Venezuela sediments edo. Sucre speciation Heavy metals La Restinga coastal lagoon Manzanares river environmental metals organic matter CFA Castillero Lagoon Cuchivero Fish Freshwater fish Gulf of Cariaco Gulf of Paria Metals Nueva Esparta Orinoco River Orinoco river Phosphorus Phosphorus speciation Playa Grande Sediment Venezuelan rivers bioavailability chemical composition degradation. edo. Anzoátegui distribution edo. Bolivar edo. Bolvar edo. Bolívar fat and protein fish flood lagoon geochemistry geochemistry study gulf of Paria laguna costera marine contamination materia orgánica pollution sediment sedimentos tissues tropical rivers venezuelan atlantic coast water quality