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VIMS Articles

2010

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Articles 1 - 30 of 45

Full-Text Articles in Life Sciences

Sponge Host Characteristics Shape The Community Structure Of Their Shrimp Associates, Kristen M. Hultgren, J. Emmett Duffy May 2010

Sponge Host Characteristics Shape The Community Structure Of Their Shrimp Associates, Kristen M. Hultgren, J. Emmett Duffy

VIMS Articles

Both body size and habitat architecture have pervasive effects on the form, function, and interactions of organisms, and can play especially important roles in structuring intimate associations between host organisms and their obligate associates. In this study, we examined how body size is related to host use in a diverse clade of closely related snapping shrimp species (Synalpheus) that live in the interior canals of sponges. Using data from an extensive survey of sponge-dwelling Synalpheus from Jamaica, we tested how sponge morphology (interior canal size and individual sponge volume) was related to the identity and diversity of Synalpheus inhabitants. In ...


Evaluating Ecosystem Response To Oyster Restoration And Nutrient Load Reduction With A Multispecies Bioenergetics Model, Rs Fulford, Dl Brietburg, Mark Luckenbach, Rie Newell Apr 2010

Evaluating Ecosystem Response To Oyster Restoration And Nutrient Load Reduction With A Multispecies Bioenergetics Model, Rs Fulford, Dl Brietburg, Mark Luckenbach, Rie Newell

VIMS Articles

Many of the world's coastal ecosystems are impacted by multiple stressors each of which may be subject to different management strategies that may have overlapping or even conflicting objectives. Consequently, management results may be indirect and difficult to predict or observe. We developed a network simulation model intended specifically to examine ecosystem-level responses to management and applied this model to a comparison of nutrient load reduction and restoration of highly reduced stocks of bivalve suspension feeders (eastern oyster, Crassostrea virginica) in an estuarine ecosystem (Chesapeake Bay, USA). Model results suggest that a 50% reduction in nutrient inputs from the ...


Oceanic Heterotrophic Bacterial Nutrition By Semilabile Dom As Revealed By Data Assimilative Modeling, Yw Luo, Mam Friedrichs, Sc Doney, Mj Church, Hw Ducklow Jan 2010

Oceanic Heterotrophic Bacterial Nutrition By Semilabile Dom As Revealed By Data Assimilative Modeling, Yw Luo, Mam Friedrichs, Sc Doney, Mj Church, Hw Ducklow

VIMS Articles

Previous studies have focused on the role of labile dissolved organic matter (DOM) (defined as turnover time of similar to 1 d) in supporting heterotrophic bacterial production, but have mostly neglected semilabile DOM (defined as turnover time of similar to 100 to 1000 d) as a potential substrate for heterotrophic bacterial growth. To test the hypothesis that semilabile DOM supports substantial amounts of heterotrophic bacterial production in the open ocean, we constructed a 1-dimensional epipelagic ecosystem model and applied it to 3 open ocean sites: the Arabian Sea, Equatorial Pacific and Station ALOHA in the North Pacific Subtropical Gyre. The ...


Growth, Reproductive Condition, And Digestive Tubule Atrophy Of Pacific Oyster Crassostrea Gigas In Gamakman Bay Off The Southern Coast Of Korea, Dh Kang, Fu-Lin E. Chu, Hs Yang, Ch Lee, Ch Lee, Hb Koh, Ks Choi Jan 2010

Growth, Reproductive Condition, And Digestive Tubule Atrophy Of Pacific Oyster Crassostrea Gigas In Gamakman Bay Off The Southern Coast Of Korea, Dh Kang, Fu-Lin E. Chu, Hs Yang, Ch Lee, Ch Lee, Hb Koh, Ks Choi

VIMS Articles

Spat of Pacific oysters (Crassostrea gigas) were collected from Gamakman Bay, Korea, and raised in a spat hardening facility located in the low intertidal zone of the bay for a "hardening/stunting" period of 10 mo. Seasonal changes in growth, reproductive condition, and digestive tubule atrophy (DTA) of these "hardened/stunted" oysters were monitored for more than a year after transplanting to a suspended longline system in a grow-out area in the bay. After transplantation, the hardened/stunted oysters showed a logarithmic increase in shell size for the first 4 mo, from June to October, and growth remained stable from ...


Management Of The Piankatank River, Virginia, In Support Of Oyster (Crassostrea Virginica, Gmelin 1791) Fishery Repletion, Juliana M. Harding, Roger L. Mann, Melissa Southworth, James A. Wesson Jan 2010

Management Of The Piankatank River, Virginia, In Support Of Oyster (Crassostrea Virginica, Gmelin 1791) Fishery Repletion, Juliana M. Harding, Roger L. Mann, Melissa Southworth, James A. Wesson

VIMS Articles

The Piankatank River is a trap-type estuary on the western shore of Chesapeake Bay that has been managed for seed oyster production since 1963. Market oyster production in the river is minimal. Repletion efforts include shell planting and seed removal. We describe sequential changes in population demographics and habitat in relation to repletion activities on eight Piankatank River public oyster reefs from 1998 through 2009. Two reef groups (northern and southern) may be distinguished by density (oysters/m(2)), biomass (e dry tissue weight), and shell volume (L/m(2)) data. Age-at-length relationships were estimated from demographic data using a ...


Observations Of Blue Crabs (Callinectes Sapidus, Rathbun 1896) On Shell Bar Oyster Reef, Great Wicomico River, Virginia, Juliana Harding, Melissa Southworth, Roger L. Mann Jan 2010

Observations Of Blue Crabs (Callinectes Sapidus, Rathbun 1896) On Shell Bar Oyster Reef, Great Wicomico River, Virginia, Juliana Harding, Melissa Southworth, Roger L. Mann

VIMS Articles

Blue crabs (Callinectes sapidus, Rathbun 1896) were sampled with commercial crab pots on Shell Bar oyster reef in the Great Wicomico River, VA, from May through October during 2006 and 2007. Weekly catch per unit effort (CPUE), sex ratio, and size (carapace width, measured in millimeters) were evaluated in the context of water temperature (measured in degrees Celsius), salinity, and daylength (measured in hours) conditions on the reef. The total number of crabs collected in 2006 and 2007 was 5,221 and 3,303, respectively. Blue crab CPU E was highest from mid-June through mid-September at water temperatures at or ...


A Comparison Of Crassostrea Virginica And C. Ariakensis In Chesapeake Bay: Does Oyster Species Affect Habitat Function?, Hd Harwell, Pr Kingsley-Smith, M. Lisa Kellogg, Standish K. Allen Jr., Dw Meritt, Kennedy Paynter, Mark Luckenbach Jan 2010

A Comparison Of Crassostrea Virginica And C. Ariakensis In Chesapeake Bay: Does Oyster Species Affect Habitat Function?, Hd Harwell, Pr Kingsley-Smith, M. Lisa Kellogg, Standish K. Allen Jr., Dw Meritt, Kennedy Paynter, Mark Luckenbach

VIMS Articles

We examined the possibility that a nonnative oyster species would provide an ecologically functional equivalent of the native oyster species if introduced into the Chesapeake Bay. Habitat complexity and associated benthic communities of experimental triploid Crassostrea virginica and Crassostrea ariakensis reefs were investigated at 4 sites of varying salinity, tidal regime, water depth, predation intensity, and disease pressure in the Chesapeake Bay region (Maryland and Virginia). Four experimental treatments were established at each site: C. virginica, C. ariakensis, 50:50 of C. virginica and C. ariakensis, and shell only. Abundance, biomass, species richness, evenness, dominance, and diversity of reef-associated fauna ...


Oyster (Crassostrea Virginica, Gmelin 1791) Population Dynamics On Public Reefs In The Great Wicomico River, Virginia, Usa, Melissa Southworth, Juliana M. Harding, James A. Wesson, Roger L. Mann Jan 2010

Oyster (Crassostrea Virginica, Gmelin 1791) Population Dynamics On Public Reefs In The Great Wicomico River, Virginia, Usa, Melissa Southworth, Juliana M. Harding, James A. Wesson, Roger L. Mann

VIMS Articles

We describe oyster population trends in the Great Wicomico River, VA, from 2000 through 2009 using quantitative fishery independent survey data collected using a stratified random design. The seven public reefs examined cover a total of 2.8 X 10(5) m(2) and vary in individual size from 1.36 X 10(4) to 7.16 X 10(4) m(2). The river is functionally divided by a sand spit into upriver and downriver regions. Oyster densities on the upriver reefs were typically an order of magnitude higher than densities on the downriver reefs within the same time period ...


Asymmetric Conservation Benefits Of Circle Hooks In Multispecies Billfish Recreational Fisheries: A Synthesis Of Hook Performance And Analysis Of Blue Marlin (Makaira Nigricans) Postrelease Survival, John E. Graves, Andrij Z. Horodysky Jan 2010

Asymmetric Conservation Benefits Of Circle Hooks In Multispecies Billfish Recreational Fisheries: A Synthesis Of Hook Performance And Analysis Of Blue Marlin (Makaira Nigricans) Postrelease Survival, John E. Graves, Andrij Z. Horodysky

VIMS Articles

We evaluated the conservation benefits of the use of circle hooks compared with standard J hooks in the recreational fishery for Atlantic istiophorid billfishes, noting hooking location and the presence of trauma (bleeding) for 123 blue marlin (Makaira nigricans), 272 white marlin (Kajikia albida), and 132 sailfish (Istiophorus platypterus) caught on natural baits rigged with one of the two hook types. In addition, we used pop-up satellite archival tags (PSATs) to follow the fate of 61 blue marlin caught on natural baits rigged with circle hooks or on a combination of artificial lure and natural bait rigged with J hooks ...


A Molecular Genetic Investigation Of The Population Structure Of Atlantic Menhaden (Brevoortia Tyrannus), Abigail J. Lynch, Jan R. Mcdowell, John E. Graves Jan 2010

A Molecular Genetic Investigation Of The Population Structure Of Atlantic Menhaden (Brevoortia Tyrannus), Abigail J. Lynch, Jan R. Mcdowell, John E. Graves

VIMS Articles

Atlantic menhaden (Brevoortia tyrannus), through landings, support one of the largest commercial fisheries in the United States. Recent consolidation of the once coast-wide reduction fishery to waters within and around Chesapeake Bay has raised concerns over the possibility of the loss of unique genetic variation resulting from concentrated fishing pressure. To address this question, we surveyed variation at the mitochondrial cytochrome c oxidase subunit I (COI) gene region and seven nuclear microsatellite loci to evaluate stock structure of Atlantic menhaden. Samples were collected from up to three cohorts of Atlantic menhaden at four geographic locations along the U.S. Atlantic ...


Regional Management Units For Marine Turtles: A Novel Framework For Prioritizing Conservation And Research Across Multiple Scales, Bryan P. Wallace, John A. Musick Jan 2010

Regional Management Units For Marine Turtles: A Novel Framework For Prioritizing Conservation And Research Across Multiple Scales, Bryan P. Wallace, John A. Musick

VIMS Articles

Background: Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques - including site-based monitoring, genetic analyses, mark-recapture studies and telemetry - can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges. Methodology/Principal Findings: To address these issues for marine turtles, we collated all ...


Evolutionary Characters, Phenotypes And Ontologies: Curating Data From The Systematic Biology Literature, Wasila M. Dahdul, Eric J. Hilton Jan 2010

Evolutionary Characters, Phenotypes And Ontologies: Curating Data From The Systematic Biology Literature, Wasila M. Dahdul, Eric J. Hilton

VIMS Articles

Background: The wealth of phenotypic descriptions documented in the published articles, monographs, and dissertations of phylogenetic systematics is traditionally reported in a free-text format, and it is therefore largely inaccessible for linkage to biological databases for genetics, development, and phenotypes, and difficult to manage for large-scale integrative work. The Phenoscape project aims to represent these complex and detailed descriptions with rich and formal semantics that are amenable to computation and integration with phenotype data from other fields of biology. This entails reconceptualizing the traditional free-text characters into the computable Entity-Quality (EQ) formalism using ontologies. Methodology/Principal Findings: We used ontologies ...


Increased Ocean Carbon Export In The Sargasso Sea Linked To Climate Variability Is Countered By Its Enhanced Mesopelagic Attenuation, M. W. Lomas, Deborah K. Steinberg, T. Dickey, C.A. Carlson, N.B. Nelson, R.H. Condon, N.R. Bates Jan 2010

Increased Ocean Carbon Export In The Sargasso Sea Linked To Climate Variability Is Countered By Its Enhanced Mesopelagic Attenuation, M. W. Lomas, Deborah K. Steinberg, T. Dickey, C.A. Carlson, N.B. Nelson, R.H. Condon, N.R. Bates

VIMS Articles

Photosynthetic CO(2) uptake by oceanic phytoplankton and subsequent export of particulate organic carbon (POC) to the ocean interior comprises a globally significant biological carbon pump, controlled in part by the composition of the planktonic community. The strength and efficiency of this pump depends upon the balance of particle production in the euphotic zone and remineralization of those particles in the mesopelagic (defined here as depths between 150 and 300 m), but how these processes respond to climate-driven changes in the physical environment is not completely understood. In the Sargasso Sea, from similar to 1996-2007, we have observed a decade-long ...


Dynamics And Distribution Of Natural And Human-Caused Hypoxia, N. N. Rabalais, Robert J. Diaz, L.A. Levin, R.E. Turner, D. Gilbert, J. Zhang Jan 2010

Dynamics And Distribution Of Natural And Human-Caused Hypoxia, N. N. Rabalais, Robert J. Diaz, L.A. Levin, R.E. Turner, D. Gilbert, J. Zhang

VIMS Articles

Water masses can become undersaturated with oxygen when natural processes alone or in combination with anthropogenic processes produce enough organic carbon that is aerobically decomposed faster than the rate of oxygen re-aeration. The dominant natural processes usually involved are photosynthetic carbon production and microbial respiration. The re-supply rate is indirectly related to its isolation from the surface layer. Hypoxic water masses (< 2 mg L-1, or approximately 30% saturation) can form, therefore, under 'natural' conditions, and are more likely to occur in marine systems when the water residence time is extended, water exchange and ventilation are minimal, stratification occurs, and where carbon production and export to the bottom layer are relatively high. Hypoxia has occurred through geological time and naturally occurs in oxygen minimum zones, deep basins, eastern boundary upwelling systems, and fjords. Hypoxia development and continuation in many areas of the world's coastal ocean is accelerated by human activities, especially where nutrient loading increased in the Anthropocene. This higher loading set in motion a cascading set of events related to eutrophication. The formation of hypoxic areas has been exacerbated by any combination of interactions that increase primary production and accumulation of organic carbon leading to increased respiratory demand for oxygen below a seasonal or permanent pycnocline. Nutrient loading is likely to increase further as population growth and resource intensification rises, especially with increased dependency on crops using fertilizers, burning of fossil fuels, urbanization, and waste water generation. It is likely that the occurrence and persistence of hypoxia will be even more widespread and have more impacts than presently observed. Global climate change will further complicate the causative factors in both natural and human-caused hypoxia. The likelihood of strengthened stratification alone, from increased surface water temperature as the global climate warms, is sufficient to worsen hypoxia where it currently exists and facilitate its formation in additional waters. Increased precipitation that increases freshwater discharge and flux of nutrients will result in increased primary production in the receiving waters up to a point. The interplay of increased nutrients and stratification where they occur will aggravate and accelerate hypoxia. Changes in wind fields may expand oxygen minimum zones onto more continental shelf areas. On the other hand, not all regions will experience increased precipitation, some oceanic water temperatures may decrease as currents shift, and frequency and severity of tropical storms may increase and temporarily disrupt hypoxia more often. The consequences of global warming and climate change are effectively uncontrollable at least in the near term. On the other hand, the consequences of eutrophication-induced hypoxia can be reversed if long-term, broad-scale, and persistent efforts to reduce substantial nutrient loads are developed and implemented. In the face of globally expanding hypoxia, there is a need for water and resource managers to act now to reduce nutrient loads to maintain, at least, the current status.


Evidence For Greater Oxygen Decline Rates In The Coastal Ocean Than In The Open Ocean, D. Gilbert, N. N. Rabalais, R. J. Diaz, J. Zhang Jan 2010

Evidence For Greater Oxygen Decline Rates In The Coastal Ocean Than In The Open Ocean, D. Gilbert, N. N. Rabalais, R. J. Diaz, J. Zhang

VIMS Articles

In the global ocean, the number of reported hypoxic sites (oxygen < 30% saturation) is on the rise both near the coast and in the open ocean. But unfortunately, most of the papers on hypoxia only present oxygen data from one or two years, so that we often lack a long-term perspective on whether oxygen levels at these locations are decreasing, steady or increasing. Consequently, we cannot rule out the possibility that many of the newly reported hypoxic areas were hypoxic in the past, and that the increasing number of hypoxic areas partly reflects increased research and monitoring efforts. Here we address this shortcoming by computing oxygen concentration trends in the global ocean from published time series and from time series that we calculated using a global oxygen database. Our calculations reveal that median oxygen decline rates are more severe in a 30 km band near the coast than in the open ocean (> 100 km from the coast). Percentages of oxygen time series with negative oxygen trends are also greater in the coastal ocean than in the open ocean. Finally, a significant difference between median published oxygen trends and median trends calculated from raw oxygen data suggests the existence of a publication bias in favor of negative trends in the open ocean.


Molecular Identification, Phylogeny And Geographic Distribution Of Brazilian Mangrove Oysters (Crassostrea), Aline Grasielle Costa De Melo, Kimberly S. Reece Jan 2010

Molecular Identification, Phylogeny And Geographic Distribution Of Brazilian Mangrove Oysters (Crassostrea), Aline Grasielle Costa De Melo, Kimberly S. Reece

VIMS Articles

Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuca (Para state) to Santos (Sao Paulo state), and C. rhizophorae from Fortim (Ceara state) to Florianopolis ...


Fate Of Macroalgae In Benthic Systems: Carbon And Nitrogen Cycling Within The Microbial Community, Amber K. Hardison, Elizabeth A. Canuel, Iris C. Anderson, Bart Veuger Jan 2010

Fate Of Macroalgae In Benthic Systems: Carbon And Nitrogen Cycling Within The Microbial Community, Amber K. Hardison, Elizabeth A. Canuel, Iris C. Anderson, Bart Veuger

VIMS Articles

High nutrient loading to coastal bays is often accompanied by the presence of bloom-forming macroalgae, which take up and sequester large amounts of C and N while growing. This pool is temporary, however, as nuisance macroalgae exhibit a bloom and die-off cycle, influencing the biogeochemical functioning of these systems in unknown ways. The objective of this study was to trace the C and N from senescing macroalgae into relevant sediment pools. A macroalgal die-off event was simulated by the addition of freeze-dried macroalgae (Gracilaria spp.), pre-labeled with stable isotopes (C-13 and N-15), to sediment mesocosms. The isotopes were traced into ...


Autotrophic Picoplankton In Mesozooplankton Guts: Evidence Of Aggregate Feeding In The Mesopelagic Zone And Export Of Small Phytoplankton, S. E. Wilson, D. K. Steinberg Jan 2010

Autotrophic Picoplankton In Mesozooplankton Guts: Evidence Of Aggregate Feeding In The Mesopelagic Zone And Export Of Small Phytoplankton, S. E. Wilson, D. K. Steinberg

VIMS Articles

Zooplankton play a key role in affecting the efficiency by which organic matter is exported to depth. Mesozooplankton consumption of detrital aggregates has been hypothesized as a mechanism for enhancing the export of picoplankton from surface layers. We analyzed the gut contents of mesopelagic copepods and ostracods using light and epifluorescence microscopy to determine if cyanobacteria and eukaryotic phytoplankton too small to be ingested individually were present. Hind-guts were dissected from multiple species collected in discrete depth intervals between 0 and 1000 m during the day and night, at contrasting sites in the subtropical (Hawaii Ocean Time-series site ALOHA) and ...


Bycatch Reduction Device Conserves Diamondback Terrapin Without Affecting Catch Of Blue Crab, Megan A. Rook, Romuald N. Lipcius, Bret M. Bronner, Randolph M. Chambers Jan 2010

Bycatch Reduction Device Conserves Diamondback Terrapin Without Affecting Catch Of Blue Crab, Megan A. Rook, Romuald N. Lipcius, Bret M. Bronner, Randolph M. Chambers

VIMS Articles

Bycatch mortality of non-target species in fisheries is a major threat to the conservation and restoration of marine and estuarine species. Attempts to reduce bycatch by fitting fishing gear with excluder devices have typically been met with resistance due to reductions in catch of target species. We examined the possibility that conservation and fishery goals could be met simultaneously. In lower Chesapeake Bay, we tested a mechanism for reducing bycatch of diamondback terrapin Malaclemys terrapin in blue-crab traps without affecting crab catch. Over 23 sampling dates during summer 2008, we compared terrapin captures at 2 shallow-water sites typical of recreational ...


Net Removal Of Nitrogen Through Ingestion Of Phytoplankton By Atlantic Menhaden Brevoortia Tyrannus In Chesapeake Bay, Patrick D. Lynch, Mark J. Brush, Elizabeth D. Condon, Robert J. Latour Jan 2010

Net Removal Of Nitrogen Through Ingestion Of Phytoplankton By Atlantic Menhaden Brevoortia Tyrannus In Chesapeake Bay, Patrick D. Lynch, Mark J. Brush, Elizabeth D. Condon, Robert J. Latour

VIMS Articles

As filter-feeding planktivores, Atlantic menhaden Brevoortia tyrannus have the potential to influence water quality through ingestion of phytoplankton and assimilation of resultant nutrients. To evaluate the influence of young-of-the-year (YOY) and age-1+ menhaden in Chesapeake Bay, rates of phytoplankton (chl a) ingestion and total dissolved nitrogen (TDN) excretion were measured experimentally across varying phytoplankton concentrations. Ingestion rates of YOY menhaden increased (0.03 to 185 mu g chl a fish(-1) min(-1)) in response to increasing phytoplankton concentration (4.98 to 198.22 mu g chl a l(-1)), while age-1+ menhaden exhibited virtually no ingestion of the phytoplankton ...


Tidal Amplification Of Seabed Light, D. G. Bowers, John M. Brubaker Jan 2010

Tidal Amplification Of Seabed Light, D. G. Bowers, John M. Brubaker

VIMS Articles

Because solar irradiance decreases approximately exponentially with depth in the sea, the increase in irradiance at the seabed from mid to low tide is greater than the decrease from mid to high tide. Summed over a day, this can lead to a net amplification of seabed irradiance in tidal waters compared to nontidal waters with the same mean depth and transparency. In this paper, this effect is quantified by numerical and analytical integration of the Lambert-Beer equation to derive the ratio of daily total seabed irradiance with and without a tide. Greatest amplification occurs in turbid water with large tidal ...


The Impact Of Conservation On The Status Of The World's Vertebrates, M Hoffmann, C Hilton-Taylor, A Angulo, M Bohm, Tm Brooks, Et Al. Jan 2010

The Impact Of Conservation On The Status Of The World's Vertebrates, M Hoffmann, C Hilton-Taylor, A Angulo, M Bohm, Tm Brooks, Et Al.

VIMS Articles

Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to ...


High Particle Export Over The Continental Shelf Of The West Antarctic Peninsula, Ko Buesseler, Amp Mcdonnell, Ome Schofield, Dk Steinberg, Hw Ducklow Jan 2010

High Particle Export Over The Continental Shelf Of The West Antarctic Peninsula, Ko Buesseler, Amp Mcdonnell, Ome Schofield, Dk Steinberg, Hw Ducklow

VIMS Articles

Drifting cylindrical traps and the flux proxy Th-234 indicate more than an order of magnitude higher sinking fluxes of particulate carbon and Th-234 in January 2009 than measured by a time-series conical trap used regularly on the shelf of the west Antarctic Peninsula (WAP). The higher fluxes measured in this study have several implications for our understanding of the WAP ecosystem. Larger sinking fluxes result in a revised export efficiency of at least 10% (C flux/net primary production) and a requisite lower regeneration efficiency in surface waters. High fluxes also result in a large supply of sinking organic matter ...


Changes In Age Composition And Growth Characteristics Of Atlantic Sturgeon (Acipenser Oxyrinchus Oxyrinchus) Over 400 Years, Mt Balazik, Gc Garman, Ml Fine, Ch Hager, Sp Mcininch Jan 2010

Changes In Age Composition And Growth Characteristics Of Atlantic Sturgeon (Acipenser Oxyrinchus Oxyrinchus) Over 400 Years, Mt Balazik, Gc Garman, Ml Fine, Ch Hager, Sp Mcininch

VIMS Articles

Populations of sturgeon (Acipenseridae) have experienced global declines, and in some cases extirpation, during the past century. In the current era of climate change and over-harvesting of fishery resources, climate models, based on uncertain boundary conditions, are being used to predict future effects on the Earth's biota. A collection of approximately 400-year-old Atlantic sturgeon spines from a midden in colonial Jamestown, VA, USA, allowed us to compare the age structure and growth rate for a pre-industrial population during a 'mini-ice age' with samples collected from the modern population in the same reach of the James River. Compared with modern ...


Challenges Of Modeling Depth-Integrated Marine Primary Productivity Over Multiple Decades: A Case Study At Bats And Hot, Vs Saba, Mam Friedrichs, Me Carr, D Antoine, Ra Armstrong, Et Al. Jan 2010

Challenges Of Modeling Depth-Integrated Marine Primary Productivity Over Multiple Decades: A Case Study At Bats And Hot, Vs Saba, Mam Friedrichs, Me Carr, D Antoine, Ra Armstrong, Et Al.

VIMS Articles

The performance of 36 models (22 ocean color models and 14 biogeochemical ocean circulation models (BOGCMs)) that estimate depth-integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ C-14 data at the Bermuda Atlantic Time series Study (BATS) and the Hawaii Ocean Time series (HOT) over nearly two decades. Specifically, skill was assessed based on the models' ability to estimate the observed mean, variability, and trends of NPP. At both sites, more than 90% of the models underestimated mean NPP, with the average bias of the BOGCMs being nearly twice that of the ocean color ...


Quantitative Pcr Assay For Mycobacterium Pseudoshottsii And Mycobacterium Shottsii And Application To Environmental Samples And Fishes From The Chesapeake Bay, Dt Gauthier, Ks Reece, J Xiao, Mw Rhodes, Hi Kator, Rj Latour, Chris F. Bonzek, Jm Hoenig, Wk Vogelbein Jan 2010

Quantitative Pcr Assay For Mycobacterium Pseudoshottsii And Mycobacterium Shottsii And Application To Environmental Samples And Fishes From The Chesapeake Bay, Dt Gauthier, Ks Reece, J Xiao, Mw Rhodes, Hi Kator, Rj Latour, Chris F. Bonzek, Jm Hoenig, Wk Vogelbein

VIMS Articles

Striped bass (Morone saxatilis) in the Chesapeake Bay are currently experiencing a very high prevalence of mycobacteriosis associated with newly described Mycobacterium species, Mycobacterium pseudoshottsii and M. shottsii. The ecology of these mycobacteria outside the striped bass host is currently unknown. In this work, we developed quantitative real-time PCR assays for M. pseudoshottsii and M. shottsii and applied these assays to DNA extracts from Chesapeake Bay water and sediment samples, as well as to tissues from two dominant prey of striped bass, Atlantic menhaden (Brevoortia tyrannus) and bay anchovy (Anchoa mitchilli). Mycobacterium pseudoshottsii was found to be ubiquitous in water ...


Science-To-Management Pathways In Us Atlantic Herring Management: Using Governance Network Structure And Function To Track Information Flow And Potential Influence, Tw Hartley, C Glass Jan 2010

Science-To-Management Pathways In Us Atlantic Herring Management: Using Governance Network Structure And Function To Track Information Flow And Potential Influence, Tw Hartley, C Glass

VIMS Articles

Hartley, T. W., and Glass, C. 2010. Science-to-management pathways in US Atlantic herring management: using governance network structure and function to track information flow and potential influence. - ICES Journal of Marine Science, 67: 1154-1163. Atlantic herring (Clupea harengus) are crucial members of the ecosystem and economy of the Northwest Atlantic, and a challenging species for management, which in the United States is a multistakeholder process, involving commercial and recreational fishing interests, conservation organizations, state and federal governments, and other interested parties. Given the large number of stakeholders, fisheries management has been conceptualized as a governance network, through which multiple parties ...


Dead In The Water: The Fate Of Copepod Carcasses In The York River Estuary, Virginia, Dt Elliott, Ck Harris, Kw Tang Jan 2010

Dead In The Water: The Fate Of Copepod Carcasses In The York River Estuary, Virginia, Dt Elliott, Ck Harris, Kw Tang

VIMS Articles

Using laboratory and field experiments we investigated three fates of copepod carcass organic matter in the York River estuary, Virginia: ingestion by planktivores (necrophagy), microbial decomposition, and removal by gravitational settling in the presence of turbulence (sinking). The ctenophore Mnemiopsis leidyi ingested live copepods and carcasses indiscriminately in feeding experiments. Microbial decomposition led to ca. 50% of carcass dry weight loss within 8 h after death. Carcass settling velocities in still water were ca. 0.1 cm s(-1), implying short residence time (hours) in the shallow estuary. However, turbulent mixing kept carcasses in suspension much of the time, reducing ...


Assessing The Apparent Imbalance Between Geochemical And Biochemical Indicators Of Meso- And Bathypelagic Biological Activity: What The @$#! Is Wrong With Present Calculations Of Carbon Budgets?, Ab Burd, Da Hansell, Dk Steinberg, Tr Anderson, J Aristegui Jan 2010

Assessing The Apparent Imbalance Between Geochemical And Biochemical Indicators Of Meso- And Bathypelagic Biological Activity: What The @$#! Is Wrong With Present Calculations Of Carbon Budgets?, Ab Burd, Da Hansell, Dk Steinberg, Tr Anderson, J Aristegui

VIMS Articles

Metabolic activity in the water column below the euphotic zone is ultimately fuelled by the vertical flux of organic material from the surface. Over time, the deep ocean is presumably at steady state, with sources and sinks balanced. But recently compiled global budgets and intensive local field studies suggest that estimates of metabolic activity in the dark ocean exceed the influx of organic substrates. This imbalance indicates either the existence of unaccounted sources of organic carbon or that metabolic activity in the dark ocean is being over-estimated. Budgets of organic carbon flux and metabolic activity in the dark ocean have ...


Effluent Organic Nitrogen (Eon): Bioavailability And Photochemical And Salinity-Mediated Release, Da Bronk, Qn Roberts, Mp Sanderson, Ea Canuel, Pg Hatcher, Et Al. Jan 2010

Effluent Organic Nitrogen (Eon): Bioavailability And Photochemical And Salinity-Mediated Release, Da Bronk, Qn Roberts, Mp Sanderson, Ea Canuel, Pg Hatcher, Et Al.

VIMS Articles

The goal of this study was to investigate three potential ways that the soluble organic nitrogen (N) fraction of wastewater treatment plant (WWTP) effluents, termed effluent organic N (EON), could contribute to coastal eutrophication - direct biological removal, photochemical release of labile compounds, and salinity-mediated release of ammonium (NH4+). Effluents from two WWTPs were used in the experiments. For the bioassays, EON was added to water from four salinities (similar to 0 to 30) collected from the James River (VA) in August 2008, and then concentrations of N and phosphorus compounds were measured periodically over 48 h. Bioassay results, based on ...