Science - Sea Turtle

Vieques is the number one nesting site for the green sea turtle!

The National Wildlife Refuge System manages lands across myriad ecosystems to conserve wildlife, plants and their habitats. Using conservation biology, strategic habitat management and other sound biological principals, the biology programs are an essential component of any refuge conservation efforts. The biology program at the Vieques NWR has helped to demonstrate the importance of Vieques for its conservation and biological diversity, within the archipelago of Puerto Rico. The program has forged partnerships with the community, universities, Municipal, Commonwealth and Federal agencies, non-government organizations and others to conserve and protect the natural resources of this beautiful island. Some of the ongoing projects include:

Sea Turtle Conservation:

Vieques has a number of significant nesting beaches for three endangered sea turtle species: leatherback (Dermochelys coracea), hawksbill (Eretmochelys imbricata) and the green sea turtle (Chelonia mydas). In fact, Vieques is the number one nesting site for the green sea turtle and among the top five for the other two species in Puerto Rico. The VNWR, the DNER and TICATOVE are the primary partners working on this project, which last 10 months of the year.

Land Crab studies: 

Land crabs populations have declined in Puerto Rico and are a protected species by the Commonwealth. Research at the VNWR focuses on the current status and health of land crabs population and their habitat. This helps the management of sustainable recreation land crab hunting at the refuge.

Bird monitoring: 

Protected forests and lagoons are important sites for migratory and resident birds. They feed, rest and some species reproduce here. Over the past ten years, surveys show that the 120 plus bird species originally reported for Vieques is more than 190 species. Monitoring in areas such as Playa Grande lagoon in the VNWR show that the individual numbers and populations of birds are also higher than previously recorded. The biology program also monitors nesting brown pelicans and birds across other areas. The delisted brown pelican, a former endangered species, nests twice a year in Vieques and has the largest nesting population in Puerto Rico.

Bat studies: 

Bats are the only native land mammals found in Puerto Rico. Bat research conducted in Vieques focuses on species diversity, populations and habitat use. Nine of the thirteen species of bats present in Puerto Rico have been reported in Vieques, including two new records. The refuge has also conducted habitat improvements for a number of bat species. 


The greenhouse is part of a number of habitat restoration projects; propagating endemic, native and endangered plant species such as matabuey (Goetzea elegans) and cobana negra (Stahlia monosperma). The greenhouse is also used for a number of educational programs, as well as to create new interpretive trails to increase people’s conservation knowledge and restore habitats for birds, amphibians and other species.

Herpetology studies:

Several herpetofauna studies have been done in Vieques for species diversity, population and health status. Other aspects focus on endangered species surveys for the Puerto Rican boa (Epicrates inornatus), the Virgin Island boa (Epicrates monensis) and the Culebra's giant lizard (Anolis roosevelti).

Other projects and studies: 

Established and run a biological research station on the refuge.

Publications and presentations at various national and international conservation & protected area conferences.  

- Endangered plant species surveys

- Flora composition and species abundance

- Control of invasive/exotic flora and fauna. Including a control for horses in partnership with Caballos Bieke Inc. and the Municipality of Vieques

- Mangrove forest, hydrology restoration and biomass monitoring

- Shark surveys and population status

- Conduct education talks and presentations at schools, universities, environmental fairs and other venues

- Habitat restoration. Including a partnership with local farmers to produce compost to improve soils condition in areas of the refuge and in neighboring agricultural areas.