Nearly half of all shark and ray species in the Western Indian Ocean are now threatened with extinction, raising urgent concerns about marine biodiversity in one of the world’s most heavily fished regions. A new global study has revealed that the ocean areas most vital for the survival of these species remain largely unprotected, leaving them exposed to intense fishing pressure.
The Western Indian Ocean, stretching from South Africa to the Indian subcontinent and encompassing island nations such as Seychelles and the Maldives, hosts around 270 species of sharks and rays. According to the International Union for Conservation of Nature’s Shark Specialist Group, 46 per cent of these species are facing a high risk of extinction due to rapid population declines driven primarily by overfishing.
Critical habitats mapped, protection remains minimal
Researchers identified 125 Important Shark and Ray Areas (ISRAs) across the region, covering nearly 2.8 million square kilometres of ocean. These areas are scientifically recognised as essential for feeding, breeding and migration throughout the life cycles of sharks, rays and chimaeras. However, the study found that only 7.1 per cent of these critical habitats overlap with existing marine protected areas, and just 1.2 per cent fall within fully protected no-take zones where fishing is banned.
Experts describe the findings as alarming. Conservation scientists note that most ISRAs remain open to both industrial and artisanal fishing, undermining the survival prospects of already vulnerable species. Many of these habitats lie in biodiversity-rich but weakly regulated waters, where enforcement of fishing rules is often inadequate.
Fishing pressure driving a silent marine crisis
The Western Indian Ocean has been described by scientists as a conservation “dark spot,” where high dependence on marine resources collides with poor fisheries management. Sharks and rays are frequently caught intentionally or as bycatch using destructive gear such as gill nets. Unlicensed fishing vessels, limited monitoring, and fishing inside protected zones further intensify the crisis.
Several species with slow growth rates and low reproductive capacity, including deepwater sharks and critically endangered rays, are particularly vulnerable. In some cases, researchers relied on fisheries records and citizen science data to identify habitats for species that are rarely studied or observed, highlighting major gaps in scientific knowledge.
Despite global commitments to protect 30 per cent of the world’s oceans by 2030, only 6.4 per cent of the Western Indian Ocean is currently under protection, and less than one-third of that area is fully protected from fishing. Scientists warn that expanding marine protected areas without placing them in ecologically important locations will not halt species decline.
The study urges governments to prioritise sharks and rays in conservation planning, using ISRAs to guide the placement and redesign of protected areas. Experts also stress that protected zones must be supported by effective fisheries management in surrounding waters, as many shark and ray species are highly mobile and often move beyond protected boundaries.
Without urgent, targeted action, researchers warn that the ongoing erosion of shark and ray populations could destabilise marine ecosystems across the Western Indian Ocean, threatening food security, livelihoods and ocean health for millions of people who depend on these waters.