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Research expedition produces first-ever comprehensive ecological surveys of Latham Island, a remote island off the coast of Tanzania and Zanzibar

Latham pinpointed as a significant marine biodiversity hotspot – 60,000+ seabirds, critically endangered sharks and rays, and reefs teeming with fish

Findings highlight the importance of considering Latham Island for designation as Tanzania’s first offshore Marine Protected Area.

Newswise — New York, NY (April 18, 2025) – A first-of-its-kind research expedition to Latham Island has unveiled one of Tanzania’s most ecologically significant marine ecosystems, with thriving seabird colonies, critically endangered sharks, and climate-resilient coral reefs.

The findings—gathered by researchers from WCS and partner institutions like Université de la Reunion, the Ministry of Blue Economy and Fisheries in Zanzibar, and the Ministry of Livestock and Fisheries in Mainland Tanzania—will be used to shape plans for Tanzania’s first offshore Marine Protected Area (MPA), which would secure long-term protection for this remote biodiversity hotspot.

Early data from the expedition revealed that Latham Island is home to the Western Indian Ocean’s largest known seabird colony, with over 7,000 pairs of masked boobies, 11,500 pairs of brown noddies, 12,000 pairs of sooty terns, and a small colony of 130 pairs of great crested terns. Beneath the waves, researchers found multiple species of sharks and rays, including the critically endangered bowmouth guitarfish and scalloped hammerhead shark, as well as records of tiger sharks, bull sharks, the highly migratory shortfin mako shark, and bluespotted maskray.

The survey also collected data on four species of marine mammals, including species typically associated with shallower waters, like the common bottlenose dolphin and the spinner dolphin, as well as species usually found in deeper waters, like the Fraser’s dolphin and the short-finned pilot whale.

“This expedition confirms what conservationists, communities, and fishers have long suspected—Latham Island is a biological gem, and its protection is vital for the region’s marine biodiversity,” said Dr. Jean Mensa, Marine Program Director for WCS in Tanzania. “This is the first comprehensive survey ever conducted here, and we hope this data will directly support efforts in Tanzania to protect this place, one of the highest ecological integrity marine locations in the country.”

Brimming with reef fish, Latham Island’s coral reefs have been shown through ongoing research to be ecologically linked to reefs in Zanzibar. The coral reef data collected on the expedition was uploaded into, to help inform ongoing efforts to identify climate-resilient reefs around the world and in the Western Indian Ocean.

“The first ecological survey of Latham Island marks a significant moment for Zanzibar and for Tanzania as a whole,” said Captain Hamad Hamad, Principal Secretary, Ministry of Blue Economy and Fisheries, Zanzibar. “Latham is a site of both historical and natural importance, and we look forward to learning more from the results of this mission, as it will help us improve the management of fishery resources and ecosystems around the island.”

Latham’s biodiversity-rich waters support the livelihoods of as many as 200 fishers and their families from both Zanzibar and mainland Tanzania, some 50-60 artisanal fishing vessels in total. Researchers who spoke with fishers found they use mostly handlines to target smaller tuna, trevallies, and red snapper, especially during the period from June to December. A smaller number of fishers from Zanzibar fish for octopus in shallower waters surrounding the island.

“The mission spanned 42 days and involved more than 50 people who together completed over 700km² of transects, collected over 650 photo quadrats to map the seabed, ran 104 transects to assess Latham’s coral reefs and fish communities, and launched 150 Baited Remote Underwater Video (BRUV) deployments to study local sharks and rays,” said Dr. Mensa. “With the data gathering now complete, the research team is now compiling our findings to share them with government partners in Tanzania to explore management possibilities for Latham.” 

The expedition and ongoing protection efforts have been made possible through the support the Bloomberg Ocean Initiative, and the WCS 30x30 Ocean Accelerator. 

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Wildlife Conservation Society (WCS)
WCS combines the power of its zoos and an aquarium in New York City and a Global Conservation Program in more than 50 countries to achieve its mission to save wildlife and wild places. WCS runs the world’s largest conservation field program, protecting more than 50 percent of Earth’s known biodiversity; in partnership with governments, Indigenous People, Local Communities, and the private sector. It’s four zoos and aquarium (the Bronx Zoo, Central Park Zoo, Queens Zoo, Prospect Park Zoo, and the New York Aquarium ) welcome more than 3.5 million visitors each year, inspiring generations to care for nature. Visit: . Follow: . For more information: +1 (347) 840-1242. .