Study Title: Effect of Water Flow on Transport of Suspended Particles and Particle-Associated Nutrients in the Everglades
Study Start Date: October 2002 Study End Date: September 2006
Web Sites: http://sofia.usgs.gov/projects/susparticles/; http://sofia.usgs.gov/projects/wtr_flux/ http://sofia.usgs.gov/sfrsf/entdisplays/waterlevels/; http://sofia.usgs.gov/exchange/harvey/harveyDATA.html; http://water.usgs.gov/nrp/jharvey/site/index.html
Location (Subregions, Counties, Park or Refuge): Northern, Central, and Southern Everglades (Palm Beach, Broward, Miami-Dade)
Funding Source: USGS-Priority Ecosystems Science (PES) Initiative
Principal Investigator(s): Jud Harvey and Greg Noe (USGS, Reston), and Jim Saiers (Yale Univ.)
Study Personnel: Jennifer O'Reilly, Joel Detty, Ying Qiu
Supporting Organizations: USGS, SFWMD, NPS/Everglades National Park
Associated / Linked Studies: Tides and Inflows at the Mangrove Ecotone (TIME) http://time.er.usgs.gov/;
Integrated Geochemical Studies in the Everglades http://sofia.usgs.gov/projects/wetland_seds/,http://sofia.usgs.gov/projects/evergl_merc/;
Freshwater Flows into Florida Bay http://sflwww.er.usgs.gov/projects/freshwtr_flow/

Overview & Objective(s): A key measure of success in the Everglades restoration is protecting water quality while increasing water quantity. The restoration's goal of increasing flow through the wetlands could have the unintended consequence of transporting contaminants farther into the Everglades than ever before. The need to augment water delivery to the Everglades will at times inevitably result in the use of water with higher than desirable total dissolved solids, particulate organic matter, sulfate, and nutrients. In addition, greater water flows may increase the downstream transport of accumulated contaminants from impacted to more natural areas of the Everglades. The rates at which those constituents will be transported and stored in surface water, subsurface porewater, and groundwater are not well known. Our studies will be definitive experimental investigations of solute and particle transport in the Everglades. Results will have significant value for predicting the possible future effects of restoring higher flows on water quality throughout the Everglades.

The objectives of the study are:

• Quantify previously unstudied processes in the Everglades such as rates of fine-particle movement and filtration by vegetation. Also quantify advective solute exchange between surface water and shallow subsurface flow paths in peat porewater that lead to increased residence times and reaction rates of dissolved constituents in the Everglades. Our study focuses on determining the effects of these processes on the transport of dissolved and fine particle forms of phosphorus and other contaminants in Everglades surface water.
• Apply the new knowledge gained from our field measurements and tracer experiments to propose improvements in currently used water-quality models (e.g. DMSTA, ELM) and new water quality models (e.g. extension of USGS SICS model) toward more accurate simulation of the effects of restoration on Everglades water quality.
• Guide the use of improved water-quality models to estimate potential rates of remobilization and transport of phosphorus (and other contaminants) stored in sediments and particles in WCA-1, 2A, 3A, and to predict potential rates of downstream movement into Everglades National Park under "restored" flows.

Status: Active

Recent Products: Harvey, J.W., Saiers, J.E., and Newlin, J.T., 2004, Solute Transport and Dispersion in Wetlands of the Everglades, South Florida. Water Resources Research, submitted ; Saiers, J.E., Harvey, J.W., and Mylon, S.E., 2003, Surface-water transport of suspended matter through wetland vegetation of the Florida Everglades. Geophysical Research Letters 30(19), 1987, doi:10.1029/2003GL018132; Noe, G.B., Scinto, L.J., Taylor, J., Childers, D.L., and Jones, R.D. 2003, Phosphorus cycling and partitioning in an oligotrophic Everglades wetland ecosystem: a radioisotope tracing study. Freshwater Biology 48(11):1993-2008.

Planned Products: Surface-Water and Ground-Water Interactions in Water Conservation Area 2A, Central Everglades, USGS SIR 2004-5069 (conditionally approved); fact sheets, data reports, journal articles.

Specific Relevance to Information Needs Identified in DOI's Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (DOI's Everglades Science Plan) [See Plan on SOFIA's Web site: http://sofia.usgs.gov/publications/reports/doi-science-plan/]

This study supports the following four projects in the DOI science plan: (1) Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement, (2) Arthur R. Marshall Loxahatchee NWR Internal Canal Structures, (3) Comprehensive Integrated Water Quality Feasibility Study, and (4) Landscape-Scale Modeling Study. Our study will determine the role of transport of fine particles in Everglades surface water in controlling storage, transport, and transformation of phosphorus (and other contaminants) in Everglades wetlands. The study will examine regional differences in fractional distribution of contaminants in different dissolved and solid forms, size distribution and chemical makeup of fine particles, transport rates of solutes and fine particles in flowing water, and rates of filtration of fine particles by vegetation and solute exchange between surface water and peat porewater. These characteristics and processes will be measured in contrasting peat and marl forming wetlands, and in wetlands with contrasting impacts of phosphorus pollution. Regional differences will be addressed through measurements at one site in central Arthur R. Marshall Loxahatchee (WCA-1), three sites along the nutrient enrichment gradient in WCA-2A, and one site each in Shark River Slough and Taylor Slough in Everglades National Park. Interactions with hydrology will be addressed through field-tracer experimentation using carefully controlled injections to determine the fate of particulate matter under different flow conditions. These studies will provide a process-based characterization of a critical unknown; the role of suspended fine particle transport as a control on phosphorus cycling and ecosystem structure in the Everglades. The results of our investigations will be implemented in comprehensive water-quality models and landscape ecosystem models that are being used to adaptively guide the restoration. In particular, the results of these studies will be crucial in predicting the effects of WCA-3A Decompartmentalization Project (DOI Science Plan p. 66) and the Loxahatchee Internal Canal Structures Project (p. 39). This study will also provide key scientific data to the Comprehensive Integrated Water Quality Studies (p. 84) and Landscape-Scale Modeling Study (p. 81). The information that our project provides will help assure success in modeling transport characteristics of solutes and fine particles (including contaminants such as phosphorus), storage times, rates of remobilization of those constituents, and rates of downstream movement in what will become a hydrologically modified Everglades ecosystem under restoration. Finally, by quantifying and modeling particle transport in this system, this study will also benefit efforts to understand a previously unstudied part of the carbon cycle in the Everglades which influences development and maintenance of the Everglades ridge and slough landscape.

Key Findings:

1. Developed reliable methods for quantifying surface water and ground water interactions throughout the vast interior wetlands of the Everglades (Choi and Harvey, 2000; Harvey and others, 2002; Krest and Harvey, 2003; Harvey and others, 2004a; Harvey and others, 2004b).
2. Quantified the effect of surface water and ground water interactions on the mercury budget of the Everglades Nutrient Removal (ENR) project, the prototype for the Stormwater Treatment Areas (STAs) (Harvey and others, 2002).
3. Conducted a successful preliminary test of tracer experimental procedures in the Everglades. Solute and fine-particle tracers were injected into surface water in Everglades National Park and their downstream movement carefully monitored. Those experiments showed that it will be possible to quantify two previously unrecognized storage processes for contaminants in the Everglades, i.e. (1) advective solute exchange between surface water and shallow subsurface flow paths in peat porewater, and (2) particle filtration by vegetation. More tracer tests are needed in additional areas of the Everglades to validate our results, however, we expect that our results will provide become key input parameters for water quality models used to predict movement of phosphorus and other solute and particle-associated contaminants under restored flows in the Everglades (Saiers, Harvey and Mylon, 2003; Harvey, Saiers, and Newlin, submitted).
4. Characterized particulate phosphorus concentrations in oligotrophic and enriched wetlands of WCA-2A with preliminary sampling in 2004. Particulate phosphorus concentrations and proportion of total phosphorus were found to increase with long-term phosphorus enrichment (Noe and others, in preparation).
5. Developed ecosystem phosphorus budgets for oligotrophic and enriched Everglades wetlands. Invasion of Typha in the Everglades results in a large increase in cycling of phosphorus from sediments to the water column as a result of macrophyte nutrient pumping (Noe and Childers, in preparation).