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Articles 1891 - 1920 of 2652

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins Jan 2008

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO2 levels. Rates of N2 and CO2 fixation and growth increased in step with increasing partial pressure of CO2 (pCO2), but only under Fe- replete conditions. N2) and carbon fixation rates at 75 Pa CO2 were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO2 …

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A Tribute To Peter George Brewer In Celebration Of His 65th Birthday, George T. F. Wong, Robert F. Anderson, Michael P. Bacon, Hein J. W. De Baar, James W. Murray, Mary I. Scranton Jan 2008

A Tribute To Peter George Brewer In Celebration Of His 65th Birthday, George T. F. Wong, Robert F. Anderson, Michael P. Bacon, Hein J. W. De Baar, James W. Murray, Mary I. Scranton

OES Faculty Publications

Peter George Brewer is an ocean chemist of the rare breed that can cross back and forth over the divide between being a front-line research scientist and being a research executive. As if that is not remarkable enough, in the process, he has also demonstrated sustained growth in the depth, breadth, and diversity of his scientific endeavors. Some of his formidable contributions to ocean chemistry have already been highlighted in a profile of him as a major mover and shaker in the field (Irion, 2001). Here, we provide additional glimpses of him from the perspective of a group of individuals …

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Forcing And Dynamics Of Seafloor-Water Column Exchange On A Broad Continental Shelf, William B. Savidge, Ann Gargett, Richard A. Jahnke, James R. Nelson, Dana K. Savidge, R. Timothy Short, George Voulgaris Jan 2008

Forcing And Dynamics Of Seafloor-Water Column Exchange On A Broad Continental Shelf, William B. Savidge, Ann Gargett, Richard A. Jahnke, James R. Nelson, Dana K. Savidge, R. Timothy Short, George Voulgaris

OES Faculty Publications

Relict sediments of elevated permeability characterize the majority of continental shelves globally (Emery, 1968). In these settings, interactions between benthic boundary layer (BBL) flows and seabed topography generate pressure fluctuations that drive advective and dispersive porewater transport, dramatically increasing the magnitude and variability of porewater solute and particulate exchange across the sediment-water interface (Huettel et al., 1996; Huettel and Rusch, 2000). On broad shallow shelves with a relatively large area-to-volume ratio, the seafloor’s role is magnified. Energetic events may reorganize bedforms across a significant fraction of the shelf, leading to altered exchange dynamics that may persist long after the organizing …

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Arctic Perennial Ice Cover Over The Last 14 Million Years, Dennis A. Darby Jan 2008

Arctic Perennial Ice Cover Over The Last 14 Million Years, Dennis A. Darby

OES Faculty Publications

Knowledge of the long-term history of the perennial ice is an important issue that has eluded study because the Cenozoic core material needed has been unavailable until the recent Arctic Coring Expedition (ACEX). Detrital Fe oxide mineral grains analyzed by microprobe from the last 14 Ma (164 m) of the ACEX composite core on the Lomonosov Ridge were matched to circum-Arctic sources with the same mineral and 12-element composition. These precise source determinations and estimates of drift rates were used to determine that these sand grains could not be rafted to the ACEX core site in less than a year. …

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Impacts Of Chromophoric Dissolved Organic Material On Surface Ocean Heating In The Chukchi Sea, Victoria J. Hill Jan 2008

Impacts Of Chromophoric Dissolved Organic Material On Surface Ocean Heating In The Chukchi Sea, Victoria J. Hill

OES Faculty Publications

Recent observations show visible light attenuation in the Arctic Ocean to be greater than previously assumed. High attenuation observed during the period prior to ice melt and increased phytoplankton production, was attributed primarily to the high levels of absorption by chromophoric dissolved organic material ( CDOM) present in these waters. Preliminary evidence suggests this material is produced by ice algae in the early spring. Optical data from the Chukchi shelf system collected in the spring and summer of 2002, were used to model energy absorption in the mixed layer by both dissolved and particulate material. In the spring, absorption by …

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Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett Jan 2008

Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett

OES Faculty Publications

We used the radiated shanny Ulvaria subbifurcataas a model species to explore the relative gut fullness from hatch to metamorphosis of wild larvae, and compared these values with those of laboratory-reared larvae fed at maximum rates. Ingestion rates of most wild larvae were above starvation levels but below the maximum feeding levels of laboratory-reared larvae. Twenty-six percent of freshly-hatched wild larvae and 11% of large, pre-settlement wild larvae had insufficient food in their stomach to satisfy metabolic requirements. These results, taken on their own, are consistent with the much hypothesized increased foraging performance and survival of larger larvae relative …

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Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs Jan 2008

Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs

OES Faculty Publications

As the international shipping fleet travels the oceans, it carries with it hidden cargoes of microbes. Fred C. Dobbs explores the hazards posed and what can be done to counteract them.

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Naturally Present Fatty Acids As Internal Calibrants For Fourier Transform Mass Spectra Of Dissolved Organic Matter, Rachel L. Sleighter, Georgina A. Mckee, Zhanfei Liu, Patrick G. Hatcher Jan 2008

Naturally Present Fatty Acids As Internal Calibrants For Fourier Transform Mass Spectra Of Dissolved Organic Matter, Rachel L. Sleighter, Georgina A. Mckee, Zhanfei Liu, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The analysis of dissolved organic matter ( DOM) by Fourier transform ion cyclotron resonance mass spectrometry ( FTICR- MS) has gained wide interest recently, driven primarily by its ultrahigh resolving power and mass accuracy. Accurate calibration of mass spectra is a key step to successfully decipher the DOM components. We propose a simple and accurate method to internally calibrate the peaks in the complex spectra without the need to add a calibrant. Mass spectra of DOM samples from the Dismal Swamp, Virginia, and the lower Chesapeake Bay display the presence of naturally occurring fatty acids which can be readily recognized …

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Determination Of Photochemically Produced Carbon Dioxide In Seawater, Emily M. White, David J. Kieber, Kenneth Mopper Jan 2008

Determination Of Photochemically Produced Carbon Dioxide In Seawater, Emily M. White, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

An analytical system was developed to determine photochemically produced carbon dioxide in marine waters. Our system was designed to measure low levels of carbon dioxide by maintaining a closed system to prevent atmospheric contamination during sample preparation, irradiation, and analysis. To detect low levels of photoproduced carbon dioxide in seawater, background dissolved inorganic carbon (DIC) was removed before irradiation. To strip out DIC, samples were acidified to pH 3.0 (converting DIC to carbon dioxide) and bubbled with low carbon dioxide air. The pH was then readjusted back to the original value, and the resulting low-DIC seawater samples were transferred pneumatically …

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Salt Marshes As A Source Of Chromophoric Dissolved Organic Matter (Cdom) To Southern California Coastal Waters, Catherine D. Clark, Liannea P. Litz, Stanley B. Grant Jan 2008

Salt Marshes As A Source Of Chromophoric Dissolved Organic Matter (Cdom) To Southern California Coastal Waters, Catherine D. Clark, Liannea P. Litz, Stanley B. Grant

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

To determine chromophoric dissolved organic matter (CDOM) sources in Southern California coastal waters, optical properties of a river outlet and adjacent tidally flushed salt marshes were monitored (dry season; June July 2001). Average absorption coefficients doubled at ebb vs. flood tides (4.8 +/- 1.5 vs. 2.1 +/- 0.9 m(-1); 300 nm), suggesting significant salt marsh CDOM inputs into coastal waters. Average spectral slopes were not statistically different for any sites or tides (0.010 +/- 0.002 nm(-1)), consistent with salt marsh CDOM dominating coastal waters. Three-dimensional fluorescence excitation-emission matrices (EEMs) at ebb tide showed contributions from terrestrial, protein, and marine humic-like …

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Shading Facilitates Sessile Invertebrate Dominance In The Rocky Subtidal Gulf Of Maine, Ron J. Etter, Robert J. Miller Jan 2008

Shading Facilitates Sessile Invertebrate Dominance In The Rocky Subtidal Gulf Of Maine, Ron J. Etter, Robert J. Miller

Biology Faculty Publication Series

Dramatic shifts in community composition occur between vertical and horizontal rocky surfaces in subtidal environments worldwide, yet the forces mediating this transition are poorly understood. Vertical rock walls are often covered by lush, diverse communities of sessile suspension-feeding invertebrates, while adjacent horizontal substrates are dominated by algae, or corals in the tropics. Multiple factors, including light, sedimentation, water flow, and predation have been proposed to explain this pattern, but experimental tests of these hypotheses are lacking. We manipulated light level and predation to test whether variation in these mechanisms could be responsible for the shift in composition of sessile communities …

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A Modelling Study Of Developmental Stage And Environmental Variability Effects On Copepod Foraging, Jerry D. Wiggert, Eileen E. Hofmann, Gustav-Adolf Paffenhöfer Jan 2008

A Modelling Study Of Developmental Stage And Environmental Variability Effects On Copepod Foraging, Jerry D. Wiggert, Eileen E. Hofmann, Gustav-Adolf Paffenhöfer

CCPO Publications

We used a stochastic Lagrangian model to study how behaviour contributes to copepod grazing success. The model simulates distinct foraging behaviours of Clausocalanus furcatus, Paracalanus aculeatus, and Oithona plumifera. Three sets of simulations were performed to investigate the effects of (a) prey-size preference; (b) variation in prey-size spectra; and (c) turbulence intensity on these species’ grazing rates. The size preference simulations demonstrate that, compared with copepodites, mature females have cell ingestion rates that are an order of magnitude lower, while carbon uptake is reduced by 35%. A prey spectrum that is skewed towards cells ,<6 >μm promotes copepodite …

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Otolith Chemistry Indicates Population Structuring By The Antarctic Circumpolar Current, Julian R. Ashford, Cynthia M. Jones, Eileen E. Hofmann, Inigo Everson, Carlos A. Moreno, Guy Duhamel, Richard Williams Jan 2008

Otolith Chemistry Indicates Population Structuring By The Antarctic Circumpolar Current, Julian R. Ashford, Cynthia M. Jones, Eileen E. Hofmann, Inigo Everson, Carlos A. Moreno, Guy Duhamel, Richard Williams

CCPO Publications

Large-scale transport of seawater in ocean currents may generate spatially complex population structure through the advection of life stages of marine fish species. To test this, we compared the chemistry of otolith nuclei from Patagonian toothfish (Dissostichus eleginoides), presently managed as spatially discrete Populations corresponding to fishing management areas along the Antarctic Circumpolar Current (ACC), which transports water eastward around the Southern Ocean. The chemistry of otolith nuclei, laid down during early life, differed significantly between fishing areas Off South America and the Antarctic and between some Antarctic areas. However, we found significant discrepancies from expectation for a …

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Mesoamerican Reef Spawning Aggregations Help Maintain Fish Population: A Review Of Connectivity Research And Priorities For Science Management, W. Heyman, W. B. Kjerfve, T. Ezer Jan 2008

Mesoamerican Reef Spawning Aggregations Help Maintain Fish Population: A Review Of Connectivity Research And Priorities For Science Management, W. Heyman, W. B. Kjerfve, T. Ezer

CCPO Publications

The life history of most marine organisms includes an obligate period of pelagic larval dispersal. Migration to spawning areas and pelagic dispersal is often well beyond the home range of these organisms. Designing marine protected areas to include a broad range of taxa and their various dispersal patterns is an important and daunting challenge. This paper addresses the issue of connectivity for one set of species in a limited geographic area. We focus on transient spawning reef fish within the Mesoamerican Reef and their connectivity. We divide our scientific review into four sections as follows: (1) ecological characterization of transient …

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Quantifying Vertical Mixing In Estuaries, W. Rockwell Geyer, Malcolm E. Scully, David K. Ralston Jan 2008

Quantifying Vertical Mixing In Estuaries, W. Rockwell Geyer, Malcolm E. Scully, David K. Ralston

CCPO Publications

Estuarine turbulence is notable in that both the dissipation rate and the buoyancy frequency extend to much higher values than in other natural environments. The high dissipation rates lead to a distinct inertial subrange in the velocity and scalar spectra, which can be exploited for quantifying the turbulence quantities. However, high buoyancy frequencies lead to small Ozmidov scales, which require high sampling rates and small spatial aperture to resolve the turbulent fluxes. A set of observations in a highly stratified estuary demonstrate the effectiveness of a vessel-mounted turbulence array for resolving turbulent processes, and for relating the turbulence to the …

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Survival Of Eastern Oysters Crassostrea Virginica From Three Lines Following Experimental Challenge With Bacterial Pathogens, Javier Gomez-Leon, Luisa Villamil, Scott A. Salger, Rachel Sallum, Antonio Remacha-Trivino, Dale F. Leavitt, Marta Gomez-Chiarri Jan 2008

Survival Of Eastern Oysters Crassostrea Virginica From Three Lines Following Experimental Challenge With Bacterial Pathogens, Javier Gomez-Leon, Luisa Villamil, Scott A. Salger, Rachel Sallum, Antonio Remacha-Trivino, Dale F. Leavitt, Marta Gomez-Chiarri

Fisheries, Animal and Veterinary Sciences Faculty Publications

Shellfish production is often affected by bacterial pathogens that cause high losses in hatcheries and nurseries. We evaluated the relative survival of larvae and juveniles of 3 Crassostrea virginica oyster lines: (1) GHP, a Rhode Island line; (2) NEHY, a line resistant to dermo and multinucleated sphere X diseases; and (3) FLOWERS, a line resistant to Roseovarius oyster disease, experimental challenge with Vibrio spp. isolates RE22 and RE101, causative agents of bacillary necrosis in Pacific oyster larvae, and the type strain of Roseovarius crassostreae, causative agent of Roseovarius oyster disease. All of the isolates were able to induce significant …

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Transverse Structure Of Wind-Driven Flow At The Entrance To An Estuary: Nansemond River, Diego A. Narváez, Arnoldo Valle-Levinson Jan 2008

Transverse Structure Of Wind-Driven Flow At The Entrance To An Estuary: Nansemond River, Diego A. Narváez, Arnoldo Valle-Levinson

CCPO Publications

Observations of current velocity profiles were combined with an analytical solution to study the transverse partition of the wind-driven flow in an estuary, the Nansemond River, which is a tributary of the James River in the Chesapeake Bay. Observations spanned two periods of nearly 3 months in autumn-winter of 2003-2004 and spring-summer 2004. The wind-driven circulation consisted of downwind flow over the shoal and upwind flow in the channel at the entrance to the estuary. This pattern developed mainly with landward winds and provided observational evidence that sustains analytical and numerical model results. The transverse structure of the flow showed …

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Absorption Spectral Slopes And Slope Ratios As Indicators Of Molecular Weight, Source, And Photobleaching Of Chromophoric Dissolved Organic Matter, John R. Helms, Aron Stubbins, Jason D. Ritchie, Elizabeth C. Minor, David J. Kieber, Kenneth Mopper Jan 2008

Absorption Spectral Slopes And Slope Ratios As Indicators Of Molecular Weight, Source, And Photobleaching Of Chromophoric Dissolved Organic Matter, John R. Helms, Aron Stubbins, Jason D. Ritchie, Elizabeth C. Minor, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

A new approach for parameterizing dissolved organic matter ( DOM) ultraviolet-visible absorption spectra is presented. Two distinct spectral slope regions ( 275-295 nm and 350-400 nm) within log-transformed absorption spectra were used to compare DOM from contrasting water types, ranging from wetlands (Great Dismal Swamp and Suwannee River) to photobleached oceanic water ( Atlantic Ocean). On the basis of DOM size-fractionation studies ( ultrafiltration and gel filtration chromatography), the slope of the 275-295- nm region and the ratio of these slopes (SR; 275-295- nm slope : 350-400- nm slope) were related to DOM molecular weight ( MW) and …

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Contrasting The 2007 And 2005 Hurricane Seasons: Evidence Of Possible Impacts Of Saharan Dry Air And Dust On Tropical Cyclone Activity In The Atlantic Basin, D. Sun, K. M. Lau, Menas Kafatos Jan 2008

Contrasting The 2007 And 2005 Hurricane Seasons: Evidence Of Possible Impacts Of Saharan Dry Air And Dust On Tropical Cyclone Activity In The Atlantic Basin, D. Sun, K. M. Lau, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, we provide preliminary evidence of possible modulation by Saharan dust of hurricane genesis and intensification, by contrasting the 2007 and 2005 hurricane seasons. It is found that dust aerosol loadings over the Atlantic Ocean are much higher in 2007 than in 2005. The temperature difference between 2007 and 2005 shows warming in the low-middle troposphere (900–700 hPa) in the dusty region in the eastern North Atlantic, and cooling in the Main Development Region (MDR). The humidity (wind) differences between 2007 and 2005 indicate significant drying (subsidence) in the Western North Atlantic (WNA) in 2007. The drier air …

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Byzantium Beneath The Black Sea, Bridget Buxton, Robert Ballard, Michael Brennan, Dwight Coleman, Katy Croff, Christopher Roman, Dan Davis, Dennis Piechota, Sergiy Voronov Jan 2008

Byzantium Beneath The Black Sea, Bridget Buxton, Robert Ballard, Michael Brennan, Dwight Coleman, Katy Croff, Christopher Roman, Dan Davis, Dennis Piechota, Sergiy Voronov

Graduate School of Oceanography Faculty Publications

This poster reports on the August 2007 Black Sea Expedition of the Institute for Archaeological Oceanography at the University of Rhode Island (IAO) and the Institute for Exploration (IFE), in collaboration with the Department of the Underwater Heritage of Ukraine. This year’s work marks a new phase in a multi-year (2000–2012) archaeological and oceanographic survey of the Black Sea. 2007 fieldwork focuses on two Byzantine shipwrecks. The 10th century C.E. shipwreck Chersonesos A (discovered in 2006) lies at 140 m depth in the suboxic zone off the Crimean peninsula. The ship carried a cargo of one-handled jars of a widely …

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Estimation Of Submarine Groundwater Discharge From Bulk Ground Electrical Conductivity Measurements, Thomas Stieglitz, John Rapaglia, Henry Bokuniewicz Jan 2008

Estimation Of Submarine Groundwater Discharge From Bulk Ground Electrical Conductivity Measurements, Thomas Stieglitz, John Rapaglia, Henry Bokuniewicz

Biology Faculty Publications

The utility of bulk ground conductivity (BGC) measurements in the estimation of submarine groundwater discharge (SGD) was investigated at four sites covering a range of hydrogeological settings, namely Cockburn Sound (Australia); Shelter Island (USA); Ubatuba Bay (Brazil) and Flic-en-Flac Bay (Mauritius). At each of the sites, BGC was surveyed in the intertidal zone, and seepage meters were used for direct measurements of SGD flow rates. In the presence of detectable salinity gradients in the sediment, a negative correlation between SGD and BGC was recorded. The correlation is site-specific and is dependent on both the type of sediment and the mixing …

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Dms Air/Sea Flux And Gas Transfer Coefficients From The North Atlantic Summertime Coccolithophore Bloom, Christa Marandino, Warren J. De Bruyn, Scott Miller, Eric S. Saltzman Jan 2008

Dms Air/Sea Flux And Gas Transfer Coefficients From The North Atlantic Summertime Coccolithophore Bloom, Christa Marandino, Warren J. De Bruyn, Scott Miller, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Dimethylsulfide (DMS) atmospheric and oceanic concentrations and eddy covariance air/sea fluxes were measured over the N. Atlantic Ocean during July 2007 from Iceland to Woods Hole, MA, USA. Seawater DMS levels north of 55 degrees N ranged from 3 to 17 nM, with variability related to the satellite-derived distributions of coccoliths and to a lesser extent, chlorophyll. For the most intense bloom region southwest of Iceland, DMS air/sea fluxes were as high as 300 mu mol m(-2) d(-1), larger than current model estimates. The observations imply that gas exchange coefficients in this region are significantly greater than those estimated using …

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Ontogenetic Changes In Feeding Ecology And Habitat Of The Damselfish Neoglyphidodon Melas At Lizard Island, Great Barrier Reef, Sai-Wing Chan Oct 2007

Ontogenetic Changes In Feeding Ecology And Habitat Of The Damselfish Neoglyphidodon Melas At Lizard Island, Great Barrier Reef, Sai-Wing Chan

Independent Study Project (ISP) Collection

This study examines ontogenetic shift in habitat and feeding ecology of the black damselfish, Neoglyphidodon melas in three patch reef sites at Lizard Island, Great Barrier Reef. This rarely studied species is unique in its coprophagous relationship with the faeces of the giant clam Tridacna gigas. Distribution and habitat composition between three sites and two reef zones was estimated with 48 Visual Belt and Point Intercept Transects. 80 Focal Animal Studies revealed specific foraging strategies and aggressive behaviours. The timing of this study permitted the inclusion of juvenile recruits resulting in a more complete and comprehensive study across developmental stages. …

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To Live With The Sea: Community-Based Management Of Marine Resources In Southwest Madagascar, Hannah Pitt Oct 2007

To Live With The Sea: Community-Based Management Of Marine Resources In Southwest Madagascar, Hannah Pitt

Independent Study Project (ISP) Collection

“God intended us to fish, and we will fish until the end,” the elderly Vezo fisherman explained, shrugging his shoulders as if in resignation to an unavoidable truth (Niry). For a people whose history, culture, and economy have revolved around the sea for generations, the idea of preservation is just not palatable, he seemed to be saying. The momentum of tradition, in other words, cannot be stopped. Yet in 23 Vezo fishing villages in the region of Andavadoaka, along the southwest coast of Madagascar, communities have collectively established seasonal and permanent restrictions on critical fishing grounds that together make up …

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Hypoxia In The Northern Gulf Of Mexico: Does The Science Support The Plan To Reduce, Mitigate, And Control Hypoxia?, Nancy N. Rabalais, R. Eugene Turner, B.K. Sen Gupta, D. F. Boesch, P. Chapman, M. C. Murrell Oct 2007

Hypoxia In The Northern Gulf Of Mexico: Does The Science Support The Plan To Reduce, Mitigate, And Control Hypoxia?, Nancy N. Rabalais, R. Eugene Turner, B.K. Sen Gupta, D. F. Boesch, P. Chapman, M. C. Murrell

Faculty Publications

We update and reevaluate the scientific information on the distribution, history, and causes of continental shelf hypoxia that supports the 2001 Action Plan for Reducing, Mitigating, and Controlling Hypoxia in the Northern Gulf of Mexico (Mississippi River/Gulf of Mexico Watershed Nutrient Task Force 2001), incorporating data, publications, and research results produced since the 1999 integrated assessment. The metric of mid-summer hypoxic area on the Louisiana-Texas shelf is an adequate and suitable measure for continued efforts to reduce nutrients loads from the Mississippi River and hypoxia in the northern Gulf of Mexico as outlined in the Action Plan. More frequent measurements …

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Benthic Mapping For Habitat Classification In The Peconic Estuary: Phase I Groundtruth Studies, Robert M. Cerrato, Nicole P. Maher Oct 2007

Benthic Mapping For Habitat Classification In The Peconic Estuary: Phase I Groundtruth Studies, Robert M. Cerrato, Nicole P. Maher

School of Marine & Atmospheric Sciences Faculty Publications

Benthic habitat maps of the estuary seafloor will increase our knowledge of range and variability in benthic habitats, will assist managers in their efforts to protect and/or restore commercially and recreationally important finfish and shellfish, will link land usage (e.g. developed vs. undeveloped areas) and water quality data to benthic habitat quality, and will make it possible to utilize faunal data as a long-term indicator of the overall “health” of the estuary. We are developing benthic habitat maps by combining high-resolution remote sensing techniques with detailed study of the physical and faunal characteristics at point locations in different seafloor environments. …

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Salt Fluxes At The Chesapeake Bay Entrance, Ruth Lane Oct 2007

Salt Fluxes At The Chesapeake Bay Entrance, Ruth Lane

OES Theses and Dissertations

Underway measurements of salinity and flow profiles were used to compute salt fluxes at the mouth of the Chesapeake Bay in spring and summer. Waters were sampled along a cross-bay transect over four tidal cycles in 1997: at the end of April, during neap tides, and in mid-July, during spring tides. Data were interpolated onto a uniform grid along the transect area. A least squares regression with semidiurnal and diurnal harmonics was fit on both salinity and flow at each point of the grid to separate tidal from non-tidal influences. The results of the least squares fit were used to …

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Limb Regeneration After Multiple Autotomy And Coxae Removal In The Blue Crab Callinectes Sapidus, Jennifer Ambler Oct 2007

Limb Regeneration After Multiple Autotomy And Coxae Removal In The Blue Crab Callinectes Sapidus, Jennifer Ambler

OES Theses and Dissertations

This study investigated limb regeneration in the juvenile blue crab, Callinectes sapidus, specifically the role of the coxa and pedal nerve innervation of the regenerative limb bud over time. The coxa is a leg segment that has been defined as the source of positional, cellular, and neuronal information needed for limb regeneration in brachyuran crabs. This study indicates that removal of coxae under regenerative and non-regenerative conditions did not deter limb regeneration. The coxa is not the exclusive location of limb regenerative information since limbs re-grew with normal positional and functional arrangement in 86% of crabs showing regeneration at removal …

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Investigating A Method To Measure Sperm Transfer In Chelidonura Sandrana (Opisthobranchia: Cephalaspidea), Kate Kunigelis Oct 2007

Investigating A Method To Measure Sperm Transfer In Chelidonura Sandrana (Opisthobranchia: Cephalaspidea), Kate Kunigelis

Independent Study Project (ISP) Collection

This paper investigates possible methods for measuring sperm transfer in the internal fertilizing, simultaneous hermaphrodite Chelidonura sandrana (Opisthobranchia: Cephalaspidea). Comparing sperm amount transferred in copulations has significance for testing the assumption that sperm transfer is linearly correlated with copulation duration as well as providing a tool for future studies. Various methods of preparing, treating, and viewing sperm samples were attempted. Two unsuccessful pilot studies were conducted to test free sperm counts and measuring sperm pellet surface area. Future research should focus on optimizing centrifugation method for surface area measurements of sperm clusters and resuspending sperm clusters to enable sperm counting. …

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Distribution Of Ultraviolet-Absorbing Sunscreen Compounds Across The Body Surface Of Two Species Of Scaridae, Elizabeth Cerny-Chipman Oct 2007

Distribution Of Ultraviolet-Absorbing Sunscreen Compounds Across The Body Surface Of Two Species Of Scaridae, Elizabeth Cerny-Chipman

Independent Study Project (ISP) Collection

Ultraviolet radiation has far-reaching effects in marine ecosystems, but many marine organisms have UV-absorbing compounds that protect them from sun-induced damage. The mucus of coral reef fish has been found to contain mycosporine-like amino acids that absorb UV light from 309-360 nm. Using UV spectrophotometry, we examined whether fish are able to allocate these MAA sunscreen compounds to areas of the body that receive the most UV radiation. We compared absorbance spectra of mucus from the body surface of dorsal, ventral, caudal and head areas in two species of Scaridae (Scarus schlegeli and Chlorurus sordidus) from Coral Bay, Western Australia. …

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