Tourmaline Reef
A shelf-edge reef in the Mona Passage, protected as a nature reserve.
Tourmaline Reef (Arrecife de Tourmaline) is a shelf-edge reef in the Mona Passage, just off Mayagüez Bay on the western coast of Puerto Rico. Because it sits far from shore, it remains one of the best-preserved reefs of its kind in the region. It was among the first coral reef protection zones established under the Puerto Rico Coastal Zone Management Program. The reef lies near Punta Guanajibo, about 7.5 nautical miles from Mayagüez, at depths up to 10 meters. The surrounding waters have moderate to high visibility, thanks to minimal sediment or terrigenous deposits.
The reef system is protected as the Tourmaline Reef Nature Reserve, managed by the Puerto Rico Department of Natural Resources (DRNA). The reserve enforces management plans and conservation measures that restrict fishing to safeguard the fragile ecosystem, which had been threatened by overfishing of red grouper (Epinephelus guttatus). Its boundaries extend across the maritime borders of Mayagüez and Cabo Rojo. Coral cover was about 40% in 2009, down from 60% in 2003. Besides coral, the reserve also protects seagrass prairies that support species such as sea turtles and the West Indian manatee.
- Location
- Mona Passage off Mayagüez Bay, western Puerto Rico
- Distance from mayagüez
- 7.5 nautical miles
- Maximum depth
- 10 meters
- Coral cover 2009
- approximately 40%
- Coral cover 2003
- 60%
- Protected area name
- Tourmaline Reef Nature Reserve (Reserva Natural Arrecife de Tourmaline)
- Managing agency
- Puerto Rico Department of Natural Resources (DRNA)
Lore & Background
Tourmaline Reef is located close to Punta Guanajibo, at 7.5 nautical miles from Mayagüez, at depths of up to 10 meters under the ocean surface. It borders waters of moderate to high visibility due to minimal terrigenous or sedimentary deposits. The reef system is protected as the Tourmaline Reef Nature Reserve, managed by the Puerto Rico Department of Natural Resources (DRNA), which provides management plans and conservation resources that limit fishing activities in the area. The reserve extends between the maritime borders of the municipalities of Mayagüez and Cabo Rojo. The coral cover of the reef was approximately 40% in 2009, a decrease from 60% in 2003. In addition to the coral ecosystem, the reserve also protects tracts of seagrass prairies, important for species such as sea turtles and the West Indian manatee.
Reader's Guide
Tourmaline Reef is notable as one of the best-preserved reefs of its type in Puerto Rico, largely because its distance from the coast has limited human impact. It was selected as one of the first coral reef protection zones under the Puerto Rico Coastal Zone Management Program, marking an early conservation effort. The reef's ecosystem was previously threatened by the overfishing of red grouper (Epinephelus guttatus), leading to the establishment of the Tourmaline Reef Nature Reserve, which limits fishing activities to preserve the delicate ecosystem. The reserve also protects seagrass prairies that are important for sea turtles and the West Indian manatee. The decline in coral cover from 60% in 2003 to approximately 40% in 2009 indicates ongoing environmental pressures, despite the protected status. The reef's location in waters of moderate to high visibility, with minimal terrigenous or sedimentary deposits, contributes to its ecological value and preservation.
Did You Know?
- Tourmaline Reef is located 7.5 nautical miles from Mayagüez.
- The reef's coral cover decreased from 60% in 2003 to approximately 40% in 2009.
- The reserve protects seagrass prairies important for sea turtles and the West Indian manatee.
- The reef was previously threatened by overfishing of red grouper (Epinephelus guttatus).
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