Sharks and rays at high risk


A group of 15 scientists have conducted a study of the global threat status of 21 species of oceanic pelagic sharks and rays and found three-quarters of them to be at high risk of extinction.

The study by Nicholas Dulvy and co-workers is the first of its kind, and is published in the most recent issue of the journal Aquatic Conservation: Marine and Freshwater Ecosystems.

Of the 16 species of pelagic sharks and rays classified as Threatened or Near Threatened according to International Union for Conservation of Nature (IUCN) guidelines, the Giant devilray (Mobula mobular) is Endangered, ten shark species are Vulnerable and a further five species are Near Threatened.

The main threats to the sharks and rays are targeted fisheries for their fins (the valuable fins are traded internationally to meet a burgeoning demand for the Asian delicacy of shark fin soup) and meat, as well as being caught as bycatch.

The group recommends that governments implement the following measures to secure effective conservation of the threatened sharks and rays: implement existing scientific advice for preventing overfishing; draft and implement binding, science-based management measures for pelagic sharks; significantly improve observer coverage, monitoring, and enforcement in fisheries taking pelagic sharks; require the collection and accessibility of species-specific shark fisheries data; conduct stock assessments for pelagic elasmobranchs; implement science-based pelagic shark catch limits; strengthen finning bans by requiring sharks to be landed with fins attached; promote research and gear modifications aimed at mitigating elasmobranch bycatch; and commence programmes to reduce and eventually eliminate overcapacity in pelagic fisheries.

For more information, see the paper: Dulvy, NK et al. (2008) You can swim but you can t hide: the global status and conservation of oceanic pelagic sharks and rays. Aquatic Conservation: Marine and Freshwater Ecosystems, 18, pp. 459"482.