March, people started speculating that since everyone will be on lockdown and not going into the water as much, that should lead to fewer shark bites," ISAF researcher Gavin Naylor told TCPalm Friday. "The numbers were a little down by midsummer in Florida, but surfers like surfing and continued to surf."
Scientifically, there is nothing that can explain if there is a causal link, he said.
"Some people have speculated there is a link to climate change or some other reason, but we just don't have the data to say so yet," he said. "The short-term trends don't suggest anything."
Shark bites in Florida
Florida accounted for nearly half of the 33 shark bites reported in the U.S. in 2020, down from 41 incidents in 2019 or by a rate of 19.5%.
People reported 16 incidents in Florida, 48% of the U.S. total, compared to 21 in 2019.
Exactly half of those occurred in surf-happy Volusia County, which typically leads the state in shark bites each year. Surfing is the top activity most likely to incur a shark bite. Worldwide, surfing accounted for 61% of bites and swimming accounted for 26%.
ISAF data suggests a downward trend in shark-human activity in Florida. In 2016, there were 36 unprovoked bites, but that number has declined nearly each year, Naylor said.
But some South Florida anglers and divers have reported a perceived increase in shark activity around their boats. The Facebook group Sportsmen Fighting for Marine Balance is working on solutions to that problem.
Meanwhile, a shark-tourism industry has spring up in Florida, generating over $220 million a year, according to a 2016 report released by Oceana.
The state has reported 851 shark bites since 1882, mostly in these top 10 counties:
- Volusia: 312
- Brevard: 150
- Palm Beach: 79
- Duval: 45
- St. Johns: 43
- Martin: 38
- St. Lucie: 35
- Indian River: 22
- Monroe: 17
- Miami-Dade: 16
Shark bite fatalities
One disconcerting statistic was the 13 fatalities worldwide, 10 of which were classified as unprovoked, up from two in 2019.
Three deaths occurred in the U.S.: one in Hawai'i, one in California and one in Maine, believed to be a first for that state:
- A 56-year-old man died from injuries sustained when a large shark of unknown species attacked him as he was paddling on his surfboard off a beach in Maui in December. Authorities would not release his name "to protect patient privacy."
- Benjamin Kelly, 26, of Santa Cruz, was attacked by a shark of unknown species while surfing off Manresa Beach at Monterey Bay in California in May.
- Julie Dimperio Holowach, 63, of New York, was attacked by a shark, believed to be a great white, while swimming off a beach in Maine in July. Great white sharks summer off New England to feed on seals that also summer there.
"It's a striking bump up from the previous year, but when you look back at some other years' data, it's not that unusual," Naylor said. "There were 10 fatalities in 2013 and 13 in 2011. These numbers tend to bounce around a lot and people have short memories. It is a cause for concern, though."
Shark bites in Australia
Australia led the world again with six fatalities, and reported 18 bites, the second-highest number behind the U.S.
The proportion of fatal attacks is higher in Australia because the environment and shark species are different, Naylor said, though there are some similarities to Florida.
"The population of Australia is a lot like it is in Florida. Much of the population lives near the coast. They love their watersports and are in the water all the time," he said. "The big difference between the two is that when a surfer gets bit at New Smyrna Beach, it's often by a blacktip and requires some stitches to recover from. But when a surfer gets bit in Australia, it's by a 2,000-pound, 15-foot-long great white shark. A nibble from a white shark can take off a leg."
ISAF defines unprovoked as "incidents in which an attack on a live human occurs in the shark’s natural habitat with no human provocation of the shark." It defines provoked as "when a human initiates interaction with a shark in some way. These include instances when divers are bitten after harassing or trying to touch sharks, bites on spearfishers, bites on people attempting to feed sharks, bites occurring while unhooking or removing a shark from a fishing net (or after being landed on a beach), and so forth."
Though boating, fishing, diving, spearfishing and beach-going was interrupted in March and April, lifeguards and charter boat skippers began seeing crowds return by mid-May as people realized outdoor activities were less risky for contracting COVID-19.
The coronavirus pandemic also created a data-collecting challenge for ISAF.
"Hospital staff dealing with crowded facilities and providing treatment to people who were sick became a higher priority than answering our requests for follow-up information on reported shark bites," Naylor said. "We knew bites occurred, but we could never confirm the context in which they occurred. So initially, it looks like the trend for shark bites is actually going down."
2020 shark bites by state (total, fatal)
- Florida: 16, 0
- Hawai'i: 5, 1
- California: 4,1
- North Carolina: 3,0
- Alabama: 1, 0
- Delaware: 1,0
- Maine: 1,1
- Oregon: 1,0
- South Carolina: 1,0
Shark bites, which average about 4 a year for a rate of 1 in 3.75 million people, are among the lowest threats to one's life compared to the annual rates and incidents for:
- Heart disease: 1 in 5 (652,486)
- Cancer: 1 in 7 (553,888)
- Vehicle crashes: 1 in 84 (44,757)
- Falls: 1 in 218 (17,229)
- Drowning: 1 in 1,134 (3,306)
- Bicycle crashes: 1 in 4,919 (762)
- Lightning: 1 in 79,746 (47)
- Train incidents: 1 in 156,169 (24)
Tips to avoid a shark bites
- Always stay in groups since sharks are more likely to attack a solitary individual.
- Do not wander too far from shore. This isolates an individual and additionally places one far away from assistance.
- Avoid being in the water during darkness or 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 sport or commercial fisherman, especially if there are signs of bait fishes or feeding activity. Diving seabirds are good indicators of such action.
- Sightings of porpoises do not indicate the absence of sharks. Both often eat the same foods.
- Use extra caution when waters are murky and avoid uneven tanning and bright colored clothing. Sharks see contrast particularly well.
- Refrain from excessive splashing and do not allow pets in the water because of their erratic movements.
- Exercise caution when occupying the area between sandbars or near steep dropoffs, which are favorite hangouts for sharks.
- Do not enter the water if sharks are known to be present and evacuate the water if sharks are seen while there. And, of course, do not harass a shark if you see one!
- Do not be passive if under attack, as sharks respect size and power.
- If you are bitten by a shark, a proactive response is advised. Claw at its eyes and gill openings, two of its most sensitive areas. Hitting a shark on the nose, ideally with an inanimate object, usually results in the shark temporarily curtailing its attack, but the result is likely to become increasingly less effective, so get out of the water during the reprieve.
Source: International Shark Attack File