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Research about Florida

Source-linked reports with geographic coverage including Florida.

At least 1,135 records · Page 63Linked to original sources
USGS2002

ATLSS PanTrack tool enables visualization of Florida panther movements

South Florida is home to the last remaining population of endangered Florida panthers, estimated at about 60 individuals. Panther survival is threatened by habitat loss and degradation, inbreeding, insufficient numbers of large prey, and disease. Because the few remaining panthers have been so intensively studied, a detailed database is available for individuals in the population. The monitoring of Florida panthers by radiotelemetry began with the radio-collaring of two individuals in 1981 and has expanded to include forty-one panthers - a majority of the population. More than 50,000 telemetry locations have been available over the observation period. PanTrack was originally developed to help define panther behavioral rules for the spatially explicit, individual-based ATLSS Deer/Panther model. The effectiveness of individual-based models depends on the availability of detailed observations about individuals on the landscape, and on the ability to find patterns in these observations that provide insight into key animal behaviors. The PanTrack tool can be adapted to display and analyze any location coordinates over background map layers. In addition to its application to panther monitoring, it has been used to display annual field observation data for Cape Sable seaside sparrows and telemetry observations for American alligators. It could also be used to display movements of simulated animals generated by spatially explicit, individual-based model.

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USGS2002

SIMSPAR model simulates the impact of hydrology on the Cape Sable seaside sparrow

SIMSPAR is a spatially-explicit, individual-based model designed as a management and evaluation tool for the Cape Sable seaside sparrow ( Ammodramus maritimus mirabilis ), an endangered subspecies of seaside sparrow that lives exclusively in the southern Everglades. The model is designed to simulate how changes in hydrology across the nesting area of the sparrow is likely to affect the reproductive success and, therefore, the population viability of the Cape Sable sparrow. SIMSPAR has been developed at the University of Tennessee under the USGS's Across Trophic Level System Simulation (ATLSS) Program.

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USGS2002

Modeling Fish Population and Biomass on the Everglades Landscape (ALFISH)

ALFISH is a model created under the Across Trophic Level System Simulation (ATLSS) Program of the U.S. Geological Survey (USGS). Its purpose is to describe fish functional groups in freshwater marshes of the greater Everglades area of southern Florida. In particular, it is intended to assess the spatial pattern of fish densities through time across freshwater marshes. This model has the capability of providing a dynamic measure of the spatially explicit food resources available to wading birds. ALFISH simulates two functional groups - large and small fish - where the larger fish can prey on the smaller fish. Both functional groups are size-structured. The marsh landscape is modeled as 500-m x 500-m spatial cells on a grid across southern Florida. The ATLSS High Resolution Hydrology model is used to provide water levels in the spatial cells on 5-day intervals. Fish populations spread across the marsh during flooded conditions and either retreat into refugia (alligator ponds), move to other spatial cells, or die if their cell dries out. ALFISH has been applied to the evaluation of alternative water regulation scenarios under the Central and South Florida Comprehensive Project Review Study. The objective of this Review Study has been to compare alternative methods for restoring historical ecological conditions in southern Florida. ALFISH has provided information on which hydrological scenarios are most likely to increase fish biomass and its availability to wading bird populations. The model also provides the opportunity for stakeholders with interests in particular subregions of the landscape to contrast the effects of alternative hydrologic plans on the availability of fish biomass in these subregions. As a demographic model, ALFISH also keeps track of the history of the effects of dry, normal, and wet hydrologic conditions on fish population size structure.

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USGS2002

Influence of hydrology on life-history parameters of common freshwater fishes from southern Florida

Fishes are essential to the successful functioning of wetland food webs in southern Florida through their roles as prey and predators. Any changes that reduce the population sizes, community composition, or availability of aquatic animals will affect all facets of the ecology of these wetlands. In particular, small and medium-size fishes are important food items for most wading bird species. For this reason, fishes have been recognized by the multi-agency groups responsible for guiding the Everglades restoration process as a key indicator group by which to measure restoration success. Despite the importance of fish for management, gaps in baseline knowledge remain. Basic demographic information, termed life-history parameters, is needed to make predictions about their resilience under alternative management scenarios. These parameters include growth rate, age at maturation, fecundity and life expectancy. However, basic life-history parameters remain to be characterized, even for abundant fish species. Adding to the challenge, life-history characteristics of important Everglades species are known to be plastic in response to environmental conditions and survivorship and recruitment schedules are certain to be influenced by variation in hydroperiod. We intend to study the effect of hydroperiod on recruitment, size/age structure, growth, and fecundity, which, in turn, determine fish population dynamics. At present, data on fish reproduction, age and growth, and other life history characteristics are confined to a few species from a limited area of long-hydroperiod marsh in central Shark River Slough. As we continue the analysis and synthesis of data from the long-term fish collections, life-history information will help explain patterns of fluctuations in the time series. Accurate life-history data are also very important in building credible simulation models like ATLSS. Without empirical life-history data from a range of environments, the model will be simplistic and inadequate.

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USGS2002

Compilation of American alligator data sets in south Florida for restoration needs

Evaluating long-term trends and developing population models requires a large amount of data collected over a number of years at a number of locations. Information on alligator densities, nesting and growth have been collected in south Florida since the 1950s by rangers and researchers in Everglades National Park (ENP) and Big Cypress National Preserve (BCNP), Florida Fish and Wildlife Conservation Commission personnel, University researchers, and private consultants. Many of the most critical data sets (those having the largest amount of data or those from particular areas or years) are not accessible for use in evaluating restoration alternatives or developing models. The data are not available in a centralized, easily accessible, welldocumented database. Further, the size and scope of these data sets are not fully known. Thousands of individual records need to be evaluated, compiled, and entered into an appropriate database. It is critical that these data sets are accessible to establish restoration targets for alligator populations, develop models, and design short and long-term monitoring tools for evaluating restoration success. Historical data is used to make assessments of populations in relation to restoration and water management practices in the Everglades. Most life history characteristics are difficult to use to assess restoration progress, because decades of data are required. Condition, on the other hand, can be calculated in a relatively simple manner. Condition can be defined as the "relative fatness of [an animal]....it is a measure of how well that animal is coping with its environment" (Taylor 1979). This definition is the key to using alligators as indicators of the health of their environment. Other parameters can be used to assess the health of a population (nesting effort, growth rate and survival, and density), but require much more data.

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USGS2002

Flow-velocity, water-temperature and conductivity data collected in Shark River Slough, Everglades National Park, during 1999-2000 and 2000-2001 wet seasons

A project within the U. S. Geological Survey Place- Based Studies Program is focused on investigation of ?Forcing Effects on Flow Structure in Vegetated Wetlands of the Everglades.? Data-collection efforts conducted within this project at three locations in Shark River Slough, Everglades National Park, during the 1999-2000 and 2000-2001 wet seasons are described in this report. Techniques for collecting and processing the data and summaries of daily mean flowvelocity, water-temperature, and conductivity data are presented. The quality-checked and edited data have been compiled and stored on the USGS South Florida Information Access website.

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USGS2002

Migration of wood-preserving chemicals in contaminated groundwater in a sand aquifer at Pensacola, Florida

Operation of a wood-preserving facility for nearly 80 years at Pensacola, FL, contaminated the near-surface groundwater with creosote and pentachlorophenol. The major source of aquifer contamination was unlined surface impoundments that were in direct hydraulic contact with the groundwater. Episodes of overtopping the impoundments and overland flow of treatment liquor and waste were also significant to the migration and contamination of the groundwater. Solutes contaminating the ground-water are mainly naphthalene and substituted phenols. Sorption did not influence retardation of solutes in transport in the groundwater. Phenol and the mono substituted methylphenols appear to be undergoing bio-transformation. Pentachlorophenol (PCP) was not found in significant concentrations in the groundwater possibly because the solubility of PCP is approximately 5 mg/L at pH 6, near the average acidity for the groundwater.

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USGS2002

Helicopter electromagnetic data from Everglades National Park and surrounding areas, Florida: Collected 9-14 December 1994

This report describes helicopter electromagnetic (HEM) data that were collected over portion of Everglades National Park and surrounding areas in south Florida. The survey was flown 9-14 December 1994. The original data set processed by the contractor, Dighem, are provided as an ASCII, xyz flight-line file. Apparent resistivity grids of the generated from the original data set and JPEG images of these grids are also provided. The data have been corrected by the U.S. Geological Survey to remove the effects of calibration errors and bird-height uncertainty. The corrected data set is included in this report as flight-line data only.

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USGS2002

The road to flamingo: An evaluation of flow pattern alterations and salinity intrusion in the lower glades, Everglades National Park

Introduction This report describes the history of roads through the Lower Glades of Everglades National Park, Florida and their influence on salinity intrusion. The chronology that lead to this work is interesting. The U.S. Geological Survey flew a series of helicopter electromagnetic surveys over portions of Everglades National Park to map saltwater intrusion starting in 1994 (Fitterman et al., 1995; Fitterman, 1996; Fitterman and Deszcz-Pan, 1998, 2002). These surveys identified variations in the electrical resistivity that were associated with changes in ground-water quality. The patterns of ground-water quality have been traced to natural saltwater intrusion, such as the effect of tidal rivers on lowering hydrologic heads far inland, and the influence of man-made structures, such as canals and roadways on surface water flow. These latter effects are of interest as they represent variations from the natural state of affairs in the park. Previous investigations had been done by Everglades National Park staff on the influence of some roads and canals on the near surface hydrology. This information was scattered through a number of National Park Service publications. In an effort to bring these materials together in an easily located reference, along with new data on flows through culverts beneath the main park road, this report was written.

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USGS2002

Wading birds as bioindicators of mercury contamination in Florida, USA: Annual and geographic variation

Mercury contamination in wetland biota is often dynamic, difficult to predict, and costly to track. In this paper, we present results from a six-year study of growing feathers of piscivorous birds as monitors of wetland Hg exposure in Florida, USA, wetlands. Between 1994 and 2000, we collected feathers of growing great egret ( Ardea alba ) nestlings from colonies in the freshwater Everglades of southern Florida, and during 1998, feathers were collected from chicks of both great egrets and white ibises ( Eudocimus albus ) at a variety of colonies throughout peninsular Florida. Coastal colonies showed significantly lower feather Hg concentrations than did inland sites. Within the Everglades, we found significant effects of both geographic location and year on age-adjusted mean total Hg concentrations in feathers. Over the course of our study, Everglades colonies maintained their Hg concentration rankings relative to one another, but all showed strongly declining Hg concentrations (mean of 73% averaged across colonies, between 1994 and 2000). Using a previously established predictive relationship between Hg consumption in food and feather Hg for great egrets, we estimated that Hg concentrations in the aggregate diet of egrets have been reduced by an average of 67%. We conclude that the Everglades has undergone a biologically significant decline in Hg availability in the wetland food web, possibly because of decreased local inputs.

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USGS2002

Effects of a coastal golf complex on water quality, periphyton, and seagrass

The objective of this study was to provide baseline information on the effects of a golf course complex on water quality, colonized periphyton, and seagrass meadows in adjacent freshwater, near-coastal, and wetland areas. The chemical and biological impacts of the recreational facility, which uses reclaimed municipal wastewater for irrigation, were limited usually to near-field areas and decreased seaward during the 2-year study. Concentrations of chromium, copper, and organochlorine pesticides were below detection in surface water, whereas mercury, lead, arsenic, and atrazine commonly occurred at all locations. Only mercury and lead exceeded water quality criteria. Concentrations of nutrients and chlorophyll a were greater in fairway ponds and some adjacent coastal areas relative to reference locations and Florida estuaries. Periphyton ash free dry weight and pigment concentrations statistically differed but not between reference and non-reference coastal areas. Biomass of Thalassia testudinum (turtle grass) was approximately 43% less in a meadow located adjacent to the golf complex (P < 0.05). The results of the study suggest that the effects of coastal golf courses on water quality may be primarily localized and limited to peripheral near-coastal areas. However, this preliminary conclusion needs additional supporting data. ?? 2002 Elsevier Science (USA).

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USGS2002

Structural instability, multiple stable states, and hysteresis in periphyton driven by phosphorus enrichment in the Everglades

Periphyton is a key component of the Everglades ecosystems. It is a major primary producer, providing food and habitat for a variety of organisms, contributing material to the surface soil, and regulating water chemistry. Periphyton is sensitive to the phosphorus (P) supply and P enrichment has caused dramatic changes in the native Everglades periphyton assemblages. Periphyton also affects P availability by removing P from the water column and depositing a refractory portion into sediment. A quantitative understanding of the response of periphyton assemblages to P supply and its effects on P cycling could provide critical supports to decision making in the conservation and restoration of the Everglades. We constructed a model to examine the interaction between periphyton and P dynamics. The model contains two differential equations: P uptake and periphyton growth are assumed to follow the Monod equation and are limited by a modified logistic equation. Equilibrium and stability analyses suggest that P loading is the driving force and determines the system behavior. The position and number of steady states and the stability also depend upon the rate of sloughing, through which periphyton deposits refractory P into sediment. Multiple equilibria may exist, with two stable equilibria separated by an unstable equilibrium. Due to nonlinear interplay of periphyton and P in this model, catastrophe and hysteresis are likely to occur.

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USGS2002

Paleoecological insights on fixed tree island development in the Florida Everglades: I. environmental controls

Palynological and geochemical analyses of sediment cores collected on two tree islands in the Florida Everglades indicate long-term hydrologic and chemical differences between tree islands and surrounding marshes and sloughs. Gumbo Limbo and Nuthouse tree islands are elongate, teardrop-shaped islands in Water Conservation Area 3B. Prior to tree island formation at both sites, pollen records indicate that sites on modern tree island heads were covered with sawgrass marshes with abundant weedy annuals. Such vegetation is characteristic of moderate water depths and hydroperiods with frequent droughts or disturbances. Contemporaneously deposited sediments on tree island tails indicate progressively deeper water conditions with increasing distance from the head; wetlands surrounding tree islands were covered by sloughs with deep water and long hydroperiods. Tree island formation occurred at about 1200 BC on Gumbo Limbo Island, with mature tree island vegetation established by about 800 AD. On Nuthouse Island, tree island formation occurred around 300 AD, shifting to mature tree island vegetation around 1400 AD. Thus, tree island formation began on these islands between 3.2 Ka and 1.7 Ka. Maturation of tree islands took between 1,000 and 2,000 years, and vegetation on these tree islands has been relatively stable for the last 600–1,200 years. Phosphorus levels on tree island heads have been extremely high (approximately six times greater than baseline levels in marshes) throughout the history of the sites, and phosphorus content in tree island tails began increasing when tree island formation occurred. Elevated phosphorus content may reflect the long-term presence of wading birds at these sites and provide a proxy for reconstructing the historic distribution of wading bird populations.

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USGS2002

Key Largo Limestone revisited: Pleistocene shelf-edge facies, Florida Keys, USA

New dates and analysis of 12 deep and 57 shallow cores allow a more detailed interpretation of the Pleistocene shelf edge of the Florida Platform as found in various facies of the Key Largo Limestone beneath the Florida Keys. In this study a three-phase evolution of the Quaternary units (Q1-Q5) of the Key Largo is presented with new subdivision of the Q5. (1) In the first phase, the Q1 and Q2 (perhaps deposited during oxygen-isotope stage 11) deep-water quartz-rich environment evolved into a shallow carbonate phase. (2) Subsequently, a Q3 (presumably corresponding to oxygen-isotope stage 9) flourishing reef and productive high-platform sediment phase developed. (3) Finally, a Q4 and Q5 (corresponding to oxygen-isotope stages 7 and 5) stabilization phase occurred with reefs and leeward productive lagoons, followed by lower sea levels presenting a sequence of younger (isotope substages 5c, 5a) shelf-margin wedges, sediment veneers and outlier reefs. The Key Largo Limestone provides an accessible model of a carbonate shelf edge with fluctuating water depth, bordering a deep seaward basin for a period of at least 300 ka. During this time, at least four onlaps/offlaps, often separated by periods of karst development with associated diagenetic alterations, took place. The story presented by this limestone not only allows a better understanding of the history of south Florida but also aids in the interpretation of similar persistent shelf-edge sites bordering deep basins in other areas.

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USGS2002

Determining the trophic guilds of fishes and macroinvertebrates in a seagrass food web

We established trophic guilds of macroinvertebrate and fish taxa using correspondence analysis and a hierarchical clustering strategy for a seagrass food web in winter in the northeastern Gulf of Mexico. To create the diet matrix, we characterized the trophic linkages of macroinvertebrate and fish taxa. present in Hatodule wrightii seagrass habitat areas within the St. Marks National Wildlife Refuge (Florida) using binary data, combining dietary links obtained from relevant literature for macroinvertebrates with stomach analysis of common fishes collected during January and February of 1994. Heirarchical average-linkage cluster analysis of the 73 taxa of fishes and macroinvertebrates in the diet matrix yielded 14 clusters with diet similarity greater than or equal to 0.60. We then used correspondence analysis with three factors to jointly plot the coordinates of the consumers (identified by cluster membership) and of the 33 food sources. Correspondence analysis served as a visualization tool for assigning each taxon to one of eight trophic guilds: herbivores, detritivores, suspension feeders, omnivores, molluscivores, meiobenthos consumers, macrobenthos consumers, and piscivores. These trophic groups, cross-classified with major taxonomic groups, were further used to develop consumer compartments in a network analysis model of carbon flow in this seagrass ecosystem. The method presented here should greatly improve the development of future network models of food webs by providing an objective procedure for aggregating trophic groups.

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USGS2002

Dynamics of pink shrimp (Farfantepenaeus duorarum) recruitment potential in relation to salinity and temperature in Florida Bay

Progress is reported in relating upstream water management and freshwater flow to Florida Bay to a valuable commercial fishery for pink shrimp ( Farfantepenaeus duorarum ), which has major nursery grounds in Florida Bay. Changes in freshwater inflow are expected to affect salinity patterns in the bay, so the effect of salinity and temperature on the growth, survival, and subsequent recruitment and harvest of this ecologically and economically important species was examined with laboratory experiments and a simulation model. Experiments were conducted to determine the response of juvenile growth and survival to temperature ( 15°C to 33°C ) and salinity ( 2‰ to 55‰ ), and results were used to refine an existing model. Results of these experiments indicated that juvenile pink shrimp have a broad salinity tolerance range at their optimal temperature, but the salinity tolerance range narrows with distance from the optimal temperature range, 20–30°C . Acclimation improved survival at extreme high salinity (55???), but not at extremely low salinity ( i.e., 5‰, 10‰ ). Growth rate increases with temperature until tolerance is exceeded beyond about 35°C . Growth is optimal in the mid-range of salinity ( 30‰ ) and decreases as salinity increases or decreases. Potential recruitment and harvests from regions of Florida Bay were simulated based on local observed daily temperature and salinity. The simulations predict that potential harvests might differ among years, seasons, and regions of the bay solely on the basis of observed temperature and salinity. Regional differences in other characteristics, such as seagrass cover and tidal transport, may magnify regional differences in potential harvests. The model predicts higher catch rates in the September-December fishery, originating from the April and July settlement cohorts, than in the January-June fishery, originating from the October and January settlement cohorts. The observed density of juveniles in western Florida Bay during the same years simulated by the model was greater in the fall than the spring, supporting modeling results. The observed catch rate in the fishery, a rough index of abundance, was higher in the January-June fishery than the July-December fishery in most of the biological years from 1989-1990 through 1997-1998, contrary to modeling results and observed juvenile density in western Florida Bay.

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USGS2002

Seepage meters and Bernoulli's revenge

Evaluation of seepage data from a network of 50 permanently deployed submarine seepage meters, specially constructed from fiberglass, indicates that the devices artificially advect (Bernoulli effect) shallow ground water. Reverse flow into the rock was not observed even when adjacent piezometers installed 2-m to 20-m below the rock-water interface indicated negative groundwater heads. Quantitative testing of five different designs, including conventional end-of-oil-drum designs, indicates that meters presenting positive relief on the sea floor are subject to the Bernoulli effect when placed in areas where there are waves and/or currents. Advection does not appear to be caused by flexing of the collection bags.

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