Scientists call for protection of newly discovered Indian Ocean hotspot for whales, dolphins

Exeter, England – Scientists call for the Indian Ocean’s Saya de Malha, a vast submerged bank hundreds of kilometres off the coast of East Africa, to be protected after the first survey of the remote area documented a diverse range of cetacean species.[1] The research team led by Greenpeace Research Laboratories at the University of Exeter (UK), which included scientists from the Seychelles and Mauritius, documented 12 species including orcas, sperm whales, and spinner, striped and bottlenose dolphins.

“Saya de Malha is a unique area that includes seagrass meadows and coral reefs, and the steeply shelving edges of the bank appear to be very important for cetaceans. Our survey suggests Saya de Malha supports a diverse range of cetacean species and the relatively shallow waters and tropical currents make it a hotspot for biodiversity, but the geography also means that little scientific work has been done here, as ships tend to avoid it.” said Dr Kirsten Thompson of the University of Exeter.

The researchers are calling for  the Saya de Malha bank to  be designated as either an Important Marine Mammal Area (IMMA) or a Marine Protected Area (MPA). IMMAs are normally designated in regions with extensive research, but Dr Thompson said scientists “just don’t have the data” on many far-offshore places, including Saya de Malha.

The study was based on visual and acoustic surveys (over a 7,700km area) using the Greenpeace vessel MY Arctic Sunrise, which was involved in a wider project to document marine life in the region during 2021. Analysis of sperm whale calls in the new study showed a “match” with a well-studied sperm whale population off the coast of Mauritius, suggesting “possible connectivity” – meaning whales may move between these two areas. More research will be needed to confirm this.

In June 2023, the United Nations adopted a treaty that aims to ensure the conservation and sustainable use of the high seas (beyond national waters). The researchers hope this will be used to protect Saya de Malha.

“The threats facing our world’s oceans are growing bigger and more urgent day by day. By protecting fragile and important habitats like Saya de Malha – placing them off-limits to destructive industries – we can begin to turn this around.

“The UN Ocean Treaty gives us a tool to protect the high seas. It should be ratified urgently and then put to use to protect ecologically vital areas like Saya de Malha,” added Chris Thorne, from Greenpeace’s Protect the Oceans campaign.

ENDS