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VIMS Articles

2007

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Full-Text Articles in Life Sciences

Abstracts Of Papers Presented At The 16th International Pectinid Workshop Halifax, Nova Scotia, Canada May 11–18, 2007, G. Jay Parsons Dec 2007

Abstracts Of Papers Presented At The 16th International Pectinid Workshop Halifax, Nova Scotia, Canada May 11–18, 2007, G. Jay Parsons

VIMS Articles

VIMS Author Contributions: Scallop dredge selectivity: A review of sequential ring size increases from 1994 to 2003 in the US sea scallop fishery By: DuPaul, William D.; Rudders, David B. Pages: 1307-1308 Industry-based sea scallop dredge surveys in support of rotational area management By: Rudders, B.; DuPaul, William D. Pages: 1337-1338 Size-selectivity of the commercial northwest Atlantic sea scallop (Placopecten magellanicus) dredge By: Yochum, Noelle; DuPaul, William D. Pages: 1355-1355


Fundulus As The Premier Teleost Model In Environmental Biology: Opportunities For New Insights Using Genomics, Karen G. Burnett, Lisa Bain, William Baldwin, Gloria Callard, Sarah Cohen, Richard Di Giulio, David Evans, M Gomez-Chiarri, Mark Hahn, Cindi Hoover, Sibel Karchner, Fumi Katoh, Deborah Maclatchy, William Marshall, Joel Meyer, Diane Nacci, Marjorie Oleksiak, Bernard Rees, Thomas Singer, John Stegeman, David Towle, Peter Van Veld, Wolfgang K. Vogelbein, Andrew Whitehead, Richard Winn, Douglas Crawford Dec 2007

Fundulus As The Premier Teleost Model In Environmental Biology: Opportunities For New Insights Using Genomics, Karen G. Burnett, Lisa Bain, William Baldwin, Gloria Callard, Sarah Cohen, Richard Di Giulio, David Evans, M Gomez-Chiarri, Mark Hahn, Cindi Hoover, Sibel Karchner, Fumi Katoh, Deborah Maclatchy, William Marshall, Joel Meyer, Diane Nacci, Marjorie Oleksiak, Bernard Rees, Thomas Singer, John Stegeman, David Towle, Peter Van Veld, Wolfgang K. Vogelbein, Andrew Whitehead, Richard Winn, Douglas Crawford

VIMS Articles

A strong foundation of basic and applied research documents that the estuarine fish Fundulus heteroclitus and related species are unique laboratory and field models for understanding how individuals and populations interact with their environment. In this paper we summarize an extensive body of work examining the adaptive responses of Fundulus species to environmental conditions, and describe how this research has contributed importantly to our understanding of physiology, gene regulation, toxicology, and ecological and evolutionary genetics of teleosts and other vertebrates. These explorations have reached a critical juncture at which advancement is hindered by the lack of genomic resources for these ...


Biodiversity Mediates Productivity Through Different Mechanisms At Adjacent Trophic Levels, Zt Long, Jf Bruno, Je Duffy Nov 2007

Biodiversity Mediates Productivity Through Different Mechanisms At Adjacent Trophic Levels, Zt Long, Jf Bruno, Je Duffy

VIMS Articles

Biodiversity may enhance productivity either because diverse communities more often contain productive species (selection effects) or because they show greater complementarity in resource use. Our understanding of how these effects influence community production comes almost entirely from studies of plants. To test whether previous results apply to higher trophic levels, we first used simulations to derive expected contributions of selection and complementarity to production in competitive assemblages defined by either neutral interactions, dominance, or a trade-off between growth and competitive ability. The three types of simulated assemblages exhibited distinct interaction signatures when diversity effects were partitioned into selection and complementarity ...


Ecosystem Services Related To Oyster Restoration, Ld Coen, Rd Brumbaugh, D Bushek, R Grizzle, Mark Luckenbach, Et Al Jun 2007

Ecosystem Services Related To Oyster Restoration, Ld Coen, Rd Brumbaugh, D Bushek, R Grizzle, Mark Luckenbach, Et Al

VIMS Articles

The importance of restoring filter-feeders, such as the Eastern oyster Crassostrea virginica, to mitigate the effects of eutrophication (e.g. in Chesapeake Bay) is currently under debate. The argument that bivalve molluscs alone cannot control phytoplankton blooms and reduce hypoxia oversimplifies a more complex issue, namely that ecosystem engineering species make manifold contributions to ecosystem services. Although further discussion and research leading to a more complete understanding is required, oysters and other molluscs (e.g. mussels) in estuarine ecosystems provide services far beyond the mere top-down control of phytoplankton blooms, such as (1) seston filtration, (2) benthic–pelagic coupling, (3 ...


Effects Of Oyster Population Restoration Strategies On Phytoplankton Biomass In Chesapeake Bay: A Flexible Modeling Approach, Rs Fulford, Dl Brietburg, Rie Newell, Wm Kemp, Mw Luckenbach Apr 2007

Effects Of Oyster Population Restoration Strategies On Phytoplankton Biomass In Chesapeake Bay: A Flexible Modeling Approach, Rs Fulford, Dl Brietburg, Rie Newell, Wm Kemp, Mw Luckenbach

VIMS Articles

Cultural eutrophication in estuaries and other coastal systems has increased over the last 50 yr. Some recently proposed strategies to reverse this trend have included the restoration of bivalve suspension feeders as an ecological tool for reducing phytoplankton biomass. The ecological benefits accruing from such bivalve restoration will be dependent on the characteristics of the estuary, as well as how restoration is implemented. We developed a filtration model to estimate the effect of bivalve restoration on the rate of phytoplankton removal over a range of spatial and temporal scales and used it to compare alternate restoration strategies for the eastern ...


The Functional Role Of Biodiversity In Ecosystems: Incorporating Trophic Complexity, J. Emmett Duffy, Bradley J. Cardinale, Kristin E. France, Peter B. Mcintyre, Elisa Thebault, Michel Loreau Apr 2007

The Functional Role Of Biodiversity In Ecosystems: Incorporating Trophic Complexity, J. Emmett Duffy, Bradley J. Cardinale, Kristin E. France, Peter B. Mcintyre, Elisa Thebault, Michel Loreau

VIMS Articles

Understanding how biodiversity affects functioning of ecosystems requires integrating diversity within trophic levels (horizontal diversity) and across trophic levels (vertical diversity, including food chain length and omnivory). We review theoretical and experimental progress toward this goal. Generally, experiments show that biomass and resource use increase similarly with horizontal diversity of either producers or consumers. Among prey, higher diversity often increases resistance to predation, due to increased probability of including inedible species and reduced efficiency of specialist predators confronted with diverse prey. Among predators, changing diversity can cascade to affect plant biomass, but the strength and sign of this effect depend ...


Specific Identification Of Western Atlantic Ocean Scombrids Using Mitochondrial Dna Cytochrome C Oxidase Subunit I (Coi) Gene Region Sequences, Ma Paine, Jan Mcdowell, John E. Graves Mar 2007

Specific Identification Of Western Atlantic Ocean Scombrids Using Mitochondrial Dna Cytochrome C Oxidase Subunit I (Coi) Gene Region Sequences, Ma Paine, Jan Mcdowell, John E. Graves

VIMS Articles

Identification of scombrids (tunas, mackerels, bonitos, etc.) is difficult when morphological characters are ambiguous or missing, such as with early life history stages or tissues found in the stomachs of predators. The mitochondrial cytochrome c oxidase subunit I (COI) gene region was evaluated as a molecular marker for the specific identification of the 17 members of the family Scombridae common to the western Atlantic Ocean. A 950 base pair region in the COI gene was sequenced from up to 20 individuals of each species, and suites of nucleotide polymorphisms that unambiguously distinguish among these scombrid species were identified. A shorter ...


Biodiversity And Food Web Structure Influence Short-Term Accumulation Of Sediment Organic Matter In An Experimental Seagrass System, Elizabeth A. Canuel, Ac Spivak, Ej Waterson, Je Duffy Mar 2007

Biodiversity And Food Web Structure Influence Short-Term Accumulation Of Sediment Organic Matter In An Experimental Seagrass System, Elizabeth A. Canuel, Ac Spivak, Ej Waterson, Je Duffy

VIMS Articles

We tested the effects of grazer diversity and food chain length on the quantity and quality of accumulated sediment organic matter (SOM) in experimental eelgrass (Zostera marina) mesocosms. By use of a factorial manipulation of crustacean grazer species richness and predator presence, we examined the effects of epibenthic consumers on SOM composition by using stable carbon isotopes (delta C-13) and lipid biomarker compounds. Grazer species composition strongly influenced nearly all measures of SOM quantity and quality. In particular, increased densities of the grazing amphipod, Gammarus mucronatus, decreased accumulation of benthic microalgae (chlorophyll a) and the relative abundance of polyunsaturated fatty ...


Characterization Of A Rediscovered Haplosporidian Parasite From Cultured Penaeus Vannamei, Lm Nunam, Dv Lightner, Cr Pantoja, Na Stokes, Kimberly S. Reece Feb 2007

Characterization Of A Rediscovered Haplosporidian Parasite From Cultured Penaeus Vannamei, Lm Nunam, Dv Lightner, Cr Pantoja, Na Stokes, Kimberly S. Reece

VIMS Articles

Mortalities of Penaeus vannamei, cultured in ponds in Belize, Central America, began during the last part of the grow-out cycle during the cold weather months from September 2004 through February 2005. Tissue squashes of infected hepatopancreata and histological examination of infected shrimp revealed that the mortalities might have been caused by an endoparasite. To confirm the diagnosis, DNA was extracted from ethanol preserved hepatopancreata and the small-subunit rRNA gene was sequenced. The 1838 by sequence was novel and phylogenetic analysis placed the P. vannamei parasite within the phylum Haplosporidia as a sister taxon to a clade that includes Bonamia and ...


Evolution Of Mycobacterium Ulcerans And Other Mycolactone-Producing Mycobacteria From A Common Mycobacterium Marinum Progenitor, Mj Yip, Jl Porter, Jam Fyfe, Cj Lavender, F Portaels, Mw Rhodes, Hi Kator, Et Al. Jan 2007

Evolution Of Mycobacterium Ulcerans And Other Mycolactone-Producing Mycobacteria From A Common Mycobacterium Marinum Progenitor, Mj Yip, Jl Porter, Jam Fyfe, Cj Lavender, F Portaels, Mw Rhodes, Hi Kator, Et Al.

VIMS Articles

It had been assumed that production of the cytotoxic polyketide mycolactone was strictly associated with Mycobacterium ulcerans, the causative agent of Buruli ulcer. However, a recent study has uncovered a broader distribution of mycolactone-producing mycobacteria (MPM) that includes mycobacteria cultured from diseased fish and frogs in the United States and from diseased fish in the Red and Mediterranean Seas. All of these mycobacteria contain versions of the M. ulcerans pMUM plasmid, produce mycolactones, and show a high degree of genetic relatedness to both M. ulcerans and Mycobacterium marinum. Here, we show by multiple genetic methods, including multilocus sequence analysis and ...


The Effects Of Female Size On Fecundity In A Large Marine Gastropod Rapana Venosa (Muricidae), Juliana M. Harding, Roger L. Mann, Catherine W. Kilduff Jan 2007

The Effects Of Female Size On Fecundity In A Large Marine Gastropod Rapana Venosa (Muricidae), Juliana M. Harding, Roger L. Mann, Catherine W. Kilduff

VIMS Articles

The life history strategy of the veined rapa whelk Rapana venosa, a temperate marine gastropod, includes generation times of 1 y, individual longevity of > 10 y, annual production of egg cases, and an adult size range of 40 to > 160 mm shell length (SL). This life history combined with the animal's generalist ecological preferences and broad physiological tolerances makes rapa whelks well suited for ecological success along a gradient of habitat and community types. Ballast water transport of veliger larvae across traditional zoogeographic boundaries has resulted in the establishment of invasive rapa whelk populations in Chesapeake Bay, USA, as ...


Influence Of Host Genetic Origin And Geographic Location On Qpx Disease In Northern Quahogs (=Hard Clams), Mercenaria Mercenaria, Lmr Calvo, Se Ford, Jn Kraeuter, Df Leavitt, R Smolowitz, Em Burreson Jan 2007

Influence Of Host Genetic Origin And Geographic Location On Qpx Disease In Northern Quahogs (=Hard Clams), Mercenaria Mercenaria, Lmr Calvo, Se Ford, Jn Kraeuter, Df Leavitt, R Smolowitz, Em Burreson

VIMS Articles

QPX (Quahog Parasite Unknown) a protistan pathogen of northern quahogs (= hard clams), Mercenaria mercenaria, has caused disease outbreaks in maritime Canada, and in Massachusetts, New York, New Jersey, and Virginia, USA. Although epizootics have occurred in wild hard clam populations, the parasite has most seriously affected cultured hard clams, suggesting that aquaculture practices may promote or predispose clams to the disease. In this investigation the influence of clam genetic origin and the geographic location at where they are grown on QPX disease susceptibility was examined in a common garden experiment. Aquaculture stocks were acquired from hatcheries in Massachusetts, New Jersey ...


Why Oyster Restoration Goals In The Chesapeake Bay Are Not And Probably Cannot Be Achieved, Roger L. Mann, Eric N. Powell Jan 2007

Why Oyster Restoration Goals In The Chesapeake Bay Are Not And Probably Cannot Be Achieved, Roger L. Mann, Eric N. Powell

VIMS Articles

Efforts to restore the native oyster in the Chesapeake Bay enjoy enormous public support and have consumed and continue to consume vast, some would argue unreasonable and unjustifiable, amounts of funding. Despite this support the stated goals of restoration efforts are poorly defined and consequently provide no realistic measures of success in terms of time, space, or biomass. Quantitative approaches used successfully in management of and rebuilding plans for other marine and estuarine species have not been appropriately applied. Basic information in oyster population dynamics and ecology has been inadequately appreciated in defining the quantitative problem. Given these limitations it ...


Correcting For Effective Area Fished In Fishery-Dependent Depletion Estimates Of Abundance And Capture Efficiency, Jf Walter, Jm Hoenig, T Gedamke Jan 2007

Correcting For Effective Area Fished In Fishery-Dependent Depletion Estimates Of Abundance And Capture Efficiency, Jf Walter, Jm Hoenig, T Gedamke

VIMS Articles

Depletion methods are widely used to estimate capture efficiency and abundance. However, they are highly dependent on the depletion area assumed. In open-ocean depletion studies, it is difficult to determine the true area of depletion. Satellite vessel monitoring systems (VMS) offer the potential to determine the area effectively fished. Observer-collected catch-and-effort data from the 1999 Atlantic sea scallop fishery in Georges Bank Closed Area II were used to obtain spatially-explicit DeLury depletion estimates of dredge efficiency and abundance, with corrections for fished area made using VMS data. Non-area-corrected efficiency estimates often had theoretically impossible values, indicating that the naively assumed ...


Top-Down And Bottom-Up Controls On Sediment Organic Matter Composition In An Experimental Seagrass Ecosystem, Ac Spivak, Elizabeth A. Canuel, Je Duffy, Jp Richardson Jan 2007

Top-Down And Bottom-Up Controls On Sediment Organic Matter Composition In An Experimental Seagrass Ecosystem, Ac Spivak, Elizabeth A. Canuel, Je Duffy, Jp Richardson

VIMS Articles

We tested the singular and interactive effects of resource availability (light) and community composition (food chain length and herbivore species richness) on eelgrass (Zostera marina) ecosystem properties and functioning with an experimental mesocosm system. Food chain length was manipulated through the presence or absence of blue crab (Callinectes sapidus) predators, whereas grazer species richness varied across three levels (zero, two, or four crustacean species). We found important and interacting effects of bottom-up and top-down forcings on sediment organic matter (SOM) composition. Light increased eelgrass and algal biomass and sediment organic carbon and nitrogen content. Increasing grazer diversity generally decreased algal ...


Eutrophication-Induced Phosphorus Limitation In The Mississippi River Plume: Evidence From Fast Repetition Rate Fluorometry, Jb Sylvan, A Quigg, S Tozzi, Jw Ammerman Jan 2007

Eutrophication-Induced Phosphorus Limitation In The Mississippi River Plume: Evidence From Fast Repetition Rate Fluorometry, Jb Sylvan, A Quigg, S Tozzi, Jw Ammerman

VIMS Articles

We assessed nutrient limitation in the Mississippi River plurne and Louisiana continental shelf during the summer of 2002 (04-08 July). We measured nutrient concentrations, alkaline phosphatase (AP) activities, chlorophyll a (Chl a) concentrations, and four fast repetition rate fluorescence (FRRF) parameters: the maximum quantum yield of photochemistry in photosystem II (PSII), F-v:F-m; the functional absorption cross section for PSII, sigma(psII); the time for photosynthetic electron transport on the acceptor side of PSII, tau(Qa); and the connectivity factor, p, in 24-h-long nutrient addition bioassays near the Mississippi River delta. Low phosphorus (P) concentrations, elevated inorganic nitrogen-to-phosphorus ratios, high ...


Epidemiological Determinants In Outbreaks Of Bitter Crab Disease (Hematodinium Sp.) In Snow Crabs Chionoecetes Opilio From Conception Bay, Newfoundland, Canada, Jeffrey D. Shields, Dm Taylor, Pg O'Keefe, E Colbourne, E Hynick Jan 2007

Epidemiological Determinants In Outbreaks Of Bitter Crab Disease (Hematodinium Sp.) In Snow Crabs Chionoecetes Opilio From Conception Bay, Newfoundland, Canada, Jeffrey D. Shields, Dm Taylor, Pg O'Keefe, E Colbourne, E Hynick

VIMS Articles

Bitter crab disease (BCD) is caused by Hematodinium sp., an endoparasitic dinoflagellate. It lives within the hemocoeloms of snow crabs Chionoecetes opilio and Tanner crabs C. bairdi, making them unmarketable due to their bitter flavor. Two recent outbreaks of BCD have occurred in Conception Bay, Newfoundland, one from 1999 to 2000 and another from 2003 to 2005. In the earlier outbreak, prevalence was highest in juvenile and primiparous females and juvenile males. It was thought to be highest in these hosts because they molt more frequently than larger males and the disease is transmitted to newly molted crabs. In the ...


Taxonomic Composition And Growth Rates Of Phytoplankton Assemblages At The Subtropical Convergence East Of New Zealand, L Delizo, Wo Smith, J Hall Jan 2007

Taxonomic Composition And Growth Rates Of Phytoplankton Assemblages At The Subtropical Convergence East Of New Zealand, L Delizo, Wo Smith, J Hall

VIMS Articles

Off the eastern coast of New Zealand, warm, saline, nutrient-poor Subtropical Waters (STW) are separated from. cool, fresher, relatively nutrient-rich Sub-Antarctic Waters (SAW) by the Subtropical Convergence (STC). The Chatham Rise, a submarine rise, restricts. the latitudinal movement of the STC as well as mixing of STW and SAW Due to this restriction, this sector of the STC is characterized by sharp gradients in temperature, macro-(nitrate, silicate and phosphate) and micro- (iron) nutrient concentrations. Shipboard incubations were conducted during austral spring 2000 and 2001 to test the hypothesis that these gradients affect the taxonomic composition and/or growth rates ...


Susceptibility Of Salt Marshes To Nutrient Enrichment And Predator Removal, La Deegan, Jl Bowen, D Drake, Jw Fleeger, Carl T. Friedrichs, Et Al. Jan 2007

Susceptibility Of Salt Marshes To Nutrient Enrichment And Predator Removal, La Deegan, Jl Bowen, D Drake, Jw Fleeger, Carl T. Friedrichs, Et Al.

VIMS Articles

Salt marsh ecosystems have been considered not susceptible to nitrogen overloading because early studies suggested that salt marshes adsorbed excess nutrients in plant growth. However, the possible effect of nutrient loading on species composition, and the combined effects of nutrients and altered species composition on structure and function, was largely ignored. Failure to understand interactions between nutrient loading and species composition may lead to severe underestimates of the impacts of stresses. We altered whole salt marsh ecosystems (similar to 60 000 m(2)/treatment) by addition of nutrients in flooding waters and by reduction of a key predatory fish, the ...


Detection Of Panulirus Argus Virus 1 In Caribbean Spiny Lobsters, Mm Montgomery-Fullerton, Ra Cooper, Km Kauffman, Jeffrey D. Shields, Re Raftlaff Jan 2007

Detection Of Panulirus Argus Virus 1 In Caribbean Spiny Lobsters, Mm Montgomery-Fullerton, Ra Cooper, Km Kauffman, Jeffrey D. Shields, Re Raftlaff

VIMS Articles

Panulirus argus Virus 1 (PaV1) is a pathogenic virus that infects Caribbean spiny lobsters P. argus in the Florida Keys. We have developed a PCR detection assay for PaV1 for the purpose of studying the natural history of the virus and for monitoring the prevalence of infection. The detection of the virus in hemolymph and other tissues is based on the PCR amplification of a 499 bp product using specific primers designed from a cloned fragment of the PaV1 genome. The sensitivity limit for the assay was 1.2 fg of purified viral DNA. The PaV1 primers did not react ...


The Importance Of Tidal And Lateral Asymmetries In Stratification To Residual Circulation In Partially Mixed Estuaries, Me Scully, Carl T. Friedrichs Jan 2007

The Importance Of Tidal And Lateral Asymmetries In Stratification To Residual Circulation In Partially Mixed Estuaries, Me Scully, Carl T. Friedrichs

VIMS Articles

Measurements collected in the York River estuary, Virginia, demonstrate the important impact that tidal and lateral asymmetries in turbulent mixing have on the tidally averaged residual circulation. A reduction in turbulent mixing during the ebb phase of the tide caused by tidal straining of the axial density gradient results in increased vertical velocity shear throughout the water column during the ebb tide. In the absence of significant lateral differences in turbulent mixing, the enhanced ebb-directed transport caused by tidal straining is balanced by a reduction in the net seaward-directed barotropic pressure gradient, resulting in laterally uniform two-layer residual flow. However ...


Temporal And Vertical Dynamics In Picoplankton Photoheterotrophic Production In The Subtropical North Pacific Ocean, Matthew Church, Hugh Ducklow, Rm Letelier, David Karl Jan 2007

Temporal And Vertical Dynamics In Picoplankton Photoheterotrophic Production In The Subtropical North Pacific Ocean, Matthew Church, Hugh Ducklow, Rm Letelier, David Karl

VIMS Articles

The marine ecosystem of the West Antarctic Peninsula (WAP) extends from the Bellingshausen Sea to the northern tip of the peninsula and from the mostly glaciated coast across the continental shelf to the shelf break in the west. The glacially sculpted coastline along the peninsula is highly convoluted and characterized by deep embayments that are often interconnected by channels that facilitate transport of heat and nutrients into the shelf domain. The ecosystem is divided into three subregions, the continental slope, shelf and coastal regions, each with unique ocean dynamics, water mass and biological distributions. The WAP shelf lies within the ...


Predation Of Cockles (Cerastoderma Edule) By The Whelk (Buccinum Undatum) Under Laboratory Conditions, Jws Scolding, Ca Richardson, Mw Luckenbach Jan 2007

Predation Of Cockles (Cerastoderma Edule) By The Whelk (Buccinum Undatum) Under Laboratory Conditions, Jws Scolding, Ca Richardson, Mw Luckenbach

VIMS Articles

The feeding rate and behaviour of whelks (Buccinum undatum) offered cockles (Cerastoderma edule) in laboratory experiments were examined. When presented with cockles in a range of sizes (10–40 mm), 14 B. undatum (34.6–88.3 mm), held individually in aquaria, consumed a wide size range of cockles. Small whelks (<40 mm) consumed cockles (<23 mm), whereas large whelks, (>60 mm) ate a greater number of larger cockles (>30 mm) and a wider size range of cockles (12–40 mm) than smaller whelks. The majority (90%) of the shells of the predated cockles were undamaged and the few (<10%) that were damaged showed only slight abrasions to the anterior and posterior shell margin. Filmed observations of B. undatum feeding on C. edule showed a method of ...


Nutrient Versus Consumer Control Of Community Structure In A Chesapeake Bay Eelgrass Habitat, James Grayland Douglass, J. Emmett Duffy, Amanda C. Spivak, John Paul Richardson Jan 2007

Nutrient Versus Consumer Control Of Community Structure In A Chesapeake Bay Eelgrass Habitat, James Grayland Douglass, J. Emmett Duffy, Amanda C. Spivak, John Paul Richardson

VIMS Articles

Nutrient loading can dramatically alter benthic communities and has been implicated in the worldwide decline of seagrass beds. Ongoing changes in food webs caused by overfishing could also contribute to seagrass decline. However, the interaction of these factors and the role of small invertebrate grazers in mediating them are poorly understood. We examined the relative impacts of nutrient loading and food web alteration on eelgrass Zostera marina L. community structure in Chesapeake Bay by manipulating nutrients, predatory crabs, and invertebrate grazers in field enclosures over 28 d in summer. Nutrient loading increased epiphyte accumulation early in the experiment, decreased eelgrass ...


Don As A Source Of Bioavailable Nitrogen For Phytoplankton, D. A. Bronk, J. H. See, P. Bradley, L. Killberg Jan 2007

Don As A Source Of Bioavailable Nitrogen For Phytoplankton, D. A. Bronk, J. H. See, P. Bradley, L. Killberg

VIMS Articles

Relative to inorganic nitrogen, concentrations of dissolved organic nitrogen ( DON) are often high, even in regions believed to be nitrogen-limited. The persistence of these high concentrations led to the view that the DON pool was largely refractory and therefore unimportant to plankton nutrition. Any DON that was utilized was believed to fuel bacterial production. More recent work, however, indicates that fluxes into and out of the DON pool can be large, and that the constancy in concentration is a function of tightly coupled production and consumption processes. Evidence is also accumulating which indicates that phytoplankton, including a number of harmful ...


Genetic Identity Of Yoy Bluefin Tuna From The Eastern And Western Atlantic Spawning Areas, J Carlsson, Jan Mcdowell, Jel Carlsson, John Graves Jan 2007

Genetic Identity Of Yoy Bluefin Tuna From The Eastern And Western Atlantic Spawning Areas, J Carlsson, Jan Mcdowell, Jel Carlsson, John Graves

VIMS Articles

We used 320 young-of-the-year (YOY) specimens of the highly migratory and overfished Atlantic bluefin tuna, Thunnus thynnus, Linnaeus 1758, to evaluate the hypothesis that Atlantic bluefin tuna comprises 2 stocks with spawning grounds in the Gulf of Mexico and in the Mediterranean Sea. Significant genetic differentiation at 8 nuclear microsatellite loci (F-ST = 0.0059, P = 0.0005) and at the mitochondrial control region (Phi(ST) = 0.0129, P = 0.0139) was detected among YOY Atlantic bluefin tuna captured on spawning grounds in the Gulf of Mexico (n = 40) versus the western (n = 255) and eastern (n = 25) basins of the ...


Influence Of Sea Ice Cover And Icebergs On Circulation And Water Mass Formation In A Numerical Circulation Model Of The Ross Sea, Antarctica, Michael S. Dinniman, John M. Klinck, Walker O. Smith Jr. Jan 2007

Influence Of Sea Ice Cover And Icebergs On Circulation And Water Mass Formation In A Numerical Circulation Model Of The Ross Sea, Antarctica, Michael S. Dinniman, John M. Klinck, Walker O. Smith Jr.

VIMS Articles

Satellite imagery shows that there was substantial variability in the sea ice extent in the Ross Sea during 2001-2003. Much of this variability is thought to be due to several large icebergs that moved through the area during that period. The effects of these changes in sea ice on circulation and water mass distributions are investigated with a numerical general circulation model. It would be difficult to simulate the highly variable sea ice from 2001 to 2003 with a dynamic sea ice model since much of the variability was due to the floating icebergs. Here, sea ice concentration is specified ...


Assessment Of Skill And Portability In Regional Marine Biogeochemical Models: Role Of Multiple Planktonic Groups, Marjorie A.M. Friedrichs, Et Al. Jan 2007

Assessment Of Skill And Portability In Regional Marine Biogeochemical Models: Role Of Multiple Planktonic Groups, Marjorie A.M. Friedrichs, Et Al.

VIMS Articles

[1] Application of biogeochemical models to the study of marine ecosystems is pervasive, yet objective quantification of these models' performance is rare. Here, 12 lower trophic level models of varying complexity are objectively assessed in two distinct regions (equatorial Pacific and Arabian Sea). Each model was run within an identical one-dimensional physical framework. A consistent variational adjoint implementation assimilating chlorophyll-a, nitrate, export, and primary productivity was applied and the same metrics were used to assess model skill. Experiments were performed in which data were assimilated from each site individually and from both sites simultaneously. A cross-validation experiment was also conducted ...


Linking Water Quality To Living Resources In A Mid-Atlantic Lagoon System, Usa, Ce Wazniak, Mr Hall, Tjb Carruthers, B Sturgis, Wc Dennison, Rj Orth Jan 2007

Linking Water Quality To Living Resources In A Mid-Atlantic Lagoon System, Usa, Ce Wazniak, Mr Hall, Tjb Carruthers, B Sturgis, Wc Dennison, Rj Orth

VIMS Articles

The mid-Atlantic coastal bays are shallow coastal lagoons, separated from the Atlantic Ocean by barrier sand islands with oceanic exchanges restricted to narrow inlets. The relatively poor flushing of these lagoon systems makes them susceptible to eutrophication resulting from anthropogenic nutrient loadings. An intensive water quality and seagrass monitoring program was initiated to track ecological changes in the Maryland and Virginia coastal bays. The purpose of this study was to analyze existing monitoring data to determine status and trends in eutrophication and to determine any associations between water quality and living resources. Analysis of monitoring program data revealed several trends ...


Recent Additions Of Warmwater Fish Species To Chesapeake Bay, Aimee D. Halvorson Jan 2007

Recent Additions Of Warmwater Fish Species To Chesapeake Bay, Aimee D. Halvorson

VIMS Articles

During September 2004 and June 2005, the Virginia Institute of Marine Science (VIMS) Juvenile Fish and Blue Crab Trawl Survey collected specimens of three warmwater fish species uncommon to Chesapeake Bay. Captures of Trachinocephalus myop.s (Snakefish), Citharichthys Wfjc/'fj/^.v (Spotted WhifT'). and Mullus auratus {Red Goatfish)are the first substantiated records for these species from Chesapeake Bay. These captures also represent extensions in the documented geographic ranges of Snakefish and Spotted Whiff. Occurrences of multiple species heretofore rarely encountered in Chesapeake Bay warrant further attention in view of concerns regarding climate change and its effect on local marine ...