This new status means that signatory countries must implement much stricter measures against fishing, trade, and habitat degradation of this shark with its distinctive silhouette. For Europe, and especially for the member states of the European Union, this change entails reviewing and strengthening their fisheries and marine conservation regulations to meet the commitments made.
The hammerhead shark, at the highest level of protection by the UN
At the latest summit of the UN Convention on the Conservation of Migratory Species (CMS), held in Campo Grande, Brazil, participating countries approved the inclusion of several hammerhead shark species in Appendix I of the treaty, the highest threat category. This list is reserved for critically endangered species, for which strict protection and a ban on intentional capture are required.
Among the affected species are the great hammerhead and the scalloped hammerhead sharks, which are considered increasingly scarce in many oceans. The great hammerhead shark (Sphyrna mokarran), one of the largest species in the group, has also been added to the list of marine fauna whose situation requires international cooperation and continuous monitoring, as shown by examples in shark sanctuaries.
The Convention, which is legally binding , obliges each signatory party to adopt specific measures in its domestic legislation to safeguard the species in Appendix I. This includes preventing their deliberate killing or capture , minimizing human pressures on their populations, and addressing other risk factors, from habitat loss to accidental capture.
The decision on the hammerhead shark is part of a broader package of agreements at COP15, in which 40 new species have been added to the CMS appendices, but the case of these sharks has attracted special attention because of the sharp decline recorded in recent years.
A historic decline in hammerhead shark populations
Strengthening international protection for the hammerhead shark is supported by compelling scientific evidence . Several studies have documented a widespread decline in oceanic sharks, with estimated decreases of up to 71% over the last fifty years. Specifically regarding the hammerhead shark, the data points to very marked declines in various regions of the world.
In some areas of national waters, records indicate that hammerhead shark populations have declined by approximately 80% compared to historical levels, with documented stranding incidents, such as the one in La Garita . This decline is not only due to targeted fishing but also to high mortality rates associated with accidental capture in nets and longlines intended for other species. The distinctive shape of its head, which gives it its name, increases the likelihood of entanglement.
Research cited by international organizations and expert groups indicates that, of the 31 species of sharks and rays analyzed in a landmark study, 24 are already endangered. These include the scalloped hammerhead shark and the great hammerhead shark, which are classified as critically endangered by the International Union for Conservation of Nature (IUCN).
Scientists emphasize that overfishing is the primary driver of this decline. Demand for meat, fins, and liver oil has pushed catches to unsustainable levels, affecting both industrial and artisanal fisheries in various regions of the world. For some researchers, the message is clear: without fishing limits based on scientific criteria and without effective controls, the future of the hammerhead shark will become increasingly uncertain.
The concern is not only environmental. Conservation experts point out that the depletion of ocean sharks and rays can compromise the health of entire marine ecosystems and, consequently, the food security of coastal communities, especially in developing countries that depend directly on fishing resources.
Obligations for Europe and other signatory countries
The inclusion of the hammerhead shark in Appendix I of the CMS means that the 133 signatories to the treaty, including the European Union and its member states, must demonstrate that they apply strict protection to this group of sharks. This involves not only limiting direct catches, but also reviewing fishing practices, controlling trade, and restoring key habitats.
For Europe, which has already made progress in regulating shark fishing and the fin trade, the new situation requires fully aligning regulations with the treaty's requirements. This could translate into more closed areas, greater restrictions on fishing gear where hammerhead sharks are caught as bycatch, and more thorough monitoring of catches and landings in European ports.
The CMS also includes Appendix II, which lists species in an unfavorable status that require enhanced international cooperation . In the case of the hammerhead shark and other large pelagic species, this translates into the need to coordinate efforts between countries that share migratory populations, both within and outside Europe, so that measures in one territory are not nullified by a lack of controls in another.
In practice, governments will need to demonstrate that their regulatory frameworks are capable of reducing human pressure on these species, whether through catch limits, temporary fishing bans, gear restrictions, or specific management plans. Conservation organizations and shark experts agree that the success of the new protection will depend on how it is implemented in the day-to-day operations of fisheries.
In other regions, such as Australia, the inclusion of the hammerhead shark in the highest category of the CMS has forced a review of exemptions that still allowed some commercial and recreational fishing. Marine biologists point out that, with this change, these species should be completely banned in all jurisdictional waters, which gives an idea of ​​the magnitude of the regulatory adjustment also expected in other member countries.
Human pressure, degraded habitats and migrations at risk
The agreements reached at COP15 come after the publication of UN reports that paint a bleak picture: almost one in four species on the CMS list is threatened with extinction globally, and approximately 49% of species are experiencing declining populations. The hammerhead shark is a prime example of this worrying trend.
Among the most influential factors are the degradation of marine habitats , pollution, the expansion of coastal infrastructure, and the intensification of industrial fishing. In the case of migratory species such as the hammerhead shark, which can travel great distances across oceans and seas, habitat fragmentation and barriers along their migration routes further aggravate the situation.
Meanwhile, a recent report warned of the "collapse" of essential migration de peces of freshwater due to causes such as dams, overexploitation, and river degradation. Although it is a different environment from the marine one, the diagnosis points to a common problem: increasingly disrupted migration routes, with cascading effects on the reproduction, feeding and survival of the species.
Policymakers and scientists agree that protecting the hammerhead shark goes far beyond simply prohibiting its direct capture. It is necessary to reduce bycatch, improve onboard monitoring systems, strengthen controls over supply chains, and advance the restoration of key ecosystems, such as breeding grounds, feeding areas, and migratory corridors.
The CMS insists that wildlife migrations, including those of sharks, show the extent to which nature ignores political borders , forcing cooperative responses that transcend national boundaries, including in the seas surrounding Europe.
Towards stronger cooperation to save the hammerhead shark
In addition to updating the appendices, the latest CMS conference has promoted concerted action plans among groups of countries for specific marine species. While some of these plans focus on other fish, such as the spiny angelfish, they reflect a trend that also affects the hammerhead shark: the need to coordinate conservation measures among states that share migratory populations.
The summit also agreed to develop, for the first time, a specific resource mobilization strategy to support developing countries. The idea is that conservation obligations, including the protection of species such as the hammerhead shark, will be accompanied by sufficient funding and technical support to ensure their implementation.
European conservation organizations have been demanding that these types of instruments translate into more concrete projects in EU and neighboring waters: from the identification of marine areas of special importance for hammerhead sharks to the training of fishermen in the safe release of incidentally caught specimens.
At the same time, experts point out that regulatory advances must be accompanied by improved scientific monitoring. Without solid data on distribution, abundance, and population trends, it is difficult to measure the true impact of protection measures. In this regard, Europe has a network of research centers and monitoring programs that can play a significant role in monitoring the hammerhead shark in the Atlantic and the Mediterranean.
The increased protection of this shark is also part of a broader context: more than 37% of the world's sharks and rays are considered at risk of extinction. The scientific community insists that, if the pressures these animals face are not addressed collectively, the ecological consequences will be difficult to reverse.
The new status of the hammerhead shark as a species under the highest international protection represents an important, but not definitive, step in its conservation: the figures of decline, the risks associated with overfishing and the degradation of the oceans show that there is still much work to be done to ensure that the decisions adopted in multilateral forums translate into seas where these predators can continue to fulfill their ecological role, including in the waters surrounding Europe.
