Explore Magazine Volume 6 Issue 1


UF Scientists Are Helping To Ensure That Everglades Restoration Achieves Its Goals


       On December 12, 2000, then-President Bill Clinton signed a bill authorizing the first stage of a $7.8 billion, 30-year restoration of the Florida Everglades. Simultaneously, hundreds of scientists were gathered in Naples, on the Everglades’ western edge, to discuss ways to ensure the restoration works.
      “Science was used as the tool to sell to the public as well as the Florida Legislature and Congress that the Comprehensive Everglades Restoration Plan (CERP) would actually work,” conference chairman G. Ronnie Best told scientists assembled for the Greater Everglades Ecosystem Restoration (GEER) Conference. “CERP is strongly built on science, but CERP is only a blueprint, a ‘concept,’ a bunch of good ideas put down on paper. It will require much research and development to ensure that CERP is implemented and built in such a way that it will, in fact, work.”
      Among this largest assembly of scientists ever gathered to discuss the Everglades were dozens of University of Florida faculty, students and alumni providing expertise on everything from alligator habitat to soil chemistry.
      One of the leaders of the UF research effort is Frank Mazzotti, director of the Center for Natural Resources – South Florida and the man responsible for promoting the university’s role in Everglades research.
      “UF’s Institute of Food and Agricultural Sciences has a traditional role in making agriculture environmentally responsible,” says Mazzotti. “Now IFAS has a new responsibility to do comprehensive natural resources planning.”
      In the Everglades, that means defining the success of the restoration effort.
     “Science can help us define success, measure success and ensure that we get the most out of restoration for the most reasonable cost,” says Best, former director of UF’s Center for Wetlands and now chief of the Restoration Ecology Branch of the USGS’ Florida Caribbean Science Center. “CERP is a dream, science can make it a reality.”
     The UF presence at the GEER Conference was impressive, as much for the breadth of its expertise as for the size of the contingent.
      “The University of Florida is definitely a player,” says H. Franklin Percival, courtesy associate professor of wildlife ecology and conservation and leader of the Florida Cooperative Fish and Wildlife Research Unit headquartered at UF. “Beyond the obvious associations of the faculty and graduate students making presentations are many more indirect ones, like people who have gotten their PhDs at UF and then gone on to positions of influence with state and federal agencies.”
      Like CERP itself, UF Everglades research falls into several general categories: water quality assessment, plant and animal population studies and public policy issues. In each of these areas, UF faculty and graduate students are engaged in research to determine the potential impacts, positive and negative, of the proposed restoration project.

Get The Water Right
      “Water is the lifeblood of the South Florida ecosystem,” according to CERP, but over the last 70 years water flowing through the Everglades has been reduced to a third of its historic volume and the quality has been seriously degraded. So the first goal of the restoration plan is “Get The Water Right.”
      Ramesh Reddy, graduate research professor and chair of UF’s soil and water science department, likens his team’s research in the Everglades to a doctor diagnosing an illness and suggesting a treatment.
      “When you get sick, the first thing the doctor does is take your temperature, then he might do a blood test and then a CAT scan,” Reddy says. “That’s a lot like what we’re doing with the Everglades. We’re looking at the soil and water at progressively more detailed levels.”
      Specifically they’re looking at phosphorus, the nutrient many believe is responsible for cattails driving out sawgrass and algae clogging once-open water in the Everglades. Unlike carbon and nitrogen, phosphorous is not easily released back into the atmosphere through chemical and biological reactions, so it accumulates in soils, in microbes and in vegetation.
      For the past 15 years, UF researchers have sampled phosphorous levels at more than 60 sites throughout Water Conservation Area (WCA) 2A, just south of the Everglades Agricultural Area. A recent study led by soil and water science Assistant Professor Bill DeBusk found that the area of WCA-2A considered “phosphorous enriched” had increased from 20,829 hectares (48 percent of the total area) in 1990 to 31,777 hectares (73 percent of the total area) in 1998.
      “If you compare the water coming in from the agricultural areas with water quality just about anywhere else in the world, it’s pretty clean,” Reddy says. “But the Everglades ecosystem is so pristine that just a small spike in phosphorus can cause changes in biological communities.”
      Reddy says the research results indicate that a phosphorus- enrichment “front” is progressing into the relatively unimpacted interior sawgrass marsh of WCA-2A, bringing with it cattails and other, non-native, species.
      “In many areas of the world cattails do a terrific job of helping to clean up water,” he says, “but in this ecosystem cattails are not good. They create an entirely different habitat.”
      Having taken the ecosystem’s “temperature,” Reddy and his colleagues are now doing the “blood test” by looking more closely at the complex relationships among carbon, nitrogen and phosphorus in the water and soil. Their goal is not only to understand the chemical processes taking place but to develop techniques that will allow them to more quickly and easily gather information from a large number of sites.
      “If you add phosphorus to a phosphorous-limited system, it accumulates in the plants and the microbes,” Reddy says. “As those plants and microbes die and decompose, they not only release phosphorus back into the system but also release nitrogen, which is really what promotes plant growth.”
      To better understand this process, the researchers are growing microbes collected from WCA-2A in the laboratory and measuring the amount of carbon dioxide, nitrogen, phosphorus and other chemicals they release.
      And the group is preparing to begin the “CAT scan” through a new $847,000 grant from the National Science Foundation to conduct molecular-level research on bacterial communities in the Everglades. Soil and water science Assistant Professor Andy Ogram is leading this effort to better understand their genetic makeup and diversity.
      “The results of this research could provide an early warning system to disruptions in the ecosystem,” Reddy says, “and they could also offer a way of measuring the success of the recovery.”
      Finally, Reddy says, his group is working to translate the baseline data they are gathering about the chemical composition of the Everglades ecosystem into a format that can be incorporated into restoration models.
      “We’re trying to develop a fundamental understanding of what’s happening in the system and then translate that data into a form that managers can use,” Reddy says.

Alligator ATLSS
      Percival has been studying alligators for 20 years, but only in the last decade has that research focused on the Everglades, despite the giant reptile’s prominent position in Everglades lore.
      “You would think that we would know more about an animal with so much mystique surrounding it,” says Percival, “but until fairly recently not much was known about the alligator.”
      Most of what was known was about alligators in northern Florida, where commercial farming provided financial incentive to better understand the living, and breeding, characteristics of the alligator.
      “Most of the funding sources for alligator research were commercial farmers,” Percival says. “You couldn’t ranch alligators in Everglades National Park so there wasn’t too much interest in funding research there.”
      Even less was known about the American crocodile. Population growth in southeast Florida had reduced the crocodile’s historic habitat to just a small area of northeastern Florida Bay and northern Key Largo by the 1970s.
         That all began to change after the two mighty reptiles were protected as endangered species, the alligator in 1967 and the crocodile in 1975. Interest in alligator and crocodile research accelerated with plans in the 1990s to restore the Everglades.
      In particular, restoration planners needed real data for the simulation model known as ATLSS that they were using to test different scenarios.
      The Everglades restoration project is arguably the largest “experiment” ever undertaken. Typically, scientists conduct an experiment, observe the results, then report those results. But the complexity and duration of this project have forced a new, more predictive approach.
      “Clearly we cannot wait until all the data have been collected, for instead of gaining the knowledge needed to save the Everglades, we will have documented its death,” Mazzotti says.
      Enter ATLSS, the Across Trophic Level System Simulation. Designed to predict how different water management strategies will impact the Everglades ecosystem, ATLSS has been adopted by federal, state and tribal authorities as the primary tool for assessing the ecological effects of different scenarios.
      Much of the Everglades research currently under way is aimed at gathering baseline data about the ecosystem or writing programs to incorporate that data into ATLSS.
      To model the impact different restoration scenarios will have on crocodilians requires real data about the animals. People like Percival, Mazzotti and UF alumni Kenneth G. Rice of the U.S. Geological Survey and Laura A. Brandt of the U.S. Fish and Wildlife Service provide these data that fuel the ATLSS simulation engine.
      “The alligator is a top-level predator and it’s a highly visible species, politically,” Percival says, “so when the ATLSS model was being developed, the alligator was one of the original species included.”
      Getting data about alligators requires an affinity for top-heavy skiffs with airplane propellers on the back and waste-deep muck where gators are one of the lesser threats. Out in this hot, humid natural laboratory, scientists and graduate students from a host of federal, state and academic agencies carry out a precision campaign to capture alligators, surgically implant tracking devices and thermometers and release them back into their “home ranges.”
      “Habitat use and thermoregulation are both closely related to hydrology,” Percival says, adding that the data from tracking and recording the body temperatures of dozens of alligators over many years indicate that changes in Everglades water conditions have caused “extreme environmental stress.”
      In addition to their work in the field, Mazzotti, Brandt and Rice are spending a lot of time in musty, old offices, leading a project to compile and compare historical data about Everglades alligators into a format that can be incorporated into ATLSS.
      “Evaluating long-term trends and developing population models require a large amount of data collected over many years and many locations,” the trio reported at the Naples conference.
      But while information on alligators has been collected in south Florida since the 1950s, only the most recent is available in a centralized, easily accessible database.
      So, with the help of a legion of graduate students, the researchers have taken on the Herculean task of compiling yellowing paper, punch cards, magnetic tape and floppy disks from a host of different federal, state and local agencies and inputting it into a modern database.
      “This study allows access to historical data required for ecological modeling and assessment of current and future status of alligator populations that would be otherwise inaccessible,” the researchers say.
      Even as alligator data are being crunched, people like Daniel H. Slone, a postdoctoral research associate in UF’s entomology and nematology department, are developing ATLSS layers that will be able to employ those data to estimate alligator populations in the Everglades under different proposed water management scenarios.
      Slone is developing an ATLSS module that employs mathematical equations to estimate the density of eggs, hatchlings, juveniles and adult alligators in 500-square-meter tracts of a 3,000-square-kilometer section of the Everglades. This information is married to maps of land elevation, habitat types and daily water levels to determine growth, reproduction and survival rates.

Wading Birds
      Peter Frederick often has a hard time explaining how he counts wading birds in the Everglades. Ecologists typically estimate the population of a species in an area by sampling randomly chosen sections and extrapolating the results to the entire area. But not Frederick.“We count them all,” says Frederick, an assistant professor of wildlife ecology. “We have a 100-percent sample.”
      Over the last 15 years, Frederick, his graduate students and technicians have logged thousands of hours in a small plane skimming at 800 feet over a 1,300-square-mile area of the central Everglades where virtually all of the wading birds congregate, spotting and photographing the colonies. They also have spent thousands more hours airboating and wading through shallow, alligator-infested waters to verify their aerial estimates.
      The researchers spend about 2.5 days per month between January and July conducting aerial surveys and another two months per year on the ground and in the water. The $250,000 annual cost is supported by a grant from the U.S. Department of the Interior through the U.S. Army Corps of Engineers.
The result, Frederick says, is one of the most comprehensive surveys ever done for any animal living in the Everglades, and one of the most revealing.

        “The movement of birds from the southwest coastal region around what is now Naples to the inland water conservation areas provides some of the most obvious evidence of coastal degradation,” Frederick says, noting that surveys conducted by the Audubon Society in the 1930s showed virtually all of the wading birds living along the southwest coast. “Today, almost all of the wading birds are in the water conservation areas because the coastal areas have been almost totally dewatered.”
      Frederick says his team has found several “ecological surprises” during its 15 years studying the Everglades wading birds — some bad and some good.
      “Up until about two years ago, our research indicated there were not enough breeding birds in the Everglades to maintain the populations,” Frederick says. “There were a lot more birds just wandering around eating than there were breeding.”
      Beginning in 1998, however, the researchers started noticing a dramatic increase in the number of nests, and while it’s too early to say for sure if this trend will continue, Frederick has a hypothesis about the cause that makes him optimistic.
      “There’s no question that conditions have been very good over the last two years,” he says. “But another possible reason for more birds deciding to breed is a dramatic drop in mercury levels in the Everglades.”
      Since 1994, in a study sponsored by the Florida Department of Environmental Protection, Frederick and several graduate students have monitored mercury levels in great egret chicks in the Everglades.
      As predators at the top of the food chain, great egrets are good barometers for the herons, ibises, storks and spoonbills that also live in the Everglades, Frederick says. Parents bring food to the nest from within a 15-mile radius, so chicks are ideal study subjects because the mercury they accumulate comes from the immediate area.
      Because chicks excrete mercury through their feathers, the researchers are able to harmlessly track the chicks’ mercury uptake by plucking a few feathers for analysis.
      The results surprised and pleased the researchers. The most significant: Between 1994 and this year, average mercury levels in the chicks’ feathers dropped 73 percent.
      “The decline overall has been dramatic, and it’s been occurring in the face of other environmental changes, such as dry conditions, that tend to push values up rather than down,” Frederick says.
      In 1994, the highest concentration of mercury in any of the colonies studied was 25 parts per million, while the lowest was 5 parts per million. In 2000, the highest concentration was 10 parts per million and the lowest was 2 parts per million. Normal background levels range from one-half part per million to 2 parts per million.
      The findings bode well for the egrets, which display a variety of ill effects from mercury poisoning, Frederick’s experiments show. At the average levels seen in 1994, young egrets would have fewer red blood cells, weigh less and be less interested in hunting.
      Chicks can excrete a lot of mercury through their feathers while they are growing but not when they become adults, so these problems tend to hit birds just as they reach maturity — which also is when they face the most stressful and dangerous part of their lives, learning to hunt and avoid predators.
      “We believe mercury poisoning definitely results in an increase in mortality, although we don’t know how much of an increase,” Frederick says.
      Mercury in products and industrial processes has been declining since the late 1980s, when battery manufacturers and others began eliminating the toxic metal. Also, Florida began imposing mercury-emissions limits on incinerators in the early 1990s that are just beginning to show results.
      Frederick says doctoral candidate Julie Heath has been studying a possible link between environmental contaminates like mercury and wading bird reproduction.
      “One of the things that has kept me awake nights is the fear that we will succeed in restoring the hydrology of the Everglades and the birds won’t respond because they’re so drugged up with mercury,” Frederick says. “If we find that these decreasing mercury levels lead to better reproduction, then it becomes much more likely that wading birds will be restored to the Everglades if we restore the hydrology.”

Back To Science
      In a presentation made near the end of the GEER Conference, Mazzotti returned to the theme Best articulated in his opening remarks.
      “For science to have an effective voice in environmental policy and decision making,” Mazzotti argues, “the following obstacles must be removed: lack of a comprehensive, regional land and water use plan; lack of a systematic effort to educate policy and decision makers about scientific knowledge gained from bioregional assessments; and institutional limitations.”
      In spite of overwhelming scientific data about the Everglades, Mazzotti argues, each “stakeholder,” including the various federal agencies, state and local governments, “is seeking to control information to benefit its own agenda, not restoration as a whole.”
      The inability of institutions participating in Everglades restoration to escape the limitations of their own agendas and philosophies may be a formidable barrier to ecological improvement, Mazzotti says.
Aaron Hoover contributed to this article.

Peter Frederick
Associate Professor, Department of Wildlife Ecology and Conservation
(352) 846-0565

Frank J. Mazzotti
Director, Center for Natural Resources – South Florida
(954) 577-6300

H. Franklin Percival
Courtesy Associate Professor, Department of Wildlife Ecology and Conservation
(352) 392-1861

K. Ramesh Reddy
Graduate Research Professor and Chair, Department of Soil and Water Science
(352) 392-1804 x317

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