Effect of salt water intrusion on the distribution of invertebrates in a GA tidal freshwater marshes from the GCE Seawater Addition Long-Term Experiment (SALTEx) project.

To characterize the effect of persistent and episodic salt water intrusion on the distribution of common freshwater marsh invertebrates, we monitored the density of adult and juvenile fiddler crabs and snails. Prior to the start of salt water addition treatments, we collected data on the distribution of crabs and snails in all 30 experimental plots (6 replicates of 5 treatments: pressed salt water addition, pulsed salt water addition, fresh water addition, procedural control structure, and control no structure). In each experimental plot, we counted the number of adult and juvenile fiddler crab burrows and snails visible on the marshs surface in a 50cm x 75cm plot (juvenile fiddler crabs were counted in only half of this area) that was positioned in the Northeastern corner of each experimental plot. Initial data was collected in March 2014. A Bentho Torch was used to measure the concentrations of cyanobacteria, diatoms, and green algae on the marsh surface in 2015 and 2016.