International Shark Attack File Report:
US unprovoked shark bites plummeted in 2024
Florida Museum of Natural History
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Bull shark jaw.
view moreCredit: Florida Museum photo by Kristen Grace
2024 was an exceptionally calm year for shark bites. Worldwide, there were only 47 unprovoked attacks, down 22 from the previous year and well below the 10-year average of 70. Four of last year’s attacks resulted in fatalities, also a significant reduction from recent years.
The International Shark Attack File, maintained by the Florida Museum of Natural History, provides data on what are considered unprovoked bites, defined as incidents in which a person does not initiate contact with a shark. Instances in which a person intentionally or unintentionally initiates contact, including spearfishing and releasing sharks from nets or hooks, are not included in the report.
“We’re interested in the natural patterns of shark behavior so that we can understand why people occasionally get bitten by these animals. Any cue or attribute that modifies an animal’s natural behavior is something that, we as scientists, want to exclude,” said Gavin Naylor, director of the Florida Program for Shark Research.
The United States consistently has the highest number of unprovoked bites, a trend that continued last year with a total of 28 reported incidents. An attack by an unknown shark species off the northwest coast of Oahu, Hawaii resulted in the only unprovoked fatality in the U.S.
With warm waters and ample shoreline, Florida had a total of 14 bites, more than any other state. Of these, eight occurred in Volusia County, which bears the unofficial title of shark bite capital of the world. Though unconfirmed, many of these bites were likely from blacktip sharks, whose breeding grounds stretch along the northeast Florida coastline. Many of the sharks in this area are juveniles and haven’t yet fully developed the ability to distinguish between humans and their natural prey, which includes fish, stingrays and other sharks.
In June, a spate of attacks in the Florida Panhandle took place within four miles of each other, injuring three people. A trio of healthcare professionals — two nurses and one paramedic — were vacationing along Watersound Beach in South Walton, FL, where a woman bitten by a bull shark was carried ashore. They and other bystanders provided lifesaving medical attention while first responders were en route to the scene. Less than two hours later, a shark bit two teenagers wading in the shallows of nearby Seacrest Beach.
Bull sharks and tiger sharks are common along Florida’s northern coast, but they rarely venture into recreational areas.
“You’ll see 20 to 30 of them patrolling the coast about 500 feet offshore, where they mind their own business,” Naylor said. Nearby dune lakes that regularly dump freshwater into the sea were reportedly blocked when the attacks occurred. This may have allowed schools of fish, which are invariably followed by sharks, to swim closer to shore than they otherwise would have.
As residents and tourists converge on the coastlines for summer holidays, the likelihood of a shark encounter increases. This was evident over the July 4 weekend when six people were injured by sharks in Texas and Florida. Five of these qualify as unprovoked bites.
“The South Padre Island bites were significant, with several incidents on the same day in the same vicinity,” said International Shark Attack File manager Joe Miguez.
Padre Island, a thin sliver of sand dunes, tidal flats and coastal prairie that begins near the U.S. Mexico border and curves north to Corpus Christi, is the largest barrier island in the world, and its southern terminus is a major tourist attraction. A woman swimming in murky water near one of the island’s sandbars was bitten on her calf, and her husband sustained mild injuries while fending off the shark. Another man was bitten nearby, and a teenager received a small wound when a shark ran into her and grazed her leg, either with its teeth or its rough skin (shark skin is composed of small, flattened teeth called denticles).
Initial reports of the Padre Island attacks speculated that a single shark may have been responsible for the attacks, and the same idea was used to explain the consecutive attacks that took place a month earlier in the Florida panhandle. While it’s possible for a single shark to bite multiple people in an area, there’s little evidence to suggest this actually takes place.
“We can’t preclude that it was the same animal, but what’s often overlooked is that the same climatic conditions that bring people into the water are the same conditions that bring sharks closer to shore,” Naylor said, meaning if there’s one shark nearby, there are likely others as well.
“This naturally increases the likelihood of human-shark encounters,” Miguez said. “In the case of the Padre Island incidents, it is much more plausible that multiple sharks were present in the area, responding to the same environmental cues.”
There were three unprovoked attacks in California, including one in which a surfboard was punctured. Globally, surfers accounted for 33% of all attacks last year.
“People surf where there are good waves, and where there are good waves, there’s turbidity, and where there’s turbidity, there are often bait fish that attract sharks. The turbidity also reduces visibility in the water, making it harder for sharks to see. Some of them make mistakes,” Naylor said.
The three remaining shark bites in the U.S. occurred in North and South Carolina.
Australia typically averages the second-highest number of reported bites and fatalities. Of the 13 shark species that have been known to bite humans, all of them have distributions in Australia’s waters. White sharks and bull sharks are particularly common. White sharks form two overlapping populations along the southwest and southeast spurs of the continent, each with a few hundred adults, down significantly from their estimated historical size.
Even relatively minor bites from a white or a bull shark can be life-threatening, contributing to the country’s high fatality rate. This number oscillates from year to year, however, and in 2019, 2022 and 2024, there were no reported fatalities from unprovoked encounters.
Ten other countries all had single bites, including one in the Red Sea off Egypt’s coast in which a man reportedly swimming outside a designated safety area was killed. Other countries include Belize, Trinidad and Tobago, The Bahamas, the Maldives, Mozambique, French Polynesia, Thailand and the Turks and Caicos.
An unusual incident off the coast of Western Sahara marked the first reported shark attack for the region. A German tourist sailing on a British catamaran traveling from the Canary Islands was attacked while swimming alongside the boat. The incident occurred in remote international waters, and it took several hours for an emergency crew to reach the scene by helicopter. The woman died from her injuries on the return trip.
A man wading through waters of the Vaitarna River in western India was bitten last year by a medium-sized bull shark. Of the species that could be identified from witness accounts, video footage of the attacks and/or the pattern of lacerations left by their teeth, bull sharks were the main culprit of last year’s bites. Unlike most other shark species, bull sharks are tolerant of freshwater environments and have been found in rivers hundreds of miles from the sea. Pregnant females often navigate upstream, where there are fewer predators that pose a danger to their young.
The chances of being bitten by a shark remain incredibly low. According to the World Health Organization, drowning is the third leading cause of accidental death worldwide, and coastal features like rip tides and strong currents pose a greater risk to beachgoers than sharks.
The International Shark Attack File provides a curated list of recommendations for further reducing your risk of a shark bite, such as removing reflective jewelry before entering the water and avoiding areas where people are fishing. For more resources, including the full 2022 report (available 9 a.m., ET, Feb. 6), you can visit the International Shark Attack File’s website. The full infographic with summary statistics and safety tips is also available for download. An individual global bite map, and graph of 20-year bite and fatality numbers and visualization of bites by U.S. state are also available.
Study takes a ‘bite’ out of shark depredation using citizen science
Researchers identify Florida’s ocean ‘bandits’ and most common depredated species
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Researchers use a sterile swab on bite wounds from a depredated fish carcass to collect genetic samples to capture transfer DNA.
view moreCredit: Florida Atlantic Harbor Branch
Shark depredation is a hot-button issue in recreational fishing, as anglers face off against these stealthy ocean bandits. These underwater thieves snatch fish straight off the line, often leaving nothing but scraps – or a broken leader – as evidence of their heist.
The Southeast, a major hub for saltwater fishing, is a depredation “hot spot” due to high fishing activity. While fisheries managers in the United States monitor shark depredation in commercial fisheries, efforts to evaluate these interactions in recreational fishing have been limited.
With Florida’s recreational fishing being economically vital and concerns about rising shark depredation, understanding its extent is crucial. A major research gap is identifying depredating shark species, as most events occur at depth and are rarely observed, making accurate identification difficult.
Florida Atlantic University Harbor Branch Oceanographic Institute researchers and collaborators have addressed these challenges by involving the public in citizen-science research. Using multiple methodologies that included social media, online angler surveys, cooperative fishery-dependent charters, and genetic analysis, the study uncovers the scope and impact of shark depredation in Florida’s recreational fisheries.
Results of the study, published in the International Council for the Exploration of the Sea (ICES) Journal of Marine Science, reveal that across methodologies, snapper-grouper species were the most frequently depredated target species group, and bull sharks and sandbar sharks were the most commonly identified depredating species. Findings show 43% of anglers experienced depredation and the probability of experiencing depredation ranged from 10% to 60% and varied both regionally and seasonally.
“Our research provides crucial insights into the growing challenge of shark depredation, helping to build a comprehensive understanding of this human-wildlife conflict and how different fishery sectors are being affected by it,” said Matt Ajemian, Ph.D., senior author, an associate research professor and director of the Fisheries Ecology and Conservation Lab (FEC) at FAU Harbor Branch.
For the project, Ajemian and his team collaborated with the University of Massachusetts Dartmouth, Cramer Fish Sciences, Mississippi State University, Mississippi-Alabama Sea Grant Consortium, and the Office of Sustainable Fisheries, National Marine Fisheries Service, from June 2020 to September 2023 to quantify frequency and impact and to analyze spatial and temporal trends.
Researchers analyzed the contents of the Facebook group, Sportsmen Fighting for Marine Balance, weekly to capture their perspectives. More than 6,500 members shared their depredation reports from Florida and elsewhere. Additionally, a quarterly online survey was distributed over a year to 4,000 randomly selected Florida saltwater fishing license holders to assess depredation trends and its impact on the fishery.
The researchers also partnered with local fishing charters to collect genetic samples from depredated fish carcasses. Sterile swabs were used on bite wounds to capture transfer DNA, but many depredation events resulted in “bite-offs,” leaving no carcass to sample.
“We quickly realized that getting those perfectly bitten carcasses that fishermen posted on social media was more the exception than the rule on the fishing charters,” said Michael P. McCallister, lead author of the study, a Ph.D. student, and research coordinator, FEC program at FAU Harbor Branch. “So, we had to quickly adapt in order to salvage those sampling events.”
To overcome this obstacle, researchers swabbed the ends of the monofilament fishing line as an alternative DNA source. It was the first time this technique was used and was successful on nearly half the time, showing promise for improving depredator species identification in both recreational and commercial fisheries.
Mutton snapper, red snapper and greater amberjack were three of the five most frequently depredated species in both the content analysis and depredation swab sampling submitted by participating charters. As the stock status of some of these species is concerning, information the researchers have provided on depredation rates of these species can help manage their recovery.
The frequency of depredation varied by season and region, with the highest occurrences in the spring and in the Florida Keys, as well as the southeast and southwest regions of the state. However, while season and region significantly influenced how often depredation occurred, they did not have a significant effect on depredation rates (the percentage of total catch lost to depredation).
“This finding suggests that other factors such as water depth, habitat type, fishing pressure, specific fishing locations, and fishing techniques may play a more direct role in determining depredation rates, influencing patterns on a finer scale beyond broader seasonal or regional trends,” said McCallister.
Shark depredation is a growing concern in recreational fishing worldwide, particularly in regions with high shark populations, such as Australia, the U.S. (Florida), the Caribbean, and parts of the Pacific.
“Our findings could help fishery managers in developing informed, science-based strategies to address shark depredation while balancing conservation and recreational fishing interests,” said Ajemian. “Additionally, this study underscores the power of citizen science. By engaging anglers directly, we can gather valuable data that might otherwise be difficult to obtain, ultimately leading to more effective and inclusive fisheries management.”
Study co-authors are Lauran Brewster, Ph.D., an assistant professor, School for Marine Science & Technology, University of Massachusetts, Dartmouth; Cheryl Dean, senior laboratory manager, Cramer Fish Sciences; J. Marcus Drymon, Ph.D., associate extension professor at Mississippi State University and marine fisheries specialist with Mississippi-Alabama Sea Grant; Clifford Hutt, Ph.D., fisheries management specialist, Atlantic HMS, NOAA Fisheries; and Thomas J. Ostendorf, a research technician, FEC program at FAU Harbor Branch.
The project was supported by the National Oceanographic Atmospheric Administration National Marine Fisheries Service through a grant from the Southeast Cooperative Research Program, awarded to Ajemian.
- FAU -
About Harbor Branch Oceanographic Institute:
Founded in 1971, Harbor Branch Oceanographic Institute at Florida Atlantic University is a research community of marine scientists, engineers, educators, and other professionals focused on Ocean Science for a Better World. The institute drives innovation in ocean engineering, at-sea operations, drug discovery and biotechnology from the oceans, coastal ecology and conservation, marine mammal research and conservation, aquaculture, ocean observing systems and marine education. For more information, visit www.fau.edu/hboi.
About Florida Atlantic University:
Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 30,000 undergraduate and graduate students across six campuses located along the southeast Florida coast. In recent years, the University has doubled its research expenditures and outpaced its peers in student achievement rates. Through the coexistence of access and excellence, FAU embodies an innovative model where traditional achievement gaps vanish. FAU is designated a Hispanic-serving institution, ranked as a top public university by U.S. News & World Report and a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. For more information, visit www.fau.edu.
Shark Depredation Recreational [VIDEO] |
Sharks steal fish straight off anglers’ lines, making Florida a hotspot for depredation—an escalating challenge in recreational fishing and other fishery sectors.
An angler holding a fish that was partially consumed by a shark.
A researcher uses a sterile swab on bite wounds from a depredated fish carcass to collect genetic samples to capture transfer DNA.
Credit
Florida Atlantic Harbor Branch
Credit
Florida Atlantic Harbor Branch
Journal
Journal of Marine Science
Method of Research
Observational study
Subject of Research
Animals
Article Title
A multifaceted citizen-science approach for characterizing shark depredation in Florida’s recreational fisheries
Article Publication Date
11-Feb-2025
