Compilation of estuarine salinity data for sites used in RESTORE Streamflow alteration assessments

Salinity and variability of salinity of shallow waters shape living resources and habitat in Gulf of Mexico estuaries. The salinity gradient is widely recognized as foundational in maintaining biological diversity and productivity of estuaries. It follows that a clear understanding of the factors controlling salinity and variability of salinity in estuarine surface waters is essential for proper stewardship and for sustaining ecological structure and function. Salinity data are collected by numerous Federal, State and local agencies as well as universities as part of routine data collection programs. We used the World Wide Web to locate salinity data in Gulf of Mexico estuaries. The primary criteria for inclusion in the compilation were a lengthy record, continuous collection with data sondes of at least hourly collection intervals. Stations that represented full estuarine gradients, from fresh to saline were prioritized. Data were compiled in separate spreadsheets for each State using comma delimitted formatting. For each State, a second spreadsheet provides information on each station. A few stations started collecting salinity as early as mid 1980s. More stations came on line by the mid to late 1990s. Starting in late 2000s many more stations came on line.