• Salty or Slightly Salty: Is Fish Species Richness affected by an obsolete navigational cut

      Patterson, Rebecca; Matthews, Loren; Reichmuth, Jessica; Saul, Bruce; Mathews, Loren; Biological Sciences; Biology; Reichmuth, Jessica; Augusta University; Georgia Southern University (1/30/2020)
      As rivers flow toward the coast, freshwater mixes with saltwater in estuaries. The mixing here creates a wide range of environments for many organisms. The Satilla River Estuary has been cut eight times, which has altered the salinity gradients that are a result of natural tidal flow. Altered salinity gradients pose a threat to migratory fish species because they are no longer able to pick up on directional cues these gradients provide, ultimately affecting species richness in the estuary. The purpose of this study is to determine if Noyes Cut has affected salinity gradients at five collection sites in Umbrella and Dover Creeks. Experimental gill nets were set one hour before max flood tide and soaked for two hours.� All fish were identified to species with total and fork lengths measured to the nearest centimeter. Noyes Cut and Parsons Creek had the most species richness while River Marsh Landing and Todd Creek experienced the lowest diversity.� We believe these large salinity fluctuations are due to a sediment deposit that blocks water flow as a result of Noyes Cut. When Noyes Cut is closed, we expect fish to redistribute into Umbrella and Dover Creeks as a result of restored salinity gradients.�

      Miranda Henderson; Canela, Jenelly; Fischer, Jeff; Reichmuth, Jessica; Biological Sciences; Fischer, Jeff; Reichmuth, Jessica; Augusta University (1/30/2020)
      Microsporidia are spore-forming obligate intracellular parasitic fungi that infect eukaryotic organisms. They are ubiquitous in nature and infections occur worldwide in terrestrial and aquatic hosts. Some species of Microsporidia have been shown to infect the hepatopancreas of shrimp, which may affect their ability to obtain nutrients, stunt their growth, and increase their susceptibility to additional diseases. Microsporidiosis in shrimp has been shown to negatively impact the commercial shrimp industry, resulting in great economic loss specifically to the state of Georgia since this fishery is the largest and most lucrative. This study was conducted to evaluate the prevalence of microsporidia in shrimp from the Satilla River Estuary in Georgia because of man-made cuts that have altered water quality conditions that could affect shrimp health specifically. Shrimp were caught at four collection sites using 6.1m (20ft) otter trawls and cast nets and were transported on ice back to the lab where they were frozen until dissection. Using bright-field light microscopy and a previously established staining technique, microsporidian spores were detected in hepatopancreas� extracts in greater than 30% of the shrimp analyzed.�