Dinâmica da qualidade da água de uma laguna costeira: caso da Lagoa de Garopaba - SC

Water quality dynamics of a coastal lagoon: case of Garopaba Lagoon - SC

Abstract

The coastal zone of Santa Catarina has faced increasing challenges due to the adopted economic development model. This study analyzed the spatial and temporal variation of physical and chemical water quality parameters and their relationship with meteorological conditions during two distinct periods of the seasonal cycle in the Garopaba Lagoon (SC). Two sampling campaigns were conducted, covering two distinct periods of the seasonal cycle, each lasting 12 weeks. Sampling was carried out at three points in the lagoon. Daily meteorological information was obtained from the MERRA-2 model. The results demonstrated a clear and sensitive response of the lagoon to meteorological variations and fluctuations in the seasonal cycle, especially regarding water temperature, turbidity, primary production (chlorophyll-a), and water level. The analyses indicated that accumulated precipitation strongly influences water level. Water temperature was strongly correlated with air temperature. pH varied abruptly in response to the dynamics between rainwater and seawater. Chlorophyll-a levels showed a significant increase in the second campaign during the closure of the spillway. Phosphate analyses revealed significant peaks, particularly near urbanized areas, suggesting sporadic inputs of anthropogenic effluents.