Tidal Marsh Restoration at Poplar Island I: Transformation of Estuarine Sediments into Marsh Soils

• Published in: Wetlands (Wilmington, N.C.) Vol. 40; no. 6; pp. 1673 - 1686
• Main Authors: Cornwell, Jeffrey C., Owens, Michael S., Staver, Lorie W., Stevenson, J. Court
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-12-2020; Springer Nature B.V
• Subjects: Acidic soils; Ammonium; Biomedical and Life Sciences; Coastal Sciences; Dewatering; Dredged materials; Dredging; Ecology; Environmental Management; Environmental restoration; Freshwater & Marine Ecology; Hydrogeology; Iron; Iron sulfides; Landscape Ecology; Life Sciences; Marsh Resilience Summit; Minerals; Nutrient concentrations; Oxidation; Phosphorus; Plant growth; Restoration; Sediments; Soil chemistry; Soil contamination; Soil erosion; Soil horizons; Soil pH; Soil surfaces; Soils; Sulfur; Sulfuric acid; Tidal flooding; Wetlands; Susquehanna River; Patapsco River; United States > US; Maryland; Poplar Island; Chesapeake Bay; Nutrients; Wetland biogeochemistry; Wetland restoration; Dredged materials; Sediment biogeochemistry
• ISSN: 0277-5212; 1943-6246
• DOI: 10.1007/s13157-020-01294-5

Dredged materials from navigation channel maintenance represent a potentially valuable resource for wetland creation and restoration. In the northern Chesapeake Bay, fine-grained sediments from Baltimore Harbor approach channels are transported by barge southward for creation of wetlands on the site of an eroded island. High concentrations of ammonium, soluble reactive phosphorus, dissolved iron, and iron sulfide minerals in channel deposits are altered by the transport and drying of these materials prior to wetland development. The oxidation of iron sulfide minerals results in low pH, with the initiation of tidal inundation removing sulfuric acid from near-surface soil horizons and moderating the soil pH. Despite the loss of ammonium during dewatering and soil processing, the resultant soils retained high concentrations of dissolved and adsorbed ammonium. Iron-associated inorganic phosphorus represented a large pool of potentially labile phosphorus and along with the high ammonium, resulted in high nutrient concentrations for plant growth. Combined with results on plant growth presented elsewhere, these data suggest that fine-grained dredged materials from non-contaminated environments are well suited for the creation of tidal wetlands after placement and seasoning 1–2 years.