Ecology and Evolutionary Biology Commons^™

Phosphorus Recycling By Profunda Quagga Mussels In Lake Michigan, Caroline Mosley

Theses and Dissertations

Quagga mussels (Dreissena rostiformis bugensis) act as ecosystem engineers in the southern basin of Lake Michigan, altering physical habitats and biogeochemical processes. Adapted to cold and oligotrophic conditions, profunda quagga mussels thrive on the soft substrate of deeper depths. At a 55 m site (10,000 mussels m-2) offshore from Milwaukee, WI, profunda mussel biomass (g m-2) was 1/3 of biomass (g m-2) measured at a 10 m comparison site (5,000 mussels m-2). Higher densities but less biomass is due to profunda mussels having less tissue for a given length and the population per m2 comprising of mostly small mussels ( …

Variability In The Spatial And Temporal Patterns Of Larval Scombrid Abundance In The Gulf Of Mexico, Sennai Y. Habtes

USF Tampa Graduate Theses and Dissertations

Accurate fishery-independent methods for assessing the abundance of marine fish stocks are important tools for proper pelagic fisheries management. The review and improvement of standardized sampling methods used in fisheries-independent sampling, and the establishment of improved models of abundance and population dynamics utilizing novel statistical techniques for fisheries management will further improve our understanding of the way in which marine fish stocks vary spatially and temporally. One of the most important and longest running surveys of fisheries-independent data in the Southeastern United States is the spring ichthyoplankton survey conducted through the Southeast Area Mapping and Assessment Program (SEAMAP).

These surveys …

Predictors Patterns And Processes Of Extinction Risk In Porgies And Seabreams (Family: Sparidae), Mia Theresa B. Conteros

Biological Sciences Theses & Dissertations

A variety of human-induced changes are having profound impacts on the marine environment, and no area on the planet remains unaffected by the detrimental effects of our activities. These stressors can potentially lead to synergistic effects, causing accelerated biodiversity loss and diminished ecosystem functioning. Identification and understanding of the factors that drive species to heightened risk of extinction are important goals in conservation.

The Sparidae are commercially important and ecologically complex marine fishes; global extinction risk assessments using the IUCN Red List of Threatened Species methodology show that 9% (13 species) have increased vulnerability to population declines from intense fishing …

South Atlantic Stream Fish Assemblages: Multi-Scale Structuring Factors, Trait Associations And Channelization, And Responses To Dam Removal, Cathy Marion

All Dissertations

South Atlantic coastal plain wadeable streams are unique and understudied freshwater environments that provide crucial habitats for a wide range of aquatic taxa. In Chapter 1, we investigated patterns in fish assemblages across South Carolina's coastal plain, and developed statistical models to identify the dominant multi-scale abiotic environmental factors that influence assemblage structure. Our analyses indicated the presence of four predominant fish assemblages that commonly occur in the coastal plain, which we termed the: 1) fluvial, 2) eastern mudminnow, 3) centrarchid, and 4) non-fluvial assemblages. Natural geographic gradients and instream habitat parameters associated with velocity, channel form, stream size, and …

Ontogenetic Diet Shifts And Prey Preference Of A Generalist Predatory Fish, Brittany Jalene Scharf

USF Tampa Graduate Theses and Dissertations

Marine ecosystems are highly dynamic and contain a diverse faunal assemblage that are subject to various natural and anthropogenic variability. Globally, seagrass ecosystems are located adjacent to coastal areas that are heavily impacted by human development and urbanization potentially altering the community structure within these ecosystem. Complex food webs connect many components of these systems, often in unexpected ways, and are ultimately based on one of two pathways: benthic (i.e., seagrass, epiphytes, microalgae, detritus) and planktonic (i.e., phytoplankton). Understanding the pathway which the food web is based gives further insight regarding the biological balance of the ecosystem; thus it is …

Using Otolith Elemental Composition To Track The Habitat Use, Movements, And Life History Patterns Of Common Snook (Centropomus Undecimalis) And Red Drum (Sciaenops Ocellatus) In The Tampa Bay Estuary, Holly Jacqueline Rolls

USF Tampa Graduate Theses and Dissertations

Knowledge of fish habitat use and connectivity is critical for understanding the structure and dynamics of fish populations and, therefore, necessary for the implementation of successful fisheries management strategies. Tagging is an effective means of providing such information, and the elemental composition contained within fish otoliths is increasingly being used as a natural tag. The chemical composition of otoliths reflects the incorporation of elements from different water bodies and can thus be used to understand the habitat use, movements, and life history patterns of fishes. To assess the applicability of otolith elemental composition as a tagging technique within the Tampa …

Identifying The Role Of Non-Native Species In The Enhanced Trophic Transfer Of Mercury In The Food Web Of Lake Erie, A North American Great Lake, Kaylin M.S. Liznick

Electronic Thesis and Dissertation Repository

Increasing mercury (Hg) concentrations in top predatory fish is concerning for human and wildlife health. This study examined the amount of Hg available to the food web of Lake Erie, and explored the role that two recently established non-native species, dreissenid mussels and round goby, have played in the trophic transfer of Hg to sport fish. A comprehensive sampling of total Hg (THg) and methylmercury (MeHg) within Lake Erie water, sediment and seston with high temporal and spatial resolution describes environmental concentrations. In addition, biotic THg and MeHg are quantified in benthic invertebrates and three fish species. A steep spatial …

Plankton Trophic Structure Within Lake Michigan As Revealed By Stable Carbon And Nitrogen Isotopes, Zachery G. Driscoll

Theses and Dissertations

Zooplankton represent a critical component of aquatic food webs in that they transfer energy from primary producers to higher trophic positions. However, their small size makes the application of traditional trophic ecology techniques difficult. Fortunately, novel techniques have been developed that can be used to elucidate feeding information between zooplankton species. I used the analysis of stable carbon and nitrogen isotope ratios to estimate the trophic structure of Lake Michigan's zooplankton community. The major zooplankton species, three size classes of seston, and seston from specific water column depths were collected in 2011 and 2012 for stable isotope analysis. Trophic position …

Freshwater Mussels (Bivalvia: Margaritiferidae And Unionidae) Of The Buffalo River Drainage, Tennessee, Matthew Philip Reed

Masters Theses

The Buffalo River in Tennessee once hosted a rich population of freshwater mussels. During the 1980s, monitoring efforts demonstrated evidence of drastic declines and extirpation of entire assemblages. Increases in municipal development in the headwater tributaries and agriculture in the main stem of the Buffalo River are suspected causes for mussel community declines throughout the river. In 2011, collection data documented evidence of recovery in the lower Buffalo River. The aims of this project were: 1) to update the status, distribution, and species composition of mussels in the Buffalo River and its major tributaries through qualitative sampling, and 2) to …

Habitat Selection And Partitioning Among Darters In Two Tributaries Of The Clinch River, And Stream Restoration Effects On Substrate Profile, Daniel James Walker

Masters Theses

The group of fish referred to as darters is extremely biodiverse. Often, several closely related species will inhabit the same areas of streams, and prior research has investigated how these species may be partitioning the resources in low-order streams in which they are sympatric. The habitat partitioning of darters in two streams in the Clinch River system, Coal and Cove Creeks, was investigated. The study sites were picked due to their involvement in both physical and biological stream restoration efforts within the last several years, including the collection, translocation, and reintroduction of rainbow darters (Etheostoma caeruleum) from reference sites in …

Microglia Respond To Both Permanent And Temporary Deaferentation In The Adult Zebrafish Olfactory Bulb, Amanda K. Mckenna

Masters Theses

The major goal of this study was to investigate a microglial response following deafferentation in the adult zebrafish, Danio rerio, olfactory bulb. Microglia were identified in the olfactory bulb using the 4c4 antibody and phagocytic-dependent labeling (DiA). Microglia responded to both methods of deafferentation namely, permanent (cautery) and temporary (Triton X- 100). On one and three days following both permanent and temporary deafferentation there was a significant increase in microglia in the treated olfactory bulb. At five and seven days after permanent and temporary deafferentation there was no longer a significant difference between the treated and untreated olfactory bulbs, …

Karenia Brevis Harmful Algal Blooms: Their Role In Structuring The Organismal Community On The West Florida Shelf, Alisha Marie Gray

USF Tampa Graduate Theses and Dissertations

Karenia brevis dinoflagellate blooms off the west coast of Florida can create devastating effects on marine communities when they release a neurotoxin known as a brevetoxin. These blooms, informally referred to as red tides, can cause massive fish kills, necessitate closures of shellfish fisheries, and can even leave lingering toxins that impact shelf communities long after the bloom has dissipated. As a result, much effort has been put into studying K. brevis bloom initiation and dynamics. However, how K. brevis blooms impact Florida's fisheries is not fully understood because the relationship between K. brevis cell counts and fish mortality is …

The Natural Life History Of Cambarus (Puncticambarus) Smilax, The Greenbrier Crayfish, Paul William Hughes

Theses, Dissertations and Capstones

The natural life history of Cambarus (Puncticambarus) smilax, the Greenbrier Crayfish, was studied in West Fork of the Greenbrier River and in Thorny Creek, a tributary of the main stem of the Greenbrier River. The Greenbrier Crayfish gets its name from the Greenbrier River watershed where it is thought to occur exclusively. Among described members of the subgenus Puncticambarus, C. smilax is a sister taxon most similar to Cambarus (Puncticambarus) robustus. Monthly collections were made within the two study sites, from August 2010 to July 2011. Collecting techniques included dip-netting, seine-netting, and hand collecting. Cambarus smilax and all other species …

The Effects That Liquid And Solid Cattle Manure Have On The Water Quality Of Drainage Ditches In Putnam County, Ohio, Janelle Horstman

Honors Projects

Lake Erie has experienced harmful algal blooms with increased frequency since the mid-1990s due to excess nutrients from Rivers, such as the Maumee River, and largely agricultural watersheds. Nonpoint source pollution from agriculture contributes to eutrophication, algal blooms, and the degradation of water quality. This creates stress on aquatic fauna, reduced aesthetic quality, odor, and limits of the water for usage of drinking, recreation, and industry. This research paper asks what the contributions of having access to manure application records, soil records, and information about antibiotics have on what is known about manure management and antibiotic resistance, which has been …

The Impact Of Multiple Nursery Areas On The Population Structure Of Atlantic Menhaden, Brevooria Tyrannus, Kristen A. Anstead

OES Theses and Dissertations

Understanding the population structure and patterns of connectivity in marine fishes is essential when making predictions about a species' resiliency and persistence in an increasingly changing environment. The Atlantic Menhaden Brevoortia tyrannus is a clupeid that plays a critical role in the marine food web and supports one of the largest fisheries on the US East Coast. In addition to a decrease in overall numbers and spawning stock biomass, recruitment levels have remained low since the 1990s. Menhaden use numerous estuaries along the Atlantic coast for juvenile development before recruiting to the adult population and the contribution of each of …