CHARACTERIZATION AND EVALUATION OF THE ENVIRONMENTAL QUALITY OF TUBARÃO ESTUARY (RN) BASED ON WATER, SEDIMENT AND SEAWEEDS
Environmental quality, Estuary, Nutrients, Heavy metals, Seaweeds, Environmental perception
Estuaries and coastal zones are dynamic systems of great environmental, economic and social importance. All over the world these areas are becoming increasingly impacted because of the anthropogenic activities caused by rapid economic growth and urbanization. This research was carried out in the Tubarão estuary, which is located in the northern coast of Rio Grande do Norte, Brazil. The estuary area is part of the Ponta do Tubarão Sustainable Development Reserve (RDSEPT). In the surroundings of this conservation unit, several economic activities are developed, such as fishing, agriculture, aquaculture, saline and oil industry, besides ecological tourism. Considering the ecological, economic and social importance of this ecosystem, a study was run to characterize and evaluate the environmental quality of the Tubarão estuary through analysis of nutrients (N and P) and heavy metals in water, sediment and seaweeds (Gracilariopsis and Hypnea). The research carried out for this purpose is composed of three chapters: (1) in the first chapter the dynamic of nutrients was investigated to understand the biogeochemical processes and to identify possible anthropogenic impacts in this tropical ecosystem; (2) the second chapter of the thesis analyzes and points out which compartments (water, sediment and seaweeds) that hold the largest concentration of heavy metals and finally the third chapter (3) which examines the RDSEPT extractivists’ environmental perception and aims to measure the population's understanding of reserve environmental issues. The results obtained in the different chapters provide important information on the state of environment of the Tubarão estuary and may contribute to the reserve management.