Protecting sharks requires a layered combination of strategies because no single policy can address the full range of threats these animals face. Overfishing affects every one of the roughly 391 shark and ray species currently classified as threatened, and it is the sole driver of decline for about two-thirds of them. The remaining third face overfishing compounded by habitat loss, climate change, or pollution. That complexity means effective conservation has to work on multiple fronts simultaneously: reducing bycatch in commercial fisheries, regulating the international fin trade, establishing marine protected areas, supporting coastal communities that depend on shark fishing, and closing enforcement gaps on the high seas.
Why Overfishing Dominates the Threat Picture
A global assessment of shark and ray populations found that overfishing is the universal threat affecting all 391 threatened species. For about 67% of those species, fishing is the only significant pressure; the remaining third face fishing combined with habitat degradation, climate change, or pollution.1Current Biology. Overfishing drives over one-third of all sharks and rays toward a global extinction crisis That finding matters for conservation planning because it tells you where the biggest gains are possible. If you could bring fishing mortality under control globally, you would remove the primary threat to the vast majority of imperiled species. Every other conservation tool, from protected areas to habitat restoration, works better once fishing pressure is reduced.
The challenge is that shark fishing is not one problem but many. Some sharks are targeted for their fins or meat. Others are caught incidentally in fisheries aimed at tuna, swordfish, or shrimp. Deep-sea trawlers pull up species that were never commercially valuable and discard them, often dead or dying. Each of these pathways calls for different interventions.
Reducing Bycatch With Better Fishing Gear
Bycatch, the accidental capture of sharks in gear set for other species, is one of the hardest problems in shark conservation because it happens across virtually every commercial fishery that uses hooks, nets, or traps. A comprehensive review of technical measures to reduce shark bycatch found that no single device works across all gear types and all species, but several modifications show genuine promise.2Reviews in Fish Biology and Fisheries. Technical mitigation measures to reduce the bycatch of sharks: there is no silver bullet Among the approaches that reduced bycatch mortality without cutting the catch of target fish were magnetic repellents attached to static gear, removing lightsticks from longlines, adding artificial lights to gillnets, optimizing gillnet mesh size, and using non-entangling fish aggregating devices.
Circle hooks on longlines present a more complicated case. They reduce the severity of injuries to hooked sharks, which improves survival after release, but they can actually increase the rate at which sharks get hooked in the first place. That tradeoff means circle hooks help only when combined with live-release protocols and quick handling procedures.
Even promising technology has limits. Magnetic and electropositive deterrents, which exploit some sharks’ sensitivity to electrical fields, failed entirely with Greenland sharks. Researchers found that these deep-water sharks use a powerful suction-feeding technique that lets them draw bait into their mouths from a distance, bypassing any hook-mounted deterrent entirely.3PubMed Central. Greenland shark (Somniosus microcephalus) feeding behavior on static fishing gear, effect of SMART (Selective Magnetic and Repellent-Treated) hook deterrent technology, and factors influencing entanglement in bottom longlines The lesson is that bycatch solutions need to be species-specific and gear-specific. A deterrent that works on a tropical reef shark might be useless for an Arctic species with a completely different feeding strategy.
When bycatch does occur, retention bans, rules that require fishers to release caught sharks rather than keep them, can reduce overall mortality. For Atlantic shortfin makos, retention bans and mandatory live-release rules have been implemented to help the depleted stock recover. But those regulations only work if sharks survive the experience of being caught and released, and survival rates vary with species, gear type, and handling time.4PubMed Central. Bycatch survival of shortfin mako sharks (Isurus oxyrinchus) in the U.S. Atlantic pelagic longline fishery
Regulating the Shark Fin Trade
The international trade in shark fins is one of the most powerful economic engines behind shark fishing. Several species have been listed under CITES (the Convention on International Trade in Endangered Species), which requires exporting countries to prove that trade is sustainable before issuing permits. In theory, that should slow the flow of fins from threatened populations. In practice, the system leaks badly.
A study examining fin trade data from 2015 to 2021 found that although minimal legal trade was reported for CITES-listed species, fins from four of those species were consistently found in Hong Kong, the world’s largest shark fin market. Eighty-one percent of the 90 known fin-exporting countries had never reported any trade in these species at all, suggesting widespread noncompliance. Genetic analysis of market samples from just one listed species revealed fins originating from six distinct populations, but legal trade had only been reported from three of those regions.5PubMed Central. International trade regulations take a limited bite out of the shark fin trade The gap between what CITES requires on paper and what actually happens in the market is enormous.
One response is to push for outright bans on fin trade rather than relying on managed-trade frameworks. An analysis of what a U.S. fin trade ban would accomplish found that it would carry few tangible economic drawbacks while having a meaningful conservation impact. The reasoning is straightforward: making all shark fisheries worldwide sustainable is the ultimate goal but is nowhere close to being achievable, so banning the fin trade serves as an interim measure that individual nations can take unilaterally.6Conservation Letters. Shark fin trade bans and sustainable shark fisheries Critics argue that bans can push trade underground or penalize well-managed fisheries, but the evidence of persistent illegal trade suggests the current regulatory approach is failing on its own terms.
DNA Barcoding and Market Surveillance
Enforcing trade regulations requires knowing which species are actually being sold, and that turns out to be harder than it sounds. Dried, processed shark fins are nearly impossible to identify by eye. DNA barcoding, a technique that matches a small tissue sample to a species database, has emerged as a key enforcement tool. Researchers in Singapore used DNA barcoding to identify the species of origin for 300 processed fins that could not be visually identified.7PubMed Central. In Troubled Waters: Applying DNA Barcoding to Monitor Singapore’s Shark Fin Trade Market surveillance like this reveals which threatened species are still entering trade and where enforcement is weakest. Without it, CITES listings are largely unenforceable at the point of sale.
Marine Protected Areas and Their Limits
Marine protected areas (MPAs) are among the most visible tools in shark conservation, and they do provide real benefits for species that stay put. A tracking study of grey reef sharks in the U.S. Pacific Remote Islands Marine National Monument found that two-thirds of satellite-tagged sharks remained exclusively within the protected area for up to 1.27 years.8Biological Conservation. Assessing the effectiveness of a large marine protected area for reef shark conservation For a relatively site-attached species near an isolated atoll, a large MPA can offer substantial protection.
But a broad evaluation of MPAs for shark and ray conservation found that both shark-specific MPAs and general MPAs were considered insufficient on their own.9Fish and Fisheries. Sharks, rays and marine protected areas: A critical evaluation of current perspectives The core issue is that many shark species are highly mobile. Porbeagle sharks in the Northeast Atlantic have been tracked across latitudinal ranges spanning thousands of kilometers and diving to depths beyond 1,800 meters, crossing multiple national jurisdictions and the high seas.10Fisheries Research. Transboundary movements of porbeagle sharks support need for continued cooperative research and management approaches Whale sharks tracked from a gathering site off Djibouti entered the waters of at least five nations, facing the risk of capture, entanglement, or boat strikes in each one.11PubMed Central. Regional movements of satellite‐tagged whale sharks Rhincodon typus in the Gulf of Aden
Telemetry data from the Revillagigedo Archipelago in the Eastern Tropical Pacific illustrate another layer of complexity. While some Galapagos and silky sharks stayed around a single island, others moved between marine protected areas separated by thousands of kilometers. One Galapagos shark made a journey of over 3,100 kilometers between MPAs, one of the longest movements ever recorded for the species.12PubMed Central. Shark movements between islands in the Revillagigedo Archipelago and connectivity to other islands in the Eastern Tropical Pacific These long-distance movements show that MPAs protect migratory sharks only during the fraction of their lives spent inside the boundaries. International collaboration and connecting protected areas through migration corridors are essential for species that treat entire ocean basins as home.
Protecting Nursery Habitat on Land and Sea
For species that use shallow coastal waters as nurseries, conservation requires a different scale of thinking. A study of juvenile rig sharks in a New Zealand harbour found home ranges of just two to seven square kilometers, suggesting that a relatively small MPA could cover an entire nursery. But the researchers made an important point: marine protected areas do not control land-based threats like sedimentation and heavy-metal pollution draining into estuaries. Protecting shark nurseries effectively requires integrating marine and terrestrial management across multiple government agencies.13PubMed Central. Temporal and spatial patterns of habitat use by juveniles of a small coastal shark (Mustelus lenticulatus) in an estuarine nursery A no-fishing zone does little good if runoff from upstream development degrades the habitat itself.
The High Seas Governance Gap
Much of the ocean lies beyond any nation’s jurisdiction, and governance there is fragmented. Regional Fisheries Management Organizations (RFMOs) are the main bodies responsible for managing fish stocks, including sharks, on the high seas. But their monitoring capacity is thin. A comparison of 17 RFMOs found that only three require 100% observer coverage on fishing vessels, and none mandate full at-sea monitoring using electronic systems. None require full transparency of observer data.14Marine Policy. An evaluation of Regional Fisheries Management Organization at-sea compliance monitoring and observer programs Without observers on boats, it is almost impossible to know what is being caught and discarded.
Data quality is also an issue. An assessment of data reporting across tuna RFMOs found substantial gaps in the identification of sharks and rays at the species level, and only about half of reported global catches were tied to specific geographic locations despite mandatory requirements to do so.15Fish and Fisheries. Assessing progress in data reporting by tuna Regional Fisheries Management Organizations If you cannot identify what was caught or where, you cannot assess population trends or set science-based catch limits. The recently adopted High Seas Treaty (the BBNJ Agreement) offers a new legal framework to protect ecosystems beyond national jurisdiction, with proposals to manage these areas under conservation-oriented standards.16Frontiers in Ocean Sustainability. The high seas treaty (BBNJ agreement) and planetary sustainability: why we should manage the entirety of ABNJ as a de facto multi-use marine protected area Whether it will translate into meaningful enforcement remains to be seen.
Community-Based Approaches and Alternative Livelihoods
Top-down regulations fail when they ignore the people whose livelihoods depend on fishing. Some of the most encouraging conservation results come from programs that work with fishing communities rather than against them. On Alor Island in Indonesia, a program aimed at reducing catches of endangered thresher sharks combined alternative livelihood support with collaborative species management and community outreach. Fishers who participated in the intervention caught 91% fewer thresher sharks than non-participants, and some saw their income increase by as much as 525% relative to what they had earned before.17Oryx. Designing and evaluating alternative livelihoods for shark conservation: a case study on thresher sharks in Alor Island, Indonesia Violations still occurred, and socio-political conflicts arose, but the researchers noted that these incidents actually catalyzed regulatory changes and strengthened stakeholder collaboration over time.
The economics of shark tourism offer a complementary argument. In Palau, shark diving generates roughly $18 million per year and accounts for about 8% of the country’s gross domestic product, while providing $1.2 million in local salaries and $1.5 million in tax revenue. If the roughly 100 sharks that interact with tourists at popular dive sites were harvested instead, they would be worth at most about $10,800 as a one-time catch. Local fishers earn more selling fish for consumption by shark divers than they would by catching sharks.18Biological Conservation. Socio-economic value and community benefits from shark-diving tourism in Palau: A sustainable use of reef shark populations Numbers like these shift the economic calculus for governments weighing conservation against commercial fishing interests, though the model only works in places with clear water, accessible reefs, and a viable tourism infrastructure.
Deep-Sea Sharks Need Special Attention
Conservation strategies designed for coastal and pelagic sharks do not translate neatly to the deep sea. Deep-sea sharks grow slowly, mature late, and produce few offspring. Their population growth rates are on average less than half those of shelf and pelagic species, and their population doubling times mean that a depleted stock could take decades or even centuries to recover. Recovery potential decreases with depth, so the deepest-dwelling species are the most vulnerable.19Environmental Conservation. Limited potential to recover from overfishing raises concerns for deep-sea sharks, rays and chimaeras
Many of these species are poorly known. The slendertail lanternshark, one of the smallest sharks in the ocean, has the slow growth and late maturity typical of deep-sea elasmobranchs, making it highly vulnerable to fishing pressure even though it has no commercial value.20PubMed. Deciphering age, growth and maturity patterns in one of the smallest but data-deficient shark species, slendertail lanternshark (Etmopterus molleri), from the East China Sea The kitefin shark, found on continental slopes worldwide and listed as Endangered in the Mediterranean, is a common bycatch of deep-sea trawling, yet it is often discarded at sea or landed under generic catch codes that mask its true harvest level.21Frontiers in Marine Science. Jaws from the deep: biological and ecological insights on the kitefin shark Dalatias licha from the Mediterranean Sea Precautionary management of deep-sea fisheries, including catch limits, depth restrictions, and bycatch monitoring, is essential before these species are depleted beyond recovery.
Climate Change as a Compounding Threat
Even if fishing pressure were fully managed, climate change adds a growing layer of risk. Experimental work on Port Jackson sharks showed that warmer, more acidic water increased their energy demands while decreasing their metabolic efficiency and impairing their ability to find food by smell. Sharks raised under elevated CO₂ conditions, alone or combined with higher temperature, grew substantially slower.22PubMed Central. Ocean acidification and global warming impair shark hunting behaviour and growth If these effects hold across species, they could undermine population recovery even where fishing has been curtailed.
Climate change is also expected to shift where sharks live. Modeling of scalloped hammerhead habitat in the tropical eastern Pacific suggests the species would migrate southward into Chilean waters by 2050 as equatorial waters warm and subtropical zones cool.23Marine Environmental Research. The impact of climate change on the distribution of Sphyrna lewini in the tropical eastern Pacific For filter-feeding species like basking sharks, altered ocean temperatures cascade through prey availability and quality, affecting nutrition, immune function, and disease risk.24Journal of Zoology and Systematics. Climate Change Impacts on Basking Shark (Cetorhinus maximus) Nutritional Status, Health, and Ecophysiology: An Integrative Systematic Review Conservation plans that assume species will stay in the same places and behave in the same ways will increasingly fall out of date as oceans change.
Rethinking the Ecological Argument
A common conservation talking point is that sharks are essential apex predators whose removal triggers cascading effects down the food chain, devastating coral reefs and other ecosystems. The science behind this claim is more nuanced than the advocacy suggests. A study across the northern Great Barrier Reef found a fourfold difference in reef shark density between sites, yet this had no detectable impact on the density or biomass of mid-level predators or prey fish.25PubMed. Revisiting the paradigm of shark-driven trophic cascades in coral reef ecosystems A review in a leading ecology journal similarly concluded that evidence for shark-induced trophic cascades benefiting herbivorous fish on coral reefs is weak.26Trends in Ecology & Evolution. The Ecological Role of Sharks on Coral Reefs
That does not mean sharks are ecologically unimportant. Research has found that certain fish populations do respond to reduced predator density, particularly territorial damselfish, whose aggressive behavior makes them especially vulnerable to predation and capable of rapid population expansion when predators are scarce.27PubMed Central. Emerging insights on effects of sharks and other top predators on coral reefs The effects are real but more selective and context-dependent than the simple “remove the shark, collapse the reef” narrative. Honest conservation messaging does not need the oversimplification. The straightforward case, that more than a third of all shark and ray species are heading toward extinction due to preventable overfishing, is powerful enough on its own.
How Media Shapes Public Support
Public perception plays a larger role in shark conservation than most people realize, because political will for fishing regulations, trade bans, and MPA creation depends partly on whether voters care about the species being protected. Research on media influence found that the way media portrays sharks directly shapes how people perceive them, with “good” or “bad” framing tracking closely to audience attitudes. Despite an established fear of sharks, public support for their conservation persists.28Ethnobiology and Conservation. The media paradox: influence on human shark perceptions and potential conservation impacts
A study of U.S. public attitudes found that perceptions, including potential biases about how often shark bites occur, track closely with the volume and tone of media coverage. Exposure to media coverage of shark bites is associated with beliefs that these events are more common than they actually are.29Biological Conservation. Values, attitudes, and media exposure: Public perception of sharks and shark conservation in the USA Conservation organizations have pushed for years to shift media language from “shark attack” to “shark bite” or “shark encounter” precisely because sensationalized language inflates perceived risk and erodes the political space for protective measures. The evidence suggests that a conservation-oriented focus in media messaging can maintain and strengthen public support for the policy changes that sharks need.
Sustainable Fisheries Certification
For shark species that can sustain commercial harvest, eco-certification programs like the Marine Stewardship Council (MSC) offer a framework to distinguish well-managed fisheries from destructive ones. The MSC’s revised standard now assesses shark finning only at the minimum acceptable level, requiring that fisheries either have a fins-naturally-attached policy or a non-retention measure that is in place and enforced.30Marine Policy. How are appropriate performance levels developed for MSC certification? A case study assessing shark finning Whether that bar is high enough is debated, but certification at least creates market incentives for better practices.
The history of these efforts is sobering. The world’s first eco-certified sustainable shark fishery, a Pacific dogfish operation, ultimately struggled due to a combination of oceanographic shifts that temporarily reduced biomass, management changes that altered fishing incentives, industry consolidation, and what researchers described as blowback from overly broad environmental messaging that failed to distinguish between sustainable and unsustainable shark fishing.31PubMed. “A prized Pacific shark”: the rise and fall (and rise again…?) of the world’s first ecolabel certified sustainable shark fishery The case illustrates a tension running through shark conservation: campaigns that treat all shark fishing as inherently destructive can undermine fisheries that are genuinely trying to operate sustainably. Getting the messaging right, drawing clear distinctions between well-managed and unmanaged harvest, matters for keeping the sustainable operators in business.