Biodiversity

Los Roques Archipelago National Park is the most important reef formation in
Venezuela and in the south Caribbean Sea (Ramirez 2001). About 56 species of
scleractinian corals and three milleporids have been reported for Los Roques.
This represents almost all the coral species reported for the country (66
scleractinian and three milleporid). Also, present in the park are nine of the 56
species of octocorals present in Venezuela. The low density of octocorals is
apparently explained by the deeper average depth of reefs in Los Roques, which
does not favor the establishment of species of this family (Ramirez 2001).

Carolina Bastidas, a Marine Biology Professor at Simón Bolívar University, told
ParksWatch that this archipelago harbors one of the highest quality coral reefs
with respect to species diversity, area of live coverage and low incidence of
diseases in the Caribbean Sea. The park has a large coverage of corals from the
Acroporidae family, which have been adversely affected in the rest of the
Caribbean region.

The marine fauna in Los Roques -characteristic of coral reefs and seagrass beds-
includes, among other taxonomic groups, about 200 crustacean species, 140
mollusk species, 45 echinoderm species and 60 sponge species (65% of the
country's). Approximately 280 fish species, from 41 genera and 31 families, have
been catalogued. This represents 35% of the species that exist in the country.
These fish have an important economic and nutritional value. Snappers, including
yellow tailed snappers (Lutjanidae), and groupers (Escombridae and Serranidae)
are of high economic value (Gondelles 1997).

The lobster (Panulirus argus) and queen conch (Strombus gigas) are also examples
of commercially valuable species found in Los Roques. The park contains the
most important unexploited populations of these species in the entire Caribbean
region (Fernández 2002). Another commercially important species is the queen
conch, which is a very large gasteropod with a shell length of about 20 cm. Due to
the alarming rates of overexploitation of its natural populations, in 1994 the
gasteropod was included in the International Union for the Conservation of Nature
(IUCN) list of "Commercially Threatened Species" and in The Red Book of
Venezuelan Fauna (Rodríguez & Rojas-Suárez 1999, AMNH 1996). Human
settlements in the Caribbean Sea use this species as a food resource and raw
material for handicrafts.

Numerous migratory birds converge in Los Roques and it is a suitable area for the
establishment of marine and pelagic bird colonies. About 92 bird species can be
found in Los Roques, 50 of which are migratory and come from North America
(Lentino, Luy & Bruni 1994). Among the most attractive birds that nest annually in
Los Roques, are the brown pelican (Pelecanus occidentalis), two bobby species (Sula
sula and S. leucogaster), the laughing gull (Larus atricilla), the common, least, and
brindled tern (Sterna hirundo, S. antillarum, S. anaethetus), the brown noddy (Anous
stolidus) and the lesser noddy (Anous minutus) (Bosque, Esclasans & Pizani 2002).
Flamingos (Phoenicopterus ruber) are also present in the park. A black colored
subspecies (Coereba flaverola lowii) of the common bananaquit is endemic to Los
Roques. Also found in are the yellow warbler (Dendroica petechia obscura) and the
common ground-dove (Columbina passerina tortugensis), which are subspecies
endemic to Venezuelan Caribbean Islands (Lentino, Luy & Bruni 1994).


Chicks and juveniles of Sula leucogaster in a 
reproductive colony at upper Canqui island

Four species of sea turtles nest in Los Roques: the loggerhead turtle (Caretta
caretta), the green turtle (Chelonia mydas), the leatherback turtle (Dermochelys
coriacea), and the hawksbill turtle (Eretmochelys imbricata) (Guada & Vernet 1992,
De los Llanos 2002). The first two are globally endangered (EN A1abd), and the
last two are critically endangered (CR A1abd, CR A1abd+2bcd) according to the
criteria used by the IUCN. The Red Book of Venezuelan Fauna categorizes the
loggerhead as vulnerable and the other three species as endangered (Rodríguez
& Rojas-Suaréz 1999). Los Roques is the most important nesting place for
Eretmochelys imbricata in Venezuela (De los Llanos 2002). Other reptiles include
the lizard Gonatodes vitattus roquensis, a subspecies endemic to the archipelago,
and Cnemidophorus lemmiscatus nigricolor, a very abundant black lizard that was
first described with a specimen from Los Roques (SCNLS 1956). Gynmnodactylus
antillensis is a species endemic to leeward Caribbean islands that has been
reported only in Bonaire, Curacao, La Orchila, Las Aves, and Los Roques.

An interesting fact about the fauna from the archipelago is that, with the
exception of the fishing bat (Noctilio leporinus), no native land mammals exist
(Gondelles 1997). Hence, any biological invasion poses a serious threat to the
biological integrity of the system. With respect to marine mammals, a recent
investigation has included Los Roques as part of the potential distribution for six
cetaceans: Balaenoptera edeni, Megaptera novaeangliae, Delphinus sp., Stenella
frontalis, Stenella longirostris, and Tursiops truncatus (Acevedo 2001). 

Approximately 38 plant species have been reported. Four mangrove species live
in the park: red mangrove (Rhizophora mangle), black mangrove (Avicennia nitida),
white mangrove (Laguncularia racemosa), and button-wood mangrove (Conocarpus
erectus). Also present are various halophilic plants like the sea purslane
(Sesuvium portulacastrum and Sporobolus pyramidatus), three cypress species
(Cyperus sp.), and many shrubs that include the salt wort (Batis maritima and
Tournefortia gnaphalodes). A specimen from Los Roques was used to describe the
grass Setaria submacrostachya to science. The cacti Stenocereus griseus, Melocactus
caesius, and Opuntia wentiana dominate areas that are high and exposed to winds.
Shallow water zones with sandy bottoms are mostly dominated by Thalassia
testudinum seagrass beds, a species widely distributed in the Caribbean Sea
(SCNLS 1956, Gondelles 1997).