Spatial Monitoring of Salinity and Stage in the Tidal Freshwater Marshes Of the Savannah National Wildlife Refuge

The tidal freshwater marshes of the Savannah National Wildlife Refuge were monitored for salinity and stage. The long term monitoring effort was part of a large environmental impact statement, which sought to model the effects of changes to the Savannah River's geomorphology to marsh speciation (flora). This data was collected to provide a baseline, which thoroughly described the dynamics of the interactions of the river's stage and salinity with marsh pore salinity, over differing spatial and time scales.The area studied was located on the Savannah River adjacent to and in the Savannah National Wildlife Refuge. The study area comprised 5400 acres of tidally influenced herbaceous riverine marsh. This area of complex river and channel braiding produces intricate patterns of flooding and salinity. To record the dynamics of salinity and stage this system was instrumented with Campbell Scientific CR10X data loggers. Each data station was equipped with multiple salinity probes and stage monitoring devices.Additionally each station was equipped with a cell phone for remote access to individual datalogger stations, to retrieve data on a daily basis to a remote server. For long-term power supply each station was equipped with a battery, charge controller and a solar panel. Additionally, a robust deployment methodology and quality assurance/quality control procedure was implemented. Deployment concerns included: weather impacts, wildlife impacts, physical logistics of serviceability, and database information flow. Nine data loggers were deployed simultaneously to capture between site variability.The probes of the data loggers (salinity and stage) were arranged to reveal within site linkages between river stage, marsh stage, river salinity, marsh surface salinity, and marsh pore water salinity. The results of this monitoring effort were compared to long term river flow. This comparison revealed the salinity of the pore water to be highly correlated to long-term river flow.It is the intent of this presentation to pass on our experience on how to deploy and maintain this type of data collection system and to show how useful and powerful the output can be. The total of our knowledge was gathered over several years of experience and refinement and we hope other environmental monitoring efforts will be able to make use of our methods when employing this valuable type of highly customizable equipment.