Project Work Plan

Overview & Objective(s):

A primary directive in the Comprehensive Everglades Restoration Plan (CERP) is to restore Everglades hydrology toward pre-drainage conditions in a manner that will successfully protect water quality and landscape structure. Water-management practices during the past century are acknowledged to have played a significant role in causing changes in the topography, water flow direction, water quality, vegetation communities, and other landscape characteristics of the Everglades (Crisfield and McVoy, 2004). Both the National Research Council and the Department of Interior have recommended research to determine how further changes in water management, in particular, changing the amount and distribution flows in a “restored” Everglades, will influence water quality and landscape structure. One concern is that plans for augmenting water flows to increase water levels in certain downstream areas could have the unintended effect of transporting surface-water contaminants (including higher than desirable levels of total dissolved solids, particulate and dissolved organic matter, sulfate, phosphorus, mercury, etc.) farther into the central and southern parts of the Everglades ecosystem than ever before.

Consequently, the restoration's goal of increasing surface-water flow while preserving water quality and the integrity of the Everglades landscape could more difficult than anticipated. Already there are parts of the northern and central parts of the Everglades (e.g. northern WCA-2A) where the characteristic Everglades landscape has been completely altered. Surface-water contaminants are stored at high concentration in soils, vegetation, peat pore water and ground water in those locations (Harvey and others, 2005). Recent estimates suggest that the movement of phosphorus from those storage locations back into the flowing surface waters now exceeds the inputs of “new” phosphorus from outside the system (Noe and Childers, in review). However, very little is known about how quickly that contamination is spreading and whether the restoration's goal of increased flows will cause the spreading of those stored contaminants at an even faster rate. Noe and others (2003) first identified the strong association between suspended particles in the water column and phosphorus cycling in Everglades wetlands. However, little was known about the transport characteristics of suspended particles in the Everglades.

Our investigation seeks a better understanding of the fundamental processes that determine transport rates of phosphorus and other contaminants to downstream locations in the Everglades. The ultimate goal is to acquire, through detailed experimentation and modeling, the parameters that will be needed to predict how “restored” flows will affect Everglades water quality in the coming years and decades.

Important questions to be addressed include, “How far is phosphorus currently being transported before being sequestered into soil and vegetation?”, “Will transport distances to downstream areas increase under restored flows?” “What are the important processes involved in phosphorus transport and storage, in particular what is the role of fine suspended particulate matter in transporting phosphorus”, and “What is the role of emergent wetland vegetation in intercepting those fine particulates”.

A related goal of our work is to understand whether interactions between flow and transport of sediment and phosphorus are an important contributor to changes in Everglades landscape patterns (i.e., loss of ridge and slough topography and tree islands), and to determine whether there are ways to manage flow and phosphorus loads together. The goal is to reduce further degradation of the remaining high-functioning parts of the ecosystem with hydrological and ecological characteristics most similar to the pre drainage Everglades system (http://www.evergladesplan.org, Science Coordination Team, 2003).

Specific Relevance to Major Unanswered Questions and Identified Information Needs: (Page numbers below refer to DOI Science Plan.)

The Science Coordination Team of the South Florida Ecosystem Restoration Task Force (http://www.sfrestore.org/) asserted the need for research on interactions between flow and ecological processes in the Everglades (Science Coordination Team, 2003). Furthermore, the National Research Council reports a lack of understanding of the role of flow as a factor contributing to landscape changes in the Everglades (National Research Council, 2003). The Monitoring and Assessment Plan (MAP) of the Comprehensive Everglades Restoration Plan (CERP) (http://www.evergladesplan.org) also calls for the need of background information on sheet flow behavior for effective restoration assessment. The need for investigations of interactions between flow and water quality is also identified as needed priority research in multiple sections of the Science Plan of the Department of Interior.

In the present work plan, sheet-flow behavior (monitored by our collaborator Ray Schaffranek) and its interactions with transport of fine suspended particulates and phosphorus will be determined in an area of well-preserved ridge and slough environment. The specific goal is to identify and characterize (as parameters for water quality models) the critical factors that influence downstream water quality and landscape maintenance.

The present study supports critical science needs in the following four projects in the DOI Everglades Science Plan: (1) Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement, (2) Arthur R. Marshall Loxahatchee NWR (WCA-1) Internal Canal Structures, (3) Comprehensive Integrated Water Quality Feasibility Study, and (4) Landscape-Scale Modeling Study.

One of the most important aspects of our work is determining the role of transport of fine suspended particles in controlling storage, transport, and transformation of phosphorus (and other contaminants) in the surface water of Everglades wetlands. Preliminary transport experiments were conducted in the first year of the investigation (Saiers and others, 2003; Harvey and others, 2005). In the second year, regional differences in the size distribution of suspended fine particulate matter and associated phosphorus were determined (Noe and others, 2004). Locations for that analysis included one site in central Arthur R. Marshall Loxahatchee (WCA-1), three sites along the nutrient enrichment gradient in WCA-2A, and one site in Shark Slough in Everglades National Park.

In FY06 we will investigate in detail the interactions between phosphorus biogeochemistry, particle transport and filtration, and water flow velocity. The site chosen for experimentation is in Water Conservation Area 3A in an area of well preserved ridge and slough topography. We will be collaborating with Ray Schaffranek's project, which will primarily be responsible for establishing two monitoring sites (one on a ridge and one in a slough) with continuous measurement of water depth, velocity, specific conductivity, and temperature profiles in the water column. At the same sites our group will be measuring detailed topography and microtopography, and sediment characteristics at the ridge and slough sites and at transition sites between them. One sampling trip will be devoted to measuring storage of nutrients in dissolved and particulate phases in water, soil, and plants at eight sites across the ridge to slough transition. Dissolved and suspended fine particulate concentrations of phosphorus and nitrogen (organic and inorganic forms) will be measured once per month at three depths of the water column in at the ridge and slough monitoring sites. Dissolved and particulate organic carbon, calcium, iron, and aluminum will also be measured at the same locations on one sampling trip. Dissolved concentrations of all elements will be determined at six depths in pore water of the Everglades peat soil on all of the monthly sampling trips.

A refined set of controlled injections of solute and particulate tracers will also be undertaken in FY06. The purpose of the tracer experiments is to investigate the interactions between phosphorus biogeochemistry, fine suspended particle transport, and variable water flow velocities. The goal is to determine in detail the fate of solutes and fine particulate matter under different flow conditions and to identify the specific physical and biological features and processes responsible for the observed levels of transport and storage. The tracer experiments will be conducted at several different velocities (manipulated by pumping) at both the ridge and slough sites over time periods ranging from hurs to tens of hurs. Results of those experiments will be modeled in detail to produce the parameters describing controlling processes, such as particle sources, size classes, and phosphorus content; transport and filtration rates of particles, water and solute storage in relatively slow moving water in zones of thick vegetation and in subsurface pore water; and chemical reactions that phosphorus undergoes in its various dissolved and particulate forms. This information is critical for improving the modeling of the cycling and transport of dissolved and particulate contaminants in the Everglades.

Modeling by our group in FY06 will be required first to interpret the results of tracer experiments, with the goal being to produce a fundamental set of transport parameters representing the role of fine suspended particles and storage of water and solute in relatively slow-moving areas of thick vegetation and subsurface pore water. Eventually we expect that our modeling concepts and parameter sets will be implemented in the more comprehensive water-quality models and landscape ecosystem models (such as DMSTA and ELM) that are being used to adaptively guide the restoration. In this way the knowledge gained from our detailed experiments will be “scaled-up” for application at larger spatial scales and at longer temporal scales. If successful, we envision the incorporation of our parameters into model applications throughout the Everglades. In particular, the results of these studies will be crucial in predicting the effects of WCA-3A Decompartmentalization Project (DOI Science Plan p. 66). This study will also provide key scientific data to the Loxahatchee Internal Canal Structures Project (p. 39), Comprehensive Integrated Water Quality Studies (p. 84), Landscape-Scale Modeling Study (p. 81) and Ridge and Slough Performance Standards.

Expected Results and Significance:

The DOI Science Plan highlights the need to understand the influence of hydrology on nutrient and contaminant transport and cycling. The National Academy of Sciences has also emphasized the importance of sediment transport to understanding and restoring the Everglades. Our proposed experiments and modeling are fundamental to building a reliable predictive capability of how the Everglades will respond to the restoration's higher flows. Our proposed combination of empirical and modeling research will support several of the critical information needs identified by the National Academy of Science and DOI Everglades Science Plan. First, this work has direct bearing on projects such as the WCA-3A Decompartmentalization Project, and Tamiami Trail Bridge Expansion projects, but it is also highly relevant to all projects related to preservation of landscape structure (e.g. Landscape-Scale Modeling Study and Ridge and Slough Performance Standards), as well as all projects concerned with changing water quality and the need for more modern water-quality performance standards in the Everglades (e.g. Comprehensive Integrated Water Quality Feasibility Study). Our study will identify the critical hydrologic, chemical, and biologic linkages that have shaped both the pre-drainage Everglades and the current landscape. This information is necessary for understanding the critical factors that sustain the ridge and slough landscape and ecosystem function, and is also necessary for predicting some of the unintended side-effects of restoration activities that may accompany increases in flow and hydrologic connectivity (a focus identified as important by both DOI and the National Academy of Science). Finally, the information gained on particle and solute transport will aid critical modeling efforts that support the Loxahatchee Internal Canal Structures Project. In conclusion, our proposed work will support key science needs for no less than six of the projects identified by DOI as critical to the success of the Everglades restoration.

Status: Active

References Cited:

Crisfield, E., and McVoy, C., 2004, Role of flow-related processes in maintaining the ridge and slough landscape, Joint Conference on the Science and Restoration of the Greater Everglades and Florida Bay Ecosystem, Palm Harbor, FL.

Harvey, J.W., Newlin, J.T., Krest, J.M., Choi, J., Nemeth, E.A., and Krupa, S.L., 2005, Surface-Water and Ground-Water Interactions in Water Conservation Area 2A, Central Everglades, USGS SIR 2004-5069 (approved).

Harvey, J.W., Saiers, J.E., and Newlin, J.T., 2005, Solute transport and storage mechanisms in wetlands of the Everglades, south Florida, Water Resources Research, 41, W05009, doi:10.129/2004WR003507.

National Research Council, 2003, Does water flow influence Everglades landscape patterns, Washington, D.C., The National Academies Press, http://books.nap.edu/catalog/10758.html, 41 p.

Noe, G.B., Harvey, J., Saiers, J., 2004, Particulate phosphorous transport in the Everglades wetland landscape, First National Conference on Ecosystem Restoration, Orlando, FL.

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.

Noe, G.B. and Childers, D.L. The effects of enrichment on Everglades wetland ecosystem phosphorus budgets. Ecosystems, (submitted, publication expected September 2006).

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.

Schaffranek, R.W., and Riscassi, A.L., 2004, Flow velocity, water temperature, and conductivity at selected locations in Shark River Slough, Everglades National Park, Florida: July 1999-July 2003, U.S. Geological Survey Data Series 110. http://pubs.usgs.gov/ds/2004/110/.

Science Coordination Team, 2003, The role of flow in the Everglades ridge and slough landscape, South Florida Ecosystem Restoration Working Group, http://www.sfrestore.org/sct/docs/SCT Flow Paper - Final.pdf, 62 p.

B. WORK PLAN

Title of Task 1: Effect of Water Flow on Transport of Solutes, Suspended Particles, and Particle-Associated Nutrients in the Everglades
Task Funding: USGS Greater Everglades Priority Ecosystems Science (GE PES)
Task Leaders: Jud Harvey, Greg Noe, Jim Saiers
Phone: (703) 648-5876
FAX: (703) 648-5484
Task Status (proposed or active): Active
Task priority: High
Time Frame for Task 1: October 2005 - September 2006
Task Personnel: Jennifer O'Reilly, Joel Detty, Ying Qiu
Task Summary and Objectives: See Overview and Objectives above

Work to be undertaken during the proposal year and a description of the methods and procedures:

1. Interpret regional patterns in physical properties and chemistry of fine suspended particles that were measured last year in a regional program of sampling in the Everglades that contrasted wetlands with different levels of hard and soft water and contrasting impacts of phosphorus pollution. The variables measured were total concentration, size distribution, elemental composition, phosphorus content of particles in the water column. Locations included one site in central Arthur R. Marshall Loxahatchee (WCA-1), three sites along the nutrient enrichment gradient in WCA-2A, and one site in Shark Slough, Everglades National Park. Knowledge of the physical and chemical characteristics of suspended sediment is necessary for efforts to predict sediment transport and fate, as well for associated contaminants, and will enable efforts to optimize Everglades restoration. Information on suspended sediment characteristics will also be applied in Objective #3, below.

2. Monitoring of phosphorus fate and storage in an area of well preserved ridge and slough landscape in Water Conservation Area 3A. This work is to be conducted in collaboration with Ray Schaffranek's project, and will investigate interactions between topography, flow velocity, vegetation type and density, and the transport of fine suspended particulates and associated phosphorus over a wet season. Two monitoring sites will be established (one on a ridge and one in a slough) with continuous measurement of water depth, velocity, specific conductivity, and temperature profiles in the water column. At the same sites this project will be measuring detailed topography and microtopography, and sediment characteristics (including phosphorus forms) at the ridge and slough sites and at transition sites between them. On a one time sampling trip we will measure storage of nutrients in dissolved and particulate phases in water, soil, and plants across the transect. On a monthly basis through the wet season we will measure dissolved and suspended fine particulate concentrations of phosphorus and nitrogen (organic and inorganic forms) at three depths of the water column in both ridge and slough. Dissolved and particulate organic carbon, calcium, iron, and aluminum will also be measured at the same locations on one sampling trip Dissolved concentrations will also be determined at six depths in pore water of the Everglades peat soil.

3. In addition to seasonal monitoring, interactions between water flow, suspended sediment transport, and phosphorus biogeochemistry will be addressed through carefully controlled injections of solute and particulate tracers. The goal is to determine in detail (1) the fate of solutes and fine particulate matter under different flow conditions in contrasting ridge and slough environments, and (2) to identify the specific physical and biological features and processes responsible for the observed levels of transport and storage. These detailed experiments are to be conducted at the spatial scale of approximately 10 m and the time scale of several days. Results of those experiments must be modeled to summarize in an efficient manner the parameters describing (1) interactions between particle sources, size classes, and phosphorus content, (2) transport and filtration rates of particles in areas of contrasting type and density of vegetation, (3) rates of water and solute storage in relatively slow moving water in zones of thick vegetation and in subsurface pore water, and (4) chemical reaction rates that change the form of phosphorus (between dissolved and particulate) and affect the residence time of phosphorus in storage and the mobility of phosphorus in forms that can be transported. This information is critical for guiding the development of water quality models which must include acceptable simplifications of the complex processes affecting phosphorus fate and storage in the Everglades.

4. The first step toward building more reliable water-quality models begins with our own modeling. Modeling the results of our experiments will specify processes such as rates of transport and filtration of fine suspended material as “parameters” that are easily transferable to models of at other times or in other places within the Everglades system. The initial modeling will necessarily be limited to small spatial scales (hundreds of meters) and relatively short time scales (days). Nonetheless, those models will provide considerable insight into how to increase the validity of existing and new water quality models in the Everglades. The value of the models will be that, even though they will be relatively simple, they will be substantially more sophisticated in their processes than some of the existing models for phosphorus transport (such as DMSTA), particularly in the specification of the form of phosphorus (dissolved or particulate), the transport characteristics of each form of phosphorus, and the associated storage times and its effects on downstream transport. Because the modeling will be based on definitive experiments using tracers, we expect to achieve an unprecedented level of new understanding about the processes controlling phosphorus movement and storage in the Everglades, principally the role of fine suspended particle (and associated phosphorus) fluxes and particle filtration, and interactions with flow velocities, and vegetation type and density. These are processes that we feel are critical to making valid predictions how phosphorus contamination and landscape characteristics are likely to change under the increased flows in some areas caused by Everglades restoration activities. The results will therefore be crucial information for accurate predictions of the water quality effects of restoration projects such as DECOMP and TAMIAMI TRAIL bridge expansion. Results will also be highly relevant to answering key questions associated with changing landscape characteristics in the Everglades (e.g. Landscape-Scale Modeling Study, Ridge and Slough Performance Standards), as well as all projects concerned with changing water quality and the need for more modern water-quality performance standards in the Everglades (e.g. Comprehensive Integrated Water Quality Feasibility Study). Finally, the information gained on particle and solute transport will aid critical modeling efforts that support the Loxahatchee Internal Canal Structures Project.

Specific Task Product(s): [List and include expected delivery date(s).]

Harvey, J.W., Newlin, J.T., Krupa, S.L., Modeling decadel timescale interactions between surface water and shallow ground water in the central Everglades, Florida, USA, Journal of Hydrology, (in press, publication expected November 2005).

Harvey, J.W., Newlin, J.T., Krest, J.M., Choi, J., Nemeth, E.A., and Krupa, S.L., 2005, Surface-Water and Ground-Water Interactions in Water Conservation Area 2A, Central Everglades, USGS SIR 2004-5069, (approved and in preparation for printing at GPO, publication expected December 2005).

Harvey, J.W. and others. Simulation of transport of solute and fine suspended particulates in the ridge and slough landscape of the Everglades (to be submitted to journal by December 2006).

Noe, G.B. and Childers, D.L. The effects of enrichment on Everglades wetland ecosystem phosphorus budgets. Ecosystems, (submitted, publication expected September 2006).

Noe, G.B., Saiers, J.E., and Harvey, J.W. Characterization of suspended particles in Everglades wetlands. (to be submitted to journal by September 2006).

Saiers, J.E., and other, Wetland processes affecting transport and interception of micron-sized suspended particulates in the ridge and slough landscape of the Everglades (to be submitted to journal by October 2006).