SOUTH FLORIDA ECOSYSTEM RESTORATION
PREDICTION AND MODELING
Within the SFER effort, NOAA's Coastal Ocean Program (COP) has continued to maintain its lead role in regard to rigorously determining the causes of present changes in the coastal ecosystem and quantitatively predicting the consequences upon that ecosystem of upstream restoration activities. The underlying concept, adaptive environmental management, was articulated in the Integrated Science Plan developed by the Science Coordination Team (formerly called the Science Subgroup of the Management and Coordination Working Group of the South Florida Ecosystem Restoration Task Force (SFERTF). In FY97 and FY98 the NOAA/COP South Florida Ecosystem Restoration Prediction and Modeling (SFERPM) program has continued to fund both field and laboratory research and model development. In addition, the SFERPM program has, on behalf of the overall interagency Program Management Committee for Florida Bay and Adjacent Coastal Regions, continued to fund a substantial Community Outreach & Education effort as well as continued to maintain the Interagency Florida Bay Science Program web site.
The SFERPM program was conceptually developed by a team of federal, state and academic regional scientists. The elements of the SFERPM program were designed to complement other components of the FY97 NOAA South Florida Ecosystem Restoration Initiative (SFERI) such as the NMFS-lead Protection of Living Marine Sources and the NOS-lead Integrated Florida Bay and Florida Keys Ecosystem Monitoring programs. A substantial fraction of SFERPM funds contribute to the Florida Keys National Marine Sanctuary (FKNMS) Management Plan and the national Coral Reef Initiative (http://www.gbrmpa.gov.au/~icri) specifically addressing direct linkages between Florida Bay, the Florida Keys, and the coral reef tracts of the FKNMS.
The Interagency Science Program in Florida Bay has continued in its efforts to develop an understanding of the structure and function of Florida Bay in the context of South Florida ecosystem restoration. Restoration implies establishing and sustaining the natural diversity, abundance, and behavior of the marine and estuarine flora and fauna, and in Florida Bay the principal factor that appears to control these parameters is freshwater input. Timing, location, type, and quality of this input are critical to Florida Bay ecology. Clearly, upstream restoration activities have a direct impact on Florida Bay although the impacts may not be immediate. Achieving the capability of predicting these impacts continues to be the ultimate goal of the SFERPM program, i.e., it implies a rigorous understanding of the physics and ecology of Florida Bay and the larger coastal ecosystem with which it is intimately connected. This understanding remains the overall objective of the Interagency Science Program for Florida Bay and Adjacent Coastal Ecosystems of which NOAA SFERPM is the largest component.
Predicting the downstream effects of Florida Bay restoration upon the sustainability of the coral reef ecosystems of the FKNMS is particularly critical to NOAA. While this issue falls somewhat outside the scope of the Interagency Florida Bay Science Program, it is notable that the geographic scopes of both the hydrodynamic and water quality modeling efforts sponsored by the Interagency Program have now been expanded to include the FKNMS downstream and the SW Florida shelf waters upstream. As noted in the FKNMS Management Plan, "little attention was given to the degradation of water quality in Florida Bay" initially. As the plan was refined, however, this linkage became, and continues to be, a major focus of the FKNMS Water Quality and Research and Monitoring Plans and, thus, is reflected in the goals and specific program elements of the SFERPM program.
The challenge to the Florida Bay research community continues to be to deliver timely information to South Florida Ecosystem Restoration managers. While this may at times be politically difficult, scientifically based restoration is viewed as an iterative process through which management alternatives are developed and selected, the preferred alternative implemented, physical and biological responses assessed, results reported to managers, and the process repeated over and over again as restoration proceeds. It is through this adaptive process that the goals continue to be achieved. SFERPM's program has two basic components: Environmental Research & Modeling and Community Education & Outreach. In a practical political sense both may be critical to the aforementioned iterative process. Implementation of management alternatives will be impossible without public support regardless of the scientific information provided to the managers.
Environmental Research & Modeling. Specific projects were selected for FY97/FY98 (two-year awards) through an open, fully competitive, peer-review process. Announcements of Availability of Funds were mailed to academic institutions, NOAA cooperative institutes, the Science Coordination Team mailing list, and given to our interagency partners. In addition, they were distributed through State and National Sea Grant offices. After careful evaluation by the Technical Advisory Panel (TAP) and the SFERPM Program Management Committee (PMC) of all planning letters received, specific projects were targeted and more detailed work plans were requested from the investigators. The criteria for evaluation included both technical merit and program relevance, and while NOAA-academic collaborative projects were encouraged, they were not required. The detailed work plans received were again evaluated by the PMC and presented to the interagency Florida Bay Program Management Committee to ensure consistency with the overall Interagency Science Program priorities and, finally, a select number were recommended for funding to COP. As in the past, all participating NOAA investigators that were selected have been required to provide substantial matching funds. In addition, supplementary funds have been acquired from other parts of NOAA and from other federal and state agencies to support particular efforts including Outreach and Education. These additional funds significantly augment what might have been achieved with COP funding alone.
Community Education & Outreach. This component of the SFERPM program is (and will continue to be) conducted by Florida Sea Grant. Before final approval by the SFERPM Program Management Committee (PMC), Sea Grant's work plan is submitted to the interagency Florida Bay Program Management Committee for their review. As with all SFER public outreach and education efforts developed at the time this effort was initiated, their activities, on behalf of the interagency PMC, were fully integrated with and approved by the then active SFER Working Group's Public Information and Education Subgroup.
SFERPM has followed the distributed project management approach pioneered within NOAA by COP. This mechanism has proven highly effective in the management of interdisciplinary federal/academic collaborative programs e.g., NECOP and SABRE. Further, it has enabled managers to bridge fundamental institutional differences between various NOAA line organizations and academic institutions.
Within SFERPM, the Program Management Committee (PMC) is responsible for both funding decisions and continuing project management. Guidance for these tasks is provided by a Technical Advisory/Review Panel (TAP) that consists of federal, state, and academic natural scientists and social scientists familiar both with the South Florida ecosystem and with various SFERTF activities (Appendix III). To assure continued interagency coordination and cooperation, members of the PMC and TAP continue to serve upon both the interagency Florida Bay Program Management Committee and the Science Coordination Team of the South Florida Ecosystem Restoration Task Force Working Group. The SFERPM PMC is currently composed of one representative from Rosenstiel School of Marine and Atmospheric Science (University of Miami) and one representative from each of two different NOAA line organizations (OAR and NMFS).
FY98 ANNUAL REPORT
I. Progress Toward Overall Goals
Environmental Research & Modeling. The SFERPM Environmental Research & Modeling program was developed as an integral component (within the constraints and structures) of the overall Interagency Science Program in Florida Bay at the direction of a NOAA Florida Bay Task Force (chaired by the director of NOAA/COP). According to the agreed upon interagency framework, individual agency research activities and implementation plans must not only be consistent with the scientific approach and priorities of the interagency Strategic Science Plan but they must also be reviewed through the interagency program management process. This was felt to be essential not only to minimize waste but also to permit sufficient flexibility in redirecting funds by collaborating agencies. The intention was (and still is) that individual agency activities be complementary rather than comprehensive i.e., that in aggregate (rather than individually) their efforts will yield answers to the basic questions posed as well as furnish timely information to restoration managers. The research objectives of the Interagency Science Program in Florida Bay were (and are) as follows:
Although NOAA has become the largest supporter of Florida Bay restoration research, at present, the NOAA SFERPM program represents only 55 % of the ca. $7M committed to the Interagency program. These obligations and relationships are fully described in the NOAA Florida Bay Research & Modeling program FY95, FY 96, SFERPM FY97, FY98 Implementation Plans signed and approved by the Assistant Administrators of OAR, NMFS, NOS, and the Director of the Coastal Ocean Program.
The "customers" of the research funded and/or conducted by the interagency partners (including NOAA) are the Interagency Florida Bay Working Group and the South Florida Ecosystem Task Force Management Working Group. NOAA's institutional expertise and its specific environmental mandates such as preserving the FKNMS and protecting living marine resources (including endangered species) have delimited SFERPM contributions to the Florida Bay Interagency program and guided the substantive content of the FY96 Implementation Plan. Specifically, SFERPM has been asked by its major research partners (DOD/ACoE, DOI/ENP, DOI/USGS, EPA, FDEP, SFWMD) to focus its research effort upon the larger oceanographic, atmospheric, geological and fisheries context within which Bay restoration will proceed. As a result a substantial fraction of SFERPM resources are directed towards studying the Bay ecosystem's interaction with and significance to the adjacent Atlantic and Gulf of Mexico coastal marine ecosystems as well as toward regulation of the Bay ecosystem by the larger scale oceanic and meteorological processes that so intimately link the coastal marine environment to the coastal terrestrial systems in South Florida. A smaller fraction is devoted to biological and chemical processes occurring within the interior of the Bay.
Community Education & Outreach. The overall goal of the Community Education & Outreach program is to connect research, science, and ecosystem management with the diverse public audiences and individual interests living beside and visiting Florida Bay and its watershed. At present, the Florida Bay Education Office is open and functional and staffed with a water quality extension agent, a science communicator, and a secretary. A memorandum of understanding between Everglades National Park (ENP), FKNMS, and Florida Sea Grant is in place, and education and outreach activities have been underway for nearly two years.
II. General Accomplishments
Funded Research. A complete list of SFERPM funded research projects (including Community Education & Outreach) is given in Appendices I and II. In addition, SFERPM maintains a web site so that project descriptions, accomplishments (updated at least biannually), recent data products and preliminary conclusions are provided as quickly as possible to the South Florida research and restoration management communities The SFERPM web site can be viewed at http://www.aoml.noaa.gov/ocd/sferpm/ . Detailed information on each project can be obtained by logging onto this site, but is also briefly summarized in the pages to follow. The Community Education & Outreach project group maintains its own web site which can be found at http://www.flseagrant.org/flbay.htm . It is also linked to the SFERPM program home page. In addition to research projects, SFERPM has funded two research support items: Data Management/Administration and Small Boat Operations.
Data Management/Administration. One measure of program success is whether or not research data is easily accessible by interested parties. The Interagency Oversight Panel noted that "...data management systems should be developed in order to facilitate data sharing and accessibility by investigators and to ensure data preservation... and to develop networks that link distributed data bases...including GIS." At the behest of SFERPM, a data management policy has been endorsed by the interagency PMC and data management team members have been assigned. A raw data database is in the early stages of design and collection of data from investigators has already begun within SFERPM with the hiring of data management personnel. As noted earlier, an augmentation of our data management/administration effort included assumption by SFERPM of the Interagency web site located at http://www.aoml.noaa.gov/flbay/ .
Small Boat Operations. A special purpose high-speed shoal draft vessel has been acquired and fitted with state of the art physical, biological and chemical sampling instrumentation. This vessel is deployed from the Key Largo Ranger Station or other convenient sites and provided to all SFERPM projects at no charge. It is already being used by SFERPM investigators for regular surveys of the Bay (the most recent maps can be viewed on the SFERPM web site) as well as for servicing the numerous fixed moorings and tower sampling platforms SFERPM maintains throughout the Bay and the FKNMS.
III. Individual Project Year Two (FY98) Accomplishments
In FY98 SFERPM funded projects addressing two general topics: improving our physical understanding of Florida Bay and characterizing the Florida Bay ecosystem and the changes it has undergone.
Regional Boundary Conditions for Florida Bay, Aikman et al.
Objectives: Our long-range goal is to determine how open ocean forcing can be incorporated into a model of Florida Bay (FB) and to address the Bay's interaction and exchange with the adjacent shelf and Gulf of Mexico. This is a key component of the NOAA focus on the large-scale regional oceanographic, atmospheric, ecological, and fisheries context within which FB restoration will proceed.
Secondarily, our goal is to initiate the extension of the NOAA Coastal Ocean Forecast System (COFS) development activity on the U.S. East Coast (Aikman et al., 1996) into the Gulf of Mexico. When this is accomplished we will have an operational nowcast and short-term forecast tool that should provide 3-dimensional and improved boundary condition information for FB. In doing so, we will be furthering the development of a tool that is germane to the NOAA responsibility of providing information and forecasts in the coastal domain for the protection of life and property and for promoting environmentally sound economic development.
Accomplishments: A 14-month (1 September 1995 to 31 October 1996) barotropic FS model simulation of wind-plus-tide-forced water level and currents has been completed and we are in the process of evaluating the results using NOS water level gauge data, observations of bottom pressure and both moored and drifting buoy current meter data from Tom Lee (RSMAS) and Ned Smith (HBOI).
For the three months of August - October 1996 the FS model has also been driven with Eta 48 km analyzed winds to compare the water level results over the same 3-month period of the model driven with Eta 29 km forecast winds. The results indicate that there is not a significant difference, although the correlation coefficients (observed vs. model water levels) are slightly higher and the rms differences are slightly lower with the model results driven by analyzed winds.
The hourly water level and barotropic current fields of the 14-month simulation have been interpolated to the RMA-10 model grid and delivered to the ACoE (Keu Kim, WES, Vicksburg, MS). The ACoE is testing these as boundary conditions for their barotropic model simulations of FB.
Evaluation results and plans for further 2-D simulations and 3-D model development and simulations have been presented at the following meetings:
FY99: At the request of the ACoE (Keu Kim, personal communication), the 14-month FS simulation will be extended four months to the end of February 1997, driven by analyzed Eta 48-km winds, and the output will be interpolated to the RMA-10 model grid and delivered to the ACoE. This will allow the ACoE to complete a 7-month (August 1996 - February 1997) simulation for salinity evaluation of their RMA-10 model in FB.
Simulations of Regional Climatic Patterns Which Impact the Florida Bay Water Cycle, Craig Mattocks
Objectives: This project has had two principal objectives: mesoscale atmospheric modeling and episodic meteorological event reconstruction. The former is critical to wind forcing of the Bay circulation model as well as rainfall inputs to south Florida and the Bay while the latter was deemed critical to understanding the south Florida ecosystem which can be strongly influenced by episodic storms and/or hurricanes, as noted by the Panel. A high-resolution version of the Advance Regional Prediction System (ARPS) model has been extended to actually predict the amount and the distribution of rainfall, not just moisture convergence and the locations of dry convective cells, as well as replication of realistic looking precipitation patterns along the sea breeze front. Moreover, ARPS has recently been enhanced to also predict the planetary boundary layer (PBL) height as a function of time and stability. Work in progress for initializing ARPS from real-time operational model history files and initializing ARPS from a realistic 3-D heterogeneous atmospheric state should substantially improve the realism of the atmospheric simulations.
Accomplishments: In earlier coarse-mesh ARPS model simulations of an August 1975 Florida Area Cumulus Experiment (FACE) sea breeze case, the atmosphere's response to incorporating realistic, modern-day horizontal gradients in the land use were striking. Enhanced diurnal heating over heavily developed areas, such as Naples-Fort Meyers and Tampa, induced strong urban heat island circulations which doubled the amount of simulated rainfall over these heavily populated regions. Rapid evaporation/drainage and heating of the porous, cultivated land south of Lake Okeechobee caused abrupt divergent deflections of the surface winds over the lake and generated a thunderstorm complex similar to the convective cells diagnosed in the real data. The arc-shaped band of maximum rainfall, associated with the lake breeze, shifted from east of Lake Okeechobee to a more realistic location at its southern shore.
The evaporation pattern correlated well with the strongest divergent and initially driest surface wind fields, in the vicinity of the greatest surface-to-air temperature/humidity differences. Moisture was picked up by the atmospheric flow over Lake Okeechobee and by the organized offshore downdrafts associated with the west coast sea breeze circulation, while the Florida Everglades "muck" soil in the interior of the state tended to resist evaporation due to its high water retention and strong capillary forces. Thus, a significant north-south mesoscale gradient in evaporation was simulated across Florida Bay.
FY99: These improvements in horizontal resolution, the specification of surface characteristics, and the inclusion of feedback mechanisms between the hydrologic and atmospheric systems should help to resolve details in the shape of thunderstorm convective cells, rectify previous underpredictions of rainfall over the Florida peninsula, and provide more reliable estimates of total freshwater input from the atmosphere into the ground surface/bay/ocean below. It will then be possible to quantify the effects that heavy or persistent rain episodes have on the salinity/nutrient composition of Florida Bay, determine the extent of sewage system overflows, and assess the degree of eutrophication by fertilizer/pesticide/contaminant runoff from agricultural and industrial areas. This work also lays a foundation for the development of more closely coupled versions of a hydro-meteorological model in the near future.
Circulation and Exchange of Florida Bay and the Connecting Waters, Lee et al.
Objective: The goal of this project is to study of the interaction and exchange of Florida Bay with the connecting coastal waters of the Gulf of Mexico and the Atlantic in the Florida Keys. The research is designed to address several of the key scientific questions presented in the NOAA/COP Florida Bay Implementation Plan concerning circulation and water quality as critical to understanding the functioning of the ecosystem and future evolution from restoration actions. Observational methods consist of a combination of bi-monthly interdisciplinary surveys, in-situ moorings, shipboard Acoustic Doppler Current Profiler (ADCP) transport transects in the major Keys flow passages, and Lagrangian surface drifters to describe and quantify the circulation within the Bay as related to local forcing and coupling with the waters of the Atlantic and Gulf. These observations will also help to provide necessary boundary conditions for physical and biological models.
Accomplishments: The enhanced moored array was deployed Sept. 1997 and will be maintained for two years. The array consists of 4 bottom mounted (ADCP's) equipped with near surface T/S sensors on the southwest Florida shelf offshore of Shark River, a Shark River plume array of 9 T/C sensors to monitor changes in the Shark River discharge near field, a single current/T/C mooring near the western boundary of Florida Bay, and 3 current/T/C moorings positioned along the Florida Keys reef tract to measure interaction and exchange between the southwest shelf, Everglades discharge, Florida Bay, Keys coastal waters and the Florida Current. In addition there is a bottom pressure array to measure cross- and along-shelf pressure gradients on the southwest shelf, as well as the cross-Keys pressure gradient.
First years results of interdisciplinary surveys show the influence of the anomalous large winter rainfall associated with El Nino, causing decreased salinities in the southwest Florida nearshore waters during what is normally the dry season. Synthesis of drifter trajectories indicate a net southerly flow from the Gulf of Mexico to the Florida reef tract through western Florida Bay that varies with season, stronger in the winter (3 to 4 cm/s) and weaker in summer (1 to 2 cm/s). Drifter trajectories are strongly influenced by local tide and wind forcing. The cause and variability of the residual background currents are being investigated.
Subtidal volume transport through Channels 5, 2 and Long Key Channel combined range from about 1000 m3/s toward the southeast to 200 m3/s toward Florida Bay. These subtidal flows are equivalent in magnitude to the mean river discharge onto the southeast U. S. shelf by all the rivers between Florida and Cape Hatteras. Approximately 500-700 m3/s flows through Long Key Channel alone when the flow is toward the southeast, which is about 100 times greater than the peak fresh water discharge out of Shark River. It appears that waters from Shark River and the seagrass die-off region of western Florida Bay will be passively advected and dispersed toward the Florida Keys Marine Sanctuary primarily through Long Key Channel by this strong southeastward background flow. The advective/dispersal time-scale for materials in the Shark River Plume to reach the FKNMS is estimated from drifter trajectories at one to two months. However, at times when the local winds are intensified from the east or northeast a cross-key pressure gradient is set up that reverses the background flow toward Florida Bay.
FY99: Research planned for FY99 will attempt to quantify the circulation in the Gulf transition area to the west and north of Florida Bay and the rates and patterns of exchange with western Florida Bay by continuing the combined use of interdisciplinary surveys with Eulerian and Lagrangian observations flow and water mass fields. The frequency of rapid surveys within Florida Bay will be increased to one per month with greater spatial coverage and more emphasis on exchange processes. Several years of observations are needed to compare more typical years with the recent El Nino year with its abnormally wet winter and increased wind forcing. We also hope to better understand the response of Florida Bay and surrounding waters to severe storm events by investigating the influence of hurricane Georges on circulation and exchange using results from our in-situ array. Considerable emphasis will be placed on publishing results from the first year intensive measurements. This information is particularly needed for boundary conditions and verification of hydrodynamic and water quality models of Florida Bay proposed by the U. S. ACoE for coupling the fine-mesh Florida Bay models to the regional circulation model that is being developed by F. Aikman and G. Mellor as part of the overall south Florida COP effort, and for planned plankton ecosystem models. Our proposed observations will also help to quantify the rates, patterns and variability of transports and interactions of waters of the southwest Florida shelf with discharges from the Everglades and Florida Bay and ultimate influences on the FKNMS. This information is needed by other investigators of the SFERPM to help understand nutrient cycles and the persistence of algal blooms, and will benefit EPA and FKNMS by providing an improved understanding of the mechanisms that regulate water quality in the reef Sanctuary and the sustainability of coral ecosystems.
Field Observations to Initialize and Verify Computer Simulations of Florida Bay Circulation, Ned P. Smith
Objective: The primary goal of this study is to assemble observations of currents, winds and water levels, and then to analyze the data in such a way that the results can be used to verify a hydrodynamic model of Florida Bay. Four specific objectives have been identified:
Accomplishments: Results of studies show that tidal currents are strongest in the northwest corner of the bay and decrease from north to south along the western boundary. Results of this three-month study suggest a net westward flow past the current meter at Station 1, and a net eastward flow past the current meter at Station 2. Further analysis will incorporate water level information, and only then can these measurements be interpreted in terms of transport into or out of the bay.
The one-year current meter record from the study site just south of the Gopher Keys indicates a quasi-steady nontidal eastward flow through the channel. Tidal currents are surprisingly strong at this location in the interior of the bay. The amplitude of the principal semidiurnal tidal constituent is 45 cm/s. The average current speed over the entire study period was 12 cm/s. Low-frequency current speeds, shown in the bottom plot, reveal a seasonality in the magnitude of peak current speeds. Relatively weak current speeds appear early, and then again late in the plot. Stronger current speeds were recorded in midwinter months, when cold fronts were moving across Florida Bay.
Results from the short study of currents in Spy Key Channel show a net westward flow was recorded during this 70-day time period. The average current speed was just under 4 cm/s. Hourly values shown in the bottom plot, however, indicate that the highest current speeds appear in the form of short bursts of eastward flow. It is likely that these occur with the passage of cold fronts. The combination of westward flow in Spy Key Channel and eastward flow in Gopher Key Channel during the same three-month time period suggests that nontidal flow patterns in the interior of Florida Bay can be very complex.
Data from Calusa Keys Channel and the Gopher Key study site are similar. At both locations, strong eastward flow was recorded. The average current speed through Calusa Keys Channel was just over 15 cm/s. The hourly current speeds shown in the bottom plot indicate a prominent tidal oscillation, although the amplitude of the principal semidiurnal constituent is only 9 cm/s. The total current speed varies between +40 and -80 cm/s. Calusa Keys Channel has a relatively small cross-sectional area (a width on the order of 20 m, and a depth of approximately 2-3 m), yet even small channels with strong current speeds can play an important role in moving water between sub-basins in the interior of the Florida Bay.
The five-month time series obtained from the Intracoastal Waterway at Bowlegs Cut shows the average current speed was 8 cm/s. Tidal currents are strong through this constricted channel. The amplitude of the principal semidiurnal constituent is 33 cm/s. Nontidal currents, shown in the bottom plot, were strongest during the first part of the study period, when cold fronts were moving through the region. Filtered current speeds of 40-50 cm/s appear in the plot. Later in the record, filtered current speeds rarely exceed 20 cm/s.
Results from the relatively short record obtained in Steamboat Channel show that the net flow was toward the northeast. The study period was not the same as that for Bowlegs Cut, but it followed immediately. The steadiness of the cumulative net displacement diagrams from these two locations suggest that the mean flow may be diverging along the Intracoastal Waterway in this area. This would be consistent with earlier studies, which have suggested a net inflow through both Whale Harbor Channel and Snake Creek. But water level variations will have to be incorporated into the calculations before the magnitude and direction of transport can be estimated.
Results of the field studies conducted between July 1997 and July 1998 do not yet include the volume transport calculations that require the integration of current meter data with water level data. These calculations will constitute an important continuation of the work reported here. Almost without exception, cumulative net displacement diagrams have revealed quasi-steady flow patterns, which in turn suggest that tidal forcing plays a prominent role in the general flow patterns of the interior of Florida Bay. Wind forcing is undoubtedly important, but these preliminary results suggest that wind forcing may act principally to perturb the mean flow patterns over time scales on the order of a few days as synoptic scale weather systems move through the area.
FY99: Data analysis will be continued through the spring of 1999 with present funding. The activity is not required after that since the ACoE model will be fully verified and on-line and the geographic scope of this project is comparatively limited. The principal deliverable of this project will be delivery to the ACoE of the interior Bay station data needed to complete verification of their circulation model.
Monitoring and Evaluation of Radar Measured Rain Estimate over Florida Bay and the Everglades, Marks and Willis
Objectives. Rain drop size distributions (DSD) are a fundamental descriptor of rain in precipitation physics. They are formed by basic precipitation physics processes, and besides being important in their own right - the moments of the distributions are related to liquid water content, rainfall rate (R), radar reflectivity factor (Z), etc., the distributions give clues to the evolution of the rain and cloud systems producing them. This study is part of an attempt to utilize the WSR-88D radar data to produce a high resolution product delineating the fresh water flux input over the Florida Bay/Everglades system for ecological studies, physical evaluation, and water management planning and decisions. The study is primarily an analysis of a continuous record of disdrometer measurements at a site in the Everglades.
Accomplishments. A raindrop disdrometer was operated during the 1996 rainy season at a site at the Everglades National Park Research Center located at 25.390같N, 80.681같W. A continuous record of 1-min DSDs was obtained. Also recorded at the site were a R. M. Young model 502 capacitive rain gage, and a Scientific Technologies ORG-105 optical rain gage, both providing corresponding 1-min R. The radar data used in this study are from the Miami WSR-88D KAMX located at 25.611같N, 80.413같W, and include both the WSR-88D digital precipitation array (DPA) hydrological product with a resolution of 4 x 4 km and 1 hr, and the full resolution raw level II radar data with a resolution of 1같 x 1 km at 5-6 min. The data used in this study cover the period 21 May 1996 through October 1996.
FY99: In FY99 this project will be completed and an operational algorithm will be turned over to our NWS and SFWMD collaborators who can than use it to generate improved estimates of rainfall over Florida Bay and the South Florida peninsula using the NEXRAD data from Miami and Key West.
The SEAKEYS/C-MAN Project: Environmental Monitoring of the Florida Keys and Florida Bay, Ogden et al. and J. Hendee
Background: The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and has continued until the present. This program, now being supported through NOAA's South Florida Ecosystem Restoration, Prediction and Modeling Program (SFERPM), implements a framework for long-term monitoring and research along the 220 mile Florida coral reef tract and in Florida Bay at a geographical scale encompassing the Florida Keys National Marine Sanctuary (FKNMS). The impetus for such a framework was the perceived marked regional decline in coral reefs and the critical need to provide data and options for resource management. The network > consists of six instrument-enhanced Coastal-Marine Automated Network (C-MAN) stations, cooperatively managed with NOAA's National Data Buoy Center, plus a proposed new one in northwest Florida Bay. These stations measure the usual C-MAN meteorological parameters, such as wind speed, gusts and barometric pressure, but have been enhanced with oceanographic instruments measuring salinity, sea temperature, fluorometry and turbidity. Artificial intelligence programs developed at AOML quality control the data, distribute in near realtime via the Internet and use the data to issue alerts as to the probability of coral bleaching in the FKNMS.
Accomplishments: Efforts are nearing completion to upgrade the existing stations at Fowey Rocks, Molasses, Sombrero, Sand Key, Dry Tortugas, and Long Key. Meetings among Principal Investigators from FIO, AOML and NDBC resulted in a constructive redesign and re-implementation of the existing network, including testing of the new WetLabs fluorometer and transmissometer sensors before deployment at the Sombrero and Long Key stations.
A complete SEAKEYS monitoring station was planned for northwest Florida Bay in cooperation with the West Florida Shelf monitoring program at the Department of Marine Science, University of South Florida. After a survey by Lee et al., the physical oceanography researchers for Florida Bay have agreed upon a location at 25o 05'00" N, 81o 05'30" W. It was installed last month by the USCG and it has not been instrumented and is delivering realtime data.
This in situ system and analysis network reported upon the possibility of local bleaching weeks before the possibility was noted by satellite remote-sensing analysis and confirmed by field workers. It is now serving as the model for a similar effort to be constructed in the Great Barrier Reef.
FY99: In FY99 all upgrades will be completed and essential backup instrumentation sensors will be purchased to minimize the downtime of the stations. Given realtime data examination if hardware is available sensors can be substituted at the first sign of irregularities in the data stream. Further software improvements and more streamline communications will be a principal focus of the data processing side of the project.
Circulation, Nutrient Influx, and Phytoplankton Growth in Florida Bay: G. Hitchcock and G. Vargo
Objectives: Results of circulation studies along the perimeter of Florida Bay, coupled with observed gradients in nutrient concentrations from the Bay to the contiguous waters of the SW Florida Shelf, suggest a significant exchange of nutrients can occur from the Shelf to the interior of the Bay (see Lee et al.). Thus any attempt to model nutrient dynamics within Florida Bay must rely upon realistic estimates of the dissolved and particulate nutrient flux across the western boundary of Florida Bay. Western boundary waters are also a source of dissolved nutrients, particulates, and sediments delivered to the coral reef track of the FKNMS. Our central objective is therefore to quantify nutrient gradients about the perimeter of western Florida Bay, with primary emphasis on the flux of inorganic, organic and particulate forms of nitrogen, phosphorus, and silica into the Bay interior. This flux will be evaluated in terms of nutrient requirements to sustain phytoplankton growth and algal blooms in the western Bay.
Accomplishments: This project began near the end of FY97 with $50K in funding provided by NOS as part of their Integrated Ecosystem Monitoring Program. The principal investigators were charged with augmenting the Physical Circulation Study of Lee et al. to sample nutrients (particulate, inorganic and organic fractions of N, P, and Si) on bimonthly cruises along a transect line from the Dry Tortugas to Cape Romano. The efforts have subsequently been expanded to include the southern edge of Florida Bay (FKNMS) west to the Dry Tortugas with funds from SFERPM. Additionally nutrient demands of phytoplankton for N, P, and Si are estimated in the boundary waters.
The initial data set indicates that rivers along the west Florida coast are seasonally important sources of N and Si to northwestern Florida Bay, the locale of diatom blooms in fall-winter. Phosphorus demands are sufficient to rapidly reduce and recycle inorganic and organic fractions within several kilometers of the river mouth. The flux of nutrients is being examined seasonally along the main channel of Florida Bay that leads from the SW Florida Shelf into the Bay; this is based upon Lagrangian-based drifter studies that quantify nutrient fluxes and demands as waters are exchanged between the Shelf and Bay. Initial results have been presented at the Annual Florida Bay Science Conference, and have been submitted for presentation at the 1999 Ocean Sciences Meeting. They are also being prepared as a Data Report.
FY99:The bimonthly cruises are continuing to monitor nutrient gradients along the initial transect from the Dry Tortugas to Cape Romano. An initial Data Report on the first six cruises, including supplemental observations as described above, will be published in November, 1998. Additional funds have provided for observations along the west Florida Shelf so that riverine nutrient sources can be compared to oceanic fluxes from the Dry Tortugas-Cape Romano section. The seasonal Lagrangian studies will then be capable of evaluating the quantity of allochthonous nutrient supply needed to sustain diatom blooms along the western perimeter of the Bay. A major thrust of the FY99 effort will be participation in a multidisciplinary Bloom Studies to be conducted in January and March 1999. The study includes zooplankton studies (Dagg, Ortner and Kleppel), primary production and nutrient uptake (Tomas et al., Jurado and Zhang) and water chemistry (Zhang and Millero). The NPS has furnished a houseboat to serve as a floating laboratory to be positioned in the Bay for periods of 10-14 days. In anticipation, surveys are being made at two week intervals and distributed to all participants via the SFERPM web site.
Fish Recruitment, Growth, and Habitat Use in Florida Bay, Hoss et al.
Objective: This project repeats a survey of the Bay conducted by some of the same scientists a decade ago to address changes in the distribution and abundance of living resources in Florida Bay, and the response to declining seagrasses, increased plankton blooms and altered salinity conditions relative to the previous decade.
FY99: In cooperation with staff at the State University of New York at Syracuse, an individual based bioenergetics model is being developed to relate the task of capturing sufficient energy to generate adequate growth to the ambient environmental conditions existing in Florida Bay. This approach will enable us to test hypotheses regarding responses of larvae to differing environmental scenarios (e.g., hypersaline and high temperature conditions). The data needed to develop the model include respiration, consumption, and egestion rates over a range of salinities and temperatures. Larval spotted seatrout are currently being reared at the Beaufort Laboratory, and their respiration rates measured using a Gilson differential respirometer at two temperatures (30 and 320 C), and five salinities (5, 10, 20, 35, and 45 ppt). Additionally, these rates will be determined for larvae at two more temperatures (26 and 280 C) for the same range in salinities. The respiration rate will be determined for juvenile spotted seatrout this November-December using a flow through respirometer. Consumption and egestion rates will also be determined for larvae and juveniles for each temperature and salinity combination.
Experimental Investigations of Salinity and Nutrient Effects on Florida Bay Plankton and Larval Sea Trout , Clarke and Bollens
Objective: Our chief objective is to experimentally determine the effects of salinity and nutrient changes on the plankton dynamics of Florida Bay. Specifically, we are testing for effects on species composition and abundance of phytoplankton, protozoan, and metazoan (including larval fish) components of the plankton. Additionally, we will test for effects on the feeding and growth of selected species, i.e. larval spotted sea trout and the copepods Acartia tonsa and Parvocalanus (Paracalanus) crassirostris.
Accomplishments: We are using well controlled and heavily replicated experimental mesocosms to investigate the importance of salinity and nutrients in controlling the plankton dynamics in Florida Bay. A raft was constructed in protected waters adjacent to the Keys Marine Laboratory, Long Key, Florida and a series of 2300 liter polyethylene enclosures were suspended from it. Enclosures were cylinders (1.0 m diameter x 4.0 m deep) constructed of 1.5 m wide panels of polyethylene heat-sealed together and providing water-tight seals. Salinities were manipulated during the first set of experiments conducted in January by adding RO water or saline solution (Instant Ocean) to ambient subsurface seawater. This additional water was pumped slowly and gently into each enclosure over a period of many hours, thereby minimizing the acute stress to the plankton. Salinity was monitored daily over the course of each experiment. Nutrients were manipulated in a second set of experiments conducted in March by adding either nitrate or phosphate to each enclosure in the nutrient enrichment treatments.
During both of these experiments each enclosure was sampled daily for zooplankton and chlorophyll as well various abiotic parameters (salinity, nutrients, temperature). At the end of each experiment all fish larvae were removed from the enclosures by repeated towing of a one half meter diameter, 110 um mesh net. Larvae and zooplankton were reserved for analysis of condition and growth.
Experiments were completed in mid March and we are now beginning a detailed analysis of species composition, condition and growth of the micro and macrozooplankton in the mesocosms. Preliminary analyses indicate that the highest survival of larval fish occurred in treatments with highest salinities. We also found that protozoans comprised a large component of the fish diets. The dominant macrozooplankton were Oithona spp. Parvocalanus (Paracalanus) crassirostris, Acartia tonsa and Eutrepina acutifrons. During the first five days of the salinity manipulation experiment, relative abundances of Parvocalanus increased and Oithona decreased in all treatments, whereas relative abundance of Longipedia increased in only the low salinity treatment. Chlorophyll values also indicate that there are significant differences between treatments.
FY99: This project is not scheduled to receive additional FY99 funding and will terminate in June 1999 when its grant ends.
Trophic Pathways in the Pelagic Environment of Florida Bay, Dagg et al.
Objective: Surprisingly, no quantitative zooplankton data was available for Florida Bay prior to the inception of this study. This multi-investigator project seeks to answer the following questions:
Accomplishments: During 1997 and 1998 cruises continued at bimonthly intervals beginning in January and ending in November. In May the additional experimental sites were added and more recently synoptic primary productivity experiments have been made at the same experimental sites. Preliminary analysis of some experiments is reported below.
Using the sizes, numerical densities, and temperatures at which the organisms were collected, metabolic requirements were calculated for the naupliar constituent of the zooplankton community. Following a trend visible since 1995, the mean naupliar metabolic rate in 1997 was lowest in January with a requirement of 0.49 mg C/l/day. The highest metabolic requirement was in September when the naupliar community of the bay required a 4.67 mg C/l/day. Ingestion demands can be approximated from these metabolic demands by assuming 1/3 of ingested carbon is used for metabolism.
Dilution experiment results are reported only for the Eastern Region Station since that has been sampled since July 96. The instantaneous grazing rate of the micro- zooplankton community in the Eastern Region were lowest in July/97, with a value of 0.04/day and highest in September 96 at 1.36/day. The mean grazing rate in the region was 0.62/day. Phytoplankton growth ranged from 0.02/day in September 97 to 2.26/day in January 97, with a mean growth rate of 1.22/day. With the exception of the September 97 experiment, phytoplankton growth exceeded microzooplankton grazing; the ratio of grazing to growth during this time averaged 0.44. Since this measure is conservative there is little question that total zooplankton grazing (including the macrozooplankton filtered out prior to these experiments) is a significant source of mortality, perhaps the predominant one, for the entire phytoplankton community.
To date samples have been collected at eight sites since 1994. These encompass the Western Bay, the Central Bay and the Eastern Bay as well as the Atlantic Transition Zone both near an inlet and relatively far from one. We can summarize the data for the first two annual cycles. The most abundant net caught copepods were Acartia tonsa, Oithona nana and Paracalanus crassirostris. Other copepods that were common but much less abundant included Tortanus setulosis, Euterpina acutifrons, Longipedia helgolandicus and Calanopia americana. The most abundant meroplankton in net samples were gastropod larvae and pelecypod larvae. While more highly variable than the copepods these were on occasion the most abundant organisms in the 64 um net tows. Other meroplankton included zoea, decapod larvae, echinopluteus and heteropod larvae. Total net zooplankton biomass was higher during the Fall of 1984 except in the Atlantic Transition Zone samples and not very different than the naupliar biomass sampled over the same period. Higher values are generally seen toward the west and the lowest in the Eastern Bay. Acartia were relatively constant across various regions while demersal plankton and Paracalanus were more abundant in the Bay interior and Oithona at the western perimeter. The difference between regions and years may well be related to a systematic difference in salinity across the Bay. Shortly after our sampling began freshwater inflow markedly increased and only at the end of the two year period did it drop back to more typical levels. More recently it has reached historical highs. Some of the zooplankton types enumerated appeared to have distinct salinity preferences although Acartia abundance seemed unrelated to salinity which is consistent with its well known physiological tolerance perimeter.
Assuming a metabolism to daily food ration ratio of 3 and a mean depth of 2 meters at our sampling locations we can calculate the potential grazing impact of the naupliar population. This ranged from 2 - 68 mg C/m2/day. Application of the same procedures to the net-caught zooplankton data yields estimates over a similar range of 2 - 85 mg C/m2/day. Over the past few years FIU has conducted monthly surveys of Bay water quality including chlorophyll concentration. Using their data (and correcting for a systematic bias in the earlier data), a carbon to chlorophyll ratio of 30 and a growth rate of one doubling per day, estimated phytoplankton production is 50 - 1790 mg C/m2/day. This is within the range of the limited phytoplankton production data available for the same regions in Florida Bay over that period which ranged from 50 - 4500 mg C/m2/d (unpublished data of C. Tomas, DEP). Dilution experiments reported above confirmed doubling rates consistent with these primary production estimates. Although this approach involves numerous assumptions the patterns that emerged seemed reasonable. The excess of primary production over grazing was most intense in the western Bay where blooms are most frequently reported while the balance was closest in the eastern Bay and along the Atlantic Transition zone where blooms are rare perimeter. Moreover, the greatest imbalance occurs during those months when blooms are reported to occur. Estimates in the eastern Bay are also roughly consistent with the dilution experiments reported above. As more recent truly synoptic primary productivity data becomes available these preliminary computations will be repeated.
The gut contents of only a few juvenile fish have been examined to date. These confirm utilization of holoplanktonic and meroplankton fauna by both pelagic anchovies and canopy dwelling killifish albeit on an opportunistic basis.
Another aspect of our present research focuses on the relationships between food concentration, food quality, the diets and egg production of an important calanoid copepod in the bay ecosystem, Acartia tonsa. A conceptual model was developed from data collected at four stations in the bay. The conceptual model compares bay-wide average copepod dynamics with those observed at Rankin Lake, a perturbed site characterized by extensive cyanobacteria blooms.
The model suggests that the perturbed site is the location of a much enhanced planktonic biomass but, perhaps more importantly, that a shift in energy flow has occurred relative to the bay-wide average. Bay-wide, micro-phytoplankton accounts for ca. 72% of the copepod diet; microzooplankton (e.g., ciliates and heterotrophic dinoflagellates) for 16% at the perturbed site when temperature did not affect egg production. We have found no correlation between food availability (micro-phytoplankton accounts for 26% of the diet, microzooplankton for 69%). The egg production of Acartia at the perturbed site was significantly higher (14.2 +/- 7.7 eggs/female/day) than the Bay-wide average (5.8 +/- 0.81 eggs/female/day), though both rates are relatively low compared to egg production rates observed in other warm-temperate and subtropical estuaries. We have begun to suspect that qualitative aspects of the food environment are important in driving egg production and perhaps other aspects of secondary production in Florida Bay.
FY99: A major thrust of the FY99 effort will be participation in a multidisciplinary Bloom Studies to be conducted in January and March 1999. The effort is planned to address a major criticism from the Interagency Oversight Panel that while general and average trends have been defined prior work has not been conducted on appropriate spatial and temporal scales to rigorously understand highly episodic bloom dynamics (fate and consequences). The Bloom Study includes zooplankton studies (Dagg, Ortner and Kleppel), primary production and nutrient uptake (Tomas et al., Jurado and Zhang) and water chemistry (Zhang and Millero).
The DOI/NPS has furnished a houseboat which we have outfitted as a floating laboratory to be positioned in the Bay for periods of 10-14 days. In anticipation, surveys of bloom distribution are being made at two week intervals and distributed to all participants via the SFERPM web site. During these experiments zooplankton studies will include measurements of grazing rate, egg production rate and the distribution and abundance of adult and larval forms.
Development of Models to Describe Ecosystem Interactions in Florida Bay, Jackson and Burd
Objective: We are studying the nutrient and trophic dynamics of the planktonic ecosystem in Florida Bay by two complementary approaches. First, we are analyzing existing data for representative basins to estimate the nutrient and carbon flows between different planktonic trophic groups and their interactions with the benthos. This modeling approach is being used to help interpret the experimental data and better understand the interactions between the different planktonic groups in Florida Bay. The results from this approach are being used to develop dynamic models which will be used to make predictions about the behavior of the system.
Accomplishments: Florida Bay is a complicated coastal system, with regions heavily influenced by freshwater inputs, anthropogenic nutrient additions, the Gulf of Mexico, and the coral of the Florida keys. It is further influenced by the system of mud banks which subdivide the region into partially-isolated basins. Biological surveys have subdivided Florida Bay into different numbers of ecological regions, ranging from 6 to 3 (e.g., Zieman et al., 1989, Phlips et al., 1995). Among the major regions is a eutrophic area around Rankin Bight in which the small alga Synechococcus sp. dominates, a westerly region heavily influenced by the Gulf of Mexico in which diatoms dominate, and an eastern region which has variable salinity and relatively low phytoplankton concentrations (e.g. Phlips et al 1995).
The relative separation of these basins makes it feasible to consider them as separate systems, although with some interactions between them. Their relatively shallow depths, mostly less than 3 m depth, gives the bottom a disproportionate influence on the system relative to most coastal systems.
If we are to understand the movement of carbon and nitrogen through the planktonic ecosystem of Florida Bay, as organic matter either imported from the seagrass communities and terrestrial runoff or produced by phytoplankton, we must first estimate the rates at which they move through the planktonic food-webs which transform them. Unfortunately, marine food-webs are complicated systems with the potential for a myriad of interactions that are not easily sampled or understood. Typical ecological studies of marine food-webs are able to measure only a few of the many interactions known or suspected to be occurring within them.
Vezina and Platt (1988) offered a method to estimate all of the food-web interactions from a limited set of measurements when they introduced inverse techniques to the analysis of marine ecosystems. These techniques can be thought of as a fancy least-squares technique that incorporates linear constraints. The constraints used by Vezina and Platt included information about known assimilation and production efficiencies of different organism groups. We have previously extended this approach by altering the food web structure and the constraints to examine the flows in the plankton and in the benthos as part of the California Basins Study (CaBS) (Jackson and Eldridge 1992, Eldridge and Jackson 1993). The results of this part of the modeling effort are being used to estimate undetermined rates of flow between various compartments.
FY99: Our modeling studies should synthesize the results of many of the field studies being made in the Florida Bay. At the least, our work should show where there are crucial gaps in our understanding that need to be studied. They should help us to understand the nature of size-structured systems in coastal environments. Hopefully, our models will provide tools which can be used for management purposes. Among the predictions which may be possible will be estimates of light irradiances in the sea grass beds as functions of anthropogenic inputs and insights into factors affecting fish production.
Pools and Fluxes of Nutrients in Florida Bay Sediments, Szmant et al.
Objective: Florida Bay has experienced extensive algal blooms since 1992. The potential role of present-day sediment nutrients, and nutrient exchange between the sediments and water column, in promoting these algal blooms is being investigated by mapping the distributions of:
Accomplishments: Our results show that sediment N and P in just the upper 2 cm of the sediment compartment comprises between 92 and 99 % of the non-biotic N in the Bay and > 99 % of the P. Therefore processes that affect the transfer of N and P from the sediments to the water column could greatly influence the availability of N to the phytoplankton community. Rates of efflux of nutrients from the sediments to the water column, estimated from porewater profiles to 7-10 cm sediment depth, indicate that simple diffusive flux is not high enough to provide for elevated concentrations of nutrients in the water column, especially in the Central and Eastern regions. Bioturbation and resuspension, however, are processes that could increase the natural flux rates to the water column.
It is noteworthy that the sediment N concentrations were lower in the Northern Transition region inspite of the higher water column NH4+ concentrations, that derive from Everglades run-off in this area. Sediment N concentrations increased towards the Central part of the Bay where water column DIN concentrations are generally lower. Therefore, sediment N and P would appear to be potentially more important as nutrient sources to primary producers in the Central, Western and Atlantic Transition zones of the Bay.
The observed spatial patterns of sediment nutrients (specifically, higher concentrations towards the Central and Western zones) could be explained by several mechanisms and sources. Groundwater seepage is being detected with 4He and 3He in the NW part of Florida Bay south of Cape Sable and Flamingo, and could be providing inputs of P to these areas. The area also receives inflow from the Shark River Slough and West Florida Shelf/Gulf of Mexico, which also have been postulated as sources of nutrients to the Florida Bay system. More localized P hot-spots close to the mangrove fringe might be derived from the feces of large populations of wading birds that historically inhabited these areas. The areas with the highest sediment total N and P also are in the vicinity of those where major seagrass loss has been documented. Thus, some of the present sediment nutrient enrichment could be from seagrass detritus having been incorporated into the sediments. These are also the areas with the higher sediment chlorophyll concentrations. The high sediment nutrients and chlorophyll may simply reflect deposition from the large algal blooms, but at the same time can be a source of nutrients and algal cells for the algal blooms. Therefore, nutrients and microalgal abundance may be cycling between the sediments and water column with no net change over time.
FY99: FY99 efforts will be devoted to data integration and targeted sampling based on these analysis rather than routine surveys. FY99 may but will not necessarily represent the final year for this effort given the relocation of the principal investigator.
The Role of Groundwater Nutrient Fluxes in the Nutrient Budget of Florida Bay, Burnett et al.
Objective: We have hypothesized that groundwater may be a significant source of nutrients to the Florida Bay ecosystem. Specifically, we are testing the hypotheses that phosphate-rich groundwater may be moving through an ancient coarse-grained siliciclastic river bed that makes its way from central Florida to underneath north central and northwest Florida Bay; and that sewage from septic tanks in the Florida Keys may travel through groundwater into Florida Bay. The siliciclastic channel appears to be a plausible source of phosphate (the primary limiting nutrient in most of Florida Bay and other South Florida coastal waters) because it will not chemically scavenge phosphate from groundwater the way limestone does. Furthermore, it runs through phosphate rich deposits in central Florida and contains phosphorite granules.
Accomplishments: One difficulty in the application of natural tracers is that they seldom have a unique source. Radon, methane, helium, and tritium can exist at some concentrations almost anywhere, including the atmosphere. It is thus necessary to examine patterns closely and consider all possible input terms.
Based on the results collected thus far, there appears to be a distinct difference in tracer patterns that develop in Florida Bay during the summer than in the wintertime. In both the June/July and August samplings, all tracers show the highest concentrations along the inside of the upper keys. The waters around Rock Harbor are particularly high. The summertime surveys also showed an indication of secondary highs for 222Rn and 226Ra in the northern bay south of Flamingo. The 222Rn and CH4 patterns for both winter samplings (December, 1997 and February, 1998) look quite different than the summertime samplings. The concentrations of radon and methane for February 1998 are significantly lower than the concentrations in the summer samplings (presented in the last report). Although the general range in concentrations in the other areas of the bay is not substantially different than that observed earlier, the pattern in the northern bay is much clearer because of the lower concentrations elsewhere. There is no significant surface water source that could have influenced the area south of Flamingo.
We thus appear to see potential groundwater signals in two areas, along the inside of the upper keys in the summertime, and in the north-central to northwestern part of the bay in the wintertime. One possible reason for this seasonal switching is enhanced flushing from the keys during the wet season (although tidal pumping is probably responsible for most subsurface discharge). Higher wintertime groundwater fluxes in the northern bay could be related to the lower sea levels which occur at that time of year.
Our nutrient data indicate that both the inner keys and northern (near Flamingo) areas of the bay are associated with moderately high (Key Largo) to high (Flamingo) concentrations of total nitrogen (TN). The waters off Key Largo are quite low in total phosphorus (TP) however, while the Flamingo waters are elevated. An examination of the TP/TN atomic ratios shows that the highest (most P-enriched) waters are in the extreme NW portion (around Cape Sable) of the bay with a secondary high off Flamingo. Areas in the northeast portion of the bay, which have substantial freshwater surface inflow, show the lowest TP/TN ratios as do the waters off Key Largo. Thus, at least in a qualitative sense, groundwater inflow may be important for nitrogen loading in the keys and phosphorus additions in the northwestern bay.
Our cumulative data on algal concentrations in Florida Bay indicate that the highest concentrations are between the high P areas in northwest Florida Bay and the high N areas in northeast Florida Bay. We hypothesize that the P is coming from the P-rich quartz sand deposits, transported by groundwater, and the N is coming from agricultural runoff, transported through Taylor Slough. The large algal blooms occur where the high P waters and high N waters mix.
FY99: We are now focusing more on individual sites of interest based largely on our survey results. Two areas that appear most interesting include Rock Harbor and Flamingo. The first chamber flux experiments were performed at these locations in early August to assess diffusional inputs. Similar experiments are planned for the coming months. Seepage meter and piezometer studies will also be pursued at these locations as well as time-series studies of tracers at selected locations over various time scales. This project was conceived of as a pilot study to provide first order estimates of the importance of this flux. Whether or not similar research will be continued beyond FY99 will depend upon this assessment and the requirements of the Water Quality Model.
Atmospheric Deposition of Nitrogen and Phosphorus to the South Florida Bay Ecosystems, Whung et al.
Objective: Measurements of nutrient input from wet deposition processes are limited in South Florida, with only one station located at the Everglades National Park. The dry deposition rate is largely unknown. Dry deposition of nitrogen can be in the form of both gas-phase (HNO3), and particulate form (NO3- and NH4+) in both small and coarse aerosols. The objective of this project is to assess the relative importance of the atmosphere as a source of nutrients to Florida Bay. This was identified by the Oversight Panel of the Interagency Florida Bay Science Program as a major unknown. This study is intended to yield:
Accomplishments: The monitoring of nutrient deposition to Florida Bay is now underway. A 10 meter meteorological tower was installed at the Keys Marine Laboratory on Long Key in April of this year. Equipment on the tower includes filterpack sampling systems, anemometry for wind speed and direction, air temperature, relative humidity, and solar radiation.
Atmospheric nitrogen to include gaseous ammonia (NH3), particulate ammonium (NH4+) and particulate nitrate (NO3-) are sampled using treated filterpacks. The preliminary results for the gaseous nitrogen species during the period of March and June showed that the NH3 concentrations varied greatly (between 0.034 and 0.76 ug/m3). The averaged particulate NH4+ and NO3- concentrations are 1.20 ug/m3 and 2.17 ug/m3, respectively. The observed atmospheric NH3 concentrations in South Florida Bay are higher than the averaged NH3 concentrations in other coastal regions (such as Tampa Bay and Chesapeake Bay).
In order for the data to be utilized by Keys Marine Laboratory personnel as well as for our research purposes, a remote data link will be installed in October that will link the data logger on the tower to a computer in the laboratory. Data from the tower can then be easily downloaded via telephone modem. This will provide a near real-time access to the meteorological data for QA/QC.
FY99: Wet deposition monitoring for phosphorus and nitrogen will begin in October. The sampling systems were also installed in April. The sampling protocol, sample analysis and shipping logistics have been worked out in collaboration with the laboratory at the Illinois State Water Survey which conducts the analysis for the National Atmospheric Deposition Program (NADP). The sample analysis will include the determination of nitrate, sulfate, ortho-phosphate and the basic cations for both the wet and dry deposition samples. Every four weeks an analysis for total nitrogen and phosphorus (including the organic fractions) will be determined. Field blanks will also be evaluated every four weeks. It is expected that the sample analyses will be available approximately two weeks after receipt of the samples. This project was conceived of as a pilot study to provide first order estimates of the importance of this flux. Whether or not similar research will be continued beyond FY99 will depend upon this assessment and the requirements of the Water Quality Model.
The Role of Suspended Calcium Carbonate in the Phosphorus Cycle in Florida Bay, Miller and Zhang
Objective: Biogenic calcium carbonates (calcite and aragonite) are the major components both in the suspended material and in the sediments in Florida Bay, and are likely to be the important chemical mechanism of phosphate removal. There have been few systematic measurements of the carbonate system and its relationship to nutrient availability. The objective of this project is to combining field measurements with critical laboratory studies to understand this complex relationship.
Accomplishments: Several cruises have been completed in 1997 to survey the water quality in Florida Bay. During these cruises, our group has measured carbonate system parameters (including total alkalinity (TA), pH, total carbon dioxide (TCO2), and partial pressure of carbon dioxide (pCO2), as well as salinity and nutrients. In addition, our group has measured samples collected by other groups. TA, pH, TCO2, and pCO2 have been used in an effort to characterize the carbonate system in Florida Bay. The carbonate system data collected have been used to evaluate the saturation state of calcite and aragonite particles that can absorb phosphate, as well as to examine the uptake of inorganic carbon by phytoplankton. A flowing multi-parameter nutrient system, developed in our lab, has been used on several of the cruises to continuously monitor nutrient concentrations. Nutrient data (nitrate, nitrite, phosphate, and silicate) have also been combined with the carbonate parameters to examine the relationship between the carbonate system and nutrient elements in Florida Bay water. Chlorophyll-a data were also collected during a cruise to evaluate primary production of Florida Bay water. The results of the carbonate, nutrient, and chlorophyll-a data are summarized in Table 1.
0 to 2 mM
0 to 2 mM
0 to 2 mM
0 to 50 mM
0-5 mg C/l
The lower values were found offshore and along the coastal line of Key West, the higher values were found in Shark River. We plan to continue to participate on cruises in Florida Bay over the next year with others working in the program.
Our laboratory investigations of phosphate interactions with calcium carbonate at present consist of the following four areas of studies:
The results of phosphate adsorption as a function of time show that the adsorption of phosphate on calcite and aragonite is a fast process. Generally, it takes about 5 minutes for the adsorbed phosphate concentration to reach a constant value. Aragonite has higher adsorptive capacity compared to that of calcite when the same amount of solid is used. Our results suggest that synthetic solids have a stronger affinity toward phosphate when compared with other natural minerals. Aragonite offers more active surface and more active adsorptive sites compared to calcite.
The desorption of phosphate from aragonite surface is also a fast process. There is a steady increase of phosphate concentration from 1 to 10 minutes. After 20 minutes the phosphate concentration in solution reaches a relatively stable value. These results show that calcium carbonate can act as a fast scavenger for phosphate. Phosphate quickly reaches equilibrium with respect to the carbonate phase. The resuspended carbonate sediment may act as a source of phosphate to the water column. The fast desorption kinetic may suggest that the interaction of phosphate on a pure carbonate surface is largely electrostatic in nature.
From pH 8.7 to pH 7.4, the adsorption of phosphate decreases. The experimental design was originally based on the assumption that phosphate adsorption obeys the conventional anion adsorption, which typically exhibits a reverse S-type pH curve: as pH increases, the adsorption decreases. The phosphate adsorption onto aragonite surface defies such generalization and makes the experiment a desorption experiment. Due to the high buffering capacity of the carbonate solid, our pH experiment was restricted to neutral pH range. The mechanism of such pH dependence of phosphate adsorption on carbonate surface is not clear at this moment and may involve the change of phosphate species as well as the interaction of phosphate species with major ions such as Ca and Mg
The adsorption of phosphate onto carbonate surfaces as a function of phosphate concentration is being studied. Combined with the kinetic data and other experimental results, the interaction mechanism of phosphate with carbonate will be elucidated. Adsorption onto calcium carbonate under natural pH shows a step-wise isothermal curve. This type of curve shows that the functional groups on aragonite surfaces are not the same and have different energy levels when interacting with phosphate. In the concentration range of our experiment we have not observed saturation (maximum adsorption concentration on the surface).
FY99: Future works of laboratory investigation of phosphate interaction with calcium carbonate include the effect of important environmental factors such as temperature and salinity on the adsorption. The effects of natural organic matters and iron oxide on the surface properties will be investigated using natural suspended materials and sediments collected during cruises.
The Sediment Record as a Monitor of Natural and Anthropogenic Changes in the Lower Everglades/Florida Bay Ecosystem, Nelsen et al.
Objective: The objective of this project is to understand the relative roles and importance of daily sedimentation/transport versus impacts of event-driven episodes of sedimentation on this ecosystem by reconstructing the history (the last 100+ years) of the critical interface between lower-peninsula Florida/Everglades and the Florida Bay. This information is essential to set restoration objectives.
Accomplishments: Sedimentary sequences from Whitewater Bay, Coot Bay and Florida Bay have been collected and analyzed. The former was collected based on its position directly adjacent to the outflow of the Shark River Slough. This area is not only the major source of freshwater to the south Florida coastal environment and subsequently into Florida Bay, but one directly controlled by water management policies that are of prime concern to studies of coastal environmental changes. Coot Bay provided an intermediate site and one potentially influenced by canal construction while sediments from Florida Bay were central to paleoenvironmental reconstruction therein. Placed within a temporal context by geochronology, sediment accumulation rates of ~1 cm per year in recovered sequences permitted evaluation back to about the turn of the century. This allowed high-resolution evaluation of other co-sampled parameters over a time period that encompasses both natural and anthropogenic changes.
Results from geochronology, that were supported by other co-sampled parameters, indicated disturbed horizons that temporally correlate with major hurricanes. These recorded disturbances range from essentially undetectable in some sheltered coastal areas to significant in the open waters of Florida Bay. Moreover, foraminifera and ostracod community structures showed changes that temporally correlated with both natural rainfall patterns and anthropogenic effects such as water management practices. Sediment burdens of heavy metals also showed time-based changes that temporally correlated with documented anthropogenic usage patterns. Stable isotope analyses, of selected species of foraminifera and ostracods from the Whitewater Bay sediments, indicate salinity stress events during periods of documented drought and reduced water flow through Shark River Slough.
During the past phase of research we have developed and refined valuable techniques for analyzing layered sediment sequences to document the regional natural and anthropogenic influences on the chemistry and benthic communities of the coastal lagoons of south Florida.
FY99: FY99 will represent the final year for this research within the context of SFERPM. By that juncture establishing the restoration criteria will be essentially complete and ongoing efforts on Bay History are anticipated to be conducted under the purview of the USGS program and the SFWMD. This may well involve some or all of the present SFERPM investigators some of whom already receive SFWMD support.
IV. Applications From Funded Projects
Management Applications. The long-term goal of research, such as the work currently sponsored for south Florida, is that the products of these research efforts ultimately manifest themselves in tangible benefits to the environment and economy. To do so, it must be applicable to the managerial decision-making process at all levels and the projects funded herein are designed to fulfill such a role either directly or indirectly. Relative to the latter, the products of many scientific projects will find their applicability over a longer time horizon by providing environmental data as ground truth to modeling efforts. On a shorter time horizon, some benefits have become available for such decision making as the research progresses as in the following examples:
Partnerships Funded or Built Through this Program. Partnerships benefit programs in today's research climate by increasing the resource pool in terms of expertise and in leveraging funding. Partnerships encouraged by the NOAA South Florida Ecosystem Restoration Prediction and Modeling include, but are not limited to, the following:
FY99 OVERALL PLAN
In FY98 SFERPM was essentially level funded. While COP was by far the major contributor, other NOAA line organizations and the National Park Service made significant contributions (Figure 1).
As in FY97, research, monitoring, and modeling projects are supported. Within NOAA, three line organizations (OAR/AOML and ARL, NMFS/SFSC. and NOS) are major participants in the SFERPM program, but the majority of SFERPM COP funding goes to academic university participants (Figure 2). In addition to these science activities, Florida Sea Grant continued to receive level funding in FY98 for conducting an Outreach/Education program on behalf of the entire Interagency Science Program in Florida Bay. A complete list of the FY98 awards is given in Appendix II. Individual project activities were described earlier.
In FY99 we anticipate essentially level funding however we have had to accommodate some changes including a major tithe upon the program ($135K) to support ship time usage by other COP programs. SFERPM itself uses none of the NOS Data Acquisition Funds relying instead upon small boats and a direct transfer of OAR Data Acquisition Funds to support its UNOLS charter work. In addition to the funds previously provided by other LO's (e.g.$100K from NOS SFERI funds to support Nutrient Monitoring along the Cape Romano/Dry Tortugas Transect and the CMAN/SEAKEYS effort) we have this year been successful in obtaining outside support for the Education/Outreach effort ($15K from FDEP and $20K from NMFS/SFERI funds). This generosity has ameliorated the worst consequences of the unanticipated ship time tithe.
Environmental Research & Modeling. It is generally agreed that the problems in the coastal ecosystem (particularly in Florida Bay) are exacerbated during unusually dry weather. With drought, the first priority for water managers has been to sustain the flows required for agriculture and the water demands of the human population. As such, hypersalinity (possibly the preconditions for seagrass die off) results. The last two years, however, have experienced much greater than average rainfall and now with El Nino well upon us, this year is likely to be the wettest of the century! Because of this anomalous situation, our plan for FY99 is to fund essentially the same projects without a formal RFP process (assuming satisfactory progress which has been confirmed by review of mandated progress reports submitted to the SFERPM program office). This extension will, we hope, afford the opportunity of sampling at least a normal, if not a dry, rainfall period. The same strategy is being undertaken by our partners in the Interagency Florida Bay Science Program subject to availability of funds within their agencies and is consistent with the long-range climate forecasts currently available.
Community Outreach/Education. FY99 will be a pivotal year for this effort and the onus will be on Florida Sea Grant to unequivocally establish the utility of this activity to our partners in the interagency program beyond assistance in conducting the Annual Conference in which they have been invaluable. In subsequent years (see below) SFERPM will no longer have sufficient resources to continue this project at the same level and if that is required the additional funds will have to come from collaborating. federal and state agencies. An important first step has been made in that one outside agency (FDEP) and one other NOAA SFERI component (NMFS) have agreed to begin contributing in FY99 and the FY99 Community Outreach/Education Plan has been rewritten to accommodate their concerns.
III. Management and Operations
NOAA/OAR/AOML will continue to be responsible for program management, data management/administration, and small boat operations. As in years past, explicit funding will be required for program management. Given the expanded scope of the effort, the position of Executive Director was established to give oversee the daily management of the program and provide the Program Management Committee Chair assistance as needed. Program management funding also contributes to data management (where we have taken the lead on behalf of the overall Interagency Science Program in Florida Bay), interagency meeting/workshop support, and secretarial support services. These funds also support the substantial web site effort both for SFERPM and on behalf of the entire Interagency Program. Program management funds are also being used to equip, maintain and operate the dedicated SFERPM trailerable research vessel which is operated through the RSMAS Marine Department under a cooperative arrangement.
OUTLOOK (FUTURE YEARS)
I. FY2000 and Beyond: Collaborative Planning and Fiscal Leveraging
COP initiated SFERPM prior to the NOAA South Florida Ecosystem Initiative request using substantial base funds. These funds are scheduled for other uses in FY2000 and beyond. Accordingly, SFERPM must consider how best to accommodate a substantial reduction in award able funds. Our plan includes termination of project areas scheduled for completion as well the transition of all or part of some project areas from a research to an operational mode or to more appropriate funding sources. A dialogue between SFERPM and both NOS and NMFS (as well as with other federal agencies such as USGS) has already been initiated in this regard. This change can be accommodated within the South Florida Ecosystem Initiative budget requests for Ecosystem Monitoring (NOS) and Living Marine Resources (NMFS) respectively. In principal projects with substantial ecosystem monitoring components would be either transferred in their entirety to NOS or the monitoring aspects of the activities underwritten by NOS and projects directed specifically at commercial or recreational fisheries would be transferred to NMFS. In addition, we are already discussing with our interagency PMC partners, collectively, the desirability of other agencies contributing to the PMC's Community Education & Outreach effort when we are no longer able to fund it entirely with SFERPM funds. These plans are depicted in the accompanying GANTT chart (Figure 3) that depicts funding year cycles rather than actual project durations (at present offset by a half year or more).
In late spring FY99, we plan a fully competitive RFP process to again make two-year awards (FY2000 and FY2001) for research and modeling projects. This will permit decisions as to individual proposals prior to FY2000 and will put us in closer synchrony with the fiscal year cycle even though the actual duration of the FY99 projects is ca. June 99 -June 00. Evolution in principal investigators and their attendant perspectives is essential if SFERPM is to evolve and to remain responsive to the needs of SFER and the interagency program. Based on our experience in SABRE, a renewed competitive announcement will result in the necessary evolution. The RFP would likely address the same general project areas along with specifically soliciting "Additional Nutrient Studies - Water Quality Model Support" being added (see Figure 3). A Water Quality model has become a high priority for the interagency Florida Bay PMC and its oversight panel and one is currently being developed under its aegis by WES of the Army Corps of Engineers (ACOE). The Dept of Defense will not, however, be able to support the process research currently deemed relevant and is looking to NOAA and the EPA to provide those critical data. No further detail about the FY2000/FY2001 RFP can be provided at this juncture. As in previous years we will endeavor to be as responsive as possible to the guidance provided the interagency program by its Oversight Panel after each Annual Florida Bay Science Conference. The next conference is scheduled for May 12-14, 1998 in Miami.
FY2001 ($1.3M) would be similar to FY2000 ($1.3M) and would represent the final year of full COP/SFER funding. In FY2002 funds would be reduced for the remaining activities to 50% ($650K) of the FY96-2001 level and in FY2003 to 25% ($325K). COP, but not NOAA, involvement is seen as terminating in FY2004 ($0). By then activities will be predominately operational (or monitoring) and the role of basic research much reduced. Monitoring the success of restoration is, however, seen as an essential NOAA task that may extend for considerably longer than the COP/SFERPM program as Restoration efforts progress upstream. This approach is intended to be fully consistent with and supportive of the Interagency Florida Bay Science Program as reported to and approved by the Science Coordination Team and the Working Group. Basically that program has four phases. The first is Strategic Planning, the second Research Phase, the third is Implementation Phase and the last is Monitoring Phase. SFERPM has been perhaps the major contributor to the first two phases and is expected to continue to be so during the recently initiated Implementation Phase during which databases from various research projects will be integrated into models testing various scenarios incorporating water management options, climatic shifts and changes in salinity regime and nutrient input. During the Monitoring Phase our role should diminish although all participants recognize that targeted research (and modeling) efforts will remain one component of the long term Interagency Program.
II. Projected Resource Issues
OAR has already provided DAS funds to provide SFERPM 60 days of leased ship time for the RV/CALANUS as an award to CIMAS. Subject to the level of DAS funding available to OAR a letter of commitment to providing SFERPM 60 days annually on CALANUS or its replacement was sent by the then head of OAR to the Dean of RSMAS last year. Continuation this chartered ship time, along with the small high-speed catamaran purchased by SFERPM but operated through the RSMAS Marine Department, will cover all anticipated ship time requirements through FY2000. When the NEXRAD rainfall project becomes operational, it will no longer require aircraft time. For FY99 flight hours will be provided to SFERPM as part of the base allotment provided to AOML's Hurricane Research Division.