1. Abstract This project will quantify what will happen to flocculent material (floc) when Everglades Restoration Act is implemented, increasing the sheet flow of water through the ridge and slough habitat. We will investigate how water increase affects transport of floc, how periphyton contributes to floc, how the net primary productivity affects floc, and how floc affects sedimentation by creating flow manipulation sites that artificially increase water flow. However, in order to carry out the proposed research we needed to conduct a preliminary experiment to make sure that the experiment could be carried out accurately. In our preliminary study we found that the flow acceleration site attained a flow mean over two times as large as the non-manipulated slough sites. We found that our flocculators could measure net transport, however due to the end of the wet season the experiment had to be cut short before an accurate reading could be made. Using a light dark bottle experiment we found that floc does have microbial activity, with an NPP of approximately 0.04 mg C * g AFDW * h-1. In the future we plan on calculating the effects of sedimentation of floc during dry down. We plan on using the preliminary study as a springboard to segue into the full research project to be carried out in the coming wet season. Introduction: - Flocculent material (floc) is suspended organic material found in the Everglades. - Floc can be produced by the sloughing of organic matter from periphyton mats. - Due to floc’s low density, water flow can easily transport floc down the slough and ridge habitat. - The sawgrass ridge habitat consists of patches of sawgrass where soil elevation is higher than surrounding sloughs. Sloughs are deeper and contain less vegetation than sawgrass ridges which channalize water south through the oligotrophic freshwater Everglades and estuaries to Florida Bay. -Over the past hundred years this water flow in the slough and ridge system has been manipulated and compartmentalized resulting in a greatly decreased flow rate. As a result of these flow reductions the slough now has shallower water depths with an increase in sedimentation and macrophyte densities. -Recent changes in water management policy aims to restore flow rates in Shark River Slough to its estimated historical flow rates. -This research project aims at characterizing factors that influence floc (figure1): 1. How does the velocity of sheet flow affect the transport of floc? 2. How does periphyton contribute to floc? 3. How Does Net Primary Productivity affect the abundance of the floc? 4. How does floc affect sedimentation of soils? 1.Net transport -Flocculators (figure 5 and 14) were placed on the soil to measure the amount of floc transported. -Each flocculator was left in the slough for varying duration until equilibrium was reached (see Figure 6). Net transport was determined when floc volume reached equilibrium. 2. NPP -We conducted a light/dark bottle experiment on samples of floc to calculate NPP and Respiration (Figure 10). -Our preliminary data was carried out in 1-22-03 for three hours in the high flow site. 3.Periphyton sloughing -Sediment traps were placed in each site just above the floc to capture the sloughed material from periphyton (Figure 12 and 14). The experiment was carried out from 1-22-03 till 2-7-03. -The accumulated matter was then dried and weighed (Graph 4). 4.Sedimentation (Future Work) - Pins were placed in the soil from the bedrock to the top of the soil. We will annually measure the distance of top of the pins to the soil surface to calculate soil elevation change (Figure 14). -We hypothesize that floc will contribute to soil elevations during severe droughts were the slough completely dries up. This will cause the floc to become incorporated into the soil. Continuation and Future Work: -We will test out hypothesis that: the net transport of floc will vary seasonably and with flow modifications. floc NPP varies seasonally and between the slough and ridge periphyton sloughing rates will vary seasonally. floc contributes to sedimentation during slough dry down. Site Description: Our research site is located in a slough near Gumbo Limbo tree island in Shark River Slough: Everglades National Park, Florida (Figure 2). It consists of a series of walls designed to increase water flow into one of our research area (Figure 3). Within this accelerated flow site we also cut out vegetation. We left one with full vegetation (FFP), another with half the vegetation removed (FHP) and the last part with all vegetation removed (FNP) Another series of walls are also organized to inhibit water flow into another research area (NF) (Figure 4). We also have two control sites in the slough system encompass both the sawgrass patches (CC) and sloughs (SC) (Figure 5). SiteDate NEP (mg C * g AFDW * h -1 )NPP StDev Resp (mg C * g AFDW * h -1 ) Resp StDev Flow 14- Feb-030.040.430.330.14 Water Flow Rates -Water flow velocities were measured biweekly using a SonTek FlowTracker Handheld ADV® (Figure 8) -We took flow measurements in the slough control sites, sawgrass sites, no flow site, sawgrass sites, and the accelerated flow sites with full, half and no vegetation. Our flow manipulation experiment began at the end of the 2002-2003 wet season (Figure 9). Water flow had already been drastically reduced. Figure 6. Hypothetical flocculator data. The mass/time at the beginning of equilibrium is the net transport rate. Figure 7. Graph of Preliminary data from flocculators. Figure 5. Flocculator partially filled with floc Figure 4. Left. Picture of no flow site. The walls block the water flow from entering our research site. Figure 5. Right. Picture of our control site. This site includes both a slough and a sawgrass ridge. -We found that NPP of floc in the accelerated flow site was approximately.04 mg C * g AFDW * h-1 (See Figure 11). -We hypothesize that NPP should vary seasonally. -We believe that more periphyton was sloughed from the slough sites because they were covered in periphyton. -We hypothesize the biomass of the sloughed material to vary seasonally. Figure 14 Picture showing pin, sediment trap and flocculator. Fluorescein Dye was added to show direction of flow -The flocculator experiment had to be terminated early due to the end of the wet season. -There is an increasing trend in mass over time but equilibrium could not ascertained (Figure 7).. - We hypothesize that net transport to vary with the change in flow rates. Figure 11 Graph displaying NPP and Respiration. Figure 10. Picture of light dark bottle experiment. Figure 8. Picture showing the SonTek flow meter. -We believe that the flow rate is higher in the flow accelerated sites. These rates were taken at the end of the wet and higher flow rates are expected during the peak of the next wet season. - The flow rates in the no flow sites could have been induced by a strong northern wind during 1-22 and 2-7 sampling period. Another wall will be placed in the no flow site to reduce the flow rate. Figure 2. Left shows a landsat image of south Florida with the flow manipulation site labeled. Landsat image compliments of FCE LTER. Figure 3. Picture of flow manipulation site. Figure 1. Conceptual model of factors that influence floc. Figure 9. Chart of velocity rates of each site taken over four sampling periods Figure 12. Picture of sediment trap Figure 13. Chart of periphyton slough collected in each experimental site. Special thanks to: We would like to thank David Iwaniec, Lynne Leonard, Alex Croft, Damon Rondeau, Sherry Mitchell-Bruker, Len Scinto, Cecilia Gordon, Tim Grahl, and everybody from the wetland ecosystem lab, Thanks for the Everglades National Park for providing funding for this project. Effects of Water Flow on Flocculent Material in the Ridge and Slough Florida Everglades Habitat Adam Wood, Daniel Childers Florida International University, Florida Coastal Everglades FCE LTER, Miami Fl 33199