Organic carbon and pesticide pollution in a tropical coastal lagoon-estuarine system in Northwest Mexico

摘要

The Altata-Ensenada del Pabe1l6n system (～360 km~2) comprises three inland lagoons, a coastal lagoon, and a bay. Inland is an important irrigation district (～330,000 ha). Agricultural drains and two sugar cane mills wastewaters are discharged into the system. Particulate organic carbon in water varied from 0.5 to 6.1 mg C/l. Organic carbon mean concentration (mg C/g dw) in sediments was 22.6 in the bay, 92.6 in the coastal lagoon, and 179.6 in the inland lagoons. Organochlorine pesticides (OCs) mean total concentration (ng/g dw) was 59.13 for inland lagoons, 35.60 for coastal lagoon, and 9.08 for the bay. A significant correlation was found between organic matter and OCs.