Assessment of demersal fishes and icthyoplancton in the Colombian Caribbean Sea, including oceanographic conditions part II: research cruiser INPA-VECEP/UE/DEMER/9510 (October-november, 1995)

Abstract

The INPA-VECEP/UE/DEMER/9510 was the second survey carried out by the INPA-VECEP/UE Fishing Program in order to evaluate the demersal fish resources in the Colombian Caribbean shelf and upper slope. This survey, on board the R/V Ancon, took place on October 19th - November 6th 1995, and consisted of 47 trawl hauls, 66 oceanographic samplings and 64 icthyoplankton samplings, in the area between 12°25.01 N-71°17.36’ W (NE of Puerto Estrella) and 08°43.25’ N-77°06.73’ W (NE of Cabo Tiburon). Taking the results of the previous cruise (DEMER/9507, July 1995) as point of reference, we remark the following results: a) increased biomass of demersal resources for the entire area (9898 t), due to higher biomass density (2.08 t/mn2); b) increased zooplankton biomass and larval number in each zone; c) lower number of eggs, especially in the NE area. Additional results were a higher availability of demersal resources in the NE zone, mainly lutjanids (snapper group) of high commercial value (2403 t), whose biomass density was 0.48 t/mn2, with a prevalence of the lane snapper (Lutjanus synagris) and mutton snapper (Lutjanus analis). During this survey oceanographic conditions were: shallow thermal homogeneity, ranging from 29.0 to 30.5 C; positive salinity gradient with latitude increase; absence of La guajira upwelling (due to absence of trade winds), causing the predominance of the Central American current, that reached La Guajira.