How Many Sharks Die a Year From Humans?

Somewhere between 80 and 100 million sharks are killed by humans every year, depending on which estimate you use and how much unreported fishing it accounts for. The most widely cited figure comes from a 2013 study that placed global shark mortality at roughly 100 million per year around the year 2000, though even the researchers behind that number acknowledged the true count could range anywhere from 63 to 273 million. More recent work has revised the baseline somewhat downward while revealing that the killing has not meaningfully slowed, and in some fisheries it has accelerated.

Where the Headline Number Comes From

The “100 million sharks a year” figure entered public consciousness from a global analysis published in Marine Policy that estimated total shark mortality from reported landings, unreported landings, discards, and finning. For the year 2000, the study calculated roughly 1.44 million metric tons of shark killed, translating to about 100 million individual animals. By 2010, that tonnage had dipped only slightly to 1.41 million metric tons, or about 97 million sharks. The enormous range of possible values, 63 to 273 million, reflects deep uncertainty about average shark body size across species and how much fishing goes unreported entirely.¹

A decade later, a study published in Science took a different methodological approach and estimated that total fishing mortality rose from at least 76 million to 80 million sharks between 2012 and 2019. Of those, roughly 25 million belonged to species already classified as threatened. The researchers found a 4% increase in mortality in coastal waters and a 7% decrease in open-ocean fisheries over that period.² These two landmark estimates are not necessarily contradictory. The earlier study cast a wider net in what it counted and acknowledged more uncertainty in its range, while the later one used updated data and somewhat different methods. The honest summary is that tens of millions of sharks die from human activity each year, the number has remained stubbornly high for at least two decades, and the true total is almost certainly larger than what gets reported.

Why the True Count Is Almost Certainly Higher

Official fishery statistics capture only a fraction of what actually happens at sea. About half of the global catch of sharks and rays is taken as bycatch and does not appear in official statistics at all.³ Artisanal and small-scale fisheries, which dominate coastal tropical waters across much of Africa, Southeast Asia, and Latin America, are especially poorly monitored. Catch rates of sharks and rays from these fisheries are chronically underreported, creating blind spots precisely where threatened species are most concentrated.⁴

Even in better-monitored industrial fisheries, discards go underreported on a striking scale. A study examining a global fishing hotspot in the eastern tropical Atlantic found that the discards of endangered and critically endangered shark species by a single observed vessel over just three months exceeded the officially reported discards for those species across the entire Atlantic for all of 2018, by a factor of anywhere from 1.3 to 11 depending on the species. Scaling up from that single vessel to the national fleet operating in the region, estimated annual discards were roughly 89 times what was officially reported.⁵ Numbers like those suggest the real annual death toll sits comfortably above even the higher-end estimates.

Commercial Fishing and Bycatch

Most shark deaths are not the result of shark-targeted fisheries. Instead, they happen as bycatch: sharks caught incidentally by boats fishing for tuna, swordfish, shrimp, and other commercially valuable species. The type of gear makes a huge difference in how many sharks die and whether any survive the encounter.

Pelagic longlines, which can stretch for dozens of miles with thousands of baited hooks, are one of the biggest killers. A study of 12 shark species caught as bycatch in the U.S. Atlantic pelagic longline fishery found survival rates ranging from just 33% for night sharks to 97% for tiger sharks, with most species falling somewhere between those extremes. Survival depended on factors like how long the shark was hooked, the water temperature, and whether the vessel was targeting swordfish or tuna.⁶ In western Pacific shark sanctuaries alone, modeling estimated that about 287,000 large pelagic sharks were captured by longlines in 2019, and roughly 110,000 of them died either during capture or shortly after release.⁷

Purse seines, the large nets used to encircle schools of tuna, are another major source of shark mortality. When these nets are set around floating fish-aggregating devices (FADs), which concentrate marine life beneath them, shark bycatch is dramatically higher than in sets targeting free-swimming tuna schools. In the European tropical tuna purse-seine fishery, FAD-associated sets accounted for more than 40% of elasmobranch bycatch, compared with less than 17% for free-school sets, and a high proportion of the sharks caught were juveniles.⁸ In the equatorial eastern Pacific, total mortality of sharks caught in FAD-associated purse seine sets ranged from 80% to 95%, combining deaths on the vessel with deaths that occurred after release.⁹ Those numbers are grim. For sharks unlucky enough to end up in a tuna purse seine near a FAD, even getting thrown back barely improves their odds.

Does Being Released Actually Save Them?

A common assumption is that releasing a shark overboard keeps it alive. But post-release survival depends heavily on species, handling practices, and the condition the shark is in when it goes back into the water. Research on discarded sharks in Pacific tuna longline fisheries found that the strongest predictors of survival were the animal’s condition at release, the type of branchline leader material used, and how much trailing fishing gear was left attached. Sharks released in good condition on monofilament leaders without trailing gear had the highest survival rates, but many sharks were already dead or dying by the time crews cut them loose.¹⁰

The implication is that “discarded” does not mean “survived.” When fishery statistics record sharks as released, a substantial but unknown fraction of those animals die anyway. This hidden post-release mortality is one of the reasons the 80-to-100-million headline number is almost certainly conservative.

Recreational Fishing and Shore-Based Catches

Recreational fishing kills far fewer sharks than commercial operations, but the toll is not trivial, and post-release mortality varies wildly by species. A study of shore-based recreational shark fishing in Texas found post-release mortality ranging from 0% for bull and tiger sharks to nearly 46% for blacktip sharks. Great hammerheads fared poorly: of two tagged individuals, one died within 30 minutes of release and the other showed signs of mortality two weeks later. Water temperature played a role too, with moribund blacktips experiencing noticeably warmer water than survivors.¹¹

Juvenile sharks are also vulnerable to catch-and-release angling. A study of juvenile lemon sharks found that about 12.5% died following release during a short tracking period, regardless of their size.¹² The takeaway for anglers: best practices matter. Minimizing fight time, keeping sharks in the water during unhooking, and avoiding fishing during extreme heat all reduce the chance that a released shark dies shortly after swimming away.

Beach Safety Programs

Several Australian states and South Africa operate shark control programs that use drumlines and large-mesh gill nets to reduce the risk of shark encounters near popular beaches. These programs are intentionally lethal. In Queensland’s Shark Control Program, the combination of non-selective fishing gear and soak times of up to three days has historically resulted in 95% at-vessel mortality for both target and non-target species.¹³ The program catches a diverse array of shark species, from small bottom-dwellers to large apex predators like tiger sharks and white sharks.¹⁴

While the absolute number of sharks killed by these programs is modest compared with global fishing, their local impact on coastal shark populations can be severe and has contributed to measurable population declines over decades. Newer technologies like catch-alert drumlines, which notify authorities immediately so sharks can be relocated alive, are being trialed as less lethal alternatives.

The Deepwater Frontier

When most people picture shark fishing, they think of fins, but an increasingly important driver of mortality is liver oil. Deepwater shark species produce squalene, a compound used in cosmetics, health supplements, and vaccine adjuvants. A 2024 study found that one-third of threatened deepwater sharks are actively targeted, and half of all species targeted for the international liver-oil trade are threatened with extinction.¹⁵ Deepwater species reproduce even more slowly than their shallow-water relatives, making them especially vulnerable to exploitation. Unlike the fin trade, the liver-oil trade has attracted relatively little public attention or regulatory pressure, which means many deepwater shark populations are declining with almost no monitoring at all.

Which Species Have Been Hit Hardest

The damage has not been distributed evenly. Open-ocean species that inhabit the same waters as commercially valuable tunas and billfishes have suffered the steepest collapses. In the Gulf of Mexico, oceanic whitetip sharks, once the most commonly encountered species, have declined by more than 99%, while silky sharks have declined by more than 90%.¹⁶ Those declines were already documented by the early 2000s and have not meaningfully reversed since.

Pacific oceanic sharks show a similar pattern. Despite finning bans enacted in 2007, there is little evidence that finning actually decreased in longline fisheries. For species like silky and oceanic whitetip sharks, which are frequently retained whole rather than just finned, banning the removal of fins while discarding the body does little to reduce overall mortality.¹⁷ The broader trend confirmed by multiple studies is that coastal shark mortality has been increasing while open-ocean mortality has slightly decreased, suggesting diverging outcomes under national versus international regulatory frameworks.¹⁸

Conservation Tools and Their Limits

The two main policy tools for protecting sharks are trade regulations and spatial protections like shark sanctuaries. On the trade side, listing species under the Convention on International Trade in Endangered Species (CITES) appears to be producing measurable improvements in management. A 2025 analysis found that CITES Appendix II listings have pushed countries to adopt stronger domestic management, including catch limits and in some cases full legal protection for species found to be too depleted to harvest sustainably.¹⁹ The practical challenge is enforcement. CITES-listed hammerhead sharks, for example, were consistently among the top five species found in Hong Kong’s retail fin market between 2014 and 2016, and exporting countries known to catch them were not among those reporting trade to CITES, suggesting widespread importation without proper documentation.²⁰

Shark sanctuaries, now established by over a dozen countries, show some positive signs: less pronounced population declines, fewer sharks observed being sold at markets, and lower overall fishing threats compared to non-sanctuary areas. But they are not silver bullets. Bycatch, ghost gear, marine debris, and habitat destruction are threats that sanctuary regulations often fail to address, and local experts consistently highlight the need for additional conservation measures.²¹ The bycatch problem is especially stubborn in sanctuaries, since declaring waters off-limits to shark fishing does nothing to stop tuna longliners passing through.²²

What Happens When Sharks Disappear

The scale of shark killing is not just a conservation concern in the abstract. Removing large predatory sharks from marine ecosystems can trigger cascading changes. A 2024 review noted that macropredatory sharks can influence prey populations and coastal ecosystems in ways that include facilitating carbon storage, and that their role may become more important as the ocean changes under a warming climate.²³ The reviewers also cautioned that large ecosystem effects from sharks are not universal; not every reef or coastal system shows dramatic changes when shark numbers drop.

Where the effects have been documented, they follow a recognizable pattern. Along the coast of eastern Australia, decades of catch data from the Queensland Shark Control Program have revealed consistent declines in the functional diversity of apex sharks alongside an increase in mid-level predators. That combination, with top predators vanishing and their prey proliferating, is the signature of a human-driven trophic cascade.²⁴ How far those ripple effects extend into fisheries productivity, reef health, and ecosystem resilience is still being studied, but the pattern is consistent enough to take seriously.

Why Sharks Cannot Bounce Back Quickly

One reason the annual death toll matters so much is that sharks are biologically terrible at recovering from it. Compared to the bony fishes that dominate commercial fisheries, sharks grow slowly, mature late, and produce few offspring. A shark might take a decade or more to reach reproductive age and then produce only a handful of pups per year, or even every other year. This low productivity means that even moderate fishing pressure can push populations into decline, and recovering from overfishing takes decades at minimum. That fundamental mismatch between the rate at which we remove sharks and the rate at which they replace themselves is why researchers keep sounding alarms despite the numbers not looking appreciably different from one decade to the next. Flat annual mortality is not stability; for a slow-reproducing group, it represents ongoing depletion.

The situation is particularly acute in tropical coastal waters, where the extinction risk for sharks is highest and where small-scale fisheries that depend on shark meat and products for protein and income are most prevalent.³ In those communities, sharks are not trophies or bycatch nuisances. They are food and livelihoods. Asking fishers to stop catching sharks without providing alternatives is not just impractical; it is asking people to absorb economic and nutritional losses that wealthier nations never face. Any realistic path to reducing the annual death toll will have to grapple with that reality as honestly as it grapples with the biology.