Salinity levels are important in estuarine systems. To maintain a healthy, naturally diverse, well-balanced estuarine ecosystem, the salinity regime must be suitable for the species residing there. Altered salinity regimes adversely affected the ecosystems by; exposing local estuarine inhabitants to high freshwater inflows during the wet season, which leads to acute declines in species abundance, and allowing too little freshwater inflow during the dry season or drought periods, which leads to gradual increases in predation, disease, and mortality rates.

See the results for salinity in the Northern Estuaries or Southern Coastal Systems.

Photo credit: Emily Nastase.

How is it measured?

Salinity is monitored in the Northern Estuaries in all three subregions. Salinity is measured by data loggers at three sites in the St. Lucie Estuary, three sites in the Loxahatchee River Estuary, and two sites in the Caloosahatchee River Estuary. The thresholds are based on the salinity envelope established for St. Lucie Estuary (12 - 20 ppt).

Salinity is monitored in the Southern Coastal Systems in all three subregions. In Biscayne Bay, it is monitored by the IBBEAM program and the indicator is based on the number of consecutive days with mesohaline conditions. The thresholds are separate for wet and dry seasons. In Florida Bay the indicator is based on three salinity metrics from the Stoplight indicator, the Overlap Metric, Mean Offset Metric, and High Salinity Metric. These three metrics were combined into a salinity score for each monitoring station, basin, and the sub-region. In the Southwest Coast, it is monitored by USGS, and the salinity metric is based on the habitat requirements for oysters, and the range is 14 - 28 ppt.