Life Sciences Commons^™

Ocean Currents And Sea Surface Heights Estimated Across The West Florida Shelf, Yonggang Liu, Robert H. Weisberg

Marine Science Faculty Publications

The across-shelf structures of the ocean circulation and the associated sea surface height (SSH) variability are examined on the west Florida shelf (WFS) for the 3-yr interval from September 1998 to December 2001. Five sets of characteristic circulation patterns are extracted from 2-day, low-pass-filtered data using the self-organizing map: extreme upwelling and downwelling structures with strong currents, asymmetric upwelling and downwelling structures with moderate currents, and a set of transitional structures with weak currents. The temporal variations of these structures are coherent with the local winds on synoptic weather time scales. On seasonal time scales they are related to both …

Bathymetric Alterations Due To Urbanization And Their Effects On Residual Salinity, Flow Field And Transport Time For Tampa Bay, Florida, Amanda J. Linville

USF Tampa Graduate Theses and Dissertations

Growth and development over the past one hundred years has resulted in the construction of causeways and navigational channels in Tampa Bay. Urbanization has lead to bathymetric alterations of the bay, and thus has effectively changed the residual salinity, flow fields, and transport time in Tampa Bay. In this study a numerical ocean model of Tampa Bay was first used to simulate the circulation for 2001-2003 using present day bathymetry. Then, an identical simulation was performed using the bathymetry generated from 1879 depth soundings. The residual (30-day time average) circulation fields and salinity, along with transport times was intercompared for …

Particulate Organic Carbon Fluxes Along Upwelling-Dominated Continental Margins: Rates And Mechanisms, Robert C. Thunell, Claudia Benitez-Nelson, Ramon Varela, Yrene Astor, Frank E. Muller-Karger

Marine Science Faculty Publications

Time series sediment trap samples were used to examine the rates and mechanisms of particulate organic carbon (POC) flux at three continental margin locations, Santa Barbara Basin, Cariaco Basin, and Guaymas Basin, marked by seasonal upwelling and high primary production. The mean POC flux in Santa Barbara Basin (0.096 g m⁻² d⁻¹) is nearly twice that of Cariaco Basin and 4 times higher than that in Guaymas Basin, with all three sites having POC fluxes significantly higher than the open ocean average (0.007 g m⁻² d⁻¹). In Cariaco Basin, the only site with available …

Community Composition Of Crustaceans And Gastropods On Caulerpa Prolifera, Halodule Wrightii And Thalassia Testudinum, Jennifer A. Gibson

USF Tampa Graduate Theses and Dissertations

No abstract provided.

Euphotic Zone Depth: Its Derivation And Implication To Ocean-Color Remote Sensing, Zhongping Lee, Alan Weidemann, John Kindle, Robert Arnone, Kendall L. Carder, Curtiss Davis

Marine Science Faculty Publications

Euphotic zone depth, z_1%, reflects the depth where photosynthetic available radiation (PAR) is 1% of its surface value. The value of z_1% is a measure of water clarity, which is an important parameter regarding ecosystems. Based on the Case‐1 water assumption, z_1% can be estimated empirically from the remotely derived concentration of chlorophyll‐a ([Chl]), commonly retrieved by employing band ratios of remote sensing reflectance (R_rs). Recently, a model based on water's inherent optical properties (IOPs) has been developed to describe the vertical attenuation of visible solar radiation. Since IOPs can be near‐analytically calculated …

Multivariate Reconstruction Of Missing Data In Sea Surface Temperature, Chlorophyll, And Wind Satellite Fields, Aida Alvera-Azcarate, Alexander Barth, J. M. Beckers, Robert H. Weisberg

Marine Science Faculty Publications

An empirical orthogonal function–based technique called Data Interpolating Empirical Orthogonal Functions (DINEOF) is used in a multivariate approach to reconstruct missing data. Sea surface temperature (SST), chlorophyll a concentration, and QuikSCAT winds are used to assess the benefit of a multivariate reconstruction. In particular, the combination of SST plus chlorophyll, SST plus lagged SST plus chlorophyll, and SST plus lagged winds have been studied. To assess the quality of the reconstructions, the reconstructed SST and winds have been compared to in situ data. The combination of SST plus chlorophyll, as well as SST plus lagged SST plus chlorophyll, significantly improves …

Developing Standards For Dissolved Iron In Seawater, Kenneth Johnson, Virginia Elrod, Steve Fitzwater, Joshua Plant, Edward Boyle, Bridget Bergquist, Kristen N. Buck

Marine Science Faculty Publications

In nearly a dozen open‐ocean fertilization experiments conducted by more than 100 researchers from nearly 20 countries, adding iron at the sea surface has led to distinct increases in photosynthesis rates and biomass. These experiments confirmed the hypothesis proposed by the late John Martin [Martin, 1990] that dissolved iron concentration is a key variable that controls phytoplankton processes in ocean surface waters However, the measurement of dissolved iron concentration in seawater remains a difficult task [Bruland and Rue, 2001] with significant interlaboratory differences apparent at times. The availability of a seawater reference solution with well‐known dissolved …

Satellite-Derived Surface Current Divergence In Relation To Tropical Atlantic Sst And Wind, Robert W. Helber, Robert H. Weisberg, Fabrice Bonjean, Eric S. Johnson, Gary S. Lagerloef

Marine Science Faculty Publications

The relationships between tropical Atlantic Ocean surface currents and horizontal (mass) divergence, sea surface temperature (SST), and winds on monthly-to-annual time scales are described for the time period from 1993 through 2003. Surface horizontal mass divergence (upwelling) is calculated using surface currents estimated from satellite sea surface height, surface vector wind, and SST data with a quasi-linear, steady-state model. Geostrophic and Ekman dynamical contributions are considered. The satellite-derived surface currents match climatological drifter and ship-drift currents well, and divergence patterns are consistent with the annual north–south movement of the intertropical convergence zone (ITCZ) and equatorial cold tongue evolution. While the …

Effects Of Ice Melting On Grace Observations Of Ocean Mass Trends, Don P. Chambers, Mark E. Tamisiea, R Steven Nerem, John C. Ries

Marine Science Faculty Publications

The Gravity Recovery and Climate Experiment (GRACE) was designed to measure variations in the Earth's gravity field from space at monthly intervals. Researchers have used these data to measure changes in water mass over various regions, including the global oceans and continental ice sheets covering Greenland and Antarctica. However, GRACE data must be smoothed in these analyses and the effects of geocenter motions are not included. In this study, we examine what effect each of these has in the computation of ocean mass trends using a simulation of ice melting on Greenland, Antarctica, and mountain glaciers. We find that the …

Progressive Dolomitization Of Florida Limestone Recorded By Alkaline Earth Element Concentrations In Saline, Geothermal, Submarine Springs, Johan Schijf, Robert H. Byrne

Marine Science Faculty Publications

Studies in the late 1970s revealed that the effluents of saline, geothermal, submarine springs on the West Florida Shelf have compositions nearly identical to seawater, except for distinct Ca enrichments and Mg depletions, probably resulting from dolomitization. During annual visits between 1996 and 2003 we collected high‐purity effluents from four submarine springs and from Warm Mineral Springs (WMS), which is located on land. Filtered effluents were analyzed for major ions and for Sr and Ba. These analyses confirm the seawater‐like composition of the effluents as well as the Ca enrichment and Mg depletion. The alkaline earth elements Sr and Ba, …

Comment On “Modern-Age Buildup Of Co2 And Its Effects On Seawater Acidity And Salinity” By Hugo A. Loáiciga, Ken Caldeira, David Archer, James P. Barry, Richard G. Bellerby, Peter G. Brewer, Long Cao, Andrew G. Dickson, Scott C. Doney, Harry Elderfield, Victoria J. Fabry, Richard A. Feely, Jean-Pierre Gattuso, Peter M. Haugan, Ove Hoegh-Guldberg, Atul K. Jain, Joan A. Kleypas, Chris Langdon, James C. Orr, Andy Ridgwell, Christopher L. Sabine, Brad A. Seibel, Yoshihisa Shirayama, Carol Turley, Andrew J. Watson, Richard E. Zeebe

Marine Science Faculty Publications

No abstract provided.

National Assessment Of Shoreline Change, Part 4: Historical Coastal Cliff Retreat Along The California Coast, Cheryl J. Hapke, David Reid

Marine Science Faculty Publications

Coastal cliff retreat, the landward migration of the cliff face, is a chronic problem along many rocky coastlines in the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information regarding trends and rates of coastal cliff retreat. There is also a need for a comprehensive analysis of cliff retreat that is consistent from one coastal region to another. To meet these national needs, the U.S. Geological Survey is conducting an analysis of historical coastal cliff retreat along open-ocean rocky coastlines of the conterminous United States and parts …

Orbital And Atmospheric Forcing Of Western Antarctic Peninsula Climate In The Holocene: The Tex86 Paleotemperature Record Of Palmer Deep, Amelia E. Shevenell, A. E. Ingalls, E. W. Domack

Marine Science Faculty Publications

A detailed TEX₈₆ sea surface temperature record is presented from a well-dated hemipelagic sedimentary sequence drilled in Palmer Deep, on the western Antarctic Peninsula continental margin (ODP Hole 1098B; 1010 m). To test the regional utility of the TEX₈₆ proxy, surface sediment samples with paired CTD casts were acquired and results show the promise of TEX₈₆ in this region. Down core TEX₈₆-derived temperatures at Site 1098 range between 0 and 6°C during the Holocene (0-12 ky). A long-term Holocene cooling of ~3°C is suggested and is punctuated by millennial scale temperature variability. The TEX_{86 …}

Long-Term And Storm-Related Shoreline Change Trends In The Florida Gulf Islands National Seashore, Cheryl J. Hapke, Mark Christiano

Marine Science Faculty Publications

Coastal erosion on Northern Gulf of Mexico barrier islands is an ongoing issue that was exacerbated by the storm seasons of 2004 and 2005 when several hurricanes made landfall in the Gulf of Mexico. Two units of the Gulf Islands National Seashore (GUIS), located on Santa Rosa Island, a barrier island off the Panhandle coast of Florida, were highly impacted during the hurricanes of 2004 (Ivan) and 2005 (Cindy, Dennis, Katrina and Rita). In addition to the loss of or damage to natural and cultural resources within the park, damage to park infrastructure, including park access roads and utilities, occurred …

Exploring The Vast Diversity Of Marine Viruses, Mya Breitbart, Luke Thompson, Curtis Suttle, Matthew Sullivan

Marine Science Faculty Publications

No abstract provided.

Coral-Based Climate Variability In The Western Pacific Warm Pool Since 1867, Terrence M. Quinn, Frederick W. Taylor, Thomas J. Crowley

Marine Science Faculty Publications

We have generated monthly resolved, stable isotope (δ¹⁸O and δ¹³C) and Sr/Ca time series from a massive Porites coral from Rabaul (4°S, 152°E): a site located in the warmest sector of the Western Pacific Warm Pool (WPWP). The coral δ¹⁸O and Sr/Ca time series are well correlated to each other and positive excursions in both records coincide with times of ENSO warm phase events. These time series contain abundant interannual variability that exhibits the well‐recognized pattern of low amplitude ENSO variation between ∼1920–1960 and high amplitude ENSO variation between 1880–1920 and 1960–1997. The …

Red Tides In The Gulf Of Mexico: Where, When, And Why?, John J. Walsh, J. K. Jolliff, B. P. Darrow, J. M. Lenes, S. P. Milroy, A. Remsen, D. A. Dieterle, Kendall L. Carder, F. R. Chen, Gabriel A. Vargo, Robert H. Weisberg, Kent A. Fanning, Eugene Shinn, K. A. Steidinger, Cynthia A. Heil, C. R. Tomas, J. S. Prospero, T. N. Lee, G. J. Kirkpatrick, T. E. Whitledge, D. A. Stockwell, T. A. Villareal, A. E. Jochens, P. S. Bontempi, Frank E. Muller-Karger

Marine Science Faculty Publications

Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus‐rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron‐rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen‐poor sea water. They and the co‐occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near‐bottom seed populations to CDOM‐rich …

Subcentennial-Scale Climatic And Hydrologic Variability In The Gulf Of Mexico During The Early Holocene, Jenna M. Lodico, Benjamin P. Flower, Terrence M. Quinn

Marine Science Faculty Publications

An early Holocene record from the Gulf of Mexico (GOM) reveals climatic and hydrologic changes during the interval from 10.5 to 7 thousand calendar years before present from paired analyses of Mg/Ca and δ¹⁸O on foraminiferal calcite. The sea surface temperature record based on foraminiferal Mg/Ca contains six oscillations and an overall ∼1.5°C warming that appears to be similar to the September–March insolation difference. The δ¹⁸O of seawater in the GOM (δ¹⁸O_GOM) record contains six oscillations, including a −0.8‰ excursion that may be associated with the “8.2 ka climate event” or a …

Evaluation Of New Grace Time-Variable Gravity Data Over The Ocean, Don P. Chambers

Marine Science Faculty Publications

Monthly GRACE gravity field models from the three science processing centers (CSR, GFZ, and JPL) are analyzed for the period from February 2003 to April 2005 over the ocean. The data are used to estimate maps of the mass component of sea level at smoothing radii of 500 km and 750 km. In addition to using new gravity field models, a filter has been applied to estimate and remove systematic errors in the coefficients that cause erroneous patterns in the maps of equivalent water level. The filter is described and its effects are discussed. The GRACE maps have been evaluated …

Cold Event In The South Atlantic Bight During Summer Of 2003: Anomalous Hydrographic And Atmospheric Conditions, Alfredo Aretxabaleta, James R. Nelson, Jack O. Blanton, Harvey E. Seim, Francisco E. Werner, John M. Bane, Robert H. Weisberg

Marine Science Faculty Publications

Unusually cold seawater temperatures were observed along much of the U.S. eastern seaboard during the summer of 2003. In this study, hydrographic and atmospheric observations from spring through summer were analyzed to track the evolution of the cold water event in the South Atlantic Bight (SAB) and investigate links to various forcing mechanisms. The hydrographic observations included 13 cross‐shelf transects over the central region of the SAB, surface temperature time series from several NDBC stations, and bottom temperatures from a mid shelf mooring. Atmospheric data were obtained from NDBC stations. Additional data included water level from NOS stations and river …

Performance Evaluation Of The Self-Organizing Map For Feature Extraction, Yonggang Liu, Robert H. Weisberg, Christopher N. K. Mooers

Marine Science Faculty Publications

Despite its wide applications as a tool for feature extraction, the Self‐Organizing Map (SOM) remains a black box to most meteorologists and oceanographers. This paper evaluates the feature extraction performance of the SOM by using artificial data representative of known patterns. The SOM is shown to extract the patterns of a linear progressive sine wave. Sensitivity studies are performed to ascertain the effects of the SOM tunable parameters. By adding random noise to the linear progressive wave data, it is demonstrated that the SOM extracts essential patterns from noisy data. Moreover, the SOM technique successfully chooses among multiple sets of …

A Determination Of Phylogeny And Hybridization History Within Clematis L. (Ranunculaceae) Using Actin And Nitrate Reductase Intron Sequences, Kimberly Fearn Do

USF Tampa Graduate Theses and Dissertations

The phylogeny of Clematis, section Viorna, was characterized in this study using molecular data. Two nuclear introns were sequenced for a variety of taxa: actin and nitrate reductase. Actin intron sequence data yielded very little phylogenetic information. Some basal clades were resolved, but there were very few well supported relationships between species of the Viorna section in both the neighbor joining and maximum parsimony analyses. Nitrate reductase intron sequence data was slightly more variable. The number of well supported relationships in both the neighbor joining and maximum parsimony analyses for nitrate reductase was greater, but still not sufficient …

An Evaluation Of The Along Track Reef Imaging System (Atris) For Efficient Reef Monitoring And Rapid Groundtruthing Of Eaarl Lidar, Nicole O. Caesar

USF Tampa Graduate Theses and Dissertations

The Along-Track Reef-Imaging System (ATRIS) is a vessel-mounted, digital camera, depth sounder and Global Positioning System (GPS) package that facilitates the rapid capture of underwater images in shallow-water benthic environments. This technology has the potential to collect ecologically significant data, particularly in benthic habitats less than 10 m in depth, with better location referencing and in less time than is required for surveys carried out by Scuba divers. In October 2004, ATRIS was tested coincidently with SCUBA-assisted video along transects on five patch reefs in Biscayne National Park. Images from both data sets were subsampled, viewed, and benthic cover under …

Assessment Of Image Analysis As A Measure Of Scleractinian Coral Growth, Steven K. Gustafson

USF Tampa Graduate Theses and Dissertations

Image analysis was used to measure basal areas of selected colonies of Montastraea annularis and Porites astreoides, following the colonies over a three-year period from 2002 to 2004. Existing digital images of permanently-marked quadrats in the Caye Caulker Marine Reserve, Belize, were selected based on image quality and availability of images of selected quadrats for all three years. Annual growth rates were calculated from the basal-area measurements. Mean growth rates (radial skeletal extension) for M. annularis and P. astreoides were 0.02 cm yr-1 and -0.20 cm yr-1, respectively. Basal area measurements demonstrated a large degree of variability. Increases were approximately …

Reproducibility Of Geochemical And Climatic Signals In The Atlantic Coral Montastraea Faveolata, Jennifer M. Smith, Terrence M. Quinn, Kevin P. Helmle, Robert B. Halley

Marine Science Faculty Publications

Monthly resolved, 41‐year‐long stable isotopic and elemental ratio time series were generated from two separate heads of Montastraea faveolata from Looe Key, Florida, to assess the fidelity of using geochemical variations in Montastraea, the dominant reef‐building coral of the Atlantic, to reconstruct sea surface environmental conditions at this site. The stable isotope time series of the two corals replicate well; mean values of δ¹⁸O and δ¹³C are indistinguishable between cores (compare 0.70‰ versus 0.68‰ for δ¹³C and −3.90‰ versus −3.94‰ for δ¹⁸O). Mean values from the Sr/Ca time series differ by …

Observing Seasonal Steric Sea Level Variations With Grace And Satellite Altimetry, Don P. Chambers

Marine Science Faculty Publications

Sea level rises and falls as the temperature and salinity of the water column varies, which is known as steric sea level. Sea level also changes as water mass is redistributed within the ocean or is added or removed. Satellite radar altimeters measure the combination of both effects, while the Gravity Recovery and Climate Experiment (GRACE) was designed to measure time variable gravity caused by movement of water mass. Theoretically, altimetry and GRACE data can be combined in order to compute the steric sea level variations. We test this by combining current GRACE and Jason 1 altimeter data and comparing …

Circulation Of Tampa Bay Driven By Buoyancy, Tides, And Winds, As Simulated Using A Finite Volume Coastal Ocean Model, Robert H. Weisberg, Lianyuan Zheng

Marine Science Faculty Publications

The circulation of Tampa Bay is investigated using a high-resolution, three-dimensional, density-dependent, finite volume coastal ocean model (FVCOM) that includes Tampa Bay, the intracoastal waterway, and the inner portion of the west Florida continental shelf. Model performance over the three-month interval, September to November 2001, is assessed against available tide gauge and velocity profiler data before using the model to describe the circulation as driven by rivers, tides, and winds. Because of a mean wind velocity vector directed down the estuary axis, we ran a parallel model experiment without winds to distinguish the estuarine circulation by gravitational convection from the …

Using Pyrosequencing To Shed Light On Deep Mine Microbial Ecology, Robert Edwards, Beltran Rodriguez-Brito, Linda Wegley, Matthew Haynes, Mya Breitbart, Dean Peterson, Martin Saar, Scott Alexander, E. Calvin Alexander Jr., Forest Rohwer

Marine Science Faculty Publications

Background: Contrasting biological, chemical and hydrogeological analyses highlights the fundamental processes that shape different environments. Generating and interpreting the biological sequence data was a costly and time-consuming process in defining an environment. Here we have used pyrosequencing, a rapid and relatively inexpensive sequencing technology, to generate environmental genome sequences from two sites in the Soudan Mine, Minnesota, USA. These sites were adjacent to each other, but differed significantly in chemistry and hydrogeology.

Results: Comparisons of the microbes and the subsystems identified in the two samples highlighted important differences in metabolic potential in each environment. The microbes were performing distinct biochemistry …

Bleaching In Foraminifera With Algal Sybionts: Implications For Reed Monitoring And Risk Assessment, Pamela Hallock, D. E. Williams, E. M. Fisher, S. K. Toler

Marine Science Faculty Publications

Reef-dwelling larger foraminifers share key characteristics with reefbuilding corals: they are prolific producers of calcium carbonate, they are physiologically dependent upon algal endosymbionts, and representatives of both groups have suffered bleaching episodes in recent decades. Since 1991, bleaching has been observed in populations of Amphistegina in all subtropical oceans, with peak bleaching in 1992 and secondary peaks in 1998 and 2005. Amphistegina populations exhibiting chronic, intermediate-intensity bleaching characteristically show anomalously high incidences of shell breakage, shell deformities, evidence of predation, and microbial infestation. Asexual reproduction is profoundly affected; broods from partly bleached parents typically have fewer individuals, many of which …

Evidence Of Multidecadal Salinity Variability In The Eastern Tropical North Atlantic, Christopher S. Moses, Peter K. Swart, Brad E. Rosenheim

Marine Science Faculty Publications

Ocean circulation and global climate are strongly influenced by seawater density, which is itself controlled by salinity and temperature. Although adequate instrumental sea surface temperature (SST) records exist for most of the surface oceans over the past 100–150 years, records of salinity really only exist for the last 40–50 years. Here we show that longer proxy records from corals (Siderastrea radians) in the eastern tropical North Atlantic are dominated by multidecadal variations in salinity which are correlated with the relationship between SST and the North Atlantic Oscillation (NAO) over the course of the 20th century. The data reveal …