Spatial Variation in Sediment Bacterial Communities Along a Salinity Gradient in a Northern Gulf of Mexico Coastal Ecosystem

Microorganisms in estuarine and coastal ecosystems are subject to changes in salinity and nutrient loads as well as threats from emerging contaminants, sea level rise, extreme weather patterns, and human encroachment. These ecosystems are of economic and ecological importance due to their biological diversity as well as their role in carbon sequestration, flood protection, and erosion prevention. However, the microbial community structure in the sediment of estuarine systems remains under researched despite the abundant ecosystem services they provide. In this study, we surveyed 25 sites within Econfina River State Park located in the eastern portion of the Northern Gulf of Mexico along a salinity gradient from freshwater upstream to coastal seagrass beds downstream. DNA extracted from the top 10 cm of sediment were 16S rRNA amplicon sequenced to determine microbial community structure. Results contribute to the understanding of microbial ecology of coastal ecosystems in the Northern Gulf of Mexico.