Latin American Journal of Aquatic Research (Jan 2009)
Seamounts in the southeastern Pacific Ocean and biodiversity on Juan Fernandez seamounts, Chile Montes submarinos en el océano Pacífico suroriental y biodiversidad en el cordón de Juan Fernández, Chile
Abstract
Seamounts are vulnerable marine ecosystems. In Chile, information on these ecosystems is quite scarce; thus, a compilation of information on their geographical distribution and biodiversity is presented herein. A total of 118 seamounts distributed in the Chilean EEZ are identified and characterized. Additionally, an in situ assessment was carried out on the Juan Fernandez seamounts 1 and 2 (JF1 and JF2), which were also oceanographically characterized. Phytoplankton, zooplankton, and marine invertebrate samples were collected and an exploratory fishing survey was executed using different gears. According to the bibliographical review, a total of 82 species have been collected on the JF1 and JF2 seamounts, highlighting fmdings of black coral species caught in lobster traps at the Juan Fernandez Archipelago. Submarine images of the marine substrate at JF1 and JF2 reveal characteristics attributable to the impact of bottom dredges, coinciding with the information obtained from the trawling fleet. The fishing activity was carried out primarily at JF2 (4,667 km of trawling). The monthly fishing effort increased considerably in 2002, 2003, and 2005, reaching values above 500 km of trawling and, thus, modifying the spatial structure of the resource aggregates on the JF2 seamount.Los montes submarinos constituyen ecosistemas marinos vulnerables. Chile presenta una escasa información acerca de estos ecosistemas, por lo que este trabajo recopila información sobre distribución geográfica y biodiversidad. Se identifican y caracterizan 118 montes en la ZEE de Chile. Adicionalmente, una evaluación in situ se desarrolló sobre los montes Juan Fernández 1 y 2 (JF1, JF2), caracterizándolos oceanógraficamente. Se recolectaron muestras de fitoplancton, zooplancton e invertebrados marinos, y se realizó pesca exploratoria con diversos artes. La revisión bibliográfica establece que en JF1 y JF2, se han capturado un total de 82 especies, destacándose la presencia de corales negros en trampas langosteras en el archipiélago de Juan Fernández. Fotografías submarinas de los montes JF1 y JF2 presentan características atribuibles al impacto de artes de arrastre de fondo, concordante con información de la flota. El esfuerzo de pesca se realizó mayormente en JF2 (4.667 km arrastrados). El esfuerzo de pesca mensual se incrementó considerablemente durante el 2002, 2003 y 2005, alcanzando valores sobre 500 km arrastrados, modificando la estructura espacial de las agregaciones de recursos en el monte JF2.
