Variations of some trace elements in a coastal system in Mauritius

Seven trace elements (Al, Cr, Mn, Ni, Zn, Cd, Pb) were determined in the river and marshes in a coastal system in Mauritius (1850 km(2), 20 degrees S and 57 degrees E, Western Indian ocean) using Inductively Coupled Plasma - Mass Spectrometry (MS) techniques. The following 4 trace elements Cr, Zn, Cd and Pb exceeded the pollution limit in either river or marsh over the period December 95- May 96 as set by the Ministry of Environment, Mauritius in 1996 under the Environment Protection Act 1991 under Section 32 (4) for Inland Surface Water Standards. At present, lead and zinc from road runoff is an increasing threat to the aquatic system whereas chromium compounds from the textile industries are potential contaminants which require further investigation. Managing the river resource and land use of the catchment to protect water quality for habitat protection and sustainable recreational use should shift the emphasis of management away from pollution standards to managing the whole resource-producing ecosystem.