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Collaborative Research: Origins Of Cods On Georges Bank: Contributions Of Early Developmental Stages For The Scotian Shelf, David W. Townsend, Irv Kornfield, Linda Kling
Collaborative Research: Origins Of Cods On Georges Bank: Contributions Of Early Developmental Stages For The Scotian Shelf, David W. Townsend, Irv Kornfield, Linda Kling
University of Maine Office of Research Administration: Grant Reports
Recent work in the Georges Bank-Gulf of Maine area has documented significant, and apparently episodic, fluxes of Scotian Shelf Water (SSW) from the Nova Scotian continental shelf to Georges Bank. SSW is a relatively cold and fresh water mass with a significant component from the St. Lawrence River, and is commonly identifiable with temperature-salinity analyses of hydrographic data and in satellite images of sea surface temperature. One such flux episode was observed last March (1997) in satellite imagery and from shipboard hydrographic sampling on Georges Bank. Qualitative at-sea analyses of ichthyoplankton sampled on the March cruise revealed a remarkably tight …
Strong Mid-Depth Currents And A Deep Cyclonic Gyre In The Gulf Of Mexico, Wilton Sturges, Eric Chassignet, Tal Ezer
Strong Mid-Depth Currents And A Deep Cyclonic Gyre In The Gulf Of Mexico, Wilton Sturges, Eric Chassignet, Tal Ezer
CCPO Publications
The main purpose of this work was to explore the possibility that the deep flow (~2000m) around the edges of the Gulf circulates in a cyclonic, or counter-clockwise direction. The existence of such flow was proposed on theoretical grounds but had not been previously documented. Our results are quite clear that such flow is reliably observed.
Organic Coatings On Sedimentary Mineral Grains, Lawrence M. Mayer
Organic Coatings On Sedimentary Mineral Grains, Lawrence M. Mayer
University of Maine Office of Research Administration: Grant Reports
A pore protection hypothesis will be tested, provide a mechanistic basis for the observed patterns of organic carbon. Relationships between organic matter and mineral surfaces will be developed by: (1) Assessing the extent of organic matter coverage on mineral grains. Is organic carbon localized in small areas or is it widely dispersed? Wide dispersal implies that major fraction must reside in small pores. This question will be tested by completing development of a promising new method based on the of gas adsorption onto mineral surfaces. Completion work will focus on the nature of naked mineral surfaces, identifying variations that derive …
Chemical Characterization Of Ambient Aerosol Collected During The Northeast Monsoon Season Over The Arabian Sea: Labile-Fe(Ii) And Other Trace Metals, Anne M. Johansen, Michael R. Hoffmann
Chemical Characterization Of Ambient Aerosol Collected During The Northeast Monsoon Season Over The Arabian Sea: Labile-Fe(Ii) And Other Trace Metals, Anne M. Johansen, Michael R. Hoffmann
All Faculty Scholarship for the College of the Sciences
Ambient aerosol samples were collected over the Arabian Sea during the month of March of 1997, aboard the German R/V Sonne, as part of the German Joint Global Ocean Flux Study (JGOFS) project. This is the third study in a series of analogous measurements taken over the Arabian Sea during different seasons of the monsoon. Dichotomous high‐volume collector samples were analyzed for ferrous iron immediately after collection, while trace metals, anions, and cations were determined upon return to the laboratory. The main crustal component was geochemically well represented by the average crustal composition and amounted to 5.94 ± 3.08 …
Global Patterns Of Dissolved N, P And Si In Large Rivers, R. Eugene Turner, Nancy N. Rabalais, D. Justic', Q. Dortch
Global Patterns Of Dissolved N, P And Si In Large Rivers, R. Eugene Turner, Nancy N. Rabalais, D. Justic', Q. Dortch
Faculty Publications
The concentration of dissolved inorganic nitrogen (DIN), dissolved nitrate-N, Total-N (TN), dissolved inorganic phosphate (DIP), total phosphorus (TP), dissolved silicate-Si (DSi) and their ratios in the world's largest rivers are examined using a global data base that includes 37% of the earth's watershed area and half its population. These data were compared to water quality in 42 subbasins of the relatively well-monitored Mississippi River basin (MRB) and of 82 small watersheds of the United States. The average total nitrogen concentration varies over three orders of magnitude among both world river watersheds and the MRB, and is primarily dependent on variations …
Valuation Of Continuous And Intermittent Phragmites Control, R. Eugene Turner, R. S. Warren
Valuation Of Continuous And Intermittent Phragmites Control, R. Eugene Turner, R. S. Warren
Faculty Publications
Quantifying the relative value of Phragmites australis and Spartina alterniflora habitat is important to evaluate the benefits and risks of different attempts to address Phragmites expansion on the U.S. eastern seaboard. Two contrasting approaches commonly used to restore tidal marsh habitats invaded by Phragmites communities involve spraying Phragmites with herbicide only when its coverage of a particular marsh area is near or close to 100%. Alternatively, after the first application, herbicide is annually applied on any surviving patches of Phragmites present in a mosaic of other marsh vegetation. A model is introduced to evaluate the relative habitat value of these …
Proteins Of Oxygen-Binding And Energy Metabolism In Muscles Of Antarctic Fishes: Evolutionary Adjustments To Life At Cold Temperature, Bruce Sidell, Michael E. Vayda
Proteins Of Oxygen-Binding And Energy Metabolism In Muscles Of Antarctic Fishes: Evolutionary Adjustments To Life At Cold Temperature, Bruce Sidell, Michael E. Vayda
University of Maine Office of Research Administration: Grant Reports
The suborder Notothenoidei is the dominant fish group of the Southern Ocean surrounding Antarctica, both in terms of number of species and biomass. For about fourteen million years, these highly successful fish evolved under stable thermal conditions that result in body temperatures of about zero degrees centigrade throughout their life histories. Evolution this cold environment has led to unusual physiological and biochemical characteristics. In some cases, the characteristics contribute to overcoming constraints of cold temperature on biological processes. In other instances, mutations that probably would have been lethal in warmer, less oxygen-rich environments than the Southern Ocean have been retained …
Engineering The Ocean, Marcia Mcnutt
Engineering The Ocean, Marcia Mcnutt
IMSA Great Minds Program ®
Developments in microprocessors, artificial intelligence, and new forms of power and communications for autonomous systems are already bringing about a revolution in our ability to explore, experiment within, and ultimately understand Earth's last frontier: the ocean. It is inevitable, with this growing capability, that there will be pressure to use the same and similar technology to manipulate and enhance the ocean environment, just as we have our terrestrial environment. We will be able to fertilize the ocean to increase its productivity, adjust its climate in an attempt to halt natural and human-induced global change, harvest its internal energy to power …
Climatic Influences On Riverine Nitrate Flux: Implications For Coastal Marine Eutrophication And Hypoxia, Dubravko Justic, R. Eugene Turner, Nancy N. Rabalais
Climatic Influences On Riverine Nitrate Flux: Implications For Coastal Marine Eutrophication And Hypoxia, Dubravko Justic, R. Eugene Turner, Nancy N. Rabalais
Faculty Publications
The average nitrate flux of the lower Mississippi River increased 3.3-fold between 1954–1967 and 1983–2000. During the same time period, the average nitrate concentration increased 2.3-fold while the average discharge increased 40%. Partitioning of the observed trend in nitrate flux among the two flux components, nitrate concentration and discharge, revealed that about 80% of the observed increase in flux could be explained by the increase in nitrate concentration. This indicates that a historical increase in the anthropogenic nutrient inputs has had a far greater impact on the lower Mississippi River nitrate flux than a change in climate. The influence of …
2003 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
2003 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
Miscellaneous
These calendars are produced monthly using David Evans' Tidecal.
2003 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
2003 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
Miscellaneous
These calendars are produced monthly using David Evans' Tidecal.
Near-Surface Currents In Desoto Canyon (1997–99): Comparison Of Current Meters, Satellite Observation, And Model Simulation, Dong-Ping Wang, Lie-Yauw Oey, Tal Ezer, Peter Hamilton
Near-Surface Currents In Desoto Canyon (1997–99): Comparison Of Current Meters, Satellite Observation, And Model Simulation, Dong-Ping Wang, Lie-Yauw Oey, Tal Ezer, Peter Hamilton
CCPO Publications
This study evaluates a data-assimilated model simulation of near-surface circulation in DeSoto Canyon (DSC), Gulf of Mexico, with emphasis on analyzing moored current-meter observations and comparing them with satellite data and model results. The study period is for two years from April 1997 to April 1999. The model results are from a high-resolution Gulf of Mexico model forced by analyzed wind and surface heat flux. Two types of data are used to deduce near-surface circulation: moored current meters at 13 locations in the DSC, and satellite sea level anomaly. The moored currents are mapped through multivariate objective analysis to produce …
The Variability Of Currents In The Yucatan Channel: Analysis Of Results From A Numerical Ocean Model, Tal Ezer, Lie-Yauw Oey, Hyun-Chul Lee, Wilton Sturges
The Variability Of Currents In The Yucatan Channel: Analysis Of Results From A Numerical Ocean Model, Tal Ezer, Lie-Yauw Oey, Hyun-Chul Lee, Wilton Sturges
CCPO Publications
The flow through the Yucatan Channel and into the Gulf of Mexico is a major component of the Gulf Stream and the subtropical gyre circulation. Surprisingly, however, little is known about the forcing and physical parameters that effect the current structures in the Channel. This paper attempts to improve our understanding of the flow through the Channel with a detailed analysis of the currents obtained from a primitive-equation model that includes the Gulf and the entire Caribbean Sea and forced by 6-hourly wind from ECMWF. The analysis includes two parts: First, the overall statistics of the model results, including the …
Bio-Optical Properties Of The Labrador Sea, Glenn F. Cota, W. Glen Harrison, Trevor Platt, Shubha Sathyendranath, Venetia Stuart
Bio-Optical Properties Of The Labrador Sea, Glenn F. Cota, W. Glen Harrison, Trevor Platt, Shubha Sathyendranath, Venetia Stuart
CCPO Publications
Three cruises were conducted during fall and spring in the Labrador Sea to investigate the effects of bio-optical properties on satellite retrievals of phytoplankton chlorophyll in this important high-latitude ecosystem. Taxon-specific and regional differences were found. Diatoms had similar to 1.5 lower chlorophyll-specific absorption but significantly higher reflectance ratios than prymnesiophytes. Particulate absorption at 443 nm for total, phytoplankton, and "detrital'' fractions was related to chlorophyll, but values were lower than reported for lower latitudes. Decreased particulate absorption is attributed primarily to pigment packaging, while low backscattering to scattering ratios result from a lower relative abundance of bacteria and picophytoplankton …
Reversing Circulation Patterns In A Tropical Estuary, Arnoldo Valle-Levinson, Kathryn T. Bosley
Reversing Circulation Patterns In A Tropical Estuary, Arnoldo Valle-Levinson, Kathryn T. Bosley
CCPO Publications
A combination of current velocity and water density measurements was used to characterize the basic patterns of water exchange in the Gulf of Fonseca, a tropical estuary on the Pacific Ocean side of Central America. The measurements were obtained during spring and neap tides in March ( dry season) and June ( wet season) of 2001 and consisted of profiles of current velocity and density along four transects. From mid-March to mid-April a time series of hourly surface current velocity maps was also obtained with a high-frequency radar system of two antennas. The sampling transects and the radar coverage concentrated …
2003 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
2003 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
Miscellaneous
These calendars are produced monthly using David Evans' Tidecal.
2003 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
2003 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans
Miscellaneous
These calendars are produced monthly using David Evans' Tidecal.
The Three Faces Of Isabel: Storm Surge, Storm Tide, And Sea Level Rise, John D. Boon
The Three Faces Of Isabel: Storm Surge, Storm Tide, And Sea Level Rise, John D. Boon
Reports
To the thousands of Tidewater residents who encountered this storm on September 18, 2003, Hurricane Isabelshowed many faces, none of them a welcome sight. I would like to dwell for a moment on three that I saw –three different physical traits that tell us not only what we‟ve just experienced from Isabel, in terms of high winds and high water, but what we might expect from other storms like her in the future. Two of these traits –storm surgeand storm tide-are governed by probability. Like rolls of the dice, they have odds but no certainty about them. The third -sea …
Extracellular Enzyme Activity And Uptake Of Carbon And Nitrogen Along An Estuarine Salinity And Nutrient Gradient, Margaret R. Mulholland, Cindy Lee, Patricia M. Gilbert
Extracellular Enzyme Activity And Uptake Of Carbon And Nitrogen Along An Estuarine Salinity And Nutrient Gradient, Margaret R. Mulholland, Cindy Lee, Patricia M. Gilbert
OES Faculty Publications
Amino acid oxidation (AAO) and peptide hydrolysis (PH) are processes affecting the recycling of organic material and nutrients. We compared extracellular AAO and PH rates to C and N uptake rates along estuarine gradients of salinity, nutrients and productivity in the Pocomoke River, a subestuary of the Chesapeake Bay. This estuary is seasonally depleted in inorganic N, and rich in dissolved organic material (DOM) throughout the year. AAO, PH, and N uptake rates measured in 1999 and 2000 were not limited to particular size fractions measured, or to auto- or heterotrophic groups of organisms. At a station near the turbidity …
Phytoplankton Assemblage Structure And Primary Productivity Along 170 Degrees W In The South Pacific Ocean, Gr Ditullio, Me Greesey, Dr Jones, Kl Daly, L Campbell, Walker O. Smith Jr.
Phytoplankton Assemblage Structure And Primary Productivity Along 170 Degrees W In The South Pacific Ocean, Gr Ditullio, Me Greesey, Dr Jones, Kl Daly, L Campbell, Walker O. Smith Jr.
VIMS Articles
Phytoplankton pigments were measured using HPLC during non-ENSO conditions in mid-summer along a South Pacific transect from 67degreesS to the equator along 170degreesW. Highest concentrations of chlorophyll a (chl a) occurred in the Polar and the Subtropical Fronts (PF and STF, respectively) with concentrations exceeding 500 ng l(-1). In the STF, there was a distinct subsurface chl a maximum (SCM) at 40 m, which gradually deepened northward to 120 m in the Subtropical Convergence Zone. Northwards, the SCM shoaled to about 30 m in the Equatorial Zone (EZ). Relatively high concentrations of fucoxanthin and 19'-butanoyloxyfucoxanthin occurred in the nutrient-rich waters …
Bacterioplankton Distribution And Production In The Bathypelagic Ocean: Directly Coupled To Particulate Organic Carbon Export?, Da Hansell, Hw Ducklow
Bacterioplankton Distribution And Production In The Bathypelagic Ocean: Directly Coupled To Particulate Organic Carbon Export?, Da Hansell, Hw Ducklow
VIMS Articles
A recently published evaluation of bacterioplankton abundance and productivity in the bathypelagic North Pacific suggests that these properties are generally coupled with particulate organic carbon (POC) fluxes. In that analysis, bacterial biomass and productivity were several-fold greater in subarctic than subtropical waters, consistent with the basin-scale distribution of POC flux and suggestive of a sinking POC --> DOC --> bacteria transformation of the carbon. To test this hypothesis, we sought to determine whether the very strong spatial and temporal gradients in POC flux in the Arabian Sea would force similar deep-ocean gradients in bacterial variables. On both a within and …
The Aqueous Phase Yield Of Alkyl Nitrates From Roo+No: Implications For Photochemical Production In Seawater, Elizabeth E. Dahl, Eric S. Saltzman, Warren J. De Bruyn
The Aqueous Phase Yield Of Alkyl Nitrates From Roo+No: Implications For Photochemical Production In Seawater, Elizabeth E. Dahl, Eric S. Saltzman, Warren J. De Bruyn
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Alkyl nitrates have been observed in remote oceanic regions of the troposphere and in the surface ocean. The mechanism for their production in the oceans is not known. A likely source is the reaction of ROO + NO (where R is an alkyl group). Steady-state laboratory experiments show that alkyl nitrates are produced in the aqueous phase via this reaction, with branching ratios of 0.23 +/- 0.04, 0.67 +/- 0.03, and 0.71 +/- 0.04 for methyl, ethyl, and propyl nitrate respectively. The branching ratios in aqueous solution are significantly higher than in the gas phase. Irradiation of surface seawaters yield …
Methods And Models For Estimating Advective Pore Water Exchange In Tidal Flats, Timothy J. Shaw
Methods And Models For Estimating Advective Pore Water Exchange In Tidal Flats, Timothy J. Shaw
Faculty Publications
No abstract provided.
A Biooptical Model Of Irradiance Distribution And Photosynthesis In Seagrass Canopies, Richard C. Zimmerman
A Biooptical Model Of Irradiance Distribution And Photosynthesis In Seagrass Canopies, Richard C. Zimmerman
OES Faculty Publications
Although extremely vulnerable to coastal eutrophication, seagrasses represent important structuring elements and sources of primary production in shallow waters. They also generate an optical signature that can be tracked remotely. Accurate knowledge of light absorption and scattering by submerged plant canopies permits the calculation of important plant- and ecosystem-level properties, including rates of photosynthesis, vegetation abundance, and distribution. The objectives of this study were to develop a realistic, yet simply parameterized two-flow model of plane irradiance distribution through a seagrass canopy submerged in an optically active water column, to evaluate its performance against in situ measurements, and to explore the …
Flow Induced By Upwelling Winds In An Equatorward Facing Bay: Gulf Of Arauco, Chile, Arnoldo Valle-Levinson, Larry P. Atkinson, Dante Figueroa, Leonardo Castro
Flow Induced By Upwelling Winds In An Equatorward Facing Bay: Gulf Of Arauco, Chile, Arnoldo Valle-Levinson, Larry P. Atkinson, Dante Figueroa, Leonardo Castro
CCPO Publications
[1] Shipborne observations of hydrographic and flow velocity profiles were combined with wind velocity measurements to describe the characteristics of the wind-induced flow in an equatorward facing bay of central Chile in South America. The measurements, which were taken from two transects and one anchor station, were made during late austral spring, between 4 and 10 December 2000. Most observations concentrated on Boca Grande, a transect that crossed the deep, northern ( equatorward) entrance to the bay. The other transect crossed the smaller and shallower, westward entrance to the bay, Boca Chica. The anchor station was located inside the bay, …
Observations Of Cross Channel Structure Of Flow In An Energetic Tidal Channel, Mario Caceres, Arnoldo Valle-Levinson, Larry P. Atkinson
Observations Of Cross Channel Structure Of Flow In An Energetic Tidal Channel, Mario Caceres, Arnoldo Valle-Levinson, Larry P. Atkinson
CCPO Publications
[1] Measurements of velocity and density profiles were made to describe the transverse structure of flow in Chacao Channel, Southern Chile (41.75 degreesS), where typical tidal velocities are similar to4 m/s. Current profiles were obtained with a 307.2 kHz Acoustic Doppler Current Profiler (ADCP) over 25 repetitions of a cross-channel transect during one semidiurnal tidal cycle. The 2.2 km long transect ran northeast/southwest across the channel. A northern channel (120 m deep) and a southern channel (85 m deep) were separated by Remolinos Rock, a pinnacle that rises to 20 m depth at similar to0.7 km from the southern side. …
Academic Fleet Renewal- Two Years Later, Larry Atkinson
Academic Fleet Renewal- Two Years Later, Larry Atkinson
CCPO Publications
(First paragraph) In November 2000, I wrote a Soapbox article on fleet renewal for Sea Technology. It is a little unsettling to see how slowly ideas move towards implementation. Nevertheless, we are making progress. In this editorial I will note a bit of that progress and try to guess where we will be in two more years.
Effects Of Epiphyte Load On Optical Properties And Photosynthetic Potential Of The Seagrasses Thalassia Testudinum Banks Ex König And Zostera Marina L, Lisa A. Drake, Fred C. Dobbs, Richard C. Zimmerman
Effects Of Epiphyte Load On Optical Properties And Photosynthetic Potential Of The Seagrasses Thalassia Testudinum Banks Ex König And Zostera Marina L, Lisa A. Drake, Fred C. Dobbs, Richard C. Zimmerman
OES Faculty Publications
The biomass and optical properties of seagrass leaf epiphytes were measured to evaluate their potential impact on the photosynthetic performance of the seagrasses Thalassia testudinum Banks ex König (turtlegrass) and Zostera marina L. (eelgrass). Turtlegrass was obtained from oligotrophic waters near Lee Stocking Island, Bahamas; eelgrass was collected from a eutrophic environment in Monterey Bay, California. Leaf–epiphyte loads were characterized visually and quantified using measurements of their phospholipid biomass. Light absorption and reflectance of the intact epiphyte layer were determined spectrophotometrically. Turtlegrass epiphytes from the oligotrophic site absorbed a maximum of 36% of incident light in peak chlorophyll absorption …
Sources Of Sediment Found In Sea Ice From The Western Arctic Ocean, New Insights Into Processes Of Entrainment And Drift Patterns, Dennis A. Darby
Sources Of Sediment Found In Sea Ice From The Western Arctic Ocean, New Insights Into Processes Of Entrainment And Drift Patterns, Dennis A. Darby
OES Faculty Publications
The geochemical fingerprint of entrained Fe oxide mineral grains in Arctic Ocean sea ice is used to determine precise sources of this sediment. This approach substantiates the importance of the Laptev Sea as a source of sea ice and even the presence of Russian ice in the Beaufort Sea off Alaska. Fe oxide grains from the Laptev Sea were found in floes in the Beaufort Sea, Chukchi Borderland, and central Arctic Ocean, demonstrating the importance of sea ice in distributing itself throughout the Arctic Ocean and the potential of transporting sediment from Russian rivers to North American shelves. Banks Island …
The Chesapeake Bay : A Synopsis, William J. Hargis Jr.