Porewater Sulfide Assessment in Subaqueous Soils formed from Late Holocene Barrier Lagoon Deposits.

In anaerobic subaqueous soils, sulfate in the estuarine water can be reduced to H₂S which, at elevated levels, can be toxic to SAV or benthic organisms. Various soil properties are known to affect the level of soluble H₂S that is produced or supported in the pore water. Therefore, four sampling sites were identified by using a recently developed subaqueous soil map of Chincoteague Bay as a guide. Recent work in estuarine marshes demonstrated that IRIS technology could be used effectively to document hydrogen sulfide in marsh soil pore water. The objectives of this study were 1) to determine if the porewater sulfide levels in subaqueous soils could be evaluated using IRIS technology, and 2) to assess the porewater sulfide levels in four soil units in Chincoteague Bay. IRIS tubes were inserted 50 cm into the subaqueous soils for periods ranging from 1 to 24 hrs. Sulfide depth functions will be presented from data collected during three different times of the year (June, September and November).