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VIMS Articles

2010

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Articles 31 - 45 of 45

Full-Text Articles in Life Sciences

Production Of Dissolved Organic Matter And Inorganic Nutrients By Gelatinous Zooplankton In The York River Estuary, Chesapeake Bay, Rh Condon, Dk Steinberg, Da Bronk Jan 2010

Production Of Dissolved Organic Matter And Inorganic Nutrients By Gelatinous Zooplankton In The York River Estuary, Chesapeake Bay, Rh Condon, Dk Steinberg, Da Bronk

VIMS Articles

Large "blooms" of ctenophores (Mnemiopsis leidyi) and scyphomedusae (Chrysaora quinquecirrha) occur throughout the York River, a sub-estuary of Chesapeake Bay. These gelatinous zooplankton blooms can influence carbon (C) and nutrient cycling through excretion of dissolved organic matter (DOM), and inorganic nitrogen (N) and phosphorus (P). We measured dissolved organic carbon, nitrogen and phosphorus (DOC, DON and DOP), ammonium (NH(4)(+)) and phosphate (PO(4)(3-)) released by M. leidyi and C. quinquecirrha in the laboratory, and estimated their contribution to in situ DOC and inorganic pools. Both species released high amounts of DOC compared with DON and DOP. DOM released by Mnemiopsis was …


Comparative Visual Function In Four Piscivorous Fishes Inhabiting Chesapeake Bay, Az Horodysky, Rw Brill, Ej Warrant, Ja Musick, Rj Latour Jan 2010

Comparative Visual Function In Four Piscivorous Fishes Inhabiting Chesapeake Bay, Az Horodysky, Rw Brill, Ej Warrant, Ja Musick, Rj Latour

VIMS Articles

Maintaining optimal visual performance is a difficult task in photodynamic coastal and estuarine waters because of the unavoidable tradeoffs between luminous sensitivity and spatial and temporal resolution, yet the visual systems of coastal piscivores remain understudied despite differences in their ecomorphology and microhabitat use. We therefore used electroretinographic techniques to describe the light sensitivities, temporal properties and spectral sensitivities of the visual systems of four piscivorous fishes common to coastal and estuarine waters of the western North Atlantic: striped bass (Morone saxatilis), bluefish (Pomatomus saltatrix), summer flounder (Paralichthys dentatus) and cobia (Rachycentron canadum). Benthic summer flounder exhibited higher luminous sensitivity …


Nitrogen Uptake By Phytoplankton And Bacteria During An Induced Phaeocystis Pouchetii Bloom, Measured Using Size Fractionation And Flow Cytometric Sorting, Pb Bradley, Mp Sanderson, Jc Nejstgaard, Af Sazhin, Me Frischer, Lm Killberg-Thoreson, Pg Verity, L Campbell, Da Bronk Jan 2010

Nitrogen Uptake By Phytoplankton And Bacteria During An Induced Phaeocystis Pouchetii Bloom, Measured Using Size Fractionation And Flow Cytometric Sorting, Pb Bradley, Mp Sanderson, Jc Nejstgaard, Af Sazhin, Me Frischer, Lm Killberg-Thoreson, Pg Verity, L Campbell, Da Bronk

VIMS Articles

Uptake of inorganic and organic nitrogen (N) by phytoplankton and bacteria was investigated during a mesocosm study conducted in Raunefjord, Norway in April 2005. One mesocosm was fertilized with nitrate and phosphate at a ratio of 16:1 and maintained in the light, while one unamended light mesocosm served as a control. Dissolved nutrients, phytoplankton and bacterial biomass, and phytoplankton community composition were monitored throughout the 26 d experiment. Uptake of (15)N-labeled ammonium and nitrate, and dual-labeled ((15)N and (13)C) urea and dissolved free amino acids (DFAA) was measured for phytoplankton and bacteria using 2 methods: size fractionation into 0.2-0.8 and …


Linkage Between Crustacean Zooplankton And Aquatic Bacteria, Kw Tang, V Turk, Hp Grossart Jan 2010

Linkage Between Crustacean Zooplankton And Aquatic Bacteria, Kw Tang, V Turk, Hp Grossart

VIMS Articles

Bacteria and metazoan zooplankton (mainly crustaceans) are often viewed as 2 separate functional groups in the pelagic food webs indirectly linked via nutrient cycling and trophic cascades. Yet a zooplankter's body carries a high abundance of diverse bacteria, often at an equivalent concentration orders of magnitude higher than the ambient bacterial concentration. Zooplankton bodies are organic-rich micro-environments that support fast bacterial growth. Their physical-chemical conditions differ from those in the surrounding water and therefore select for different bacterial communities, including anaerobic bacteria that otherwise may not thrive in a well-oxygenated water column. The zooplankton body provides protection to the associated …


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. …


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 more than …


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. Throughout the system, the highest observed densities were …


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 …


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 > 50% …


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 …


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

Bycatch Reduction Device Conserves Diamondback Terrapin Without Affecting Catch Of Blue Crab, Megan A. Rook, Rn Lipcius, Bret M. Bronner, Randolph 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 offered. For YOY menhaden, a type-III …


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 to …


Quantitative Pcr Assay For Mycobacterium Pseudoshottsii And Mycobacterium Shottsii And Application To Environmental Samples And Fishes From The Chesapeake Bay, Dt Gauthier, Kimberly S. Reece, J Xiao, Mw Rhodes, Hi Kator, Rj Latour, C F. Bonzek, J Hoenig, W. K. 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, Kimberly S. Reece, J Xiao, Mw Rhodes, Hi Kator, Rj Latour, C F. Bonzek, J Hoenig, W. K. 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, Troy W. 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, Troy W. 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 …