Concentraciones de pb, cd, ni, cr y cu en amphimedon viridis y niphates erecta (haplosclerida: niphatidae) en dos ecosistemas marinos del Mar Caribe Venezolano

The total Pb, Cd, Ni, Cr and Cu concentrations in two species of marine sponges (Amphimedon viridis and Niphates erecta) were determined, as well as the bioavailable fraction of these elements in sediments at the Archipelago Los Roques National Park and Bergantin Bay, Venezuela, with the aim of assessing the ability of such species to reflect the conditions of the marine environment in terms of metal contamination. Fifteen samples of sponges and five of sediments were taken in both marine environments and the determination of heavy metals was carried out by atomic absorption spectrometry with electrothermal atomization, after acid digestion in the case of sponges or extraction 0.11M acetic acid in the case of sediments. The sediments showed no significatif differences of the elements Ni and Cu in both sites. Heavy metal concentrations in sponges showed significant differences between the locations studied. In Los Roques Cd was the element with the highest concentration, while Pb, Cr and Cu were higher in Bergantin Bay. Differences between species were local, yielding to N. erecta the highest values of Cu in Bergantin Bay and for Ni in Los Roques.