Depredation
& Shark Diving
What Is Depredation?
Depredation occurs when a shark or other predator removes or damages a fish that has been hooked or caught by an angler. It is a growing concern for recreational and commercial fishermen throughout Florida.
It is hypothesized that shark diving increases depredation by teaching sharks to associate boats with food. However, current research does not support the conclusion that Florida’s shark diving industry is the primary driver of depredation.
A sandbar shark depredates a little tunny from a fishing line in Jupiter, Florida. Photo: Tobey Curtis/NOAA Fisheries
What Does the Research Show?
Research shows that depredation rates vary significantly across Florida and are highest in the Florida Keys and western Florida Panhandle —
areas where there are currently no established shark diving operations.
Scientists believe depredation is influenced by multiple factors,
including:
• Increased fishing pressure
Studies have also identified bull sharks and sandbar sharks as species most commonly associated with depredation. In contrast, lemon sharks are among the species most frequently encountered during Florida shark dives.
• Habitat degradation
• Declining fish populations
• Growing coastal populations
• Increased boating activity
These findings suggest that depredation is influenced by multiple factors and that the sharks most often encountered during shark dives are not necessarily the same species most frequently involved in depredation events.
• Recovery of some shark populations
Depredation is a complex issue that cannot be explained by a single cause.
Depredation Didn't Start
with Shark Diving
Shark depredation has existed for as long as people have fished.
One of the most common claims made in support of H.R. 3831 is that attractant-based shark diving is responsible for increasing shark depredation. History tells a very different story.
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Long before modern shark-diving operations existed, anglers were already describing sharks stealing hooked fish.
In the mid-1930s, Ernest Hemingway wrote about sharks "apple-coring" bluefin tuna—attacking hooked fish so aggressively that anglers were left with little more than the head, tail, and backbone.
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Nearly a century later, marine scientists reached the same conclusion.
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A 2026 review published in the ICES Journal of Marine Science examined 100 years of shark depredation in U.S. Atlantic recreational fisheries. The researchers concluded that depredation is fundamentally the result of overlap between anglers, sharks, and the fish both are trying to catch — a conflict that has changed over time with fishing effort, shark abundance, and prey availability.
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FIGURE 1 (a, b) Two depredated, or "apple-cored," bluefin tuna caught off Bimini, the Bahamas (images from Ed Pritchard, antiquefishingreels.com); (c, d) Hemingway stands proudly next to the (c) first and (d) second documented intact bluefin tuna caught off Bimini, the Bahamas as a result of his successful modifications to fishing tackle and techniques (images from Hemingway, 1935).
An angler's perspective
The article Biologists Consider Shark Depredation, written by lifelong recreational angler Charles Paxton, makes an important point:
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Shark depredation was occurring long before shark populations recovered, long before federal shark protections, and long before shark diving became a tourism industry.
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Rather than blaming shark diving, the article argues that depredation has always been part of fishing and that today's conflicts are influenced by many factors, including the number of anglers on the water, where people fish, the abundance of target species, and how fish are fought and landed.
What the science actually says
The same scientific review found no single solution to shark depredation. Instead, researchers identified several approaches — including improved fishing practices and technical deterrents —and emphasized that any mitigation strategy is likely to reduce, not eliminate, depredation.
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The author also highlights advice that dates back to Hemingway: landing fish quickly reduces the amount of time a struggling fish attracts sharks. Modern fisheries researchers have echoed that same recommendation.
The Bottom Line
Shark depredation is not a new problem, and it did not begin with shark diving.
Historical accounts, nearly 100 years of documented observations, and modern scientific research all show that depredation has accompanied recreational fishing for generations.
The evidence suggests it is a complex interaction between sharks, anglers, and target fish —
not something created by Florida's responsible shark-diving industry.
Scale Matters
Shark Diving
- Operates within approximately 46.3 square miles off Palm Beach County
- Represents just 0.013% of Florida’s adjacent federal waters
- Approximately 2,160 shark diving trips annually
The scale of fishing activity in Florida vastly exceeds
the scale of shark-based ecotourism.
Recreational Fishing
- Approximately 80 million fishing trips annually
- More than 2.4 million licensed saltwater anglers
- Over 1 million registered recreational boats
Current scientific evidence does not support the claim that Florida’s shark diving industry is the primary cause of depredation.
Addressing depredation will require science-based solutions that consider all contributing factors, rather than focusing on a small ecotourism sector operating in a tiny fraction of Florida’s waters.