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Full-Text Articles in Life Sciences

Fall 2004, Nsu Oceanographic Center Oct 2004

Fall 2004, Nsu Oceanographic Center

Currents

No abstract provided.


Biology And Ecology Of Larval Lobsters (Homarus Americanus): Implications For Population Connectivity And Larval Transport, Eric R. Annis Aug 2004

Biology And Ecology Of Larval Lobsters (Homarus Americanus): Implications For Population Connectivity And Larval Transport, Eric R. Annis

Electronic Theses and Dissertations

The connectivity of marine populations and the degree to which they are considered open or closed has important implications for the ecology, management, and resilience of commercially harvested species. Larval exchange is a primary determinant of the level of connectivity between populations, and this thesis examines the intrinsic and extrinsic factors influencing larval transport and the distribution of larvae of the American lobster (Homarus americanus). The potential for larval transport is directly proportional to the planktonic larval duration. Our field data suggest development times in situ were up to three times faster than previous laboratory development times, indicating that potential …


A Physiochemically Constrained Seawater Culturing System For Production Of Benthic Foraminifera, Christopher J. Hintz, G. Thomas Chandler, Jay M. Bernhardt, Daniel C. Mccorkle, Suzanne M. Havach, Jessica K. Blanks, Timothy J. Shaw Jun 2004

A Physiochemically Constrained Seawater Culturing System For Production Of Benthic Foraminifera, Christopher J. Hintz, G. Thomas Chandler, Jay M. Bernhardt, Daniel C. Mccorkle, Suzanne M. Havach, Jessica K. Blanks, Timothy J. Shaw

Faculty Publications

No abstract provided.


Spring 2004, Nsu Oceanographic Center Apr 2004

Spring 2004, Nsu Oceanographic Center

Currents

No abstract provided.


Relating Water And Otolith Chemistry In Chesapeake Bay, And Their Potential To Identify Essential Seagrass Habitats For Juveniles Of An Estuarine-Dependent Fish, Spotted Seatrout (Cynoscion Nebulosus), Emmanis Dorval Apr 2004

Relating Water And Otolith Chemistry In Chesapeake Bay, And Their Potential To Identify Essential Seagrass Habitats For Juveniles Of An Estuarine-Dependent Fish, Spotted Seatrout (Cynoscion Nebulosus), Emmanis Dorval

Biological Sciences Theses & Dissertations

A quantitative understanding of habitat use of estuarine-dependent fishes is critical to the conservation of their most essential habitats. Because recruitment and fitness may be influenced by the quality of juvenile habitats, developing methods to quantify habitat-specific survivorship is pivotal to such understanding. An initial step to quantify survivorship is to validate the habitat-specific natural tags contained in otoliths. To this aim I investigated the variability in the chemistry of surface waters and otoliths of juvenile spotted seatrout, Cynoscion nebulosus, in five seagrass habitats of Chesapeake Bay, namely: Potomac, Rappahannock, York, Island, and Eastern Shore. I measured Mg, Ca, …


Feasibility Of Mapping Benthic Biotopes In The Hudson River, Nicole P. Maher, Robert M. Cerrato Mar 2004

Feasibility Of Mapping Benthic Biotopes In The Hudson River, Nicole P. Maher, Robert M. Cerrato

School of Marine & Atmospheric Sciences Faculty Publications

Successful management of aquatic resources requires comprehensive maps that identify the spatial distribution and extent of potentially vulnerable habitats and their resident biota (e.g., essential fish habitat). We illustrate a technique that describes submerged landscapes not only in terms of geophysical properties, but also in terms of the resident biotic communities. Biological community distribution was highly correlated with the geophysical provinces initially identified by Bell et al. (2000). However, fewer groups of stations (created mainly by combining provinces) explained almost as much of the variation in benthic community structure and was a better description of the major biotopes in this …


Dedication Of The William Jennings Hargis, Jr. Library, Virginia Institute Of Marine Science, College Of William And Mary Jan 2004

Dedication Of The William Jennings Hargis, Jr. Library, Virginia Institute Of Marine Science, College Of William And Mary

Miscellaneous

No abstract provided.


Winter 2004, Nsu Oceanographic Center Jan 2004

Winter 2004, Nsu Oceanographic Center

Currents

No abstract provided.


Lagrangian Modelling Studies Of Antarctic Krill (Euphausia Superba) Swarm Formation, Eileen E. Hofmann, A. G. Edward Haskell, John M. Klinck, Cathy M. Lascara Jan 2004

Lagrangian Modelling Studies Of Antarctic Krill (Euphausia Superba) Swarm Formation, Eileen E. Hofmann, A. G. Edward Haskell, John M. Klinck, Cathy M. Lascara

CCPO Publications

A two-dimensional Lagrangian particle model was developed to examine the spatial distribution of Antarctic krill (Euphausia superba). The time-dependent location of particles, which represent krill individuals, is determined by random diffusion, foraging activity, and movement induced by the presence of neighbours. Foraging activity is based on prescribed food conditions and is such that krill swim slower and turn more frequently in areas of high food concentration. The presence or absence of neighbours either disperses krill, if the local concentrations become too dense, or coalesces krill, if concentrations become too dilute, respectively. Predation on krill is included and affects …


A Modelling Study Of The Influence Of Environment And Food Supply On Survival Of Crassostrea Gigas Larvae, Eileen E. Hofmann, Eric N. Powell, Eleanor A. Bochenek, John M. Klinck Jan 2004

A Modelling Study Of The Influence Of Environment And Food Supply On Survival Of Crassostrea Gigas Larvae, Eileen E. Hofmann, Eric N. Powell, Eleanor A. Bochenek, John M. Klinck

CCPO Publications

A biochemically based model was developed to simulate the growth, development, and metamorphosis of larvae of the Pacific oyster (Crassostrea gigas). The unique characteristics of the model are that it: (1) defines larvae in terms of their protein, neutral lipid, polar lipid, carbohydrate, and ash content; (2) tracks weight separately from length to follow larval condition; and (3) includes genetic variation in growth efficiency and egg quality to better simulate cohort population dynamics. The model includes parameterizations for filtration, ingestion, and respiration, which determine larval growth rate, and processes controlling larval mortality and metamorphosis. Changes in larval tissue …


Black Carbon In Estuarine And Coastal Ocean Dissolved Organic Matter, Antonio Mannino, H. Rodger Harvey Jan 2004

Black Carbon In Estuarine And Coastal Ocean Dissolved Organic Matter, Antonio Mannino, H. Rodger Harvey

OES Faculty Publications

We measured black carbon (BC) in ultrafiltered, high-molecular weight dissolved organic matter (UDOM) in surface waters of Delaware Bay, Chesapeake Bay, and the adjacent Atlantic Ocean (U.S.A.) to investigate the importance of riverine and estuarine dissolved organic matter (DOM) as a source of BC to the ocean. BC was 5-72% of UDOM-C (27 ± 17%), which corresponds to 8.9 ± 6.5% of dissolved organic carbon (DOC), with higher values in the heavily urbanized midbay region of the Delaware Estuary and lower yields in the river and coastal ocean. The spatial and seasonal distributions of BC along the salinity gradient of …


Age And Growth Of Scotia Sea Icefish, Chaenocephalus Aceratus, From The South Shetland Islands, M. La Mesa, J. Ashford, E. Larson, M. Vacchi Jan 2004

Age And Growth Of Scotia Sea Icefish, Chaenocephalus Aceratus, From The South Shetland Islands, M. La Mesa, J. Ashford, E. Larson, M. Vacchi

OES Faculty Publications

Samples of Chaenocephalus aceratus (Lönnberg) were collected during a trawl survey carried out around the South Shetland Islands in January–February 2002. Fish were caught by commercial bottom trawl fishing down to 500 m depth, using a stratified randomized sampling design. As observed in other recent surveys within the same area, C. aceratus represented one of the predominant species. Overall, 357 specimens ranging from 13 and 67 cm (TL) were selected for the present study. Ages were estimated by counting annuli present in the sagittal otoliths, exposed by grinding and polishing along their sagittal plane. To estimate the precision of age …


Stability At Hydrothermal-Vent Mussel Beds: Dynamics At Hydrothermal Vents: Evidence For Stable Macrofaunal Communities In Mussel Beds On The Northern East Pacific Rise, Jennifer Carolyn Dreyer Jan 2004

Stability At Hydrothermal-Vent Mussel Beds: Dynamics At Hydrothermal Vents: Evidence For Stable Macrofaunal Communities In Mussel Beds On The Northern East Pacific Rise, Jennifer Carolyn Dreyer

Dissertations, Theses, and Masters Projects

No abstract provided.


Parasitism In Deep-Sea Chemosynthetic Mussels: Parasitism In Bathymodiolus Mussels From Deep-Sea Seep And Hydrothermal Vents, Megan E. Ward Jan 2004

Parasitism In Deep-Sea Chemosynthetic Mussels: Parasitism In Bathymodiolus Mussels From Deep-Sea Seep And Hydrothermal Vents, Megan E. Ward

Dissertations, Theses, and Masters Projects

No abstract provided.


Spatial Variations In Benthic Invertebrate Assemblages In And Around The Georges Banks Closed Areas, Andrew Clayton Walker Jan 2004

Spatial Variations In Benthic Invertebrate Assemblages In And Around The Georges Banks Closed Areas, Andrew Clayton Walker

Dissertations, Theses, and Masters Projects

No abstract provided.


Survival And Habitat Preferences Of White Marlin (Tetrapturus Albidus) Released From The Western North Atlantic Recreational Fishery, Andrij Z. Horodysky Jan 2004

Survival And Habitat Preferences Of White Marlin (Tetrapturus Albidus) Released From The Western North Atlantic Recreational Fishery, Andrij Z. Horodysky

Dissertations, Theses, and Masters Projects

No abstract provided.


Reproductive Biology Of American Shad, Alosa Sapidissima, In The Mattaponi River, Aaron Reid Hyle Jan 2004

Reproductive Biology Of American Shad, Alosa Sapidissima, In The Mattaponi River, Aaron Reid Hyle

Dissertations, Theses, and Masters Projects

No abstract provided.


Metapopulation Dynamics, Habitat Quality, And Spatial Scale: Variation In Reproductive Output Of The Baltic Clam, Macoma Balthica, In Shallow Systems Of The Chesapeake Bay, Kristen Adams Delano Jan 2004

Metapopulation Dynamics, Habitat Quality, And Spatial Scale: Variation In Reproductive Output Of The Baltic Clam, Macoma Balthica, In Shallow Systems Of The Chesapeake Bay, Kristen Adams Delano

Dissertations, Theses, and Masters Projects

No abstract provided.


A Study Of The Eastern Oyster, Crassostrea Virginica: (1) Dermo Tolerance, Survival, Growth, Condition And Hsp70 Expression In Different Geographic Stocks; (2) Heat Tolerance And Effects Of Sublethal Heat Shock On Survival And Hsp70 Expression Of Infected And Uninfected Oysters, Vincent G. Encomio Jan 2004

A Study Of The Eastern Oyster, Crassostrea Virginica: (1) Dermo Tolerance, Survival, Growth, Condition And Hsp70 Expression In Different Geographic Stocks; (2) Heat Tolerance And Effects Of Sublethal Heat Shock On Survival And Hsp70 Expression Of Infected And Uninfected Oysters, Vincent G. Encomio

Dissertations, Theses, and Masters Projects

The diseases Dermo and MSX have devastated Chesapeake Bay populations of the eastern oyster, Crassostrea virginica. The protozoan Perkinsus marinus, which causes Dermo, is particularly problematic since it persists over a wide range of salinities and temperatures. An objective of this dissertation was to determine whether specific wild oyster stocks had developed natural resistance to Dermo and if several parameters (survival, growth, condition and energy reserves) were associated with resistance. Another objective was to characterize heat shock protein (hsp70) expression in the eastern oyster. Heat shock proteins such as hsp70 protect organisms from thermal stress and other stressors, and this …


Ichthyofaunal And Dietary Analysis Of Sympatric Piscivores In A Chesapeake Bay Littoral Zone: Including Bioenergetic Models Of Growth And Diel Temperature Sanctuary Use, Christian Harding Hager Jan 2004

Ichthyofaunal And Dietary Analysis Of Sympatric Piscivores In A Chesapeake Bay Littoral Zone: Including Bioenergetic Models Of Growth And Diel Temperature Sanctuary Use, Christian Harding Hager

Dissertations, Theses, and Masters Projects

The first section of this dissertation describes the ichthyofaunal community of a mesohaline Chesapeake Bay April--November. Fish assemblages were sampled using two seine gears, a small seine that sampled 352 m 2 and a 914m haul-seine that sampled 144,473 m2. The small seine collected 32 finfish species. The larger gear captured 31 finfish species, including 17 that were not sampled by small gear. Sampled diversity was greater but density estimates were similar to those determined previously by other investigators using flume-net, drop-ring, and otter trawl techniques. Nocturnal abundance of larger fishes far exceeded daylight. Fish abundance and size distribution varied …


Interactive Regulation Of Dissolved Copper Toxicity By An Estuarine Microbial Community, Christina L. Dryden, Andrew S. Gordon, John R. Donat Jan 2004

Interactive Regulation Of Dissolved Copper Toxicity By An Estuarine Microbial Community, Christina L. Dryden, Andrew S. Gordon, John R. Donat

OES Faculty Publications

Cultured marine microorganisms under copper stress produce extracellular compounds having a high affinity for copper (copper-complexing ligands). These ligands are similar in binding strength to those found in natural waters, but few studies have examined the relationship between copper, copper-complexing ligand concentrations, and natural microbial populations. A series of in situ experiments in the Elizabeth River, Virginia, revealed that an intact estuarine microbial community responded to copper stress by production of extracellular, high-affinity copper-complexing ligands. The rate of ligand production was dependent on copper concentration and resulted in a reduction of the concentration of free cupric ions, Cu2+, …


Light Dependence Of Selenium Uptake By Phytoplankton And Implications For Predicting Selenium Incorporation Into Food Webs, Stephen B. Baines, Nicholas S. Fisher, Martina A. Doblin, Gregory A. Cutter, Lynda S. Cutter, Brian Cole Jan 2004

Light Dependence Of Selenium Uptake By Phytoplankton And Implications For Predicting Selenium Incorporation Into Food Webs, Stephen B. Baines, Nicholas S. Fisher, Martina A. Doblin, Gregory A. Cutter, Lynda S. Cutter, Brian Cole

OES Faculty Publications

The potentially toxic element selenium is first concentrated from solution to a large but highly variable degree by algae and bacteria before being passed on to consumers. The large loads of abiotic and detrital suspended particles often present in rivers and estuaries may obscure spatial and temporal patterns in Se concentrations at the base of the food web. We used radiotracers to estimate uptake of both selenite (Se(IV)) and C by intact plankton communities at two sites in the Sacramento/San Joaquin River Delta. Our goals were to determine (1) whether C and Se(IV) uptake were coupled, (2) the role of …


Analytical Intercomparison Between Flow Injection-Chemiluminescence And Flow Injection-Spectrophotometry For The Determination Of Picomolar Concentrations Of Iron In Seawater, Andrew R. Bowie, Peter N. Sedwick, Paul J. Worsfold Jan 2004

Analytical Intercomparison Between Flow Injection-Chemiluminescence And Flow Injection-Spectrophotometry For The Determination Of Picomolar Concentrations Of Iron In Seawater, Andrew R. Bowie, Peter N. Sedwick, Paul J. Worsfold

OES Faculty Publications

A lab- and ship-based analytical intercomparison of two flow injection methods for the determination of iron in seawater was conducted, using three different sets of seawater samples collected from the Southern Ocean and South Atlantic. In one exercise, iron was determined in three different size-fractions (< 0.03 &μm, < 0.4 μm, and unfiltered) in an effort to better characterize the operational nature of each analytical technique with respect to filter size. Measured Fe concentrations were in the range 0.19 to 1.19 nM using flow injection with luminol chemiluminescence detection (FI-CL), and 0.07 to 1.54 nM using flow injection with catalytic spectrophotometric detection with N, N-dimethyl-p-phenylenediamine dihydrochloride (FI-DPD). The arithmetic mean for the FI-CL method was higher (by 0.09 nM) than the FI-DPD method for dissolved (< 0.4 μm) Fe, a difference that is comparable to the analytical blanks, which were as high as 0.13 nM ( CL) and 0.09 nM (DPD). There was generally good agreement between the FI-CL determinations for the < 0.03 μm size fraction and the FI-DPD determinations for the < 0.4 μm size fraction in freshly collected samples. Differences in total-dissolvable ( unfiltered) Fe concentrations determined by the two FI methods were more variable, reflecting the added complexity associated with the analysis of partially digested particulate material in these samples. Overall, however, the FI-CL determinations were significantly (P = 0.05) lower than the FI-DPD determinations for the unfiltered samples. Our results suggest that the observed, systematic inter-method differences reflect measurement of different physicochemical fractions of Fe present in seawater, such that colloidal and/or organic iron species are better determined by the FI-CL method than the FI-DPD method. This idea is supported by our observation that inter-method differences were largest for freshly collected acidified seawater, which suggests extended storage (>6 months) of acidified samples as a possible protocol for the determination of dissolved iron in seawater.


Relevant Scales In Zooplankton Ecology: Distribution, Feeding, And Reproduction Of The Copepod Acartia Hudsonica In Response To Thin Layers Of The Diatom Skeletonema Costatum, Alexander B. Bochdansky, Stephen M. Bollens Jan 2004

Relevant Scales In Zooplankton Ecology: Distribution, Feeding, And Reproduction Of The Copepod Acartia Hudsonica In Response To Thin Layers Of The Diatom Skeletonema Costatum, Alexander B. Bochdansky, Stephen M. Bollens

OES Faculty Publications

We investigated the interaction of the copepod Acartia hudsonica in relation to thin layers of the diatom Skeletonema costatum. Thin layers have recently received much attention, since they are common and persistent features in the water column, often overlooked by traditional sampling methods. Their frequent abundance in coastal oceans and the high biomass associated with them has led to the assumption that they are important grazing sites of calanoid copepods. We employed 2-m tall tower tanks that allowed us to simulate thin layers. Three variables representative of three time scales were considered: the distribution of copepods in the tanks …


Advection, Krill, And Antarctic Marine Ecosystems, Eileen E. Hofmann, Eugene J. Murphy Jan 2004

Advection, Krill, And Antarctic Marine Ecosystems, Eileen E. Hofmann, Eugene J. Murphy

CCPO Publications

Advective processes are recognized as being important in structuring and maintaining marine ecosystems. In the Southern Ocean advective effects are perhaps most clearly observed because the Antarctic Circumpolar Current (ACC) provides a connection between most parts of the system, including open ocean and continental shelf regions. The ACC also provides a mechanism for large-scale transport of plankton, such as Antarctic krill (Euphousia superba Dana), which is an important component of the Southern Ocean food web. This overview provides a summary of recent observational and modelling results that consider the importance of advection to the Southern Ocean ecosystem and, in particular, …


Physical Forcing Of Phytoplankton Community Structure And Primary Production In Continental Shelf Waters Of The Western Antarctic Peninsula, Barbara B. Prézelin, Eileen E. Hofmann, Mark Moline, John M. Klinck Jan 2004

Physical Forcing Of Phytoplankton Community Structure And Primary Production In Continental Shelf Waters Of The Western Antarctic Peninsula, Barbara B. Prézelin, Eileen E. Hofmann, Mark Moline, John M. Klinck

OES Faculty Publications

Analyses of a multidisciplinary data set, collected in continental shelf waters of the Western Antarctic Peninsula (WAP) during austral summer of January 1993, identified a previously unrecognized forcing mechanism that sets up a physical and chemical structure that supports and assures site-specific diatom-dominated communities and enhanced biological production (Prézelin et al., 2000). This forcing is active when the southern boundary of the Antarctic Circumpolar Current (ACC) flows along the shelf edge, thereby facilitating onshelf bottom intrusions of nutrient-rich Upper Circumpolar Deep Water (UCDW), which then is upwelled or mixed into the upper water column. At times or locations where UCDW …


Influence Of Short-Term Variations In Food On Survival Of Crassotrea Gigas Larvae: A Modeling Study, Eric N. Powell, Eleanor A, Bochenek, John M. Klinck, Eileen E. Hofmann Jan 2004

Influence Of Short-Term Variations In Food On Survival Of Crassotrea Gigas Larvae: A Modeling Study, Eric N. Powell, Eleanor A, Bochenek, John M. Klinck, Eileen E. Hofmann

OES Faculty Publications

A biochemically-based model was developed to simulate the growth, development, and metamorphosis of larvae of the Pacific oyster, Crassostrea gigas. The model defines larvae in terms of their protein, lipid, carbohydrate, and ash content and includes variation in growth efficiency and egg quality to better simulate cohort population dynamics. Changes in tissue composition occur as the larva grows and in response to the biochemical composition of the food. The premise behind this modeling study was that certain periods of larval life are more critical than others with respect to the availability of food and that food quality is as …


Pathobiology Of Mycobacteria In Striped Bass (Morone Saxatilis), David T. Gauthier Jan 2004

Pathobiology Of Mycobacteria In Striped Bass (Morone Saxatilis), David T. Gauthier

Dissertations, Theses, and Masters Projects

Striped bass (Morone saxatilis) in Chesapeake Bay, USA, are experiencing an epizootic of mycobacteriosis. This disease, caused by bacteria in the genus Mycobacterium, causes granulomatous lesions of the skin and viscera. Diseased fish are often emaciated, and fish with skin lesions may be significantly disfigured. The overall goal of this work was to examine aspects of the pathobiology of mycobacteria in striped bass via laboratory exposure studies and cellular assays. Striped bass were injected intraperitoneally with a sublethal dose of Mycobacterium marinum, M. shottsii, or M. gordonae and sampled for histology and bacteriology at regular intervals to 45 weeks post-injection …


Evaluating Restored Oyster Reefs In Chesapeake Bay: How Habitat Structure Influences Ecological Function, Janet A. Nestlerode Jan 2004

Evaluating Restored Oyster Reefs In Chesapeake Bay: How Habitat Structure Influences Ecological Function, Janet A. Nestlerode

Dissertations, Theses, and Masters Projects

A shortage of shell resources for restoring reefs of the Eastern oyster, Crassostrea virginica, has led to widespread use of substitute materials. The effectiveness of such alternative substrates as habitat for reef-associated fauna other than oysters is largely unresolved. I investigated the habitat value of oyster shell, surf clam (Spisula solidissima) shell, and pelletized coal ash reefs for benthic and nektonic communities. Oyster recruitment, survival, and growth were monitored on reefs of oyster and surf clam shell near the mouth of Chesapeake Bay and York River, USA. Oyster shell supported greater oyster growth and survival and offered the highest degree …


Natural Dermo Resistance And Related Defense Mechanisms In Eastern Oysters, Crassostrea Virginica, With Implications For Restoration, Shawn Michael Stickler Jan 2004

Natural Dermo Resistance And Related Defense Mechanisms In Eastern Oysters, Crassostrea Virginica, With Implications For Restoration, Shawn Michael Stickler

Dissertations, Theses, and Masters Projects

American oyster (Crassostrea virginica) stocks on the East Coast in general, and in Chesapeake Bay in particular, have been in decline over the past half-century in large part due to Dermo disease, caused by the protist parasite Perkinsus marinus. Efforts to restore oysters for their ecological and economic value have centered on the development and use of hatchery-based seed selectively bred for disease resistance. Selective breeding could benefit from the incorporation of oysters from wild stocks that have developed "natural Dermo resistance", but few such stocks have been identified and verified. This dissertation describes reciprocal common-garden experiments carried out at …