The anthropic contamination and its effects on three estuaries of Ceará coastline, Brazilian Northeast - a review

Abstract

Estuaries, where rivers meet the ocean in coastal areas, have attractive biodiversity for exploration and human activities.  However, the anthropic activities interfere on natural dynamics, impacting the estuaries by habitat destruction and the addition  of compounds capable of generating lethal and sublethal effects on organisms. In the Ceará State, the estuaries of the rivers Ceará,  Pacoti and Jaguaribe are relevant because their locations, socioeconomic importance and interactions with coastal communities.  Due to the advance of deterioration in the quality of these estuaries, this paper presents a review considering the presence of  contaminants in water and sediment, and their toxic effects to the biota. Increasing contamination was evidenced for these  estuaries, mainly due to metals, especially over the last 10 years. Biological damages were seen on local species and laboratorial  toxicity tests indicated the toxicity potential, both acute and chronic, of the contaminants in the three estuaries, including at  Pacoti estuary, which was a former reference location. Despite protection initiatives, the impacts on these estuaries are frequent,  continuous and increasing. The data highlight that there are serious gaps of knowledge about the local contamination and  reinforce the urgent need for more research and control actions to prevent future impacts of ecosystem scale.