RELATIONSHIP BETWEEN SALINITY AND ALGAL BIOMASS IN COASTAL WATERS OF GEORGIA

Climate change predictions suggest that weather patterns are becoming more erratic with an increase in the frequency of intense storms. These storms coupled with an expected sea level rise will result in more saltwater intrusion on the limited freshwater bodies on coastal and barrier islands. Seawater incursion will increase salinity levels by converting fresh and brackish water environments into saline habitats. This change can cause significant stress and reduction in biodiversity of these unique aquatic systems on the islands. The goal of this project is to map the spatial and temporal distribution (and correlations) of salinity, nutrients, algae and chlorophyll-a on Sapelo Island, Georgia. Field physicochemical parameters were measured in the field using handheld probes while lab samples were analyzed using benchtop equipment. Algae and chlorophyll-a biomass were measured in the field using the Bentho Torch, while lab samples were analyzed using an Algae Guard. The highest nitrate and phosphate concentrations were 2.62 mg/L and \u3e2.75 mg/L, respectively. Green algae, diatoms, and cyanobacteria biomass ranged from 0 µg/L to 399 µg/L, while total chlorophyll-a biomass had a maximum of 623 µg/L. Spatial regression analysis showed that there was a 35% positive correlation among pH, phosphate (combined), and diatom biomass. ArcGIS analysis showed geospatial correlations among salinity, phosphate, diatoms and human habitation. Algal diversity decreased as the water became more saline. These preliminary results imply that climate change has the potential to adversely impact aquatic systems. Temporal analyses will show how these relationships change on a seasonal scale