Heavy metal concentrations in different sediments fractions and depths from Bahía Blanca Estuary (Argentina).

BUZZI, NATALIA S; MARTÍNEZ, MARÍA VICTORIA; GARCÍA, FABIÁN E; BOTTÉ, SANDRA E; MARCOVECCHIO, JORGE E.

Mar del Plata

Congreso; CERF 2012 Mar del Plata, Argentina The Changing Coastal and Estuarine Environment: A Comparative Approach; 2012

Instituto de Investigaciones Marinas y Costeras (IIMyC) CONICET -- UNMDP and Lab. Ecología, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina East Carolina University, Greenville, NC, USA

Estuaries and coastal zones, together with their corresponding wetlands, usually act as sinks of land materials,including pollutants,from agricultural, industrial and urban origins. Aquatic environments are increasingly being contaminated with different kinds of organic and inorganic pollutants. Tidal flats are very extensive in the Bahía Blanca Estuary, and the granulometry of their sediments varied along the system, being principally silt-clay in the inner part (more than 90%): fine sediments are generally accepted to accumulate higher contaminants levels. The semiterrestrial burrowing crab Neohelice granulata (Brachyura, Varunidae) is an eurihaline species widely distributed along the Atlantic coast of South America from Rio de Janeiro (Brazil) to Patagonia (Argentina). These crabs are omnivorous and detritivorous, feeding from sediments and are perfectly adapted to aquatic or terrestrial habitats. The aim of this study was to determine the concentrations of some heavy metals in different sediments fractions from different depths, collected in the inner zone of Bahía Blanca Estuary (Argentina) and finally to analyze their relation with the levels of these pollutant in the hepatopancreas and gills of Neohelice granulata. The metals (cadmium, zinc, copper, chromium, lead and nickel) present in both fractions, more than 63 μm and less than 63 μm grain-size sediments from different depth (1, 2, 4, 8 cm) were analyzed by ICP-OES. Preliminary results showed a similar behavior of all these metals in both fractions of the analyzed sections. The level of Cd was under the detection limit of the method, however it was present in hepatopancreas and gills of both sexes of the burrowing crab N. granulata. Ni and Cr levels were low and constant in the coarse fraction as well as in the silt-clay one but changeable in hepatopancreas and gills from crabs. Finally, Pb demonstrated a similar pattern in all samples evaluated, but it was only found in hepatopancreas of male crabs. NOTA: RESUMEN ACEPTADO- EL EVENTO SE DESARROLLARÁ EN NOVIEMBRE DE 2012