POLLUTION EFFECTS OF THE TUY RIVER ON THE CENTRAL VENEZUELAN COAST - ANTHROPOGENIC ORGANIC-COMPOUNDS AND HEAVY-METALS IN TIVELA MACTROIDEA

Bivalve samples were collected at seven sampling stations located betw een the town of Machurucuto and the Bay of Higuerote, Venezuela, cover ing approximately 70 km of coastline. samples were collected both east and west of the Tuy River mouth, which has a plume known to move in a north-westerly direction. Petroleum hydrocarbons, both aliphatic (n-a lkanes and UCM) and polyaromatic (PAHs), were detected and quantified in the samples. These hydrocarbons were found to be primarily derived from fossil fuels. Halogenated organics consisted mostly of polychlori nated biphenyls (PCBs) and some chlorinated pesticides, primarily of t he DDT group. Heavy metals such as Pb, Cu, Ni, Zn, Cr and Cd were anal ysed in the samples. The results clearly show the influence of the Tuy River plume on the water quality of the coastal zone, particularly th at located west of the river mouth. One sampling station, located just east of the river mouth, also showed significant influence from the r iver plume.