Shark populations under threat from longline fishing

The fastest sharks in the oceans find few refuges from longline fishing, according to an international study.

Shark populations under threat from longline fishing

The fastest sharks in the oceans find few refuges from longline fishing, according to an international study.

Three-quarters of the marine habitats of North Atlantic blue sharks may be overlapped by longline gear each month, while up to 62% of the shortfin mako’s territory is also affected.

Internationally protected species such as the great white and porbeagle sharks are also at risk, according to the study published in scientific journal Nature yesterday.

Almost 2,000 sharks were tracked with satellite tags by team of over 150 scientists from 26 countries.

Prof Carlos Duarte, professor of marine science at King Abdullah University of Science and Technology in Saudi Arabia, says the data collated could provide a “blueprint” for locating marine protected areas on the high seas.

The ocean’s fastest shark, the shortfin mako, has experienced abundant regional population declines, and large sharks on the high seas account for over half of all by-catch of this species in target fisheries.

Several types of shark found in Irish and European waters are on the “red list” of endangered species issued by the International Union for Conservation of Nature.

A group of Irish scientists recently called on Michael Creed, the agriculture, fisheries and food minister, to ensure that targeted fisheries of elasmobranch species or sharks are not permitted in Irish waters, either by commercial vessels or by sea anglers.

Last year, a Spanish fishing vessel, Virxen da Blanca,was detained in Irish waters with over 168,000kg of “bycatch” shark on board while “fishing for tuna”.

A special sitting of Clonakilty District Court last September heard the vessel had 164,250kg of blue shark, 98kg of mako shark, and 1,250kg of shark fins

Shark fins can fetch a high price in Asia, where they are used in sharkfin soup. The fins are often removed while the shark is still alive and it can then no longer swim effectively and either suffocates or is eaten by other predators.

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