Half of the sharks, rays, and chimaeras in the Arabian Sea are at risk of extinction, according to research by the Environment Agency-Abu Dhabi (EAD).The results of the 2017 IUCN Regional Red List assessment of 153 species, which was carried out in collaboration with the International Union for the Conservation of Nature and the Shark Specialist Group, highlighted the need for urgent action to conserve populations and habitats.It said more than half of the species (78) are considered threatened with an elevated risk of extinction within the region.A further 27 species were assessed as being close to entering a threatened category in the near future. Only 19 species were assessed as being in a healthy state while for another 29 species, there was insufficient scientific information to evaluate their risk of extinction.Overfishing was considered the main cause of threat due to both targeted and incidental capture, the research said."The results are a call for action and highlight the urgent need for regional cooperation in research and policy efforts", said Dr Shaikha Al Dhaheri, EAD’s executive director, Terrestrial and Marine Biodiversity Sector."The rapid development and expansion of deep sea fishing operations in the southeastern Arabian Sea are of concern. There is a need to monitor fisheries, and their catches, to better understand the species being caught, and their status’, added Dr Nick Dulvy, co-chair of the IUCN SSG and researcher at Simon Fraser University.