The world’s fastest shark may be swimming towards disaster after a major fisheries body failed to address continued overfishing of the highly vulnerable species, conservationists have warned.

The shortfin mako – which can reach speeds of up to 43mph – is fished worldwide but is not subject to any international fishing quotas. It is considered exceptionally vulnerable in the North Atlantic, where scientists have recommended all landings be reduced by at least two-thirds to prevent overfishing.

Member states of the International Commission for the Conservation of Atlantic Tunas (ICCAT), which includes the European Union, agreed last year to narrow landing conditions and to report and review all mako catches in 2018. But a review of January to June landings shows catches were already 50% higher than the annual recommended threshold – proving that ICCAT is wildly off track in reducing the shark’s mortality and stopping its overfishing, according to Ali Hood, director of conservation at the UK-based Shark Trust.

“ICCAT has failed to make time to responsibly review and amend a measure for one of the most imperilled species within its purview, and it’s simply outrageous,” said Hood.

“Most of the blame falls squarely with the EU, which – despite being responsible for the vast majority of mako catches – offered no explanation or plan for improvement.”

ICCAT’s 52 party states oversee the conservation of tuna and tuna-like species in the Atlantic Ocean and surrounding seas. The body has adopted bans on retaining other highly vulnerable shark species, including the bigeye thresher and oceanic whitetip shark, but has failed to adequately protect the mako, said Sonja Fordham of Shark Advocates International.

Fordham added: “It is deeply discouraging to see ICCAT go to great lengths to improve the scientific understanding and monitoring of mako fisheries, only to have managers shirk their responsibility to prevent population depletion.”

The mako – a cousin of the great white shark – is a prized catch for commercial fisheries and sport anglers alike. Although sharks are technically considered bycatch, with tuna and swordfish usually the target, in many fisheries they make up the majority of landings: in the Azores, sharks represent more than 80% of the catch in some longline fisheries, said Hood.

“The shark bycatch is what makes the fishery economically viable,” she added. “Mako are landed for their meat and fins: the meat is of high value and consumed in continental Europe, with a particular market in Italy. The fins are destined for export.”