Ecology and Evolutionary Biology Commons^™

North American River Otter (Lontra Canadensis) Presence And Habitat Analysis In Florida As Compared To Historical Data, Samantha Wilber

USF Tampa Graduate Theses and Dissertations

North American river otters are considered common in the state of Florida, but their populations have not been studied since the 1980’s. Since that time, Florida’s human population has more than doubled, and many natural areas of Florida have been developed. The aim of this study was to determine the presence or absence of river otters at locations in Florida which they historically inhabited. Forty-six sample sites where otters were historically found were obtained from the Florida Museum of Natural History Mammals Master Database (FMNH MMD). These sites were condensed to two focus areas, in and around Alachua and Collier …

Identifying Humanized Ecosystems: Anthropogenic Impacts, Intentionality, And Resource Acquisition At Crystal River (8ci1) And Roberts Island (8ci41), Charles Trevor Duke

USF Tampa Graduate Theses and Dissertations

The impact of human activity on ecosystems is an issue at the forefront of global concern. Marine ecosystems are a particular concern, given their importance for human sustenance. Through the removal of species that are highly susceptible to the effects of overfishing, global fisheries have been driven to near collapse in recent decades. The long-term effects of such practices has resulted in declines in mean trophic level of aggregate fish catches over time, as well as decreasing diversity of species available for regular harvest (Jackson et al. 2001; Pauly et al. 1998). These supposedly “modern” problems have been recently identified …

Emergent Insect And Neotropical Migratory Bird Interactions And Responses To Habitat, Hydrology, And Progressive Urbanization In The Tampa Bay Region, Nathaniel Lee Goddard

USF Tampa Graduate Theses and Dissertations

The growing human population threatens the many of the earth’s biological systems. In the last 600 years extinction rates risen from 1 extinction per million species per year (E/MSY) in the 1400’s to 50 E/MSY today. During this time period 1.5% of all known birds have gone extinct, because they could not adapt quickly enough to human mediated changes. The goal of this dissertation was to determine how urbanization and anthropogenic services needed to support urban areas impact cypress dome wetland aquatic insect and migratory bird populations that depend on them. In Central Florida cypress dome hydroperiods are driven by …

A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary

USF Tampa Graduate Theses and Dissertations

Because nitrogen isotopes are fractionated along the soil-plant-insect-bat-guano pathway, it may be possible to reconstruct environmental and climatic changes reflected in the nitrogen isotopic composition of guano. A 1.5-m core of bat guano from Zidită Cave (western Romania) provides a record of climatic and anthropogenic influence on the regional nitrogen cycle and paleoenvironmental controls on nitrogen transforming processes. Increasing and decreasing trends of nitrogen isotopic composition (δ¹⁵N values) correspond well with changes in the influence of farming practices, deforestation, and forest expansion. These influences likely had a significant effect on the openness of the nitrogen cycle, resulting in …

Historical And Current Population Patterns Of The Staghorn Coral (_Acropora Cervicornis_) In Dry Tortugas National Park, Kaitlyn Lizza

USF Tampa Graduate Theses and Dissertations

Acropora cervicornis was once one of the dominant reef building corals of the Caribbean, Florida Keys, and Dry Tortugas (DRTO), but since the 1970’s populations have been decimated throughout their geographic range. Recently, a repopulation was documented through detailed benthic surveys conducted by the U.S. Geological Survey at three locations (Pulaski Shoal, East Key, and Loggerhead Key) within DRTO. Benthic surveys using the U.S Geological Survey’s Along-Track Reef Imaging System (ATRIS) revealed hundreds of previously undocumented colonies.

These discoveries have provided a unique data-set, allowing a comparison between the historical (1883, 1976) and contemporary distributions (2009, 2011) of A. cervicornis. …

Comparison Of Gastropod Assemblages From Natural And Phosphate Mine Lakes Of Central Florida, William A. Mailand

USF Tampa Graduate Theses and Dissertations

Investigations were made examining the relationships between gastropod species richness and abundance across 20 phosphate and 20 natural lakes in Central Florida. In additional to lake category, age of phosphate lakes was used to determine if phosphate lakes ever approximate natural lakes. Additional physical, chemical, and biological parameters, including chlorophyll a, Ca, secchi, phosphorous, conductance, fish predation, and recreational lake use were investigated in order to determine if they affected gastropods with lake age. Comparisons were also made between gastropod species richness and average abundance and two groups of dominant vegetation categories: Panicum, a structurally complex macrophyte, and Typha …

Impacts Of Agrochemical Pollution On Aquatic Communities And Human Disease, Neal T. Halstead

USF Tampa Graduate Theses and Dissertations

The global human population is expected to exceed 9 billion individuals by 2050, putting greater strain on the natural resources needed to sustain such a population. To feed this many people, some expect agricultural production will have to double and agrochemical use will have to increase anywhere from two- to five-fold relative to the turn of the century. Although industrial agriculture has provided many benefits to society, it has caused declines in biodiversity, both directly (e.g., through conversion of habitat) and indirectly (e.g., through contamination of adjacent natural habitats). Agricultural activity has also been linked to increased prevalence and intensity …

Comparison Of Isotope-Based Biomass Pathways With Groundfish Community Structure In The Eastern Gulf Of Mexico, Sheri Ann Huelster

USF Tampa Graduate Theses and Dissertations

This study compared traditional community analysis with stable-isotope trophic analysis to define process-based trophic elements of community structure in the eastern Gulf of Mexico, and developed a predictive capability regarding changes to fish community structure that would be expected from increasing eutrophication. Specifically, it used an existing trawl survey program (SEAMAP) to compare invertebrate herbivore (sponge and sea urchin) isotopes with groundfish isotopes, and then compared the resulting spatial patterns with spatial variation in community structure, as identified by cluster analysis. The comparison was applied to seven NMFS survey zones that extended offshore from the Caloosahatchee River, FL northwest to …