Phytoplankton serve as the bottom of the marine food web and therefore play an essential role in marine ecosystems. On the other hand, coastal phytoplankton communities can adversely affect the marine ecosystem and humans. A variety of techniques have been developed to measure and study phytoplankton, including in situ methods (e.g., flow cytometry) and laboratory methods (e.g., microscopic taxonomy). These provide accurate measurements of phytoplankton taxa and concentrations, yet they are limited in space and time, and synoptic information is difficult to obtain with these techniques. Optical remote sensing may provide complementary information for its synoptic nature, as demonstrated by satellite estimates of major phytoplankton taxa in major ocean basins. It has remained a challenge, however, for coastal and estuarine waters due to their optical complexity. One pioneering work relied on hyperspectral absorption spectra of phytoplankton pigments (Millie et al., 1995), from which Gymnodinium breve (i.e., Karenia brevis) blooms on the West Florida shelf could be detected and quantified in situ. However, whether a similar approach can be developed for estuarine waters where toxic blooms are often found is still unknown. Thus, the objective of this study is to test and develop an approach to classify major phytoplankton taxa found in two estuaries in Florida, U.S.A., based on optical analysis of the phytoplankton absorption spectra. In this study, over 250 surface water samples were collected on numerous cruise surveys from two Florida estuaries (Tampa Bay, ∼1000 km2 on the west coast; and the Indian River Lagoon, ∼900 km2 on the east coast). The samples were filtered and then processed using standard NASA protocols to determine 1) their spectral absorption coefficients due to phytoplankton pigments, aph (λ) (m-1), and 2) their chlorophyll a concentrations (mg m-3). aph (λ) was further normalized by Chl a, resulting in chlorophyll-specific absorption coefficient, a aph∗ (λ) (m2 mg-1). For each sample, phytoplankton cell counts were enumerated by the Florida Wildlife Conservation Commission (FWC) Fish and Wildlife Research Institute (FWRI) through microscopic taxonomy. The a aph∗ (λ) data were then categorized based on the dominant phytoplankton taxa, and were separated as either bloom or non-bloom using a 100,000 cell∕L threshold of the dominant taxa. Three techniques were tested for classifying phytoplankton taxa using absorption spectra; a first derivative summation, a relative height analysis, and an integration analysis. The integration technique proved to be the most successful of the three. This technique performed an integration of a aph∗ (572-600nm) against a linear baseline, and yielded an 81% success rate (13 of 16 samples) and 9% false positive rate (13 of 144 samples) in separating blooms of the dinoflagellate Pyrodinium bahamense from other bloom and non-bloom taxa found in the Tampa Bay estuary. The same integration technique, but with the wavelength range shifted to 471 nm - 490 nm, was also applied to the samples collected in the Indian River Lagoon estuary from summer 2011 to study the green flagellate of the class Pedinophyceae.. The results showed an 80% success rate (8 of 10 samples) and a 0.5% false positive rate (1 of 156 samples) in separating the Pedinophyceae bloom taxa from other bloom and non-bloom taxa found in both the Indian River Lagoon and Tampa Bay. The number of bloom samples was relatively low (16 from Tampa Bay and 10 from IRL). Thus, the results from this study are preliminary and will require more sampling in order to further develop this technique to a practical method for field use. However, the results obtained from this study are comparable to those from other techniques for classification of phytoplankton taxa, for example, BreveBuster, SIPPER, FlowCAM, and satellite ocean color remote sensing of the open ocean. Yet this technique extends to optically complex estuarine waters, and therefore may represent a step towards the ultimate goal of applying satellite remote sensing in characterizing phytoplankton taxa in estuaries. Once confirmed with more samples from the same two estuaries as well as from other estuaries, an immediate next step may be the implementation of in situoptical instruments on either buoys (e.g., MARVIN in Tampa Bay) or flow-through systems to provide continuous characterization of major phytoplankton taxa in the two estuaries.

Thesis (M.S.)--University of Florida, 2004. / Title from PDF title page (viewed on July 7, 2005). Includes vita. Includes bibliographical references (p. 83-85).

Gene Transfer Agents (GTAs) are phage-like pthesiss that are produced by many alpha proteobacteria in late stationary growth phase and are capable of transferring chromosomal genes (termed "constitutive transduction"). Examination of alpha proteobacterial genomic sequences indicated widespread occurrence of GTA-like elements. The goal of this study was to investigate gene transfer potential of GTAs of marine alpha proteobacteria in culture as well as in natural marine environments. Another goal was to determine the potential of bacterial symbionts from zooxanthellae and coral to genetically transfer beneficial properties between symbionts. Ruegeria mobilis (ID 45A6) was isolated from cultures of the coral endosymbiotic dinoflagellate, Symbiodinium spp. A goal of the research was to determine if GTAs from this isolate have the capability of transferring genes to environmental recipients and have an impact on settlement of coral larvae. Little is known about coral settlement cues, yet there may be contributions from the extensive symbiotic relationship of coral reef-associated bacteria. Several gene transfer experiments in different environments were performed using transformed isolates of Ruegeria mobilis containing a transposon marker gene. Experiments were also performed using GTAs from the Ruegeria mobilis isolate to observe any impact GTAs have on coral larval settlement, using larvae from the brooding coral, Porites astreoides, and from the reef building coral, Montastraea faveolata. Gene transfer frequencies from statistically significant gene transfer experiments resulted in an average of 2.92 × 10-1 (transfer recipients to total viable population). Coral settlement experiments resulted in a statistically significant increase in larval settlement with the addition of GTAs for 80% of the executed experiments. The entire study has demonstrated that GTA-mediated gene exchange is much higher than any other mode of horizontal gene transfer and it has been established that these genes can be exchanged between bacterial taxa. GTAs can also have an impact on coral larval settlement mechanisms that are not yet completely understood. GTA-mediated beneficial gene exchange may be an important driver in adaptation to an evolving planet.

A hierarchical and standardized environmental disturbance index, specifically designed for karst landscapes, was created by van Beynen and Townsend (2005). To assess the applicability of the index and provide recommendations for its refinement, the index was applied in four west-central Florida counties and interviews were conducted with local and state officials, community planners, and land resource managers. The karst disturbance index consists of 30 indicators contained within five broad categories: geomorphology, hydrology, atmosphere, biota, and culture. Data was readily available for most environmental indicators used to construct the index. Overall, levels of disturbance vary between the counties due to the level of urbanization, with the highly populated Hillsborough and Pinellas Counties having higher degrees of disturbance than less developed Pasco and Hernando Counties. While this result may seem obvious, the measure of disturbance using many indicators provides benchmarks of levels of disturbance that can be reassessed with time and highlights those aspects of the environment most in need of attention. Several minor issues arose during the testing: the need for broader indicator descriptions that encompass a variety of scenarios, a new water quality indicator, obsolete sinkhole data, and a lack of data for biota indicators. The lack of data for certain indicators suggests where future research efforts can be directed.

The purposes of this research were to determine the efficacy of using the Ogawa® passive sampling device (PSD) to measure ammonia and to identify significant ammonia sources adjacent to Hillsborough and Tampa Bay. Ninety-four samplers were deployed over a 180-km2 area for two weeks in October 2001. Within the area sampled were located suburbs, an urban center, major highways, port activities, fertilizer manufacturing, wastewater treatment, coal-combustion power plants, warehousing and dairy farming. The sampled locations were arranged in a triangular grid pattern spaced 1.5 km apart. The pattern was designed to locate circular hot spots with a minimum radius of 0.75 km. The minimum, maximum, mean, and median ammonia concentrations were 0.06, 15, 2.0, and 1.5 mg/m3, respectively, and the estimated precision was 16%. Hot spots identified from kriged concentration data coincided with inventoried ammonia sources. The relative bias and precision of the PSD based on collocation with an annular denuder system were (plus or minus) 30 % and 20 %.

Several studies have found separation of biogeographic provinces on the West Florida Shelf (WFS), but the location of this separation differs depending on different organisms with faunal boundaries proposed at Apalachicola, Cedar Key, Anclote Key. Tampa Bay, Charlotte Harbor, Cape Romano, or Cape Sable. Biogeographic boundaries can be gradual over a given space and are often species-specific. Analyses of marine benthic mapping and community characterization of Florida’s West-central coast shallow water (depth) hardbottom habitats indicate a major shift in the benthos across Tampa Bay. Quantitative benthic surveys of 29 sites yielded a total of 4,079 individuals of nine stony coral species and 1,918 soft coral colonies. Populations were dominated by four species of corals: Siderastrea radians, Oculina robusta, Solenastrea hyades, and Cladacora arbuscula. Most corals were less than 10 cm in diameter. Cluster analyses of coral density and major functional group percent cover showed distinct differences in hard and soft coral densities and species demographics from south to north with clear spatial patterns between regions. These benthic hardbottom coral communities change over a relatively small spatial scale (10’s of km), indicating a biogeographical province or ecosystem region boundary in marine benthic communities at, or very near, the mouth of Tampa Bay. Broader studies are needed to identify the shifts in benthic community biogeography along the West Florida Shelf.

Document formatted into pages; contains 115 pages. / Title from PDF of title page. / Original thesis was submitted in HTML and can be accessed at http://www.lib.usf.edu/EDT-db/theses/available/etd-10262001-162331/unrestricted/default.htm / Thesis (M.S.)--University of South Florida, 2002. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The purposes of this research were to determine the efficacy of using the Ogawa]a passive sampling device (PSD) to measure ammonia and to identify significant ammonia sources adjacent to Hillsborough and Tampa Bay. Ninety-four samplers were deployed over a 180-km2 area for two weeks in October 2001. Within the area sampled were located suburbs, an urban center, major highways, port activities, fertilizer manufacturing, wastewater treatment, coal-combustion power plants, warehousing and dairy farming. The sampled locations were arranged in a triangular grid pattern spaced 1.5 km apart. The pattern was designed to locate circular hot spots with a minimum radius of 0.75 km. The minimum, maximum, mean, and median ammonia concentrations were 0.06, 15, 2.0, and 1.5 mg/m3, respectively, and the estimated precision was 16%. Hot spots identified from kriged concentration data coincided with inventoried ammonia sources. / ABSTRACT: The relative bias and precision of the PSD based on collocation with an annular denuder system were (plus or minus) 30 % and 20 %. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

The purpose of this study was to describe and explain participants’ perceptions of Tampa Bay Area Writing Project (TBAWP) influence on professional learning over time. This study explored Writing Project impact on professional learning by accessing the oral histories of three educators who were involved in TBAWP between 1998 and 2004. The research question was: • In what ways, if any, has long-term involvement in the Tampa Bay Area Writing Project impacted the teaching practice, career growth, and professional learning of participating educators? This qualitative study employed constructivism as the theoretical framework. Analysis of study data resulted in specific findings. Educators’ stories revealed Writing Project participation significantly impacted their teaching practice, career growth, and professional learning. The lasting impact of Writing Project involvement was seen in the ways in which educators infused the concept of community into their teaching practice, accepted leadership positions within the profession, and ultimately went on to conduct professional learning experiences for educators. Data analysis generated a conceptual model that examines the lasting impact of educator professional learning. Implications of this finding are significant for longitudinal inquiry of educator professional learning and for impact studies of long-term Writing Project involvement. In addition to providing exemplars of educator stories of practice over time, the study contributed to development of a fuller understanding of effective professional development, educator professional learning, and the lasting impact of Writing Project involvement.

Improvements for environmental monitoring and assessment were achieved to advance our understanding of sea-land interactions and nutrient cycling in a coastal bay.; The comprehensive assessment techniques for monitoring of water quality of a coastal bay can be diversified via an extensive investigation of the spatiotemporal nutrient patterns and the associated eco-hydrological trends in a coastal urban region. With this work, it is intended to thoroughly investigate the spatiotemporal nutrient patterns and associated eco-hydrological trends via a two part inquiry of the watershed and its adjacent coastal bay. The findings show that the onset of drought lags the crest of the evapotranspiration and precipitation curve during each year of drought. During the transition year, ET and precipitation appears to start to shift back into the analogous temporal pattern as the 2005 wet year. NDVI shows a flat receding tail for the September crest in 2005 due to the hurricane impact signifying that the hurricane event in October dampening the severity of the winter dry season in which alludes to relative system memory. The k-means model with 8 clusters is the optimal choice, in which cluster 2 at Lower Tampa Bay had the minimum values of total nitrogen (TN) concentrations, chlorophyll a (Chl-a) concentrations, and ocean color values in every season as well as the minimum concentration of total phosphorus (TP) in three consecutive seasons in 2008. Cluster 5, located in Middle Tampa Bay, displayed elevated TN concentrations, ocean color values, and Chl-a concentrations, suggesting that high colored dissolved organic matter values are linked with some nutrient sources. The data presented by the gravity modeling analysis indicate that the Alafia River Basin is the major contributor of nutrients in terms of both TP and TN values in all seasons. Such ecohydrological evaluation can be applied for supporting the LULC management of climatic vulnerable regions as well as further enrich the comprehensive assessment techniques for estimating and examining the multi-temporal impacts and dynamic influence of urban land use and land cover.

No description available.