Turneffe Atoll Biodiversity Initiative


Turneffe Atoll is the largest and most biologically diverse coral atoll in the Western Hemisphere. Located 25 miles east of Belize City and surrounded by deep oceanic waters, Turneffe is approximately 30 miles long and 10 miles wide.

The islands, some larger than 5,000 acres, are covered by at least 77 different vegetation types. Mangrove forests are interspersed with brackish lagoons, covering most of the low-lying areas. A reef crest and magnificent shallow coral buttresses is followed by reef rim on the outer reef drop-off. Oceanic Society has been working to study and protect the marine life of Turneffe Atoll for more than a decade, and we have owned and operated our Blackbird Caye Field Station on Turneffe Atoll since 2001.

Loggerhead turtle. © Mario Mota

Biological Significance

Turneffe's healthy reefs support diverse species including the endemic white spotted toadfish and white lined toadfish. The abundant sponges offer rich feeding grounds for the endangered hawksbill sea turtle and atoll beaches serve as nesting sites for loggerhead and green sea turtles. Historically, Blackbird Caye South was known to have the largest sea turtle nesting site on the Atoll, and in recent years, loggerhead turtles have successfully nested at the Blackbird Oceanic Field Station beaches.

What makes Turneffe Atoll so important?

*It harbors the largest of the American crocodile population (approximately 200-300 individuals) and highest concentration of American crocodiles. © Birgit Winningnesting activity in Belize. American crocodiles are listed as Vulnerable globally.

*It is the only offshore range for the Antillean manatee, an Endangered subspecies. Both single animals and cow-calf pairs have been observed.

*Its littoral forests and brackish lagoons support amphibians, such as the green tree snake, a sub-species endemic to Turneffe that includes some individuals with a brilliant blue coloration.

*It is an important feeding and calving ground for bottlenose  Bottlenose Dolphin group. © Nicole Duplaixdolphins (approximately 150-200), which are common to Turneffe's lagoon and shallow reefs.

*At least 60 species of birds are found at Turneffe during the height of the migratory season, including 18 species of nesting birds. Endangered and threatened nesting species include the Least Tern, Roseate Tern and the White Crowned Pigeon, which also feeds in the littoral forest.

*The large expanses of intact mangrove and seagrass habitat and shallows serve as a huge nursery area for a wide array of fish  Least Tern chicks. © Wayne Sentmanspecies, crocodiles, manatees, dolphins and invertebrates. In addition to rich nursery areas, Turneffe has at least three known important fish spawning aggregation sites.

Many of the species found on and around Turneffe are listed as endangered. Some are found nowhere else (endemic). 

The atoll's ecosystems are largely intact, although pressure for development is escalating; overfishing has become a problem, and coral bleaching and diseases remain constant threats.


Nassau Grouper. © Linda Searle

Until 2000, commercial development at Turneffe consisted of small-scale dive resorts and a fishing resort. However in recent years, transfer of land from public to private ownership has escalated deforestation of prime natural habitats. Lack of protection for the largely intact natural forest and clearing for developments presents the greatest threat to the survival of all terrestrial wildlife on Turneffe.

Rainbow parrotfish, the largest herbivorous fish in the Atlantic Ocean, are totally dependent on mangrove nursery areas and are becoming locally extinct in some locations due to mangrove clearance, which also threaterns reef health through algal overgrowth.

Divers cutting sea turtle out of net. Courtesy Melanie McField

Illegal fishing is a growing problem, exacerbated by the lack of any enforcement presence on the atoll. In particular, it involves the harvesting of undersized and out of season marine species. Illegal fishing gear can harm non-target species such as manatees and sea turtles.


After decades of effort by Oceanic Society and many other organizations working in Belize, Turneffe Atoll was declared a marine reserve in late 2012. This exciting announcement lays important legal groundwork for the long-term protection of Turneffe. Yet it is just the beginning of a much longer process to fully define and manage the reserve, and much work remains to be done, including:

  • Continued scientific monitoring of threatened species and ecologically sensitive areas to inform reserve implementation, and evaluate the effectiveness of management measures.
  • Further research to identify and prioritize important marine and terrestrial habitats for preservation.
  • Eco-tourism programs to support sustainable local livelihoods within the reserve.
  • Logistical and financial support for reserve enforcement.
  • Acquisition of land for preservation.
  • Evaluating and planning for climate change impacts.

And much, much more. Join us in assuring a sustainable future for Turneffe Atoll by contributing to Oceanic Society's research and conservation programs in Belize.

Please help make a difference for marine life in Turneffe Atoll.

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