Content on this page was last updated in 2006. Some of the content may be out of date. For more information: http://www.fws.gov/caribbean/Refuges/Navassa/
Navassa Island: Marine Ecosystems
A reef wall (Photo: SEFSC/NOAA)
The most up-to-date description of the overall health and condition of the shallow and deeper coral reefs of Navassa is given in Miller et al.(2005). Generally, the coral reefs are in good, healthy condition, although artisanal fishing pressure from Haiti is a growing threat. Except for a few transient Haitian fishers that periodically spend some time on the island as squatters, Navassa is uninhabited. Since mining activity for guano and other phosphorus-rich deposits ended at the beginning of the 20th century, there have been no anthropogenic disturbances to the marine habitats, except for a relatively small amount of marine debris leftover from earlier industrial activities and from recent fishing at Lulu bay. The effects of "ghost fishing" by lost and broken fish traps and nets are not yet known.
A Navassa seascape (Photo: NOAA)
Many of the habitats with high coral cover are in deep water (>20 meters) and are exposed to strong ocean currents and surge. This feature may provide some protection from coral bleaching from elevated water temperatures. Corals in the shallower habitats (<20 meters) appear to be free from disease, but a white plague-appearing disease is found on some brain corals at some deeper sites. To date, Navassa has not been threatened by the aquarium trade in corals, live rock, or living reef organisms. Aquatic invasive species are not known to occur.
Artisanal fishing at Navassa is unmanaged and NWR regulations are not enforced.
Within the last few years, the Haitian wooden fishing boats have been powered by small outboard engines, and the fishing techniques have been upgraded from hook-and-line and simple fish traps to include net fishing. Finfish catch appears non-selective and includes predominantly small common reef fishes.
Quantitative data are not available for these fishing efforts. Net fishing has added new species to the fishing catch such as the queen conch (Strombus gigas) and hawksbill sea turtle (Eretmochelys imbricata). The extent to which larger commercial fishing vessels from other Caribbean nations operate in Navassa waters is unknown.
Fish trap used by Haitian fishers (photo: Keith Pamper/Shedd Aquarium)
The most common fish trap used by the Haitian fishers is the Antillean "Z" trap. It takes the form of a double chevron or "Z" with two down-curving "horse-neck" entrance funnels. Typically, these measure between 180 and 230 cm in length and are 60 cm high. (Illustration: FAO Document repository: Fishing with traps and pots. FAO 2001).