Mystery predators are eating anglers’ fish off the hooks. Florida study finds culprits
Sport fishing has more than its share of wild stories, but there is nothing exaggerated about a growing plague of mangled fish being reeled in along the nation’s southern coastline, researchers say.
Mysterious apex predators are involved, and a newly published study by Florida Atlantic University is identifying the culprits.
It’s sharks, specifically bull sharks, lemon sharks and sandbar sharks, according to FAU’s Harbor Branch Oceanographic Institute.
“The Southeast, a major hub for saltwater fishing, is a depredation ‘hot spot’ due to high fishing activity. ... A major research gap is identifying depredating shark species, as most events occur at depth and are rarely observed,” the institute reported in a Feb. 11 news release.
“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 ... and genetic analysis, the study uncovers the scope and impact of shark depredation in Florida’s recreational fisheries.”
The incriminating genetic evidence was gathered by partnering with fishing charters to collect DNA swab samples from half-eaten fish carcasses. In cases where the entire fish was taken, the monofilament fishing line was swabbed for DNA, the report says.
The study was published Feb. 7 in the Council for the Exploration of the Sea (ICES) Journal of Marine Science. Among the experts contributing to the data were 2,259 Florida recreational saltwater fishing license holders, officials said.
A survey of the anglers revealed:
- 43% of anglers surveyed said they lost catches to depredation
- 344 participants saw the predator that ate their fish and 86.6% said it was a shark
- Among the non-shark predators eating catches were dolphin (6.6%), barracuda (5.2%), Goliath grouper (1.4%) and alligators (0.3%)
- Sandbar sharks (which can reach about 8 feet) and bull sharks (which grow to about 13 feet) were identified as the culprits in three out of every four events
- Mutton snapper, red snapper and greater amberjack were among the most frequently plundered species off Florida’s coastline
- The frequency of depredation varied by season and region, with the highest occurrences during spring in the Florida Keys
Identifying the responsible predators is considered a first step in finding deterrents, scientists said.
“Shark depredation is a complex and polarizing human-wildlife conflict that represents a significant issue facing recreational fisheries,” the study concluded.
“We hope these findings will facilitate discussions between stakeholders and both state and federal fishery managers as they work to develop actionable management measures to address this conflict.”
This story was originally published February 20, 2025 at 11:10 AM with the headline "Mystery predators are eating anglers’ fish off the hooks. Florida study finds culprits."