Understanding anuran community dynamics in temporary wetlands: The interaction and importance of landscape and biotic processes

The major objective of this study was to determine the relative importance of landscape factors, local abiotic factors, and biotic interactions in influencing tadpole community structure in temporary wetlands. I also examined the influence of agricultural activities in South-central Florida by comparing tadpole communities in native prairie wetlands (a relatively unmodified habitat) at the Kissimmee Prairie Sanctuary (KPS) to tadpole communities in three agriculturally modified habitats found at MacArthur Agro-Ecology Research Center (MAERC). Environmental characteristics were measured in 24 isolated wetlands, and tadpoles were sampled using throw-traps and dipnets during the 1999 wet season (June–October). Landscape characteristics were expected to predominately influence all aspects of community structure because anurans associated with temporary wetland systems are likely to exist as metapopulations. Both landscape characteristics (wetland proximity to nearest woodland and the amount of woodland surrounding the wetland) and biotic interactions (fish predation) had the largest influence on tadpole community structure. Predatory fish influenced tadpole communities more than expected due to the ubiquity of wetlands, lack of topographic relief, and dispersal abilities of several fish species. Differences in tadpole community structure among habitat types were attributed to differences in woodland attributes and susceptibility to fish colonization. Furthermore, agricultural modification of prairie habitats in South-central Florida may benefit amphibian communities, particularly woodland-dwelling species that are unable to coexist with predatory fish. From a conservation standpoint, temporary wetlands proximal to woodland areas and isolated from permanent water sources appear to be most important to amphibians. In addition, the high tadpole densities attained in these wetlands suggest that these wetlands serve as biological hotspots within the landscape, and their benefits extend into the adjacent terrestrial matrix. Further research efforts are needed to quantify the biological productivity of these systems and determine spatial dynamics of anurans in surrounding terrestrial habitats. ^

Correspondence of historic salinity fluctuations in Florida Bay, USA, to atmospheric variability and anthropogenic changes

Florida Bay is a highly dynamic estuary that exhibits wide natural fluctuations in salinity due to changes in the balance of precipitation, evaporation and freshwater runoff from the mainland. Rapid and large-scale modification of freshwater flow and construction of transportation conduits throughout the Florida Keys during the late nineteenth and twentieth centuries reshaped water circulation and salinity patterns across the ecosystem. In order to determine long-term patterns in salinity variation across the Florida Bay estuary, we used a diatom-based salinity transfer function to infer salinity within 3.27 ppt root mean square error of prediction from diatom assemblages from four ~130 year old sediment records. Sites were distributed along a gradient of exposure to anthropogenic shifts in the watershed and salinity. Precipitation was found to be the primary driver influencing salinity fluctuations over the entire record, but watershed modifications on the mainland and in the Florida Keys during the late-1800s and 1900s were the most likely cause of significant shifts in baseline salinity. The timing of these shifts in the salinity baseline varies across the Bay: that of the northeastern coring location coincides with the construction of the Florida Overseas Railway (AD 1906–1916), while that of the east-central coring location coincides with the drainage of Lake Okeechobee (AD 1881–1894). Subsequent decreases occurring after the 1960s (east-central region) and early 1980s (southwestern region) correspond to increases in freshwater delivered through water control structures in the 1950s–1970s and again in the 1980s. Concomitant increases in salinity in the northeastern and south-central regions of the Bay in the mid-1960s correspond to an extensive drought period and the occurrence of three major hurricanes, while the drop in the early 1970s could not be related to any natural event. This paper provides information about major factors influencing salinity conditions in Florida Bay in the past and quantitative estimates of the pre- and post-South Florida watershed modification salinity levels in different regions of the Bay. This information should be useful for environmental managers in setting restoration goals for the marine ecosystems in South Florida, especially for Florida Bay.

Understanding anuran community dynamics in temporary wetlands: the interaction and importance of landscape and biotic processes

The major objective of this study was to determine the relative importance of landscape factors, local abiotic factors, and biotic interactions in influencing tadpole community structure in temporary wetlands. I also examined the influence of agricultural activities in South-central Florida by comparing tadpole communities in native prairie wetlands (a relatively unmodified habitat) at the Kissimmee Prairie Sanctuary (KPS) to tadpole communities in three agriculturally modified habitats found at MacArthur Agro- Ecology Research Center (MAERC). Environmental characteristics were measured in 24 isolated wetlands, and tadpoles were sampled using throw-traps and dipnets during the 1999 wet season (June - October). Landscape characteristics were expected to predominately influence all aspects of community structure because anurans associated with temporary wetland systems are likely to exist as metapopulations. Both landscape characteristics (wetland proximity to nearest woodland and the amount of woodland surrounding the wetland) and biotic interactions (fish predation) had the largest influence on tadpole community structure. Predatory fish influenced tadpole communities more than expected due to the ubiquity of wetlands, lack of topographic relief, and dispersal abilities of several fish species. Differences in tadpole community structure among habitat types were attributed to differences in woodland attributes and susceptibility to fish colonization. Furthermore, agricultural modification of prairie habitats in South-central Florida may benefit amphibian communities, particularly woodland-dwelling species that are unable to coexist with predatory fish. From a conservation standpoint, temporary wetlands proximal to woodland areas and isolated from permanent water sources appear to be most important to amphibians. In addition, the high tadpole densities attained in these wetlands suggest that these wetlands serve as biological hotspots within the landscape, and their benefits extend into the adjacent terrestrial matrix. Further research efforts are needed to quantify the biological productivity of these systems and determine spatial dynamics of anurans in surrounding terrestrial habitats.

Physiological performance measures and tolerance limits of estuarine indicator species in south Florida

Current water management practices in South Florida have negatively impacted many species inhabiting Florida Bay. Variable and high salinity has been identified as a key stressor in these estuaries. The Comprehensive Everglades Restoration Plan (CERP) includes water redistribution projects that will restore natural freshwater flows to northeastern Florida Bay. My studies focused on the following central theme and hypotheses: Biological performance measures (i.e., growth, reproduction, survival), behavior (i.e., habitat preference and locomotor behavior) and diversity of estuarine fish will be controlled by changes in salinity and water quality that will occur as a result of the restoration of freshwater flow to the bay. A series of acute and subchronic physiological toxicity studies were conducted to determine the effects of salinity changes on the life stages (embryo/larval, juvenile, adult) and fecundity of four native estuarine fish (Cyprinodon variegatus, Floridichthys carpio, Poecilia latipinna, and Gambusia holbrooki). Fish were exposed to a range of salinity concentrations (freshwater to hypersaline) based on salinity profiles in the study areas. Growth (length, weight) and survival were measured. Salinity trials included both rapid and gradual change events. Results show negative effects of acute, abrupt salinity changes on fish survival, development and reproductive success as a result of salinity stress. Other studies targeted reproduction and critical embryo-larval/neonate development as key areas for detecting long-term population effects of salinity change in Florida Bay. Adults of C. variegates and P. latipinna were also examined for behavioral responses to pulsed salinity changes. These responses include changes in swimming performance, locomotor behavior and zone preference. Finally, an ecological risk assessment was conducted for adverse salinity conditions in northeastern Florida Bay. Using the U.S. EPA's framework, the risk to estuarine fish species diversity was assessed against regional salinity profiles from a 17-year database. Based on the risk assessment, target salinity profiles for these areas are recommended for managers.^

Central Vestibulopathy in a Female Collegiate Basketball Player: A Case Study

We present a unique case of a collegiate athlete who suffered from a mild head injury following a multi-car motor vehicle accident and was later diagnosed with central vestibulopathy.

Distribution of Diatoms and Development of Diatom-Based Models for Inferring Salinity and Nutrient Concentrations in Florida Bay and Adjacent Coastal Wetlands of South Florida (USA)

The composition and distribution of diatom algae inhabiting estuaries and coasts of the subtropical Americas are poorly documented, especially relative to the central role diatoms play in coastal food webs and to their potential utility as sentinels of environmental change in these threatened ecosystems. Here, we document the distribution of diatoms among the diverse habitat types and long environmental gradients represented by the shallow topographic relief of the South Florida, USA, coastline. A total of 592 species were encountered from 38 freshwater, mangrove, and marine locations in the Everglades wetland and Florida Bay during two seasonal collections, with the highest diversity occurring at sites of high salinity and low water column organic carbon concentration (WTOC). Freshwater, mangrove, and estuarine assemblages were compositionally distinct, but seasonal differences were only detected in mangrove and estuarine sites where solute concentration differed greatly between wet and dry seasons. Epiphytic, planktonic, and sediment assemblages were compositionally similar, implying a high degree of mixing along the shallow, tidal, and storm-prone coast. The relationships between diatom taxa and salinity, water total phosphorus (WTP), water total nitrogen (WTN), and WTOC concentrations were determined and incorporated into weighted averaging partial least squares regression models. Salinity was the most influential variable, resulting in a highly predictive model (r apparent 2  = 0.97, r jackknife 2  = 0.95) that can be used in the future to infer changes in coastal freshwater delivery or sea-level rise in South Florida and compositionally similar environments. Models predicting WTN (r apparent 2  = 0.75, r jackknife 2  = 0.46), WTP (r apparent 2  = 0.75, r jackknife 2  = 0.49), and WTOC (r apparent 2  = 0.79, r jackknife 2  = 0.57) were also strong, suggesting that diatoms can provide reliable inferences of changes in solute delivery to the coastal ecosystem.

Beyond the Pay: Current Illicit Activities of the Armed Forces in Central America

The growth of criminal gangs and organized crime groups has created unprecedented challenges in Central America. Homicide rates are among the highest in the world, countries spend on average close to 10 percent of GDP to respond to the challenges of public insecurity, and the security forces are frequently overwhelmed and at times coopted by the criminal groups they are increasingly tasked to counter. With some 90 percent of the 700 metric tons of cocaine trafficked from South America to the United States passing through Central America, the lure of aiding illegal traffickers through provision of arms, intelligence, or simply withholding or delaying the use of force is enormous. These conditions raise the question: to what extent are militaries in Central America compromised by illicit ties to criminal groups? The study focuses on three cases: Nicaragua, El Salvador, and Honduras. It finds that: Although illicit ties between the military and criminal groups have grown in the last decade, militaries in these countries are not yet “lost’ to criminal groups. Supplying criminal groups with light arms from military stocks is typical and on the rise, but still not common. In general the less exposed services, the navies and air forces, are the most reliable and effective ones in their roles in interdiction. Of the three countries in the study, the Honduran military is the most worrying because it is embedded in a context where civilian corruption is extremely common, state institutions are notoriously weak, and the political system remains polarized and lacks the popular legitimacy and political will needed to make necessary reforms. Overall, the armed forces in the three countries remain less compromised than civilian peers, particularly the police. However, in the worsening crime and insecurity context, there is a limited window of opportunity in which to introduce measures targeted toward the military, and such efforts can only succeed if opportunities for corruption in other sectors of the state, in particular in law enforcement and the justice system, are also addressed. Measures targeted toward the military should include: Enhanced material benefits and professional education opportunities that open doors for soldiers in promising legitimate careers once they leave military service. A clear system of rewards and punishments specifically designed to deter collusion with criminal groups. More effective securing of military arsenals. Skills and external oversight leveraged through combined operations, to build cooperation among those sectors of the military that have successful and clean records in countering criminal groups, and to expose weaker forces to effective best practices.

The Allelic Abundance of Afghanistan, a Pool for West and South Eurasian Genes and a Blockade against Eastern Admixture

In this study, I divided samples from individuals within Afghanistan based upon geography (i.e., north versus south). I determined allelic frequencies and other statistical parameters for 15 STR loci (i.e., D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, Dl3S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA). I conducted pairwise comparisons with 19 neighboring Eurasian populations to assign Gstatistics and p-values. Categorizing the populations into five groups (i.e., Central Asia, East Asia, South Asia, the Middle East, and the Caucasus/Anatolia), I derived values for intra-population, inter-population, and total variance. Admixture analyses determined the highest allelic contributions to be from the Caucasus/ Anatolia, while negligible contributions were made by Central Asia and East Asia. A Correspondence Analysis revealed clustering of both northern and southern Afghanistan with Georgia, Turkey, northern Iran, and southern Iran of the Caucasus/ Anatolia and the Middle East. A Neighbor-Joining phylogenetic tree was constructed to generate bootstrap values over 1, 000 reiterations.

Atlantic Ais in the Sixteenth and Seventeenth Centuries: Maritime Adaptation, Indigenous Wrecking, and Buccaneer Raids on Florida’s Central East Coast

The Ais were a Native American group who lived along the Atlantic shoreline of Florida south of Cape Canaveral. This coastal population’s position adjacent to a major shipping route afforded them numerous encounters with the Atlantic world that linked Europe, Africa, the Caribbean, and the Americas. Through their exploitation of the goods and peoples from the European shipwrecks thrown ashore, coupled with their careful manipulation of other Atlantic contacts, the Ais polity established an influential domain in central east Florida during the sixteenth and seventeenth centuries. The pre-contact peoples of Florida’s east coast, including the ancestors of the Ais, practiced a maritime adaptation concentrated on the exploitation of their bountiful riverine, estuarine, and marine environments. The Ais then modified their maritime skills to cope with the opportunities and challenges that accompanied European contact. Using their existing aquatic abilities, they ably salvaged goods and castaways from the Spanish, French, English, and Dutch vessels dashed on the rocks and reefs of Florida’s coast. The Ais’ strategic redistribution of these materials and peoples to other Florida Native Americans, the Spaniards of St. Augustine, and other passing Europeans gained them greater influence. This process, which I call indigenous wrecking, enabled the Ais to expand their domain on the peninsula. Coastal Florida Native Americans’ maritime abilities also attracted the attention of Europeans. In the late seventeenth century, English buccaneers and salvagers raided Florida’s east coast to capture indigenous divers, whom they sent to work the wreck of a sunken Spanish treasure ship located in the Bahamas. The English subsequently sold the surviving Native American captives to other Caribbean slave markets. Despite population losses to such raids, the Ais and other peoples of the east coast thrived on Atlantic exchange and used their existing maritime adaptation to resist colonial intrusions until the start of the eighteenth century. This dissertation thus offers a narrative about Native Americans and the Atlantic that is unlike most Southeastern Indian stories. The Ais used their maritime adaptation and the process of indigenous wrecking to engage and exploit the arriving Atlantic world. In the contact era, the Ais truly became Atlantic Ais.

Physiological performance measures and tolerance limits of estuarine indicator species in South Florida

Current water management practices in South Florida have negatively impacted many species inhabiting Florida Bay. Variable and high salinity has been identified as a key stressor in these estuaries. The comprehensive Everglades Restoration Plan (CERP) includes water redistribution projects that will restore natural freshwater flows to northeastern Florida Bay. My studies focused on the following central theme and hypotheses: Biological performance measures (i.e., growth, reproduction, survival), behavior (i.e., habitat preference and locomotor behavior) and diversity of estuarine fish will be controlled by changes in salinity and water quality that will occur as a result of the restoration of freshwater flow to the bay. A series of acute and subchronic physiological toxicity studies were conducted to determine the effects of salinity changes on the life stages (embryo/larval, juvenile, adult) and fecundity of four native estuarine fish (Cyprinodon variegatus, Floridichthys carpio, Poecilia latipinna, and Gambusia holbrooki). Fishe were exposed to a range of salinity concentrations (freshwater to hypersaline) based on salinity profiles in the study areas. Growth (length, weight) and survival were measured. Salinity trials included both rapid and gradual change events. Results show negative effects of acute, abrupt salinity changes on fish survival, development and reproductive success as a result of salinity stress. Other studies targeted reproduction and critical embryo-larval/neonate development as key areas for detecting long-term population effects of salinity change in Florida Bay. Adults of C. variegatus and P. latipinna were also examined for behavioral responses to pulsed salinity changes. These responses include changes in swimming performance, locomotor behavior and zone preference. Finally, an ecological risk assessment was conducted for adverse salinity conditions in northeastern Florida Bay. Using the U.S. EPA's framework, the risk to estuarine fish species diversity was assessed against regional salinity profiles from a 17-year database. Based on the risk assessment, target salinity profiles for these areas are recommended for managers.

Present-day Pattern Variations in the Central and Eastern Pacific El Nino

El Niño and the Southern Oscillation (ENSO) is a cycle that is initiated in the equatorial Pacific Ocean and is recognized on interannual timescales by oscillating patterns in tropical Pacific sea surface temperatures (SST) and atmospheric circulations. Using correlation and regression analysis of datasets that include SST’s and other interdependent variables including precipitation, surface winds, sea level pressure, this research seeks to quantify recent changes in ENSO behavior. Specifically, the amplitude, frequency of occurrence, and spatial characteristics (i.e. events with maximum amplitude in the Central Pacific versus the Eastern Pacific) are investigated. The research is based on the question; “Are the statistics of ENSO changing due to increasing greenhouse gas concentrations?” Our hypothesis is that the present-day changes in amplitude, frequency, and spatial characteristics of ENSO are determined by the natural variability of the ocean-atmosphere climate system, not the observed changes in the radiative forcing due to change in the concentrations of greenhouse gases. Statistical analysis, including correlation and regression analysis, is performed on observational ocean and atmospheric datasets available from the National Oceanographic and Atmospheric Administration (NOAA), National Center for Atmospheric Research (NCAR) and coupled model simulations from the Coupled Model Inter-comparison Project (phase 5, CMIP5). Datasets are analyzed with a particular focus on ENSO over the last thirty years. Understanding the observed changes in the ENSO phenomenon over recent decades has a worldwide significance. ENSO is the largest climate signal on timescales of 2 - 7 years and affects billions of people via atmospheric teleconnections that originate in the tropical Pacific. These teleconnections explain why changes in ENSO can lead to climate variations in areas including North and South America, Asia, and Australia. For the United States, El Niño events are linked to decreased number of hurricanes in the Atlantic basin, reduction in precipitation in the Pacific Northwest, and increased precipitation throughout the southern United Stated during winter months. Understanding variability in the amplitude, frequency, and spatial characteristics of ENSO is crucial for decision makers who must adapt where regional ecology and agriculture are affected by ENSO.

Present-day Pattern Variations in the Central and Eastern Pacific El Nino

El Niño and the Southern Oscillation (ENSO) is a cycle that is initiated in the equatorial Pacific Ocean and is recognized on interannual timescales by oscillating patterns in tropical Pacific sea surface temperatures (SST) and atmospheric circulations. Using correlation and regression analysis of datasets that include SST’s and other interdependent variables including precipitation, surface winds, sea level pressure, this research seeks to quantify recent changes in ENSO behavior. Specifically, the amplitude, frequency of occurrence, and spatial characteristics (i.e. events with maximum amplitude in the Central Pacific versus the Eastern Pacific) are investigated. The research is based on the question; “Are the statistics of ENSO changing due to increasing greenhouse gas concentrations?” Our hypothesis is that the present-day changes in amplitude, frequency, and spatial characteristics of ENSO are determined by the natural variability of the ocean-atmosphere climate system, not the observed changes in the radiative forcing due to change in the concentrations of greenhouse gases. Statistical analysis, including correlation and regression analysis, is performed on observational ocean and atmospheric datasets available from the National Oceanographic and Atmospheric Administration (NOAA), National Center for Atmospheric Research (NCAR) and coupled model simulations from the Coupled Model Inter-comparison Project (phase 5, CMIP5). Datasets are analyzed with a particular focus on ENSO over the last thirty years. Understanding the observed changes in the ENSO phenomenon over recent decades has a worldwide significance. ENSO is the largest climate signal on timescales of 2 - 7 years and affects billions of people via atmospheric teleconnections that originate in the tropical Pacific. These teleconnections explain why changes in ENSO can lead to climate variations in areas including North and South America, Asia, and Australia. For the United States, El Niño events are linked to decreased number of hurricanes in the Atlantic basin, reduction in precipitation in the Pacific Northwest, and increased precipitation throughout the southern United Stated during winter months. Understanding variability in the amplitude, frequency, and spatial characteristics of ENSO is crucial for decision makers who must adapt where regional ecology and agriculture are affected by ENSO.

Curriculum development in a heritage language community-based school: A Qualitative inquiry regarding a Brazilian-Portuguese program in South Florida

This research aimed to describe, understand, and discuss the curriculum development process of a Brazilian-Portuguese heritage language community-based school in South Florida. This study was guided by the following research questions: (a) What roles does this HL community-based school aim to play for its students? This investigation was also related to the subsidiary question: (b) How does this HL community-based school organize its curriculum development process? In order to explore these research questions, I observed and interviewed teachers and coordinators based on a qualitative research approach. I analyzed the interviews’ transcripts, and the program’s website with a central focus of describing and understanding their curriculum development process. Hopefully, the findings will help Brazilian and other HL community schools toward discussing and elaborating their own curriculum development, as well as to look for specific teacher training courses.