Hidrografía y cambios estructurales del mesozooplancton en el golfo de Cariaco, en dos períodos contrastantes

Abstract

In order to study the environmental response mesozooplankton in the Gulf of Cariaco, biomass, species composition and abundance in October 2010 (relaxation time) and April 2012 (time of upwelling) was analyzed. Samples were collected at 19 stations throughout the gulf. Zooplankton samples were collected by vertical tows using a Bongo net for 15 minutes. It was measured in situ salinity, temperature, dissolved oxygen concentration and nutrients. Levels of salinity, temperature and oxygen for relaxation time ranged from 35.89 to 36.29; From 27.13 to 29.5°C; 3.24 to 4.34 mg.L -1 , respectively; while upwelling ranged from 25.76 to 36.86; From 21.66 to 29.1°C; 5.81 to 7.14 mg.L -1 , respectively. Biomass and abundance mesozooplankton presented signi cant temporal variation was greater relaxation, unlike phytoplankton abundance showed no temporary di erences.15 zooplankton groups in upwelling relaxation and 10 were identi ed; the composition re ected the dominance of copepods and cladocerans, being thirdly the gelati - nous plankton (apendiculates and siphonophores). During the relaxation period biomass and abundance higher, mainly at the entrance of the Gulf (zone 1), in uenced by the waters of the Manzanares river it was recorded. Temporary di erences remain an important attribute in the mesozooplankton community in the Gulf of Cariaco and spatial variations.