Asociaciones de foraminíferos bentónicos recientes en la plataforma marina de las Guayanas

Resumen

A total of 183 benthic foraminiferal species have been identified in the continental shelf of Guianas, being the most abundant: Ammonia beccarii, Ammonia tepida, Eponides repandus, Fursenkoina schreibersiana, Hanzawaia concentrica, Lobatula lobatula, Nonionella atlantica, Nonionoides grateloupi, Quinqueloculina lamarckiana and Uvigerina peregrina. Multivariate analysis (Q-Cluster) with samples containing more than 1% of the total individuals produces four bathymetric groups parallel to the coast: coastal (<16 m), littoral (17-42 m), middle shelf (43-60 m) and outer shelf (>60 m). The absolute dominance of the euryhaline species A. tepida up to 42 m depth characterises the input of fresh waters from the Amazon river. The occurrence in the shelf of species associated with the NADW as Hoeglundina elegans and Planulina ariminensis evidences the effect of upwelling in the outer shelf of Surinam.