RESUMO
Distribution and density of two holothurian species in Cubagua Island, Venezuela. Holothurian populations in the Caribbean have been significantly depleted in some areas, and others are still in danger to satisfy international markets. In Venezuela, this marine resource has been illegally exploited since the early 1990s. To contribute with their management and protection, this work analyzed the distribution, abundance and population structure of two commercial holothurians Isostichopus badionotus and Holothuria mexicana in Cubagua Island shores. A total of 52 stations were studied around the island during the year 2008. Surveys included visits to each station, for which a band transect of 50m² with four replicates were carried out. The results show that I. badionotus has a higher distribution on the East coast of the island, and is found over Thalassia testudinum beds or bivalve molluscs aggregations, with an average density of 0.011ind/m², C.I. 95%=0.005-0.017, n=122, and a general abundance estimated in 117ind/ha. H. mexicana has been practically depleted (0.001 ind/m2 C.I. 95%=0.0002-0.0013, 7.7 ind/ha, n=8). We recommend the maintenance of the total ban adopted in 1997 to assure the protection of these species, mainly because no previous data supported the start of the fishery, and also, because the current densities are still very low when compared to other areas in Venezuela and the Caribbean. These are animals easy to catch, susceptible to overfishing, and with a very low recovery rate; thus, more control is required from the local authorities. Rev. Biol. Trop. 59 (2): 843-852. Epub 2011 June 01.
En algunas zonas del Caribe, poblaciones enteras de holoturias han sido agotadas. En Venezuela, éste recurso ha sido explotado ilegalmente desde inicios de 1990. Por esta razón, se planteó estimar la distribución, abundancia y estructura poblacional de las holoturias comerciales Isostichopus badionotus y Holothuria mexicana en la isla Cubagua. Para ello, durante el año 2008, se realizaron cuatro transectas bandas de 50m² cada una en 52 estaciones ubicadas alrededor de la isla. Entre los resultados obtenidos destacan: I. badionotus presenta mayor distribución en el lado este de la isla, sobre fondos de Thalassia testudinum o bancos de moluscos bivalvos; con una densidad promedio de 0.011±0.022ind/m² (n=122), y una abundancia general estimada en 117ind/ha. Se identificaron cinco posibles zonas de crianza para esta última especie. H. mexicana ha sido prácticamente agotada (0.001±0.002ind/m², 7.7ind/ ha, n=8). Se recomienda mantener la veda total implantada en 1997, principalmente por no tener conocimiento de las densidades previas al inicio de la pesquería; por considerar que la densidad actual sigue siendo muy baja en comparación con otras zonas de Venezuela, y por ser animales de fácil captura, rápidamente sobreexplotables y de recuperación lenta.