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Research about Florida

Source-linked reports with geographic coverage including Florida.

At least 991 records · Page 55Linked to original sources
USGS2007

Altered mangrove wetlands as habitat for estuarine nekton: are dredged channels and tidal creeks equivalent?

Hasty decisions are often made regarding the restoration of "altered" habitats, when in fact the ecological value of these habitats may be comparable to natural ones. To assess the "value" of altered mangrove-lined habitats for nekton, we sampled for 1 yr within three Tampa Bay wetlands. Species composition, abundance, and spatial distribution of nekton assemblages in permanent subtidal portions of natural tidal creeks and wetlands altered by construction of mosquito-control ditches and stormwater-drainage ditches were quantified through seasonal seine sampling. Results of repeated-measures analysis of variance and ordination of nekton community data suggested differences in species composition and abundance between natural and altered habitat, though not consistently among the three wetlands. In many cases, mosquito ditches were more similar in assemblage structure to tidal creeks than to stormwater ditches. In general, mosquito ditches and stormwater ditches were the most dissimilar in terms of nekton community structure. These dissimilarities were likely due to differences in design between the two types of ditches. Mosquito ditches tend to fill in over time and are thus more ephemeral features in the landscape. In contrast, stormwater ditches are a more permanent altered habitat that remain open due to periodic flushing from heavy runoff. Results indicate that environmental conditions (e.g., salinity, current velocity, vegetative structure) may provide a more useful indication of potential habitat "value" for nekton than whether the habitat has been altered. The type of ditching is therefore more important than ditching per se when judging the habitat quality of these altered channels for fishes, shrimps and crabs. Planning should entail careful consideration of environmental conditions rather than simply restoring for restoration's sake.

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USGS2007

Spatially continuous interpolation of water stage and water depths using the Everglades depth estimation network (EDEN)

The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level monitoring, ground-elevation modeling, and water-surface modeling that provides scientists and managers with current (2000-present), online water-stage and water-depth information for the entire freshwater portion of the Greater Everglades. Continuous daily spatial interpolations of the EDEN network stage data are presented on a 400-square-meter grid spacing. EDEN offers a consistent and documented dataset that can be used by scientists and managers to (1) guide large-scale field operations, (2) integrate hydrologic and ecological responses, and (3) support biological and ecological assessments that measure ecosystem responses to the implementation of the Comprehensive Everglades Restoration Plan (CERP) The target users are biologists and ecologists examining trophic level responses to hydrodynamic changes in the Everglades.

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USGS2007

USGS Tampa Bay Pilot Study

Many of the nation's estuaries have been environmentally stressed since the turn of the 20th century and will continue to be impacted in the future. Tampa Bay, one the Gulf of Mexico's largest estuaries, exemplifies the threats that our estuaries face (EPA Report 2001, Tampa Bay Estuary Program-Comprehensive Conservation and Management Plan (TBEP-CCMP)). More than 2 million people live in the Tampa Bay watershed, and the population constitutes to grow. Demand for freshwater resources, conversion of undeveloped areas to resident and industrial uses, increases in storm-water runoff, and increased air pollution from urban and industrial sources are some of the known human activities that impact Tampa Bay. Beginning on 2001, additional anthropogenic modifications began in Tampa Bat including construction of an underwater gas pipeline and a desalinization plant, expansion of existing ports, and increased freshwater withdrawal from three major tributaries to the bay. In January of 2001, the Tampa Bay Estuary Program (TBEP) and its partners identifies a critical need for participation from the U.S. Geological Survey (USGS) in providing multidisciplinary expertise and a regional-scale, integrated science approach to address complex scientific research issue and critical scientific information gaps that are necessary for continued restoration and preservation of Tampa Bay. Tampa Bay stakeholders identified several critical science gaps for which USGS expertise was needed (Yates et al. 2001). These critical science gaps fall under four topical categories (or system components): 1) water and sediment quality, 2) hydrodynamics, 3) geology and geomorphology, and 4) ecosystem structure and function. Scientists and resource managers participating in Tampa Bay studies recognize that it is no longer sufficient to simply examine each of these estuarine system components individually, Rather, the interrelation among system components must be understood to develop conceptual and predictive modeling tools for effective ecosystem adaptive management. As a multidisciplinary organization, the USGS possesses the capability of developing and coordinating an integrated science strategy for estuarine research founded on partnerships and collaborative efforts, multidisciplinary teams of scientists, and integrated field work, data analysis and interpretation, and product development. The primary role of the USGS in Tamps Bay research was defined with our partners based upon this capability to address estuarine issues using an integrated science approach with a regional perspective and within a national context to complement the numerous ongoing scien efforts by state and local agencies that address local issues within Tamp Bay. Six primary components of the USGS Tamp Bay Study address critical gaps within each of the the four estuarine system components and focus on: 1.) Examining how natural and man-made physical changes affect ecosystem health through mapping and modeling. 2.) Identifying sources and quality of groundwater, surface water, and sediment, 3.) Identifying sources and quality of groundwater, surface water, and sediment, 4.) Assessing the natural and man-made changes affecting wetland health and restoration, 5.) Identifying and measuring the impact of urbanization on seafloor habitats, Providing a web-based digital information management system of information for scientists and the public, including a system that supports the work of those officials who must make decisions that affect the state of the bay. The Tampa Bay Study is in its sixth year and will continue through September 2007. This paper presents a non-inclusive summary of key findings associated with the six primary project components listed above. Component 4 (above) is described in detail in the following chapter 13. More information on the Tampa Bay Study is available from our on-line digital information system for the Tampa Bay Study at http://gulfsci.usgs.gov.

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USGS2006

Salinity and temperature tolerance experiments on selected Florida Bay mollusks

The ultimate goal of the Comprehensive Everglades Restoration Plan (CERP) is to restore and preserve the unique ecosystems of South Florida, including the estuaries. Understanding the effect of salinity and temperature changes, beyond typical oscillations, on the biota of South Florida's estuaries is a necessary component of achieving the goal of restoring the estuaries. The U.S. Geological Survey has been actively involved in researching the history of the South Florida Ecosystem, to provide targets, performance measures, and baseline data for restoration managers. These experiments addressed two aspects of ecosystem history research: 1) determining the utility of using molluscan shells as recorders of change in water chemistry parameters, primarily salinity, and 2) enhancing our in situ observations on modern assemblages by exceeding typically observed aquatic conditions. This set of experiments expanded our understanding of the effects of salinity, temperature and other water chemistry parameters on the reproduction, growth and overall survivability of key species of mollusks used in interpreting sediment core data. Observations on mollusks, plants and microbes made as part of these experiments have further refined our knowledge and understanding of the effects of ecosystem feedback and the role salinity and temperature play in ecosystem stability. The results have demonstrated the viability of several molluscan species as indicators of atypical salinity, and possibly temperature, modulations. For example Cerithium muscarum and Bulla striata demonstrated an ability to withstand a broad salinity and temperature range, with reproduction occurring in atypically high salinities and temperatures. These experiments also provided calibration data for the shell biogeochemistry of Chione cancellata and the possible use of this species as a water chemistry recorder. Observations made in the mesocosms, on a scale not normally observable in the field, have led to new questions about the influence of salinity on the localized ecosystem. The next phase of these experiments; to calibrate growth rate and reproductive viability in atypical salinities is currently underway.

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USGS2006

Vegetation classification for south Florida natural areas

Introduction A critical component of any ecological restoration program is documenting the temporal changes in the spatial extent, pattern, and proportion of plant communities within the landscape. The Comprehensive Everglades Restoration Plan (CERP - www.evergladesplan.org), authorized as part of the Water Resources and Development Act (WRDA) of 2000 (U.S. Congress, 2000), is an $8 billion hydrologic restoration project for all of south Florida. CERP includes 68 separate projects to be managed over the next 30 years by the South Florida Water Management District (SFWMD), the U. S. Army Corp of Engineers (USACE), and other State and Federal agencies. Restoration Coordination and Verification (RECOVER) is a system-wide program of the CERP, designed to organize, manage, and provide the highest quality scientific and technical support during implementation of the restoration program (RECOVER, in prep.). It is the role of RECOVER to develop and implement a system-wide Monitoring and Assessment Plan (MAP) (RECOVER, 2004) and to document how well the CERP is meeting its objectives for ecosystem restoration. One critical component of the MAP is vegetation mapping to document changes in the spatial extent, pattern, and proportion of plant communities within the Everglades landscape. A major aspect of the vegetation mapping project was determining a classification system for labeling vegetation categories utilizing a grid method. The grid method was created specifically for use in the CERP RECOVER vegetation monitoring and assessment project (Rutchey and others, in prep). The CERP RECOVER vegetation mapping project utilizes aerial photography and photointerpretation techniques (with ground truthing) to identify and label vegetation classes. A classification system that had sufficient flexibility and detail to enable the designation of vegetation classes using various remote sensing platforms and identification techniques needed to be developed. The classification system had to be hierarchical, represent distinct ecological communities, individual species, and physical characteristics such as density and height. In addition, it was desirable to have a classification system that allowed exotic species and cattail to be identified using density classes. The classification system was developed specifically for peninsular south Florida and the Florida Keys, from Lake Okeechobee in the north to Key West in the south (Figure 1). Specific areas of interest include Everglades National Park, Big Cypress National Preserve, Biscayne National Park, Florida Panther National Wildlife Refuge, Loxahatchee National Wildlife Refuge, the State of Florida Water Conservation Areas, Holeyland Wildlife Management Area, Rotenberger Wildlife Management Area, J.W. Corbett Wildlife Management Area, Pal-Mar Wildlife Management Area, the Lake Okeechobee Littoral Zones, and additional coastal wetlands of south eastern Miami-Dade County. In addition to being used for mapping of CERP affected areas, the National Park Service-South Florida/Caribbean Network is using the classification for mapping the remaining areas of Everglades National Park and Big Cypress National Preserve outside the CERP footprint, Florida Panther National Wildlife Refuge, Biscayne National Park, and Dry Tortugas National Park.

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USGS2006

Creation of GIS compatible, historic detailed soil data sets for the Collier and Miami-Dade Counties, Florida

When soils data are in digital format compatible with geographic information systems (GIS), a wide variety of analyses and display capabilities are afforded. Detailed information on soils that may be important to Everglades ecosystem restoration has been created in hardcopy form using traditional soils mapping techniques. However, accurate conversion of these analogue geographic data to GIS compatible information is a complicated process. Because detailed digital soils data for Southern Florida were not yet available from the US Department of Agriculture, the U.S. Geological Survey (USGS) Eastern Geographic Science Center (EGSC) developed a means for digitizing and attributing historic soil survey data for GIS analysis. This report documents that process and the two soil survey datasets created through it, one for Collier and one for Miami-Dade Counties in Florida. First, the sources for the soils data are described. Then the approach used to determine how data would be collected and organized is provided, followed by details of the spatial data collection and attribute data encoding.

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USGS2006

Fixed-wing airplane versus helicopter surveys of manatees (Trichechus manatus)

The abundance of manatees, as with most marine mammals, is difficult to determine because they are visible for only short periods of time while at the surface of the water (Eberhardt et al. 1979, Powell et al. 1981). Aerial surveys are generally considered to be the most accurate method of counting manatees, although there is no doubt that some undetermined proportion is missed (Irvine and Campbell 1978, Shane 1981, Kinnaird 1985, Packard et al. 1985). When designing aerial censuses for manatees two types of aircraft are usually considered: fixed-wing and rotary-wing airplanes (Irvine 1982). Fixed-wing airplanes normally are used because helicopters are prohibitively expensive to hire (often over twice that of a fixed-wing airplane). Helicopters, however, have been assumed to yield more accurate counts for manatees (personal observations; J. Fletemeyer and J. Provancha, personal communication) because their slower air speed and greater maneuverability reduce the proportion of animals missed due to some of the biases inherent in fixed-wing airplane counts (Caughley 1974). To assess how effective fixed-wing aircraft are in determining the number of manatees in an area, a series of paired total-count aerial surveys were done in winter 1978-79. A Bell 47G helicopter was used to obtain a “count” to compare with counts made from a Cessna 172 fixed, high-wing airplane. The experiment was conducted at two different sites and on five consecutive days at each site. The first location was Crystal River, which is a clear, spring-fed river that flows about11 km into the Gulf of Mexico on the central west coast of Florida. The second site was an 8-km-long section of the Indian River, which is a large, turbid estuary adjacent to Cape Canaveral on the east coast of Florida.

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USGS2006

Distribution patterns of individually identifiable West Indian manatees ( Trichechus manatus ) in Florida

Photographs of distinctively scarred manatees ( Trichechus manatus ) were taken at aggregation sites throughout Florida and assembled into a catalog for identifying individuals. Resightings of known manatees in different years or at different locations enabled us to document site fidelity and long-distance movements. Of the 891 individuals included in the catalog as of August 1986, 470 (53%) were resighted at least once. We documented 219 cases of seasonal returns to specific aggregation sites and 98 instances of movements between areas. Movements in excess of 820 km were documented for individuals on the east coast of Florida. Rapid movements south during early winter, as well as northerly spring movements, verify a seasonal migration pattern for many individuals along Florida's east coast. The wide-ranging migratory habits of manatees in Florida must be considered if meaningful management strategies are to be developed and implemented.

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USGS2006

Descriptions and preliminary report on sediment cores from the southwest coastal area, Part II: Collected July 2005, Everglades National Park, Florida

Twelve cores were collected from six sites in the southwest coastal area of Everglades National Park, Florida, in July 2005. These six sites create transects up three river systems that are part of the complex network of channels and bays that form the mangrove and coastal glades – Lostmans River system, Harney River system, and Shark River system. The three transects are linked to two cores collected in 2004 from Big Lostmans Bay and Tarpon Bay. A preliminary model of changes in flow through the southwest coastal zone is proposed based on an examination of the sediments and an initial assessment of key indicator species of mollusks within the cores. Throughout the time period recorded by deposition of these cores, flow to the southwest coastal area has been predominantly through the Shark River channels, diminishing to the north toward the Lostmans River system. The Lostmans system was less influenced by freshwater flow and more emergent than the two systems to the south. Freshwater flow has periodically reached the mouths of the Harney and Shark River systems, but these areas have persistently been zones of mixed estuarine environments, typical of transition zones. Evidence for a substantial change in the flow regime is found in the mid-system cores from the Harney and Shark Rivers. The lower portions of both cores were deposited in freshwater environments, with no indication of estuarine influence; however, a shift towards more estuarine conditions occurs in the upper portions of the cores and a loss of the larger freshwater fauna. These results are preliminary. The next step will be to develop age models and to conduct quantitative analyses of the fauna, flora, and sediment geochemistry at these sites. Results of the quantitative analyses will provide information on the natural and anthropogenic changes that have occurred in the southwest coastal system that will allow resource managers to set targets for restoration.

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USGS2006

Relationships between reef fish communities and remotely sensed rugosity measurements in Biscayne National Park, Florida, USA

The realization that coral reef ecosystem management must occur across multiple spatial scales and habitat types has led scientists and resource managers to seek variables that are easily measured over large areas and correlate well with reef resources. Here we investigate the utility of new technology in airborne laser surveying (NASA Experimental Advanced Airborne Research Lidar (EAARL)) in assessing topographical complexity (rugosity) to predict reef fish community structure on shallow (<10 m deep) patch reefs. Marine portions of Biscayne National Park, Florida, USA, were surveyed remotely using the EAARL, and reef fish populations were visually surveyed on 10 patch reefs at independent, randomly selected stations ( n = 10–13 per reef). Rugosity at each station was assessed in situ by divers using the traditional chain-transect method (10-m scale), and remotely using the EAARL submarine topography data at multiple spatial scales (2, 5, and 10 m). The rugosity and biological datasets were analyzed together to elucidate the predictive power of EAARL rugosity in describing the variance in reef fish community variables and to assess the correlation between chain-transect and EAARL rugosity. EAARL rugosity was not well correlated with chain-transect rugosity, or with species richness of fishes (although statistically significant, the amount of variance explained by the model was very low). Variance in reef fish community attributes was better explained in reef-by-reef variability than by physical variables. However, once the reef-by-reef variability was taken into account in a two-way analysis of variance, the importance of rugosity could be seen on individual reefs. Fish species richness and abundance were statistically higher at high rugosity stations compared to medium and low rugosity stations, as predicted by prior ecological research. The EAARL shows promise as an important mapping tool for reef resource managers as they strive to inventory and protect coral reef resources.

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USGS2006

Waste injection into a deep limestone in northwestern Florida

During a three-month trial period, 70 million gallons of industrial wastes were successfully injected at moderate pressures into a deep limestone in the westernmost part of Florida. The movement of these wastes is expected to be predominantly southward toward the natural discharge area which is presumed to be far out in the Gulf of Mexico. The limestone lies between two thick beds of clay (aquicludes) and contains 13,000 parts per million salty water. A series of aquifers and aquicludes appear capable of preventing contamination of the overlying fresh-water aquifers.

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USGS2006

Packer testing in water wells near Sarasota, Florida

During February and March 1964, the U. S. Geological Survey ran caliper, conductance, and temperature logs on several wells in the Sarasota area. The Florida Geological Survey had previously run gamma ray and electric logs on the same wells . Two flowing wells were selected for packer testing . The two wells are about the same depth, penetrate essentially the same geologic horizons, and are about 16 miles apart. The packers were set in the wells between the producing horizons of the formations penetrated and each of the horizons was tested for head, amount of production, and quality of water . One of the tests produced excellent results, indicating that the various producing zones were effectively isolated by the packers and that different quality of water , quantity of water , and a different head was available from each zone. The other test did not show sharp differences but did indicate the extent of contamination of the producing horizons in a flowing well which had been capped for approximately two years. These tests indicate that packer testing can measurably add to knowledge of the separation of permeable zones.

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USGS2006

Test hold in aquifer with many water-bearing zones at Jacksonville, Florida

One of the deepest water ‐exploration wells in the southeastern United States was completed in 1966 at Jacksonville , Florida . It was drilled to a depth of nearly 2,500 feet to supply geologic and hydrologic information on the deeper unexplored part of the Floridan aquifer . This aquifer consists of a series of water producing zones separated by nonproducing zones . An important new fresh‐ water producing zone was found, and the contact between the fresh water and salt water was located. The well was completed in three separate zones so that it could be used to monitor the the deeper part of the aquifer to detect any salt‐ water encroachment. This paper describes the objectives, techniques, and results of drilling the test well.

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USGS2006

Hydrogeochemical effects of injecting wastes into a limestone aquifer near Pensacola, Florida

Acidic industrial wastes have been injected into deep wells in a limestone aquifer near Pensacola, Florida, since 1963. Prior geohydrologic studies in the area had indicated that the limestone aquifer contained nonpotable water and was overlain by an extensive clay confining layer. Two injection wells are presently being used to inject the waste at a rate of approximately 2,000 gallons per minute. The injection pressures are about 200 pounds per square inch. Over 3 billion gallons have been injected. Data from a current study indicate that the waste may extend outward about 1 mile from the injection wells, and pressure effects may extend outward more than 25 miles. Monitor wells show that pressure changes are following a predictable pattern. No wastes have been detected in a monitor well open to the Floridan aquifer immediately above the Bucatunna Clay Member of the Byram Formation and 100 feet from one of the injection wells. A monitor well open to the receiving formation was constructed about 1,300 feet south of the injection wells. Geochemical effects of the wastes were detected at this well about 10 months after injection began. In early 1968, the pH of the waste was lowered to about 3. Effects of this waste, which included a large increase in calcium, were detected at the monitor well about 5 months later.

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USGS2006

Monitoring of subsurface injection of wastes, Florida

Injection of waste liquids into Florida's subsurface is physically feasible in many places but should be accompanied by monitoring of the waste-receiving aquifer system in addition to the injection facility. Monitoring of the interaction of factors including hydrogeologic conditions, well construction, waste volumes and characteristics, and potable-water sources is desirable to assure that fresh-water resources are not being adversely affected. An effective aquifer-system monitoring program includes on-site wells located close to an injection well and open to the next-higher permeable stratum, satellite wells located hundreds to several thousands of feet from an injection well and open to the receiving aquifer, and regional wells located miles from individual injection wells and open to the receiving aquifer. An extensive aquifer-system monitoring program associated with two waste-injection facilities near Pensacola, Florida, has provided data which have aided hydrologists to understand the aquifer system's response to the injection and, accordingly, to evaluate the potential for affecting the area's fresh-water resources.

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USGS2006

Chemical changes in an industrial waste liquid during post-injection movement in a limestone aquifer, Pensacola, Florida

An industrial waste liquid containing organonitrile compounds and nitrate ion has been injected into the lower limestone of the Floridan aquifer near Pensacola, Florida since June 1975. Chemical analyses of water from monitor wells and backflow from the injection well indicate that organic carbon compounds are converted to CO 2 and nitrate is converted to N 2 . These transformations are caused by bacteria immediately after injection, and are virtually completed within 100 m of the injection well. The zone near the injection well behaves like an anaerobic filter with nitrate respiring bacteria dominating the microbial flora in this zone. Sodium thiocyanate contained in the waste is unaltered during passage through the injection zone and is used to detect the degree of mixing of injected waste liquid with native water at a monitor well 312 m (712 ft) from the injection well. The dispersivity of the injection zone was calculated to be 10 m (33 ft). Analyses of samples from the monitor well indicate 80 percent reduction in chemical oxygen demand and virtually complete loss of organonitriles and nitrate from the waste liquid during passage from the injection well to the monitor well. Bacterial densities were much lower at the monitor well than in backflow from the injection well.

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USGS2006

Seasonal variation in habitat use by marsh fishes

We used I-m 2 throw traps to examine habitat use by smallsized fishes within a mosaic of wet prairies and sloughs in the headwaters of the St. Johns River, Florida between August 1992 and November 1995. Estimates of total fish density and biomass varied temporally, but did not differ significantly between habitats. Patterns of habitat use, however, differed among the five numerically dominant species. Bluefin killifish, mosquitofish, and golden topminnows were more abundant in sloughs than in wet prairies. In contrast, Everglades pygmy sunfish were more abundant in wet prairies than in sloughs. Finally, the abundance of least killifish did not differ between habitats. Fish densities were positively correlated with plant biomass (i. e., habitat complexity) and negatively correlated with water depth (i. e., hydrology). Species richness and composition were similar among habitats. However, consistent differences in the relative abundance of numerically dominant species between habitats indicated some degree of habitat-specific assemblage structure. Most species were concentrated into deeper sloughs during drying events. This assemblage of small-sized fishes appears to respond relatively rapidly to changes in habitat structure and hydrologic conditions. We therefore recommend that resource managers consider using fishes as indicator taxa to evaluate the efficacy of ongoing restoration and management efforts in wetland systems.

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