Regresar

Vertical distribution and seasonal abundance of microzooplankton and its relationship with some environmental variables in Turpialito, Gulf of Cariaco, Venezuela

Abstract:

The vertical distribution of microzooplankton and its relationship to certain environmental variables was carried out in a locality on the Gulf of Cariaco (Turpialito). Monthly samples were collected with a Niskin bottle (5 L) to measure temperature, chlorophyll a, oxygen, salinity, seston., on the surface, and at 0, 8, 21 and 34 meter depths during the period October 1992-December 1993. Samples fof microzooplankton were collected filtering seawater through a 20-μm sieve. Samples were preserved with neutralized formaldehyde (5%). The maximum concentrations of microzooplankton were located from 5 to 15 m, the highest value (32×104 org/ m3) was measured in December 1993, while the smallest values (< 2×10 4 org/m3) were observed between December 1992 and February 1993. Nuclei of high phytoplankton biomass (5μg/L) were observed between 4 and 16 m. Multiple regression analysis indicated the phytoplankton biomass, measured as concentration of chlorophyll a, was the factor that explained the highest variability (34%) of microzooplankton abundance, followed by surface temperature (21%). We discuss the repercussions of the variability of these factors with regard to the patterns of zooplanktonic production in the area.