Acta Biológica Colombiana (Jul 2003)
Environmental Conditions of Pilón de Azúcar Beach (Guajira, Colombia), InferedFrom the Foraminifers Population of a Sediment Simple
Abstract
Foraminifers are organisms, which due to their specific environmental requirements, are used as bio-indicators of marine environments. In this study we evaluated a sample of sediment from the “Pilón de Azúcar” beach (Guajira, Colombia), in order to deduce the physico-chemical conditions of such coastal environment, based on the group of 14 foraminifers found in it. We detect one hundred individuals belonging to 29 species,19 genus, 14 families, 8 super families, and 3 suborders: Rotaliina, Miliolina, Textularina. The more represented species were: Ammonia beccari, sobrina form; Discorbis rosea, Quinqueloculina sp., Amphistegina sp. and Cibicides antilleanus. In relation with the nature of the shell, 69 individuals had calcareohialine, 27 calcareous porcelained and 4 individual shad agglutinated shells. This variety of forms indicate that the predominant organisms found, are exposed to high concentrations of calcium carbonate, normal salinity and a pH not too low for the formation of their shells. 98% of the registered organisms belong to benthonic environments of the continental marine platform or from the transition zone, that generally inhabit in bioclastic sediments. The presence of fossil foraminifers (7%), indicated that there was an active erosive process in the coast that interferes with the accumulation of organic matter. In conclusion, this beach has a diverse and dynamic environment with the normal conditions of open Caribbean marine environment.
