Dissolved and particulate heavy metals distribution and regulation in coastal lagoons. A case study from mar chiquita lagoon, Argentina

BELTRAME M. ORNELA; DE MARCO SILVIA G.; MARCOVECCHIO JORGE E.

ESTUARINE COASTAL AND SHELF SCIENCE

Elsevier

Año: 2009 vol. 85 p. 45 - 56

0272-7714

Mar Chiquita Coastal Lagoon is located on the Atlantic coast of Argentina, and has been declared a Biosphere Reserve under the UNESCO Man and Biosphere Programme (MAB). This coastal lagoon constitutes an estuarine environment with a very particular behaviour and it is ecologically important due to its biological diversity. The aim of the present study was to evaluate the distribution and geochemical behaviour of several heavy metals in this coastal system, focusing on their distribution in both the dissolved phase (< 0.45 µm) and the suspended particulate matter. The hydrological parameters (salinity, temperature, turbidity, pH, dissolved oxygen) and concentration of total particulate and dissolved metals (Cd, Cu, Ni, Zn, Fe, Pb, Cr and Mn) were measured along two years (2004 - 2006) at two different sites. Salinities varied in a wide range. Hydrological parameters did not present any evidence of abnormality in their distributions. Suspended particulate matter showed neither seasonal variation nor a relationship with tide, indicating that in this shallow coastal lagoon neither tides nor rivers regulate the particulate matter input. Heavy metals behaviour, in both dissolved and particulate phases, did not show any relationship with tide and seasons. Mar Chiquita showed a large input of dissolved and particulate metals. Therefore, human activities, especially intensive agriculture, within the drainage basin of Mar Chiquita Coastal Lagoon, have caused serious metal impact.