REPORT OF THE FLORIDA BAY

SCIENCE OVERSIGHT PANEL

 

Perspectives from the 1999 Florida Bay Science Conference

 

Submitted to the

 

Program Management Committee of the

Interagency Florida Bay Science Program

 

 

By

 

John E. Hobbie, chair

Marine Biological Laboratory

Woods Hole, Massachusetts

 

William C. Boicourt

Horn Point Laboratory

University of Maryland Center for Environmental Science

Cambridge, Maryland

 

Linda Deegan

Marine Biological Laboratory

Woods Hole, Massachusetts

 

Kenneth L. Heck, Jr.

Dauphin Island Sea Laboratory

Dauphin Island, Alabama

 

Steven C. McCutcheon

Hydrologic and Environmental Engineering

Athens, Georgia

 

John D. Milliman

Virginia Institute of Marine Science

College of William and Mary

Gloucester Point, Virginia

 

Hans W. Paerl

University of North Carolina

Morehead City, North Carolina

INTRODUCTION

 

The Florida Bay Science Oversight Panel (FBSOP) is an independent peer-review group charged with providing regular, broad, technical, and management review of the Interagency Florida Bay Science Program (hereafter called the Florida Bay Program).  This panel was first convened August 17, 1993 at the request of George T. Frampton, Assistant Secretary for Fish and Wildlife and Parks of the U.S. Department of Interior.  The panel reviews agency plans, Program Management Committee (PMC) strategies for program development, scientific quality of research, modeling and monitoring, and research results (Armentano et al. 1994, Armentano et al. 1996).  The FBSOP consists of senior scientists with significant experience in estuarine research and major estuarine restoration programs but who have no involvement in Florida Bay Program projects.  Since the 1998 review and report, Neil Armstrong and Charles Yentsch have resigned and William Boicourt (substitute member on the 1998 FBSOP) and Hans Paerl (member of the original 1993 panel) have rejoined the FBSOP.  Following the initial August 17, 1993 evaluation, the PMC has requested reviews that have taken place October 17-18, 1995, December 10-12, 1996, May 12-14, 1998, and November 1-5, 1999.  Starting in 1995, the FBSOP has participated in the Florida Bay Science Conferences by formally leading question and answer sessions and by providing written reports to the PMC that present critical reviews and recommendations for advancing and coordinating the program.  Previous reports include Boesch et al. (1993), Boesch et al. (1995), Boesch et al. (1997), and Boesch et al. (1998).  The authors of this fifth report are the members of the FBSOP, all of who attended the 1999 Florida Bay and Adjacent Marine Systems Science Conference.

 

At the request of the PMC, FBSOP members also suggest membership and chair ad hoc advisory panels of experts in specialized subject areas who participate in technical workshops where critical research issues, interagency coordination, and management alternatives are addressed.  These advisory panels also provide written recommendations that the PMC accepts as guidance in coordinating the interagency program (Armentano et al. 1997).  The Florida Bay workshops have included the Modeling Workshop (April 17-18, 1996), Nutrients (July 1-2, 1996), Design and Specification of the Florida Bay Water Quality Model (October 22-24, 1996), Higher Trophic Level Initiative (November 4-5, 1997), Seagrass Model Workshop (January 13-14, 1998), Paleoecology and Ecosystem History (January 22-23, 1998) and Progress Review of Florida Bay Models (May 11, 1998).  Other PMC workshops and research team meetings, at which members FBSOP were not present include the Physical Science Team Workshop (September 4-5, 1997), Hurricane Georges Retrospective (November 20, 1998), Physical Science Team meeting (March 22, 1999), Phytoplankton Bloom Workshop (May 25-26, 1999), Higher Trophic Level Team Planning Workshop (June 14, 1999), Florida Bay Salinity Modeling Workshop (August 30-31, 1999), and Florida Bay Water Quality Model (September 13, 1999).

 

The 1999 Florida Bay and Adjacent Marine Systems Science Conference was held at the Westin Beach Resort, in Key Largo, Florida, on November 1-5.  Forty-four oral presentations were organized around the five central questions in the PMC Strategic Plan for the Interagency Florida Bay Science Program (Armentano et al. 1997, 1994).  Sixty-two posters on scientific investigations were displayed on November 3rd.  Emphasizing for the first time the necessary links to resource management, a special session of eight synthesis papers addressed the theme of "What do we know now and what do we need to know for restoration."  The Florida Bay section of the conference ended with a panel discussion by resource and research managers and Florida Bay science program managers with the theme of "Setting a direction, what can we expect from science?"  Abstracts of the presentations and posters were available for the Conference (Anonymous 1999).

 

Because of the recent expansion of the interagency program, a special one-day session was held on Friday, November 5th, with 19 oral reports on Research on Adjacent Marine Systems.  Scientists reported on various aspects of the ecology and environment for Biscayne Bay, the Dry Tortugas region, and Southeast and Southwest Florida Coastal Ecosystems, and the Caloosahatchee Estuary.  These new research areas are not a part of the FBSOP review.

 

Finally, the quality of the research in the Florida Bay Program has received national recognition by the recent approval of a 6 yr NSF Long Term Ecological Research (LTER) project at the edge of the southern Everglades.  The highly competitive LTER program consists of 25 intensively studied sites across the U.S.  This new project builds on data and understanding developed in the Florida Bay Program.  It will investigate nutrient dynamics as parcels of water flow through freshwater marshes and mangrove estuaries to Florida Bay.  Long-term sampling and short-term mechanistic studies will be used to investigate primary productivity, organic matter accretion and turnover in soils and sediments, and consumer dynamics and productivity.

 

GENERAL FINDINGS

 

Summary.  The Florida Bay Program consists mostly of high-quality research projects that attract complementary funding and national attention from the NSF’s LTER program, NOAA’s Sea Grant, and other programs.  Although problems are inevitable, the FBSOP finds good focus, adequate management of the research, and continual progress in understanding the interactions and events that drive the dynamic Florida Bay ecosystem.  One problem is the need for an immediate decision about the effectiveness of the physical models under development.  The five central questions of the Strategic Plan (Armentano et al. 1997) continue to provide an organizing focus.  As the Florida Bay Program matures it encompasses new research, synthetic modeling, and fuller integration across disciplines; this progress is accompanied by new difficulties and challenges, many of which are mentioned by the FBSOP in this report.

The following list is a concise set of issues and findings of the FBSOP in approximate order of priority.  Following this are findings and comments on the large issues of the FBSOP Review Process, the Modeling Evaluation Group, the Progress of Synthesis, and the Progress of the Research Teams.  Lastly, there are comments on research on the five central questions of the Strategic Plan.

 

1.  Synthesis.  The development of a series of comprehensive reports of current scientific understanding and uncertainties should be a high priority activity, vital to obtaining the best science.  Good starts to synthesis were made in draft reports on the State of the Bay (Brock 1999) and a Florida Bay Conceptual Model (Rudnick 1999).  Another significant step towards synthesis was the publication of two compilations.  One was an entire special issue of the journal Estuaries.  The other is a NOAA publication on paleo-salinity.  However, the draft reports still need to be completed and the information in the compilations still needs to be synthesized before these can begin to help in the management of research and of natural resources.  A more extensive discussion is found in a later section – Comments on the Progress of Synthesis.

 

2.  State Funding and Participation in the Florida Bay Program.  One of the unique and effective aspects of the Florida Bay Program is the cooperation between the state and federal agencies.  The State of Florida has well-recognized scientists with expertise in benthic processes and fisheries health, including seagrass productivity and geochemistry of sediments.  The degree of experience in South Florida ecosystems and field capability available from the Florida Marine Research Institute and Department of Environmental Protection cannot be replaced by the federal agencies involved, even by contract.  Unfortunately, the reported reduction of $1 million in state funds could not come at a worse time.  The other Florida Bay research projects are beginning to focus on the importance of benthic process and connect research on circulation, water quality, eutrophication, sedimentation, and higher trophic level modeling to sea grasses and the commercially and recreationally important fisheries in Florida Bay and surrounding waters.  The FBSOP understands the equity of investigating other state marine ecosystems and the fairness of allotting public resources evenly, but effectiveness, leadership, and leverage also must be factored into how public resources are directed.  Without sustained funding for critical field investigations by irreplaceable state experts, the Florida Bay Program could be severely hindered.  This comes in the two critical years that are expected to produce workable circulation, salinity, water quality, seagrass, and ecosystem models to address pressing restoration and management issues.

 

3.  Scientific Program Manager.  The recent appointment of Dr. William Nuttle as the Executive Officer of the Program has been an instant success.  The FBSOP has observed a major upgrade in its communication with the PMC.  Dr. Nuttle not only organizes and focuses several scientific teams but he has shown substantial initiative in several other areas.  One example is the publication, in cooperation with the Nature Conservancy, of several popular articles about Florida Bay and the Florida Bay Program.  These are informative and provide an excellent vehicle to inform the public and resource managers about the environment of the Bay and the various research efforts involved.  But the FBSOP noted several areas of concern.  First, several of the planned synthetic overviews of research were not given at the Science Conference.  We hope that some of the PMC members are not withdrawing from their vital coordination duties.  Second, in the past year there was a change in the theme of workshops from peer-reviews of scientific topics to the planning and coordination of research teams.  Good communication should not be a substitute for the peer-review workshops that deal with review of science issues.  Third, Dr. Nuttle’s appointment is for two years.  With excellent foresight, NOAA plans to make a temporary appointment of a career NOAA Corps Officer until someone of Dr. Nuttle’s caliber is recruited.  This position is of utmost importance to the success of the Program.  The FBSOP hopes it will not take another two years to fill the position.

 

4.  Making Links to Restoration and Resource Managers.  The links between the science and management programs are increasing to the point where a coordinator or manager may be needed.  This need arises because the Florida Bay Program must not only acquire scientific understanding but also the information must be presented in a form that is both understandable and useful to restoration and resource managers.  There is growing pressure from government agencies for the Florida Bay Program to provide this information; in effect the PMC is asked to address management objectives in their program planning.  This pressure arises from the interest of the Vice-President and other cabinet members, from the interest of department heads in the administration, and from the Congressional funding for the restoration of the South Florida ecosystem.  It appears that this pressure has created a mismatch between the expectations of the restoration and resource managers and the PMC.  The FBSOP notes that a schedule for products must be constructed that is driven and fashioned by both scientists and managers.  Scientists have to present a realistic timetable, be prepared to defend the scientific rationale for the schedule, and make every effort to provide management-oriented information along with evaluations of the reliability of their conclusions.  Managers must not allow urgent needs for restoration to cripple the scientific program.  Given the magnitude of the job of scientific organization and management, the PMC and the agencies should consider the appointment of a manager/coordinator to link the science program and the needs of restoration and resource management.

 

5.  Team Progress.  As the Program matures, research teams are becoming more effective at organizing, coordinating, and directing research (see a later section on Comments on Team Development).  The Physical Science Team has made excellent progress in defining a conceptual model and pursuing vital monitoring and data collection programs to fill gaps in knowledge.  It is ready for the calibration and testing of mathematical models with sufficient data on bathymetry, boundary conditions, meteorology, hydrology, and internal salinity and circulation.  The team is now ready to decide the effectiveness of RMA-10 and FATHOM, of water quality transport models, and where further efforts should be directed.  The Seagrass Research Team also has done well in coordinating research and exploring some of the causes of die-off.  The team has a very good conceptual model and seems to be making progress in testing the conceptual model.  They expect to become more quantitative by developing a predictive model.  One modeling group should be chosen based on ability to interact with the field scientists.  The Phytoplankton Bloom Team has made slow progress.  A healthy debate seems ongoing about the appropriate conceptual model to guide monitoring and research.  A belated model building is underway but must become better connected with the research program; the progress of the water quality modeling should be carefully assessed.  The Nutrient Team was initially well coordinated and effective, especially in publication of the whole-system nutrient mass balances.  They must now define the basin-scale nutrient balances and details of nutrient cycling in the Bay.  The Higher Trophic Level Team still seems disorganized and needs to construct a conceptual model.  Some of the best projects, for example, the construction of a model of lobsters and the study of human impacts on the life history of the roseate spoonbill, are not an official part of the Florida Bay Program.  The FBSOP strongly recommends that an open solicitation for process work on benthic organisms be highlighted in the next funding cycle.  The sophistication of the understanding of water column organisms and processes far exceeds the understanding of the benthos.  This imbalance is striking in an ecosystem that is a little over 1 m deep, dominated by seagrass, and in which there are likely strong links between the benthos and water column such as benthic filter feeders.

 

6.  Streamlining the FBSOP Review Process.  As detailed in a later section titled “Comments on the Florida Bay Program Review Process”, the growth of the Florida Bay Program causes problems for the FBSOP.  It is no longer possible to make informed comments about the program from information gained solely at the Science Conference and at the specialized workshops.  The solution is to have special briefings for the FBSOP that will synthesize the progress in the various scientific areas.  In addition, there should be reports from standing committees and representatives of the FBSOP should attend every workshop – but this is possible only if there is adequate forewarning of the date.  The Science Conference itself should be shortened to no more than three days.

 

7.  Oversight of the Modeling Evaluation Group (MEG).  As described in a later section on the MEG, this group is performing the valuable function of reviewing the development of models.  It should now begin to focus more on operational models for resource assessment and management.  To avoid a situation where the PMC might receive contradictory advice from the MEG and from the FBSOP, the MEG should report through the FBSOP.  This procedure requires that a member of the FBSOP be a member of the MEG.

 

8.  Detailed Basin Investigations.  Although it is assumed that much of the salinity range across the Bay is explained by evaporation and residence times of separate basins, there is an obvious lack of basin-scale studies.  These are clearly needed in the eastern and central parts of the Bay.  Vital questions include: how long are residency times of water masses; how much communication is there between adjacent basins; and what is the evaporation across the Bay?  There were earlier plans to carry out intensive monitoring of some basins; these plans should be implemented.

 

9.  Uniform Basic Data Sets.  The development of a set of change scenarios, basic

forcing functions, and boundary conditions and response variables for model calibration, validation and comparison is an essential management element and model performance measure of the Florida Bay Program.  Circulation and transport pathways are invoked in recruitment models and in hypotheses about hypersaline water flowing off mud banks without checking consistency with the physical information at hand.  "Wet-year," "low-wind year," and "long residence time," characterizations have been made, but without an apparent connection to the data.  A canonical data set will not only aid the experimental design, assessment, and monitoring for biological resources, but will also facilitate model validation and allow comparison between models that make predictions for different components of the ecosystem.  Currently there is no uniform set of variables available for model development or prediction, making comparison of model results impossible.  This becomes more critical as the Program develops a suite of models designed to answer specific questions.  Putting these different model outputs together to create a coherent picture of the Bay will not be possible if everyone is testing their own scenarios or calibrating their models to differing base data.  The FBSOP strongly advises the PMC to develop, distribute, and maintain the quality of canonical data sets describing typical, wet, dry, cool, hot, storm, and drought conditions of Florida Bay over time.  The data should include bathymetry, meteorology, freshwater and wastewater inflow, circulation, salinity (primary), water quality, benthic conditions, and biological resources both seasonally and synoptically.  Forcing functions such as climate cycle (ENSO), Loop Current position, Gulf Stream eddies (seaward of the Keys), and hurricane events should be readily available.

 

10.  Paleo Studies.  The paleoecology projects are commended for producing both a synthesis (Nelsen et al. 1999) and papers in the June 1999 special issue of Estuaries (Halley and Roulier 1999, Brewster-Wingard and Ishman 1999, Swart et al. 1999).  Paleoecology is one of the best components of the Program and seems most ready to produce a synthesis to guide management and restoration decisions in the short-term while long-term operational models are under development.  Although the FBSOP finds that the paleoecology work has been the most productive to date, some weaknesses are evident that the PMC and the investigators should address.  First, many historic features of the Bay still are not well understood.  If the U.S. Geological Survey and other agencies have general paleoecology research funding, these funds can be productively directed towards using Florida Bay as a laboratory where ecological history has been studied by a variety of methods.  Second, a review of the existing projects indicates a number of significant gaps that should be addressed.  (1) The consistency in Pb-210 and C-14 dating by atomic mass spectroscopy must be established before pre-1940 records can be reliably dated to define the natural state of the Bay, Nelsen et al. (1999) and Brewster-Wingard et al. (1999, pp. 182-183) not withstanding.  Whether or not resource managers and the public decide to try and restore Florida Bay to a pristine state, information is needed about previous ecological history of the Bay.  For example, what was the state before freshwater diversion occurred in the Everglades and the Flager Railroad embankment was constructed?  (2) The spatial and temporal natural variability (see Nelsen et al. 1999) must be established to a higher degree of confidence to support resource and restoration decisions.  (3) Other environmental proxies should be considered with the 80 yr rainfall record at Homestead, such as tree rings to tease out annual rainfall and evaporation variability across the Bay.  (4) Measurements of the Mg/Ca ratio shown by Dwyer and Cronin (Anonymous 1999, p. 158) are a doubtful proxy because the useful range of paleo-salinity occurs on the Mg/Ca-Salinity asymptote.

 

11.  Sedimentology.  There has been an obvious lack of concerted effort to study the carbonate sediments and their formation, even though they represent the major sediment source for the entire Bay.  Where, for instance, are they being formed and at what rate(s)?  Two groups (Millero et al. in Anonymous 1999, p. 76) and Zhang et al. (in Anonymous 1999, p. 152) address some key geochemical questions, although mostly water-column geochemistry, but they do not address the over-riding sedimentological questions, such as when and where sediments are produced, how fast, and possible rates of dissolution.

 

12.  Plans for Studying Effects of Hurricanes.  The Hurricane Georges Retrospective workshop summary (FBSOP Briefing Book, November 1-5, 1999) and report (Nature Conservancy, July 1999, Florida Bay Watch Report) are well-focused preliminary evaluations of the impact of a hurricane.  These data provide the first real opportunity in the Program to test the important hypothesis that the Florida Bay ecosystem is reset by hurricanes or other storms.  In general, the analysis seems complete and valid enough to establish that a storm of the track and magnitude of Georges does not significantly reset the water quality and ecology of Florida Bay.  However, to forecast longer-term effects, it would be useful to quantify the export of seagrass.  Also, the effect of ammonium on longer-term phytoplankton productivity should be investigated when the water quality model is calibrated.  A formal plan should be drafted for the collection of data before and after storms more severe than Georges.  While there is no need to make measurements during or immediately after a large hurricane, a plan must define exactly the priorities of what needs to be measured and when and where.  A plan should be in place or updated before the 2000 hurricane season.

 

13.  Long-term Plans for Monitoring and for Studying Other Major Environmental Impacts.  There is a need for a plan designed to detect future trends in water quality and biological resources.  Resource managers at the 1999 Science Conference called for exactly such a scientifically defensible, sustainable, long-term monitoring plan (Mark Rodson, Florida Fish and Wildlife Conservation Commission, and Mike Collins, South Florida Water Management District, Panel Discussion: Setting a Direction, What Can We Expect From Science, November 4, 1999 Science Conference).  The plan should consider the impacts of oil spills, drought, and El Niño/La Niña.  The oil spill simulations conducted for the west Florida shelf in the early to mid-1990s by Florida State University should be investigated to see what Florida Bay resources might be at risk.  These resources (e.g., the western sea grass beds) should be adequately defined before a spill occurs to ensure an adequate damage assessment.  Quantifying the effects of drought and the resulting hypersalinity or the effects of an El Niño/La Niña will be difficult.  The long-term monitoring programs must measure the best parameters frequently enough at critical locations.  There should be flexibility so as to be able to change the monitoring frequency and intensity from year to year.

 

14.  Groundwater.  Concluding that groundwater flux to the Bay has minimal importance seems to be a bit premature.  The talk by Z. Top (in Anonymous 1999, p. 151) shows that groundwater flux might explain some of the local geochemical signatures and anomalies seen in Florida Bay waters.  Measuring groundwater, of course, is difficult at best, and to date both the University of Miami and the Florida State University teams have struggled to reach conclusions based only on geochemical proxies.  But this should not rule out groundwater as a potential source for dissolved species.  The "River of Sand" hypothesis may be overstating the case, but can not be dismissed without careful evaluation.

 

COMMENTS ON THE FLORIDA BAY PROGRAM REVIEW PROCESS

 

The Problem.  The Florida Bay Program has grown.  It is no longer practical for the FBSOP to review each science project or to understand every method used for a measurement.  It is probably also true that the FBSOP can no longer learn everything it needs to know through attendance at the Science Conference.  A more efficient way has to be found to inform the FBSOP about the program in general, about the state of knowledge about each of the scientific questions, and about the status and plans for synthesis and modeling.  The FBSOP found that the 1999 conference was too long and involved too many important objectives to evaluate comfortably all of the advances and innovations by the Program.  Happily, the PMC did not unilaterally expand the purview of the FBSOP to adjacent marine systems until this matter could be considered at length.

 

Use of Synthetic Briefings, Ad hoc Workshops, and Standing Committee Reports.  One way for the FBSOP to gain the knowledge required to evaluate the Program and the scientific advances is through a longer briefing on each question conducted by an integrator and organizer.  These briefings must be synthetic rather than detailed.  Longer synthesis talks, such as “Sources of salinity variations and forecasting changes in the Bay” and “Results from paleoecology studies” at the 1999 Science Conference, set the stage for an efficient perusal of individual posters, at which FBSOP members and scientists in general could discuss points one-on-one.

 

Additional information for the FBSOP would come from the future scientific workshops evaluated by standing or ad hoc committees of expert reviewers chaired or attended by FBSOP members.  These workshop panels bring in scientists with broad expertise and experience to supplement the FBSOP.  As the Program has matured, however, there is also the need for some panels to evolve to become standing committees, like the Modeling Evaluation Group (MEG), to provide continuity in the evaluations. 

 

In the past the PMC made a point to have members of the FBSOP chair most of these committees.  While there is no need for a member of the FBSOP to be the committee chair, the FBSOP must continue to be involved if at all possible.  Accordingly, the FBSOP must have long-term adequate advance notice for these meetings.  Plans must be made at least three months in advance and in some cases six months in advance, with some flexibility for reaction to opportunities involving event sampling and other unscheduled occurrences.  If there can not be direct involvement of the FBSOP, the evaluation panel chair should be invited to the next FBSOP meeting to advise and report. 

    

We note the decline in the number of peer-reviewed workshops centered on the five central questions and an increase in workshops centered on coordinating and organizing the research teams.  This has contributed to a decline in the information available to the FBSOP.  While we do not advocate that workshops should be held solely to help the FBSOP, it does appear that several scientific workshops should be held before the next Science Conference.  The recommended topics are: (1) assessment of the circulation, salinity, water quality, and sea grass models by the Model Evaluation Group, (2) sea grass research and assessment, (3) nutrient and eutrophication programs, and (4) higher trophic level research and assessment.

 

Synthetic modeling and the interface with managers have become so critical that the FBSOP will need a firmer connection and reporting process from the MEG standing committee.

 

Annual Science Conference and FBSOP Meetings.  Depending on the PMC purpose, future Science Conferences may need to be streamlined to no more than three days if the FBSOP will be required to review and report on the progress.  If at all possible, the meetings of the FBSOP should be held every 12 months to better manage the amount of progress to be evaluated.  Eighteen months is too long to keep previous evaluations and progress in mind, especially when the Science Conference has matured and is beginning to address the needs of resource managers.

 

The 1999 Science Conference featured (1) new and innovative work to spur the interest of the Program investigators, (2) synthetic talks by team leaders and PMC members with the goal of briefing resource managers, and (3) a panel discussion of science needs of managers.  While parts were interesting, collectively they were not very informative for all the members of the FBSOP.

 

COMMENTS ON THE MODELING EVALUATION GROUP (MEG)

 

Concerns.  One issue posed to the FBSOP by the PMC during this review was the role of the MEG in giving advice to the PMC.  The PMC is concerned that future advice from the FBSOP and MEG could be inconsistent.  The Program is also maturing and there is concern about how to use modeling to translate the excellent research on Florida Bay into operational actions for management of all important resources in the Bay.  Finally there is concern about how to manage the communication between the MEG and the FBSOP.

 

Functionality.  As the Florida Bay research becomes more mature and synthetic, the urgent needs are to evaluate proposed models, to review progress on existing models, and to suggest links and improvements.  The MEG was set up for this purpose.

 

In general, it appears that reviewers found the MEG to be balanced and effective in the past evaluations.  Generally, the existing panel has adequately determined important issues and clearly expressed the need to address these issues.  Most of the issues identified by the MEG are explicitly consistent with the broader concerns of the FBSOP.  Coordination of the May 1998 MEG meeting and the FBSOP meeting at the 1998 Science Conference led to identification of several concerns (Boesch et al. 1998, D’Elia et al. 1998).  The expertise on the MEG is also sufficiently broad and the participants do not take part in Florida Bay research.

 

Present and Future Scope.  To date, the MEG has evaluated the science synthesis modeling, plans to develop operational models, and data collection.  This scope should continue but should begin to focus more on operational models for resource assessment and management.  Data collection programs to define boundary and initial conditions should continue to be within the purview of the MEG until credible, calibrated models are achieved.  Review of the coordination of the synthesis modeling and development of operational models should remain the purview of the MEG.  The FBSOP will review overarching science validity and integration of the synthesis modeling to distill research and monitoring efforts.

 

Review and Management.  Clearly, the FBSOP cannot focus on more than the most critical elements of the MEG reviews.  The November 1-5, 1999 Science Conference established that the Florida Bay Program has grown to the point that the PMC must find a different format for the FBSOP to critically review and advise on the overall program and especially on the MEG.  To this end, the MEG probably needs to meet regularly, perhaps as often as twice per year.  However, the FBSOP does believe that adequate supervision of a standing subcommittee or group through the chair of the FBSOP is feasible.  MEG needs to have a clear charge and to report to the FBSOP as an advisory committee so that the lines of communication with the Program are straightforward.  To aid in communication, a FBSOP member must always attend the MEG meetings.

 

Expertise and Integrating Science to Support Resource Management.  The MEG needs to be better in tune with the pragmatic issues of translating scientific advances into resource management.  Several modeling efforts are reaching critical stages; a well-managed process is necessary to critically evaluate the scientific and management credibility of the models being delivered.  Although the balance in the MEG between modeling experts and water quality and circulation process experts could be tilted even more towards quantitative modelers as existing members resign, the quantitative assessment approach and broad insight into management issues have proven useful in the past MEG evaluations.  Overall, the MEG could benefit from more expertise in (1) the application and management of research for resource assessment and management, (2) ecosystem modeling, and (3) hydrodynamics.  This should be kept in mind when replacements are needed.

 

In addition, the PMC should consider appointing to the MEG one additional member with broad experience in focusing research investigations on resource management issues.  The ideal combination would be a former resource manager with appreciation for, or direct experience in using model simulations, monitoring information, and research investigations.  Finally, the PMC should clarify or restate the charge to the MEG and address past recommendations in the report card to the FBSOP each time a review is undertaken.  The charge and update from the PMC should clearly address changes in resources and cooperation, and any other pragmatic issues the PMC needs to address.

 

COMMENTS ON PROGRESS OF SYNTHESIS

 

The 1998 Report of the FBSOP recommended the development of a series of Synthesis Reports – comprehensive reports of current scientific understanding and uncertainties.  These reports will guide planning of additional scientific research as well as provide information to restoration and resource managers, and to the public.  This is a high priority, critical issue for the Florida Bay Program that is vital to obtaining the best possible science.  While difficult to achieve, a good synthesis is very important for the Program.

               

Each Synthesis Report should contain most of the following information: (a) historic information, (b) response to natural events and human changes, (c) current status and trends for each resource or condition, (d) understanding of ecological or physical/chemical controls and interactions, (e) future scenarios, and (f) management implications.  All Synthesis Reports and even Conceptual Models must undergo peer review from outside the Program.

 

Good starts to synthesis were made in the mini-syntheses presented in the May 15, 1999 mid-year summary of activities, the draft State of the Bay (Brock 1999), the draft Narrative for a Florida Bay Conceptual Model (Rudnick 1999), and the Nature Conservancy's popular articles about Florida Bay and the Program.  However, these are but the first steps.  None of the mini-syntheses provide the status of the resources in Florida Bay (there is incomplete information from the Higher Trophic Level team); most are team reports that focus on what future research should occur.  Brock (1999) has a better focus on the status and trends but the section on “Management Implications” needs improvement.  Rudnick (1999) exists as an incomplete draft only; many unsupported statements and conclusions must be justified by the detailed information and references contained in a larger document such as the Synthesis Reports.  The popular articles are informative and an excellent vehicle to inform the public and resource managers about the Bay and the various research efforts involved.  The Nature Conservancy intends to highlight the role of the Program in future articles as should be required.  Nevertheless, these popular articles also lack some credibility because the scientific basis of various statements cannot be traced to peer-reviewed papers or Synthesis Reports.

 

                Another significant step towards synthesis was the publication of two compilations.  One consisted of a volume of papers titled “Florida Bay: a dynamic subtropical estuary” (special issue of Estuaries).  The other is a NOAA publication that is summarized from a chapter in a book.  Nelsen et al. (1999) titled this NOAA publication “Paleo-Salinity Changes in the Lower Everglades and Florida Bay Ecosystems.”  It is urgent that the paleoecology data be brought together into a single, synthesized overview of the best possible information on ecological conditions over time at different locations in Florida Bay.  The fragmentary pictures presented in the papers of these two compilations are confusing and of little use to scientists and managers who do not have extensive experience in paleoecology.

 

In the longer time frame, a major compendium about the Bay could be assembled based upon the Synthesis Reports and the popular articles.  This book could contain color maps and photos to make it an attractive summary of knowledge about Florida Bay, past and future.  One goal of such a book would be to illustrate the value of Florida Bay as a national resource, worthy of continued high levels of research effort and funding.

 

COMMENTS ON PROGRESS OF THE RESEARCH TEAMS

 

Introduction.  The FBSOP was glad to see the report on the progress of the research teams (Summary of Research in the 1999 Science Conference briefing book).  As the Program matures, teams dealing with the research areas are becoming more effective at organizing, coordinating, and directing research (Armentano et al. 1997).  This development is very important for the Florida Bay Program; accordingly we have made extensive comments on the teams.

 

First however, we note differences in team synthesis and modeling approaches.  Starting with an excellent dynamic conceptual model, the Physical Science Team is directly linking well-focused critical data collection activities to define operational model boundary conditions.  Although a redundant investigative model, FATHOM, was funded, this model attempt was not productive.  The Nutrient Team was on the same track to proceed from a conceptual model to an operational model before stalling.  The Phytoplankton Bloom Team has an exciting model building exercise (Burd and Jackson, Texas A&M) to interpret monitoring data and process investigations.  This fills in for the lack of a solid conceptual model of bloom dynamics and occurrence.  Unfortunately, this model building approach is not making substantial progress due to a lack of coordination and support for the operational water quality model.  The Sea Grass Team, who may have the best conceptual model overall, is on a similar track but they are even more neglectful of the final operational model requirements and have not fully adopted a quantitative approach to synthesis.  This team has gone so far as to request that three model-building teams be funded.  Yet, there is no provision for adequate peer-review and coordination with operational water quality model development (see previous reviews in D’Elia et al. 1996, Boesch et al. 1996).  The Higher Trophic Level Team has not completed development of a comprehensive conceptual model but with some enterprise include other exceptional recruitment modeling of the spiny lobster by outside investigators.  Whether this team can go directly from rudimentary statistical analyses of resource status and trend monitoring to an operational energetics model of the higher trophic levels cannot be forecast until a better conceptual model and leadership is in place.

 

The Physical Science Team has made excellent progress in defining a conceptual model and pursuing vital monitoring and data collection programs to fill gaps in knowledge.  This team has evidently closely tracked the development of models and ensured that sufficient data are available to define bathymetry, boundary conditions, meteorology, hydrology, and internal salinity and circulation for calibration and model testing.  In parallel, this team has pursued a physical understanding of the circulation and salinity in Florida Bay, exchange with the West Florida shelf and the Shark River Plume, flow through the Keys, and flow in Hawks Channel.

 

The Physical Science Team must address two urgently critical matters.  The lack of adequate salinity simulations is delaying process investigations, and water quality and biological modeling (e.g., Butler in Anonymous 1999).  The Team must also focus their proven data collection skills on inter-basin flow, exchange, and mixing to obtain a comparable understanding of basin by basin flow, tidal and freshwater effects, salinity and nutrient balances, and evaporation leading to hypersalinity.

 

The Team has undertaken tactful internal reviews (Summary of Research on Florida Bay, Science Program for Florida Bay and Adjacent Marine Systems: Research Team Reports – April 1999, Lee et al. Physical Science Team report to the PMC, FBSOP Briefing Book, November 1-5, 1999) and are ready to decide how effective the RMA-10, FATHOM, and water quality transport models can be and where further efforts should be directed.  The PMC must empower this Team to make critical decisions in coordination with the needs of other teams.  One way to obtain broadly based input into the decision is through a meeting with the MEG.  Before this happens, however, the Physical Science Team would have to decide upon a charge for the meeting in which the necessary decisions are clearly stated.

 

The FBSOP notes that the salinity modeling effort using RMA-10 missed vital deliverables (WES 1995).  The RMA-10 project failed to achieve a credible salinity simulation, to use modern bathymetry data, to link the Everglades ground water and surface simulations to accurately simulate freshwater effects on salinity in Florida Bay, and to provide an operational model for the Jacksonville District and the South Florida Water Management District.  Only simulations of flow in the passes between the Keys to evaluate railroad and highway embankments seem credible (Dortch in Anonymous 1999).  The inability to make preliminary simulations of freshwater effects, either for the Restudy or the Florida Bay Program, severely undercuts the foresight and leadership that the Jacksonville District used in commissioning this study in 1995.  The FBSOP agrees that the Jacksonville District should pause at least until WES remedies the ponderous execution of the RMA-10 model due to too much discretization (see Boesch et al. 1996, D’Elia et al. 1996, Armstrong et al. 1996), and until a satisfactory linkage with finite difference water quality models are worked out (see Boesch et al. 1998, Boesch et al. 1996, D’Elia et al. 1996, Armstrong et al. 1996).  Even then, the District is advised to consider other modeling approaches that can be effective in using modern bathymetry data, up-to-date estimates of freshwater flows, and will adequately support water quality modeling.

 

The FATHOM project is equally troubling.  The project seems to have been funded without due consideration of the consensus of Florida Bay investigators (D'Elia et al. 1996) and by an agency that specializes in biological resources and not hydrography and physical oceanography.  The 1995 outside reviews of FATHOM noted that the code has not been peer-reviewed and uses the questionable, inherently over-diffusive linear reservoir theory to represent residual circulation.  These same concerns were addressed by Boesch et al. (1998) and D’Elia et al. (1998).  The progress to date is convincing that the FATHOM model should be dropped.  Although the transport through the Florida Bay system probably could be tuned to a reasonable agreement with the data at the expense of having to slow down the exchanges between individual basins, these calibration coefficients would not be physically realistic or predictive of advection and mixing over the banks.  The mechanism for assigning the arbitrary exchanges would remain unclear.

 

The second urgent matter for this team must be the definition of exchange between basins in the Bay, necessary for physical and biological modeling efforts.  The physical and biological investigators reached a consensus in 1996 for interbasin monitoring and modeling (D’Elia et al. 1996, also see Ad hoc Committee on Nutrients 1996).  The dye studies and other investigations cancelled in 1999 must be carried out as soon as possible.  In addition, time series of salinity patterns would be more useful for verification than point-to-point comparisons.  Typically, time series are more telling of model performance.  A model can be very good, but slightly miss the exact position of a high-gradient region.  The point-to-point comparison might indicate a large discrepancy, whereas the model might be working very well overall.

 

The Nutrient Team was initially well coordinated and effective, especially in pursuing publication of the global nutrient mass balances in the journal Estuaries (Rudnick et al. 1999).  However, the team has not moved to the next stage of defining basin-scale nutrient balances and has not begun the vital third stage of defining detailed nutrient cycling in the Bay, especially defining benthic exchange.  The result is that nutrient cycling investigations in the mangrove fringe and other projects are not clearly connected and useful (April 1999 Report to FBSOP).  The LTER project will add to the critical mass with outside funding, but will not be very effective unless a more detailed conceptual model is developed to guide the interaction.  Coordination is also vital since the LTER project depends on the original project started by the South Florida Water Management District, which may not be sustained over the life of the NSF funding.  Besides the recognition by the NSF that Florida Bay studies are of high quality, the one other bright spot is the strength added by the integration of Bill Krucyinski and the U.S. EPA into this team.

 

The most troubling issue for the Nutrients and Phytoplankton Bloom teams is that the innovative model building effort of Texas A&M is out of synch and disconnected.  The water quality model funding has not been adequate to keep close coordination with the Nutrients, Phytoplankton Bloom, and Sea Grass teams to develop the much-needed operational water quality and sea grass model.  The water quality model calibration could have been further advanced if the data analysis of Jackson and Burd (1999) had been completed by the summer of 1998 and the efforts of Burd and Jackson (1999) available in early 1999.  This illustrates how urgently schedules and definitive objectives are required for each team (Boesch et al. 1998).

 

The Nutrient Team should first expand the conceptual planning to encompass operational modeling and synthesis, and then integrate ongoing projects.  The PMC should engage the MEG to review the revised conceptual model and schedule for integration so that the FBSOP can adequately advise whether the innovative model building should be pursued.  The initial calibration of the water quality model seems credible enough that this project should be paused until the overall modeling effort is reviewed and better planned and implemented.  Once the circulation and salinity models are selected and calibrated, when there are well-defined products from the nutrient and phytoplankton model building effort (Burd and Jackson 1999), and when sea grass interpretative syntheses are ready, then the development of an operational water quality model should be restarted.  Dortch and Cerco should be funded to attend meetings of the Nutrients, Phytoplankton Bloom, and Sea Grass teams to help develop adequate schedules and objectives, especially for process investigations.

 

The Phytoplankton Bloom Team has made some slow progress.  A healthy debate seems ongoing about the appropriate conceptual model to guide monitoring and research.  Belated model building is underway (Burd and Jackson in Anonymous 1999, p. 125) but seems disconnected from the research program and development of an operational model.  This isolation has led to some redundancies and missed opportunities such as coordination with Mark Dortch and Carl Cerco of the Army Waterways Experiment Station.  It is not clear that this team has adequately recognized benthic effects.  This team must quickly formulate and communicate a sound conceptual model while the operational water quality modeling effort pauses.  If a viable conceptual model acceptable to the team does not appear in a few months, the team must reassess the goals and timetables of the modeling effort.  The project with Texas A&M must be adequately coordinated other parts of the program.

 

            There is still an unresolved issue about the different methods used to quantify the amount of chlorophyll in the water column.  The methods used have changed over time and have been different for different investigators.  This makes it nearly impossible to create a synoptic picture or historical reconstruction of algal abundance in Florida Bay

 

The Seagrass Research Team also has done well in coordinating research and exploring some of the causes of die-off.  The team has a very good conceptual model (see figure in Zieman et al. in Anonymous 1999, p. 7) and seems to be making progress in testing the conceptual model. They expect to improve the quantification of their projects through mathematical modeling and have directed that three modeling groups be engaged to formulate research models.  This is excessive.  The FBSOP advises that one of the major values of modeling is the interaction of modelers with field researchers and other modeling efforts during model development.  The choice of the modeling groups must include an examination of the past interactions.  Given the critical nature of this task, the MEG and FBSOP should review the proposals before funding.  Rather than directing funding to questionable choices, a request for proposal should be issued to be sure the best ideas and approaches are available to the Program.

 

The Higher Trophic Level Team still seems disorganized.  This team lacks clear leadership in the development of a conceptual model, leaving the impression that the program is fragmented.  In part the fragmentation occurs because some of the best projects on modeling lobsters and defining the impact on the life history of the roseate spoonbill due to land use and water management, come from outside projects.  Inside projects, those funded as a part of the Florida Bay Program on shrimp, other fisheries, and benthic invertebrates, are bogged down in statistical explorations or limited to recent, and some times incomplete, monitoring.  At this stage it is not clear if these efforts lack the resources necessary or if the team is not adequately insightful in coordinating and designing monitoring programs like other teams.  Clearly the team is behind in developing a solid conceptual model; there certainly are adequate resources for this exercise.  The FBSOP strongly recommends that an open solicitation for process work on benthic-organisms be highlighted in the next funding cycle.  The sophistication of the understanding of water column organisms and processes far exceeds the understanding of the benthos.  This imbalance is striking in an ecosystem that is a little over 1 m deep, dominated by seagrass, and in which there are likely strong links between the benthos and the water column such as the benthic filter feeders.

 

PROGRESS IN ADVANCING THE STRATEGIC PLAN FOR FLORIDA BAY

    

The five central questions of the Strategic Plan (Armentano et al. 1997) remain vital and useful.  The only shortcomings involve the continuing problem of how to track and organize research on paleoecology and sedimentation, and there are indications that the implementation of the Strategic Plan may not automatically facilitate foresight on developing issues or how to handle these issues.  Developing issues include interactions of the benthos and water column as well as any linkage with ground water and eutrophication in Florida Bay.  Although the FBSOP is pleased to see the reliance on and the appropriate integration of the paleoecology studies by most of the research teams organized around the five strategic questions, it is troubled by the lack of attention to sedimentation.  The unique carbonate sediments and evolution of the interesting banks of the Bay are not only of academic interest.  We doubt that the occurrence of eutrophication and sea grass die off will be fully understood until the effects of the carbonate sediment on phosphorus, turbidity, and resuspension of sediments are understood.  In the long term, failure to understand the formation and disappearance of the banks does not allow prediction of any catastrophic shift in habitats and ecosystems of the Bay.

 

Central Question #1:  How and at what rates do storms, changing freshwater flows, sea level rise and local evaporation/precipitation influence circulation and salinity patterns within Florida Bay and the outflow from the Bay to adjacent waters?

 

In the last review, the FBSOP again noted the general need for accelerating the development of conceptual models and syntheses, primarily to focus the research and to enhance interdisciplinary communication (Boesch et al. 1998, Boesch et al. 1996, Boesch et al. 1995, Boesch et al. 1993).  The dependency of biological and chemical research on the development of circulation and modeling constructs is now especially acute.  Therefore, central question one of the Strategic Plan (Armentano et al. 1997) remains very important.

 

Substantial progress has been made toward understanding the hydrography of Florida Bay.  A comprehensive data set of salinity and flow measurements, impressive in coverage and continuity, has been assembled and the initial interpretations have been distributed to the community of investigators.  Quantitative estimates of fluxes through the Key passages have been carefully constructed.  A state-of-the-art, high-resolution meteorological model has been implemented for southern Florida, Florida Bay, and the Keys.  As is typical, the development, calibration, and evaluation of the circulation, empirical transport and water quality models await collection of data on interbasin exchange and refined estimation of freshwater inflows.  Partly because of this delay in data collection, and the dependence of the other components on these efforts, a continuing, critical concern of the FBSOP is whether credible, validated models will be forthcoming within a reasonable time.  Perhaps more troubling is the apparently slowness with which identified problems have been addressed.  Obvious discrepancies in the specification of freshwater inflow and bathymetry were encountered, yet neither a simplified scaling of the inflow, nor the existing modern bathymetry from the U.S. Geological Survey was incorporated into the RMA-10 model.  At present, the Program is looking at the RMA-10 model that can properly propagate tides through the Bay (a necessary, but far insufficient test of necessary model capability), and the FATHOM model with explicitly tuned exchanges between basins, neither of which yet can match the salinity field with acceptable accuracy.  The salinity field is a good integrator of transport processes, and matching this field is the first major test of model capability.  The second major test is residual transport, both across Florida Bay as a whole, and between basins.  A reasonable match of the salinity field and the transport field (which are somewhat independent) provides confidence that the models are ready, not only to elucidate transport pathways, but also to produce accurate estimates of basin residence time, which are essential for biological and chemical research projects.

 

Admittedly, the very shallowness and bank-and-channel complexity of the Florida Bay estuarine system challenges both modeling and observational attacks.  But now that the observational and modeling bases for the periphery have been established to a satisfactory level, more attention needs to be directed to the measurement and understanding of exchange among the basins of the Bay.  These are the residual flows that were mentioned in the last FBSOP report (Boesch et al. 1998).  Innovative techniques of direct measurement, or tracer studies with rhodamine WT or sulfur hexafluoride combined with high-resolution temperature and salinity studies and remote sensing may be required.

 

The past two FBSOP reviews (Boesch et al. 1998, Boesch et al. 1996, Boesch et al. 1995) and the 1996 MEG review (D’Elia et al. 1996) and the earlier Florida Bay Modeling Workshop (Armstrong et al. 1996) have called for extending the modeling into the third spatial dimension, despite the shallowness of the central and inner Florida Bay system.  Although this goal should be kept firmly in mind, the achievement of a calibrated and evaluated circulation and salinity transport model is paramount.

 

The high-resolution meteorological model showed tantalizing possibilities, not only for the development of spatially resolved rainfall estimates, but also for providing rational spatial assignments for evaporation, transpiration, and other important exchanges.  Application possibilities should be explored, not only for the use of this model in monitoring the effects of large spatial changes in the South Florida and Florida Bay ecosystem, but also for judicious hindcasting to reconstruct the atmospheric and hydrologic history of the Florida Bay decline.  In addition, the NEXRAD rainfall measurement technique has matured to the point that the project should be made operational.  A downside to these encouraging developments is the continuing lack of careful evaporation measurements over Florida Bay (suggested in Boesch et al. 1998).  Though difficult and fraught with potential error, these measurements seem crucial for either hindcasting or monitoring ecosystem change in this estuary.

 

Central Question #2:  What is the relative importance of the influx of external nutrients and of internal nutrient cycling in determining the nutrient budget of Florida Bay? What mechanisms control the sources and sinks of the Bay's nutrients?

 

Strategic question two remains vital to the Program.  The use of preliminary nutrient balances seemed to have served well in guiding nutrient investigations overall.  The peer-reviewed publication of the preliminary nutrient balance (Rudnick et al. 1999) indicates that this phase of the work has been exceptional.  The preliminary nutrient balance seems to put the impact of freshwater nutrients and wastewater from the Keys into much better perspective.  Segmenting the Bay into an eastern part compared with the whole Bay indicates where wastewater from the Keys may and may not contribute to widespread productivity and eutrophication.  As intended, the nutrient balance highlights uncertainties in boundary conditions or fluxes of nutrients into and out of Florida Bay.  The flux of nutrients from the west Florida Shelf, to which the Shark River contributes, and through the Keys into Hawks Channel clearly is dominant.  The decision to expand the western boundary to better include the effects of the Shark River is clearly justified by the analysis of Rudnick et al. (1999).

 

Work on nutrient attenuation in the mangrove fringe and along transects perpendicular to the shoreline as well as improved knowledge of the fate of nutrients in the Everglades seem to have helped understand the northern flux of nutrients and freshwater into the Bay backcountry.  Similarly, a knowledge of the dynamics of the nutrient flux and a prediction of the effects on Florida Bay of increases in freshwater are making the connection between scientific investigations and management issues in the South Florida Restudy.

 

Ground water introduction of nutrients in critical areas of the Bay is thought to be limited or unimportant (Rudnick et al. in Anonymous 1999, personal communication, session on Question 2).  However, the controversial river of sand hypothesis does not have seemed to been adequately investigated to know if ground water upwelling might play some role, even locally.

 

CENTRAL QUESTION #3:  What regulates the onset, persistence and fate of planktonic algal blooms in Florida Bay?

 

Phytoplankton blooms are of intense public, management and scientific concern in Florida Bay.  Concerns include associated declines in water quality (decreased water clarity, hypoxia, anoxia, toxicity), altered biogeochemical cycling, and trophic changes.  Major phytoplankton groups responsible for these blooms include diatoms (in the Western Bay) and cyanobacteria (North-Central Bay basins).  Bioassay and stoichiometric analyses indicate that growth of bloom organisms is at least partially controlled by nutrient availability; with phosphorus limitation predominating in the Eastern regions and N being the most important limiting nutrient in the Western part of the Bay.  Field and laboratory results indicate that the north central region of the Bay at times may exhibit N and P co-limitation.  Monitoring and remote sensing studies indicate that geographic partitioning between cyanobacteria-dominated and diatom-dominated blooms has existed in the Bay since the late 1980s.  Remote sensing of these blooms (coupled to diagnostic pigment-based ground truthing) may prove useful in tracking long-term changes in location, biomass and taxonomic composition of blooms.  Limitations to this approach include restrictions in the effective optical depth over which blooms can be detected and characterized, and complications in data interpretation in the presence of bottom-dwelling microflora under optically clear conditions.  Therefore, coupling this approach to field-based ground truthing will remain essential.  Also, while diagnostic pigment-based approaches yield useful data on level of the algal group (i.e., cyanobacteria vs. diatoms, chlorophytes, etc.), species changes within these groups may not be detected, necessitating field verification.

 

There appear to be strong inverse relationships between biogenic silica (Si) accumulations (as diatom) and soluble Si concentrations, with availability possibly restricted at lowest concentrations.  Silica may play a role as a secondary limiting nutrient, potentially modifying phytoplankton community responses to either N or P enrichment in the Bay.  In addition, Fe may modulate phytoplankton community responses, although this possibility needs further experimental verification as to its general importance.  It was pointed out that Fe availability might modify P mobility via sediment Fe-S-P interactions.  These interactions may also play a role in determining the relative importance of seagrass vs. phytoplankton-dominated communities in various locations of the Bay.

 

                Light quality and quantity play important roles in determining phytoplankton community productivity and compositional responses to nutrient availability.  The interactions between nutrient and light availability are the basis for competition, particularly in turbid regions of the Bay.  Low light adapted, nutrient (N and P) uptake efficient coccoid cyanobacteria (i.e., Synechococcus spp.) may predominate under relatively turbid conditions (i.e., North-Central Bay regions), while higher light adapted diatoms predominate in clearer waters.

 

                The relative role of grazing in determining phytoplankton community growth and compositional responses remains unclear.  Preliminary evidence indicates that while grazing may not be a prime determinant of phytoplankton community compositional responses, it may play an important role in nutrient regeneration, which could have long-term ramifications for community productivity and composition.

 

                These findings need to be synthesized in the context of the physical “driving” features that characterize the various basins exhibiting phytoplankton blooms.  The interactions of these factors with such basic physical features as vertical mixing, water retention times and transport within and between the basins should be clarified.  There is a wealth of limnological (especially reservoir limnology) knowledge pointing to the importance of water retention time in determining phytoplankton community composition.  Specifically, cyanobacteria are often favored under long retention time conditions.  Is this (combined with the fact that they flourish under turbid, organic matter-rich conditions) a prime factor that controls their dominance in the relatively isolated north-central basins?  This question is of paramount importance not only for understanding the ecophysiological basis for cyanobacterial dominance, but will also be needed to develop and verify models coupling hydrodynamic with nutrient controls of phytoplankton productivity and composition in response to changing freshwater input and accompanying altered nutrient inputs to the Bay.

 

                There is a consensus developing that phytoplankton blooms in this shallow system are in part dependent on benthic physical-chemical (i.e., nutrient release and associated diffusional dynamics) and biotic (sediments as “seed stocks”, sources of grazing) conditions, making it essential to functionally couple sediment with water column processes.  Sediment resuspension, bottom-water redox gradients, infaunal grazing, competition for nutrients with benthic microalgal communities are all likely to play regulatory roles in phytoplankton bloom development and maintenance.  These interactions must be more explicitly integrated in process and modeling assessments of the Bay’s response to changing hydrodynamic and nutrient conditions (both naturally- and anthropogenically-driven).

 

                Microalgae can form blooms in both planktonic and benthic habitats.  It has been mentioned at this Conference that benthic microalgal productivity, biomass and associated nutrient transformations may, in many instances, exceed rates and amounts in the water column.  In this regard, the “core” of microalgal production and eutrophication dynamics may be being overlooked.  While the public focus is clearly on the “greening” of the water column, from an ecosystem nutrient flux, cycling and control perspective, the most significant “greening” may in fact be taking place in the benthic microalgal community.  The comparative roles and importance of these ecologically distinct, but interactive communities in ecosystem production and nutrient cycling dynamics needs to be clarified.

 

                Overall, better integration of specialized studies examining nutrient and light interactions with bloom-forming phytoplankton taxa with large-scale hydrodynamic with nutrient input/export and biotic forcing features is needed.  In this regard, the specialized studies must find a home and purpose in a unified conceptual model which strives to identify dominant and ancillary controls on phytoplankton (and benthic microalgal) productivity and community composition.  This model should serve as the guiding force for including (or omitting) specific nutrient input and loss terms (e.g., nitrogen fixation, denitrification, P solubilization and precipitation) in numerical models capturing processes essential for describing, quantifying and assessing ecosystem material fluxes, productivity and species composition.

 

                The monitoring program on which process research, modeling and synthesis rely, should best incorporate spatial and temporal scales capable of capturing both episodic (i.e., hurricanes, floods) and chronic (drought) events.  Such events are key determinants of phytoplankton bloom initiation, maintenance and control.

 

                It would help immensely if a conceptual model could be constructed that articulates the integrative roles physical, chemical and biotic processes (that have all been identified individually) play in the establishment, maintenance and control of phytoplankton (and benthic microalgal) blooms in the Bay.  This should serve as a guide for identifying (in a hierarchical fashion) controlling environmental factors.  It should also identify where and how these factors should be incorporated in hydrodynamic, and water quality models.  This effort will require a “hero”, that is an individual or small group of individuals who can foster the development of a multidisciplinary conceptual framework, identify informational gaps, integrate with and complement modeling efforts, and create the essential informational exchange between researchers, managers and the FBSOP.

 

CENTRAL QUESTION #4:  What are the causes and mechanisms for the observed changes in the seagrass community of Florida Bay? What is the effect of changing salinity, light, and nutrient regimes on these communities?

 

Seagrasses are clearly the dominant biological feature of Florida Bay.  Of the more than 10,000 samples (0.25 m²) taken in the Bay during 1995 to 1997, approximately 97% contained seagrass.  In addition, the entire South Florida coastal zone, including the area within the Florida Keys National Marine Sanctuary, is dominated by seagrass habitats.  Therefore, the findings of the seagrass researchers have special significance and are of central importance to the overall scientific enterprise in south Florida coastal environments.

 

New results relevant to seagrass communities were presented at the 1999 Science Conference.  These included the documentation of continuing change in Florida Bay seagrass communities, significant progress in statistical modeling of the relationships between physico-chemical variables and seagrass parameters, and important progress in testing the main hypotheses proposed to explain seagrass die-off.  With respect to seagrass species composition and abundance, seagrass cover has continued to increase during the past several years, although turtlegrass has shown little net change and most of the increase has resulted from expanding coverage by shoalgrass (Durako et al., Zieman et al., Anonymous 1999).  Thus, the dominance of turtlegrass is declining as mixed turtlegrass and shoalgrass stands become more common.  While the increases in seagrass cover are encouraging in some ways, as they may reflect improvements in water quality, shifts from turtlegrass to shoalgrass often are associated with declining light availability, as is the appearance of the recently observed star grass.  Fortunately, the manner in which light fields may be changing in Florida Bay can be evaluated soon, when data from the recently initiated light monitoring efforts (a result of recommendations from the 1998 Seagrass Modeling Workshop) are available.  In addition, a recent die-off has been discovered north of Barnes Key, which has characteristics very similar to those observed during the initial seagrass die-off in 1987.  Seagrass loss has also been reported in Madeira Bay.  These recent observations of seagrass die-off led to the organization of a pre-Conference field trip to the Barnes Key site, and an ad hoc workshop, which produced a plan for an important series of observations and experiments to test several of the remaining hypotheses that might explain seagrass die-off (see below).

 

Reports on the potential links between elevated sediment sulfide concentrations and seagrass mortality (an hypothesis long proposed to account for seagrass die-off) have been further explored by Carlson et al. (Anonymous 1999), who presented a conceptual model that posits a series of events and processes that could initiate sulfide toxicity.  Other data from laboratory experiments presented by Koch et al. (Anonymous 1999) and Erskine and Koch (Anonymous 1999) suggest a more limited role for sulfide in producing significant seagrass mortality, even at highly elevated concentrations.  As noted below, a series of additional laboratory studies and fieldwork is planned to help understand how sulfide concentrations may influence seagrass growth and abundance and clear up uncertainties between the two conflicting sets of results.

 

Statistical modeling has been commissioned by the Restudy consistent with the recommendations from the 1998 Seagrass Modeling Workshop (Fourqurean et al., Anonymous 1999).  The goal of this work is to seek relationships between water quality variables and seagrass species composition and abundance, which if sufficiently strong, can be used to predict the effects of various alterations in Florida Bay salinity regimes.  To date the best models developed explain more than 50% of the variance in seagrass community parameters.  While it is essential to improve the accuracy of the models, continued refinement holds promise for producing models that can be use to describe the type of seagrass assemblages expected under a variety of salinity and water quality regimes.

 

In addition, other modeling efforts are proposed.  These include both seagrass unit models and landscape models.

 

While not part of the seagrass research program, the paleoecological investigations (e.g., Orem et al., Dryer et al., and Cronin et al.) continue to add highly relevant information for the understanding of how recent seagrass changes fit into the matrix of historical expansion and contractions of seagrass cover.  At present it appears that seagrass coverage, as estimated both by the abundance of seagrass-associated microfossils and by chemical signatures in the sediments, has shown repeated cycles of expansion and contraction.  Thus, the recent changes in seagrass cover apparently are not unprecedented.  However, as noted previously, the paleoecological data come from only a few selected locations, limiting the confidence that can be placed in their general applicability.  Therefore, it would be extremely valuable to have additional paleoecological information from more sites throughout the bay.

 

The mesocosm studies (Chesnes et al., Montague et al., Anonymous 1999) have recently begun to produce data on how fluctuating salinities may affect turtlegrass, shoalgrass and widgeon grass.  Unfortunately, operational difficulties continue to plague the mesocosm facility, which have slowed progress and resulted in problems with maintaining proper controls.  There are plans for future studies that will investigate salinity x light interactions.  However, it still is not possible to test how hypersalinity might affect seagrass growth and survival.  There still remains a need to do this, as it is one of the remaining hypotheses that could explain the initial 1987 large-scale seagrasss die-off.

 

Investigations of Labyrinthula occurrence continue, and conceptual models of how Labyrinthula infection might originate and be transmitted as well as interactions with environmental stresses are now clearly developed.  What remains to be done is an experimental assessment of how Labyrinthula might affect turtlegrass shoot density and biomass.  This has been a need that was recognized in the FBSOP report on the 1998 Science Conference.  The recently observed seagrass die-off provides an opportunity to do the critical experiment that will test the Labyrinthula hypothesis.  We emphasize that this work must be done before a clear answer to the importance of Labyrinthula as an agent of seagrass mortality can be obtained.  As noted below, it now appears that the work will be done, as a result of the findings of the ad hoc seagrass workshop convened during the 1999 Science Conference.

 

This ad hoc workshop, organized by the Seagrass Team Leaders to evaluate proper responses to the 1999 die-off in the Barnes Key area, resulted in recommendations for a rapid mobilization to map the extent of the die-off, including both the western Bay in the vicinity of Barnes Key, as well as the northeastern bay, another area where die-offs have recently been reported.  In addition, a monitoring program was also designed, with detailed plans for implementation.  Perhaps most importantly, plans were developed to determine experimentally whether Labyrinthula infection influences seagrass growth and biomass.  Plans have also been made to experimentally investigate the hypothesis that hypersaline water may lead to elevated and toxic sulfide concentrations in the sediments, which could ultimately to seagrass die-off.  It is critical that adequate funding be made available, so that this work can be carried out while active die-off is occurring.

 

Finally, the Seagrass Team Leaders and investigators should be commended for their initiative in organizing the ad hoc workshop, and successfully developing a plan to critically evaluate the most likely factors that may initiate seagrass die-off.  In addition, a general increase in the planned use of experiments by investigators is a welcome development that will add rigor to the science being done, and one that has been needed for some time.  It is also noteworthy that the resources to initiate additional light measurements and to begin modeling efforts have been made available by the funding agencies.  It is, therefore, quite clear that during the past year steady progress in answering the major unresolved questions about the causes of seagrass die-off has been made, and that a clear plan for the next phase of research efforts is in place.

 

CENTRAL QUESTION #5:  What is the relationship between environmental and habitat change and the recruitment, growth and survivorship of animals in Florida Bay?

 

The higher trophic level group has made progress on an overall conceptual model in the past two years.  They have developed a very general framework illustrated that includes direct, indirect, and habitat changes on the broad community and they have identified several components of the myriad of species in the bay for focused work.  This is reflected in the general food web diagram and the ‘DeAngelis” diagram which illustrates the importance of ontogenetic change and habitat use.  They have begun to think about what physical forcing functions and data field they need from the modelers to project change in biotic components.  They have also begun some work directed at process level information, exemplified by the pink shrimp and zooplankton work, that will be useful for making predictions.  The higher trophic level team has also made progress in understanding certain specific components of the resources.  In addition, one-on-one conversations with Nancy Thompson indicate that the background work done to develop the conceptual model has been useful for the Florida Keys Carrying Capacity Project on defining critical species, communities, and habitats.  The team is obviously having an impact on management analyses for several components of the overall south Florida Program and managers who direct research funding should recognize the importance of this program to several broad scale projects.

 

The work on higher trophic levels will continue to benefit from frequently held, externally reviewed, workshops.  The first of these workshops helped focus the program on developing a conceptual model and was followed by internal agency working group meetings to develop the model.  Nancy Thompson indicates that consensus building by the team and then consensus building on the PMC took time.  The simplified food web and “DeAngelis” diagram are very good starts but need additional and stronger scientific leadership to coalesce on research objectives and development of management tools.  Development of the program seems lethargic and still lacks a firmly directed conceptual model and driving objectives.  They have not discussed a bioenergetics model or any other concept by which to organize the research and then develop the management tools.  Given the number of species subsumed by the designation ‘higher trophic level’, this effort will require an individual or small group of individuals who can foster the development of a multidisciplinary conceptual framework, identify informational gaps, integrate with and complement modeling efforts, and create the essential informational exchange between researchers, managers and the FBSOP.  Providing financial support for this component of the work should recognize the importance of this person or persons.  Support for external reviewers will be critical to maximizing the benefit of the workshops in bringing new perspectives and a broader array of researchers to these problems.

 

The works presented by Johnson and Ekland (Anonymous 1999) relating fish abundance to salinity and temperature are very appropriate first steps in synthesizing broad-based information on higher trophic levels.  This kind of work was identified by the Oversight Panel as a priority three years ago and should allow simple extrapolation of broad scale changes in the fish community in response to a changing physical environment and development of testable hypotheses.  Although correlations of the fish community with the underlying habitat (e.g., seagrass community type and structure or mud bottom) was not mentioned as part of the analysis objectives, the FBSOP assumes that the researchers recognize the importance of the ‘habitat’ as a predictive factor.

 

Longer-term work, however, needs to be based on mechanistic understanding of the ecosystem and organisms.  Future species level work needs to be modeled after the examples of the spiny lobster and spoonbill work.  Both of these projects are based on an excellent understanding of the natural history of the resource, are spatially integrated and can approach with great credibility predictions of bay-wide impacts on populations.  The FBSOP has repeatedly pointed to the focus and elegance of the spiny lobster effort as exemplary work that allows research focused on the needs of a specific organism to be linked to larger scale ecosystem change.

 

The work on the wading birds also provides an excellent opportunity for linking the natural history information to broader ecosystem change by modeling.  This project demonstrated an excellent understanding of freshwater impacts on NE colonies and crashes, as well as longer-term trend in numbers.  Lorenz showed convincing ad hoc linkage of wetland loss and land use development on the Keys to the crash of colonies and migration of colonies or individuals to the northwestern areas of the Bay.  This project seems to have reached the limit of extrapolation and use in management decisions because of a lack of information on predicted hydroperiod and simulation of re-plumbing impacts.  The next step is to make explicite the links between hydroperiod, forage fish in the wetlands, bird feeding, and management decisions.  This is a project that should be used as a pattern for other projects intended to describe state of the resources and to link changes to land use and management activities.

 

                These types of single species studies were complemented by some very nice work focused on evaluating broad changes in food webs.  This was illustrated by the work presented by Chasar (Anonymous 1999) who used C and N stable isotopes to look for changes in food resources supporting benthic and pelagic consumers.  This work was well framed within the larger conceptual framework and provided a clear testable hypothesis.

 

Unfortunately, even the general conceptual model did not seem to be well integrated into some of the presentations.  Some presentations were data rich, but not presented in context with testable hypothesis or management criteria to explain the reason for the sampling.  The presentation by Settle was particularly disappointing, as it seemed to present a smattering of studies with no clear focus or clear link to the over arching question.  What links all of these studies together?

 

The current emphasis is too focused on measurement of standing stocks and unidirectional response of the biotic community to change in physical forcing functions, with little work considering the ecological function of organisms.  This is particularly disappointing given the existing general knowledge of the importance of animals in structuring seagrass systems.  For example, work at this conference demonstrated that phytoplankton blooms in this shallow system are in part dependent on benthic physical-chemical (i.e., nutrient release) and biotic (benthic algae as “seed stocks” to the water column, and as sources of grazing) conditions, making it essential to functionally couple sediment with water column processes.  Sediment resuspension, bottom-water redox gradients, infaunal grazing, and competition for nutrients with benthic microalgal communities are all likely to play regulatory roles in phytoplankton bloom development and maintenance.  These interactions must be more explicitly integrated in process and modeling assessments of the Bay’s response to changing hydrodynamic and nutrient conditions (both naturally- and anthropogenically-driven).

 

There is very little information on the infauna and epifauna community in the benthic environment.  These small animals can be important grazers on seagrass epiphytes and benthic algae and are also the food for the fish species taken in the commercial and recreational fisheries.  Perhaps the decline in seagrass is a simple response to the loss of a benthic grazer caused by salinity fluctuations.  The only work in this area is the work on the mollusk community by Lyons (Anonymous 1999).  While this has been a useful and comprehensive study, it was limited in its taxonomic scope.  These samples still exist and if the other taxonomic groups were identified and counted, this survey would provide a baseline for the development of testable hypotheses.

 

The FBSOP strongly recommends that an open solicitation for process work on benthic-organisms be highlighted in the next funding cycle.  The sophistication of the understanding of water column organisms and processes far exceeds the understanding of the benthos.  This imbalance is striking in an ecosystem that is a little over 1 m deep, dominated by seagrass and in which there are likely strong links between the benthos and the water column.  The level of understanding of zooplankton has reached the level of understanding sufficient for the needs of the program and it is time to bring the understanding of the benthic component up to an equivalent level.  For example, a first cut at estimating benthic fauna grazing rates could be done by linking the abundance and distribution of molluscan fauna done by Bill Lyons with general estimates of mollusk filtering rates derived from existing literature.

 

The level of funding given to higher trophic levels, such as fish, does not seem to be proportional to the public and management interest in these as performance measures.  There also seems to be some continuing problems with funding for studies that have been identified as central to understanding higher trophic levels in Florida Bay.  Some of the work is not funded as part of a strategic work plan targeted at the Florida Bay, but is being funded by other programs which are independent of Florida Bay needs.  A case in point is the work on spiny lobster presented by Butler that the FBSOP has consistently identified as a powerful approach.  In one case, work identified as central by previous FBSOP reviews is being funded by end of the year surplus monies.  Without that accident of timing, the work would not be occurring.  It was also difficult to tell what research was funded and what was proposed but not active.  For example, the work estimating growth rates of young sea trout using otoliths was given as an example of process oriented work, yet it does not seem to have progressed beyond what was presented last year.  Subsequent discussions with individuals indicated that for a variety of reasons, this was not actually an ‘active’ research project.

 

REFERENCES

 

Anonymous.  1999.  Florida Bay and Adjacent Marine Systems Science Conference: Program and Abstracts, Florida Bay Program Management Committee, Key Largo, FL.

Armentano, T. V., M. Robblee, P. Ortner, N. Thompson, D. Rudnick, J. Hunt. 1994. Science plan for Florida Bay: a science planning document provided to the Interagency Working Group on Florida Bay.

Armentano, T., J. Hunt, D. Rudnick, N. Thompson, P. Ortner, M. Robblee, R. Halley. 1997. Strategic plan for the Interagency Florida Bay Science Program. Prepared by the Florida Bay Program Management Committee.

Boesch, D. F., N. E. Armstrong, C. F. D’Elia, N. G. Maynard, H. W. Paerl, S. L. Williams. 1993. Deterioration of the Florida Bay Ecosystem: an Evaluation of the Scientific Evidence, Report to the Interagency Working Group on Florida Bay.

Boesch, D. F., N. E. Armstrong, J. E. Cloern, L. A. Deegan, R. D. Perkins, S. L. Williams. 1995. Report of the Florida Bay Science Review Panel on Florida Bay Science Conference: A Report by Principal Investigators, Report to the Program Management Committee, Florida Bay Research Program.

Boesch, D. F., N. E. Armstrong, J. E. Cloern, L. A. Deegan, S. C. McCutcheon, R. D. Perkins, S. L. Williams. 1997. Annual Report of the Florida Bay Science Oversight Panel: Perspectives from the 1996 Florida Bay Science Conference and Review of the Strategic Plan, Report to the Program Management Committee, Interagency Florida Bay Science Program.

Boesch, D. F., W. C. Boicourt, K. L. Heck, Jr., J. E. Hobbie, S. C. McCutcheon, J. D. Milliman. 1998. Annual Report of the Florida Bay Science Oversight Panel: Perspectives from the 1996 Florida Bay Science Conference, Report to the Program Management Committee, Interagency Florida Bay Science Program.

Brewster-Wingard, G. L., S. E. Ishman. 1999. Historical trends in salinity and substrate in central Florida Bay: a paleoecological reconstruction using modern analogue data, Estuaries, 22(2B), 358-368.

Brock, R. J., ed. 1999. State of the Bay: The Condition of Florida Bay in 1998, draft report.

Halley, R. B., L. M. Roulier. 1999. Reconstructing the history of eastern and central Florida Bay using mollusk-shell isotope records. Estuaries, 22(2B), 369-383.

Nature Conservancy. 2000. Florida Bay’s Murky Past, Florida Bay Watch, newsletter in draft.

Nelsen, T. A., G. Garte, C. Featherstone, P. Blackwelder, T. Hood, C. Alvarez-Zarikian, P. Swart, H. Wandless, J. Tefry, S. Metz, W. J. Kang, L. Tedesco, M. A. Capps, M. A. O’Neal. 1999. Paleo-Salinity Changes in the Lower Everglades and Florida Bay Ecosystems, NOAA COP/SFERPM, Atlantic Oceanographic and Meteorological Laboratories, Miami, FL.

Rudnick, D. T. 1999. Narrative for a Florida Bay Conceptual Model, draft.

Swart, P. K., G. Healy, L. Greer, M. Lutz, M. Saied, D. Anderegg, R. E. Dodge, D. Rudnick. 1999. The use of proxy chemical records in coral skeletons to ascertain past environmental conditions in Florida Bay, Estuaries, 22(2B), 384-397.

U.S. Army Waterways Experiment Station.  1995.  A comprehensive surface and groundwater hydrologic modeling system for evaluating the impacts of the C-111 Canal on regional water resources, work plan for the Jacksonville District of the Corps of Engineers.