title: Surface water sulfate dynamics in the northern Florida Everglades.
abstract: Sulfate contamination has been identified as a serious environmental issue in the Everglades ecosystem. However, it has received less attention compared to P enrichment. Sulfate enters the Arthur R. Marshall Loxahatchee National Wildlife Refuge (Refuge), a remnant of the historic Everglades, in pumped stormwater discharges with a mean concentration of approximately 50 mg L(-1), and marsh interior concentrations at times fall below a detection limit of 0.1 mg L(-1). In this research, we developed a sulfate mass balance model to examine the response of surface water sulfate in the Refuge to changes in sulfate loading and hydrological processes. Meanwhile, sulfate removal resulting from microbial sulfate reduction in the underlying sediments of the marsh was estimated from the apparent settling coefficients incorporated in the model. The model has been calibrated and validated using long-term monitoring data (1995-2006). Statistical analysis indicated that our model is capable of capturing the spatial and temporal variations in surface water sulfate concentrations across the Refuge. This modeling work emphasizes the fact that sulfate from canal discharge is impacting even the interior portions of the Refuge, supporting work by other researchers. In addition, model simulations suggest a condition of sulfate in excess of requirement for microbial sulfate reduction in the Refuge.
authors.affiliation: Center for Louisiana Waters Studies, Inst. of Coastal Ecology and Engineering, Univ. of Louisiana at Lafayette, P.O. Box 42291, Lafayette, LA 70504, USA. hxw7894@louisiana.edu
authors.forename: Hongqing
authors.initials: H
authors.lastname: Wang
authors.forename: Michael G
authors.initials: MG
authors.lastname: Waldon
authors.forename: Ehab A
authors.initials: EA
authors.lastname: Meselhe
authors.forename: Jeanne C
authors.initials: JC
authors.lastname: Arceneaux
authors.forename: Chunfang
authors.initials: C
authors.lastname: Chen
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Harwell
mesh_terms: D005431:Florida; D005618:Fresh Water / Q000032:analysis*; D008956:Models, Chemical; D013431:Sulfates / Q000032:analysis*; D014872:Water Movements; D014877:Water Pollution, Chemical / Q000032:analysis; D053833:Wetlands
chemical_list: D013431:Sulfates