Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

VIMS Articles

2000

Discipline
Keyword

Articles 1 - 30 of 32

Full-Text Articles in Life Sciences

Atmospheric Co2 Evasion, Dissolved Inorganic Carbon Production, And Net Heterotrophy In The York River Estuary, Peter Raymond, James E. Bauer, Jonathan Cole Dec 2000

Atmospheric Co2 Evasion, Dissolved Inorganic Carbon Production, And Net Heterotrophy In The York River Estuary, Peter Raymond, James E. Bauer, Jonathan Cole

VIMS Articles

Direct measurements of the partial pressure of CO2 (pCO2) and dissolved inorganic carbon (DIC) were made over a 2‐yr period in surface waters of the York River estuary in Virginia. The pCO2 in surface waters exceeded that in the overlying atmosphere, indicating that the estuary was a net source of CO2 to the atmosphere at most times and locations. Salinity‐based DIC mixing curves indicate there was also an internal source of both DIC and alkalinity, implying net alkalinity generation within the estuary. The DIC and alkalinity source displayed seasonal patterns similar to that of pCO2 and were reproducible ...


Temperature Effects On Export Production In The Open Ocean, Ea Laws, Pg Falkowki, Walker O. Smith Jr., H Ducklow, Jj Mccarthy Dec 2000

Temperature Effects On Export Production In The Open Ocean, Ea Laws, Pg Falkowki, Walker O. Smith Jr., H Ducklow, Jj Mccarthy

VIMS Articles

A pelagic food web model was formulated with the goal of developing a quantitative understanding of the relationship between total production, export production, and environmental variables in marine ecosystems. The model assumes that primary production is partitioned through both large and small phytoplankton and that the food web adjusts to changes in the rate of allochthonous nutrient inputs in a way that maximizes stability, i.e., the ability of the system to return to steady state following a perturbation. The results of the modeling exercise indicate that ef ratios, defined as new production/total production = export production/total production, are ...


Epizootiology Of The Parasitic Dinoflagellate Hematodinium Sp In The American Blue Crab Callinectes Sapidus, Ga Messick, Jeffrey D. Shields Nov 2000

Epizootiology Of The Parasitic Dinoflagellate Hematodinium Sp In The American Blue Crab Callinectes Sapidus, Ga Messick, Jeffrey D. Shields

VIMS Articles

Hematodinium sp. is a parasitic dinoflagellate that infects and kills blue crabs Callinectes sapidus. Periodic outbreaks of dinoflagellate infections with subsequent high host mortalities prompted a study of the epizootiology and distribution of the crab pathogen. Hemolymph samples from over 13 000 crabs were assessed for infections over 8 yr. Moderate to high prevalences were found at several locations along the Atlantic and Gulf coasts of the United States. In the coastal bays of Maryland and Virginia, prevalence followed a seasonal pattern, with a sharp peak in late autumn. Infections were significantly more prevalent in crabs measuring less than 30 ...


Seasonal Variations Of Size-Fractionated Phytoplankton Along The Salinity Gradient In The York River Estuary, Virginia (Usa), Y Sin, Rl Wetzel, Ic Anderson Oct 2000

Seasonal Variations Of Size-Fractionated Phytoplankton Along The Salinity Gradient In The York River Estuary, Virginia (Usa), Y Sin, Rl Wetzel, Ic Anderson

VIMS Articles

The dynamics of phytoplankton size structure were investigated in the freshwater, transitional and estuarine zones of the York River over an annual cycle. The contribution of large cells (microplankton, >20 mu m) to total concentrations of chlorophyll a increased downstream during winter, whereas that of small cells (nanoplankton, 3-20 mu m; picoplankton, <3 mu m) increased downstream during summer. In the freshwater region, the contribution of micro phytoplankton to total concentrations of chlorophyll a was significant during warm seasons (spring and summer) but not during colder seasons (winter), whereas the contribution of small-sized cells (especially picoplankton) increased during cold seasons. Temperature, light and high flushing rate appear to control phytoplankton community structure in the freshwater region. In the transitional region, nano-sized cells dominated the phytoplankton population throughout all seasons except during the spring bloom (April) when the chlorophyll a concentration of micro playtoplankton increased. Size structure in the transitional region is most likely regulated by light availability. In the mesohaline region, nano- and pico-sized cells dominated the phytoplankton population during the summer bloom, whereas micro-sized cells dominated during the winter bloom. Factors controlling phytoplankton community Size structure in the mesohaline zone may be riverine nitrogen input, temperature and/or advective transport from up-river. Based on these results, the spatial and seasonal variations in size structure of phytoplankton observed on the estuarine scale may be determined both by the different preferences for nutrients and by different light requirements of micro-, nano- and picoplankton. The results suggest that analyses of phytoplankton size structure are necessary to better understand controls on phytoplankton dynamics and to better manage water quality in river-dominated, estuarine systems.


Changes In Bacterioplankton Metabolic Capabilities Along A Salinity Gradient In The York River Estuary, Virginia, Usa, G. E. Schultz, H. W. Ducklow Sep 2000

Changes In Bacterioplankton Metabolic Capabilities Along A Salinity Gradient In The York River Estuary, Virginia, Usa, G. E. Schultz, H. W. Ducklow

VIMS Articles

Changes in metabolic capabilities of bacterial communities along the estuarine salinity gradient may affect the extent of organic matter processing and bacterial growth and accumulation during transit through the system; As part of a larger study of estuarine microbial processes, we attempted to quantify differences in bacterial community structure using Biolog plates. Biolog GN plates (Biolog, Inc., Hayward, CA, USA) were used to determine differences in bacterioplankton community metabolic potential. Biolog GN microplates are 96-well microtiter plates in which each well contains an individual carbon source as well the redox dye tetrazolium violet. As bacteria grow and oxidize each substrate ...


Haplosporidiosis In The Pacific Oyster Crassostrea Gigas From The French Atlantic Coast, R Renault, Na Stokes, Et Al, Em Burreson Aug 2000

Haplosporidiosis In The Pacific Oyster Crassostrea Gigas From The French Atlantic Coast, R Renault, Na Stokes, Et Al, Em Burreson

VIMS Articles

Two cases of haplosporidian infection occurred during 1993 in Pacific oysters Crassostrea gigas from the French Atlantic coast. The localization and ultrastructure of the plasmodia are described. In situ hybridization of infected tissue sections was conducted with DNA probes for oyster-infecting haplosporidians. The Haplosporidium nelsoni-specific DNA probe MSX1347 hybridized with the C. gigas parasite, and the H, costale-specific probe SSO1318 did not hybridize. Total genomic DNA was extracted from the infected tissue sections for polymerase chain reaction (PCR) amplification of the haplosporidian. PCR amplifications with H. nelsoni-specific primers and with 'universal' actin primers did not yield the expected products of ...


Bacterial Consumption Of Doc During Transport Through A Temperate Estuary, Pa Raymond, Je Bauer Jul 2000

Bacterial Consumption Of Doc During Transport Through A Temperate Estuary, Pa Raymond, Je Bauer

VIMS Articles

Bacterial utilization of natural levels of dissolved organic carbon (DOC) was measured in the York River estuary, a sub-estuary of the Chesapeake Bay. This study was undertaken in order to elucidate spatial and temporal changes in bacterial carbon utilization and to evaluate its importance as a pathway for organic matter transformation in estuaries. Multiple pools of DOC were defined based on decomposition kinetics. The first pool (G(1)) made up a mean of 2.8% of total DOC and had turnover times of less than or equal to 5 d. The second pool (G(2)) comprised an average of 4 ...


Local Demographics Of The Polychaete Chaetopterus Pergamentaceus Within The Lower Chesapeake Bay And Relationships To Environmental Gradients, Ml Thompson, Linda C. Schaffner Jul 2000

Local Demographics Of The Polychaete Chaetopterus Pergamentaceus Within The Lower Chesapeake Bay And Relationships To Environmental Gradients, Ml Thompson, Linda C. Schaffner

VIMS Articles

Chaetopterus pergamentaceus is an abundant and functionally important species within the soft sediment, subtidal benthic community of lower Chesapeake Bay. The present study elucidates spatial relationships in density, individual ash-free dry weight, total station ash-free dry weight and growth rates for juveniles and adults from 2 yrs of sampling (1994, 1995) at 12 stations in the lower Chesapeake Bay. A strong inverse relationship (r(2) = 0.69) was observed between growth rates and total density for juveniles when data from a low(1994) and high(1995) recruitment year were considered. Common parameters among stations characterized by high density/low growth ...


Zoosporulation Of A New Perkinsus Species Isolated From The Gills Of The Softshell Clam Mya Arenaria, Sm Mclaughlin, Bd Tall, A Shaheen, Ee Elsayed, M Faisal Jun 2000

Zoosporulation Of A New Perkinsus Species Isolated From The Gills Of The Softshell Clam Mya Arenaria, Sm Mclaughlin, Bd Tall, A Shaheen, Ee Elsayed, M Faisal

VIMS Articles

A gill-associated Perkinsus sp. isolated from the softshell clam (Myo arenaria) is described as a new species, P. chesapeaki sp. nov. Examination of the parasite in seawater cultures revealed life cycle stages and zoosporulation processes similar to those described for other species of the genus Perkinsus. Prezoosporangia developed thickened cell walls upon contraction of the cytoplasm and development of a distinctive clear area between the cell wall and the protoplast. Successive bipartition of the protoplast led to the formation of hundred's of zoospores within mature sporangia. Zoospores were released into seawater through one or more discharge tubes, Ultrastructural studies ...


Joint Effects Of Larval Dispersal, Population Regulation, Marine Reserve Design, And Exploitation On Production And Recruitment In The Caribbean Spiny Lobster, Wt Stockhausen, Rom Lipcius, Bm Hickey May 2000

Joint Effects Of Larval Dispersal, Population Regulation, Marine Reserve Design, And Exploitation On Production And Recruitment In The Caribbean Spiny Lobster, Wt Stockhausen, Rom Lipcius, Bm Hickey

VIMS Articles

A spatially explicit population-dynamics model for the Caribbean spiny lobster (Panulirus argus) in Exuma Sound Bahamas, was used to investigate the joint effects of marine reserve design and larval dispersal via hydrodynamic currents on an exploited benthic invertebrate. The effects of three hydrodynamic scenarios tone diffusion-only and two advection-diffusion cases), one exploitation level, and 28 reserve configurations (7 sizes x 4 locations) on catch and larval production were simulated. The diffusion-only scenario represented the condition in which settlement did not vary substantially over broad spatial scales; in contrast, the advection-diffusion scenarios represented realistic hydrodynamic patterns and :introduced broad spatial variation ...


'Candidatus Xenohaliotis Californiensis', A Newly Described Pathogen Of Abalone, Haliotis Spp., Along The West Coast Of North America, Cs Friedman, Kb Andree, Ka Beauchamp, Jd Moore, Tt Robbins, Jeffrey D. Shields, Rp Hendricks Mar 2000

'Candidatus Xenohaliotis Californiensis', A Newly Described Pathogen Of Abalone, Haliotis Spp., Along The West Coast Of North America, Cs Friedman, Kb Andree, Ka Beauchamp, Jd Moore, Tt Robbins, Jeffrey D. Shields, Rp Hendricks

VIMS Articles

Withering syndrome is a fatal disease of wild and cultured abalone. Haliotis spp., that inhabit the west coast of North America. The aetiological agent of withering syndrome has recently been identified as a member of the family Rickettsiaceae in the order Rickettsiales. Using a combination of morphological, serological, life history and genomic (16S rDNA) characterization. we have identified this bacterium as a unique taxon and propose the provisional status of 'Candidatus Xenohaliotis californiensis', The Gram-negative. obligate intracellular pleomorphic bacterium is found within membrane-bound vacuoles in the cytoplasm of abalone gastrointestinal epithelial cells. The bacterium is not cultivable on synthetic media ...


Limitation Of Bacterial Growth By Dissolved Organic Matter And Iron In The Southern Ocean, Mj Church, Da Hutchins, Hw Ducklow Feb 2000

Limitation Of Bacterial Growth By Dissolved Organic Matter And Iron In The Southern Ocean, Mj Church, Da Hutchins, Hw Ducklow

VIMS Articles

The importance of resource limitation in controlling bacterial growth in the high-nutrient, low-chlorophyll (HNLC) region of the Southern Ocean was experimentally determined during February and March 1998. Organic- and inorganic-nutrient enrichment experiments were performed between 42 degrees S and 55 degrees S along 141 degrees E. Bacterial abundance, mean cell volume, and [H-3]thymidine and [H-3]leucine incorporation were measured during 4- to 5-day incubations. Bacterial biomass, production, and rates of growth all responded to organic enrichments in three of the four experiments. These results indicate that bacterial growth was constrained primarily by the availability of dissolved organic matter. Bacterial ...


Phenotypic Clines, Plasticity, And Morphological Trade-Offs In An Intertidal Snail, Gc Trussell Feb 2000

Phenotypic Clines, Plasticity, And Morphological Trade-Offs In An Intertidal Snail, Gc Trussell

VIMS Articles

Understanding the genetic and environmental bases of phenotypic variation and how they covary on local and broad geographic scales is an important goal of evolutionary ecology. Such information can shed light on how organisms adapt to different and changing environments and how life‐history trade‐offs arise. Surveys of phenotypic variation in 25 Littorina obtusata populations across an approximately 400‐km latitudinal gradient in the Gulf of Maine revealed pronounced clines. The shells of snails from northern habitats weighed less and were thinner and weaker in compression than those of conspecifics from southern habitats. In contrast, body size (as measured ...


Induced Defenses In Response To An Invading Crab Predator: An Explanation Of Historical And Geographic Phenotypic Change, Gc Trussell, L. D. Smith Feb 2000

Induced Defenses In Response To An Invading Crab Predator: An Explanation Of Historical And Geographic Phenotypic Change, Gc Trussell, L. D. Smith

VIMS Articles

The expression of defensive morphologies in prey often is correlated with predator abundance or diversity over a range of temporal and spatial scales. These patterns are assumed to reflect natural selection via differential predation on genetically determined, fixed phenotypes. Phenotypic variation, however, also can reflect within-generation developmental responses to environmental cues (phenotypic plasticity). For example, water-borne effluents from predators can induce the production of defensive morphologies in many prey taxa. This phenomenon, however, has been examined only on narrow scales. Here, we demonstrate adaptive phenotypic plasticity in prey from geographically separated populations that were reared in the presence of an ...


New Dimensionless Indices Of Structural Habitat Complexity: Predicted And Actual Effects On A Predator's Foraging Success, A Bartholomew, Rj Diaz, G Cicchetti Jan 2000

New Dimensionless Indices Of Structural Habitat Complexity: Predicted And Actual Effects On A Predator's Foraging Success, A Bartholomew, Rj Diaz, G Cicchetti

VIMS Articles

Ecologists have long known that complex habitats often provide prey with refuges from predation. This is true for a wide variety of habitat types in terrestrial, freshwater and marine systems. Despite the recognized importance of structural habitat complexity, ecologists have defined and measured complexity in many different ways. We propose 2 new indices of structural habitat complexity that are dimensionless, that can be applied across various habitat types and scales, and that directly measure how structural complexity interferes with a predator's foraging ability. These indices are: the total area of cover within a habitat divided by the total area ...


Ruth Dixon Turner 1914-2000 - In Memoriam, R Mann Jan 2000

Ruth Dixon Turner 1914-2000 - In Memoriam, R Mann

VIMS Articles

No abstract provided.


Mortality And Hematology Of Blue Crabs, Callinectes Sapidus, Experimentally Infected With The Parasitic Dinoflagellate Hematodinium Perezi, Jeffrey D. Shields, Christopher M. Squyars Jan 2000

Mortality And Hematology Of Blue Crabs, Callinectes Sapidus, Experimentally Infected With The Parasitic Dinoflagellate Hematodinium Perezi, Jeffrey D. Shields, Christopher M. Squyars

VIMS Articles

On the eastern seaboard of the United States, populations of the blue crab, Callinectes sapidus, experi-ence recurring outbreaks of a parasitic dinoflagellate, Hematodinium perezi. Epizootics fulminate in summer and autumn causing mortalities in high-salinity embayments and estuaries. In laboratory studies, we experimentally investigated host mortality due to the disease, assessed differential hemato-logical changes in infected crabs, and examined proliferation of the parasite.


Carbon Cycling In A Tidal Freshwater Marsh Ecosystem: A Carbon Gas Flux Study, Sc Neubauer, Wd Miller, Iris C. Anderson Jan 2000

Carbon Cycling In A Tidal Freshwater Marsh Ecosystem: A Carbon Gas Flux Study, Sc Neubauer, Wd Miller, Iris C. Anderson

VIMS Articles

A process-based carbon gas flux model was developed to calculate total macrophyte and microalgal production, and community and belowground respiration, for a Peltandra virginica dominated tidal freshwater marsh in Virginia. The model was based on measured field fluxes of CO2 and CH,, scaled to monthly and annual rates using empirically derived photosynthesis versus irradiance, and respiration versus temperature relationships. Because the gas exchange technique measures whole system gas fluxes and therefore includes turnover and seasonal translocation, estimates of total macrophyte production will be more accurate than those calculated from biomass harvests. One Limitation of the gas flux method is that ...


Strategies For Assessing The Implications Of Malformed Frogs For Environmental Health, Jg Burkhart, Robert C. Hale Jan 2000

Strategies For Assessing The Implications Of Malformed Frogs For Environmental Health, Jg Burkhart, Robert C. Hale

VIMS Articles

The recent increase in the incidence of deformities among natural frog populations has raised concern about the state of the environment and the possible impact of unidentified causative agents on the health of wildlife and human populations. An open workshop on Strategies for Assessing the Implications of Malformed Frogs for Environmental Health was convened on 4-5 December 1997 at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina. The purpose of the workshop was to share information among a multidisciplinary group with scientific interest and responsibility for human and environmental health at the federal and state ...


Feeding Habits Of Young-Of-Year Striped Bass Morone Saxatilis, And White Perch, Morone American In Lower James River, Va, Paul J. Rudershausen, Joseph G. Loesch Jan 2000

Feeding Habits Of Young-Of-Year Striped Bass Morone Saxatilis, And White Perch, Morone American In Lower James River, Va, Paul J. Rudershausen, Joseph G. Loesch

VIMS Articles

A total of 188 young-of-year (YOY) striped bass, Marone saxatilis, and 199 YOY white perch, Marone americana, were collected by pushnet, seine and trawl during 24-hour periods from June through August, 1992 in lower James River, Virginia. The purpose was to identify prey and temporal and spatial feeding habits. Copepods were the most numerous prey of both species. Fishes and mysids comprised the largest volumetnc percentage of diets of striped bass and white perch, respectively. Using an index of relative importance, leptodorids and copepods were the most important prey of striped bass and white perch, respectively. Botl1 species shifted from ...


Estimates Of Naked Goby (Gobiosoma Bosc), Striped Blenny (Chasmodes Bosquianus) And Eastern Oyster (Crassostrea Virginica) Larval Production Around A Restored Chesapeake Bay Oyster Reef, Jm Harding, Roger L. Mann Jan 2000

Estimates Of Naked Goby (Gobiosoma Bosc), Striped Blenny (Chasmodes Bosquianus) And Eastern Oyster (Crassostrea Virginica) Larval Production Around A Restored Chesapeake Bay Oyster Reef, Jm Harding, Roger L. Mann

VIMS Articles

Naked gobies (Gobiosoma bose) and striped blennies (Chasmodes bosquianus) rely on oyster reefs for nesting sites, feeding grounds, and refugia from predation by upper level piscivores. Seasonal densities of Eastern oysters (Crassostrea virginica), naked gobies, and striped blennies on Palace Bar Reef, Piankatank River, Virginia were quantified and used to develop species-specific larval production estimates. Densities of oyster adults, juveniles, and articulated shell valves (the result of recent mortality) did not significantly change from November 1995 to November 1996. Naked goby and striped blenny densities varied with substrate type and season; peak fish densities for both species were observed in ...


Autumnal Biomass And Potential Productivity Of Salt Marsh Fungi From 29 Degrees To 43 Degrees North Latitude Along The United States Atlantic Coast, Sy Newell, Lk Blum, Re Crawford, T Dai, M Dionne Jan 2000

Autumnal Biomass And Potential Productivity Of Salt Marsh Fungi From 29 Degrees To 43 Degrees North Latitude Along The United States Atlantic Coast, Sy Newell, Lk Blum, Re Crawford, T Dai, M Dionne

VIMS Articles

It has been established that substantial amounts of fungal mass accumulate in standing decaying smooth cordgrass (Spartina alterniflora) marshes in the southeastern United States (e.g., in standing decaying leaf blades with a total fungal organic mass that accounts for about 20% of the decay system organic mass), but it has been hypothesized that in marshes farther north this is not true. We obtained samples of autumnal standing decaying smooth cordgrass from sites in Florida to Maine over a 3-year period. The variation in latitude could not explain any of the variation in the living fungal standing crop las determined ...


Progression Of Diseases Caused By The Oyster Parasites, Perkinsus Marinus And Haplosporidium Nelsoni, In Crassostrea Virginica On Constructed Intertidal Reefs, Aswani Volety, Frank O. Perkins, Roger Mann, Pr Hershberg Jan 2000

Progression Of Diseases Caused By The Oyster Parasites, Perkinsus Marinus And Haplosporidium Nelsoni, In Crassostrea Virginica On Constructed Intertidal Reefs, Aswani Volety, Frank O. Perkins, Roger Mann, Pr Hershberg

VIMS Articles

The progression of diseases caused by the oyster parasites Perkinsus marinus and Haplosporidium nelsoni were evaluated by periodic sampling (May 1994-December 1995) of eastern oysters Crassostrea virginica on an artificial reef located in the Piankatank River, Virginia. The infections observed were recorded as a function of: (1) prevalence and intensity; (2) oyster size and age; and (3) depth below mean low water at which the host oyster was found on the reef. Only a very small number of oysters were infected with the two species of pathogens on the oyster reef during the first 11 months of Life. In the ...


A Review Of Issues In Seagrass Seed Dormancy And Germination: Implications For Conservation And Restoration, R J. Orth, Mc Harwell, Em Bailey, A Bartholomew, J Jawad, A Lombana, Ken Moore, J Rhode, H Woods Jan 2000

A Review Of Issues In Seagrass Seed Dormancy And Germination: Implications For Conservation And Restoration, R J. Orth, Mc Harwell, Em Bailey, A Bartholomew, J Jawad, A Lombana, Ken Moore, J Rhode, H Woods

VIMS Articles

Seagrasses have received considerable attention over the past 2 decades because of the multiple ecological roles they play in estuarine and coastal ecosystems and concerns over worldwide losses of seagrass habitat due to direct and indirect human impacts. Restoration and conservation efforts are underway in some areas of the world, but progress may be limited by the paucity of information on the role of seeds in bed dynamics. Although flowering occurs in most of the 58 seagrass species, seed germination data exist for only 19 of the 42 species that have some period of dormancy, with only 93 published references ...


A Comparison Of Size Selectivity And Relative Efficiency Of Sea Scallop, Placopecten Magellanicus (Gmelin, 1791), Trawls And Dredges, David Rudders, Wd Dupaul, Je Kirkley Jan 2000

A Comparison Of Size Selectivity And Relative Efficiency Of Sea Scallop, Placopecten Magellanicus (Gmelin, 1791), Trawls And Dredges, David Rudders, Wd Dupaul, Je Kirkley

VIMS Articles

During August and September 1997 and May 1998, three comparative fishing experiments were conducted aboard commercial sea scallop trawl and dredge vessels to assess the efficacy of gear restrictions found in Amendment 3 to the Sea Scallop Fishery Management plan (SSFMP). This amendment involved certain gear restrictions including minimum mesh and ring sizes and maximum Scar widths and was intended to equate the performance of sea scallop trawls and dredges with respect to size selectivity and efficiency. Statistical analysis indicated that selectivity and efficiency were not equal for the two gear types. while absolute gear size selectivity could not be ...


Restoring The Oyster Reef Communities In The Chesapeake Bay: A Commentary, Roger L. Mann Jan 2000

Restoring The Oyster Reef Communities In The Chesapeake Bay: A Commentary, Roger L. Mann

VIMS Articles

Restoration of the oyster Crassostrea virginica resource to the Chesapeake Bay is a widely supported goal. This manuscript explores the questions of why, how, and in what time frame this should be attempted. Restoration goals based simply on support of a commercial fishery fail to address the role of the oyster as a cornerstone species within the Chesapeake Bay and should only be considered in the context of a long-term sustainable fishery exploitation. The argument is proffered that a restored resource sustaining a fishery at the historical harvest level is unrealistic, because: (1) harvest probably exceeded biological production for much ...


Oyster Reef Restoration: Convergence Of Harvest And Conservation Strategies, Dl Breitburg, Ld Coen, Mark Luckenbach, Roger L. Mann, M Posey, J. A. Wesson Jan 2000

Oyster Reef Restoration: Convergence Of Harvest And Conservation Strategies, Dl Breitburg, Ld Coen, Mark Luckenbach, Roger L. Mann, M Posey, J. A. Wesson

VIMS Articles

Oyster reef restoration, protection, and construction are important to meeting harvest, water quality, and fish habitat goals. However, the strategies needed to achieve harvest and conservation goals have often been considered to be at odds. We argue that these goals are. in fact, compatible and that the same strategies will promote a sustainable harvest of the resource, increased filtration of estuarine waters, and increased provision of structured habitat for finfish, crabs, and other organisms that utilize oyster reefs or receive benefit indirectly from them. Creation or designations of unharvested sites (refuge sites) are key components of these strategies. Unharvested reefs ...


Prevalence Of Perkinsus Spp. In Chesapeake Bay Soft-Shell Clams, Mya Arenaria Linnaeus, 1758 During 1990-1998, Sm Mclaughlin, M Faisal Jan 2000

Prevalence Of Perkinsus Spp. In Chesapeake Bay Soft-Shell Clams, Mya Arenaria Linnaeus, 1758 During 1990-1998, Sm Mclaughlin, M Faisal

VIMS Articles

Prevalence and intensity of Perkinsus spp. infections were determined in soft-shell clams Mya arenaria during 1990 to 1998 based upon incubation of rectal tissues in Ray's fluid thioglycollate medium. During the study, soft-shell clams were collected from 18 sites in the upper Chesapeake Bay in Maryland. Enlarged hypnospores were found in similar to 7% (114/1,705) of the soft-shell clams. Peak prevalences occurred in the fail of 1992 with similar to 53% (16/30) at Piney Point and 50% (15/30) at Eastern Neck, and in August 1995 with similar to 64%(18/28) and similar to 37 ...


Toward Design Criteria In Constructed Oyster Reefs: Oyster Recruitment As A Function Of Substrate Type And Tidal Height, Fx O'Beirn, Mark Luckenbach, Ja Nestlerode, Gm Coates Jan 2000

Toward Design Criteria In Constructed Oyster Reefs: Oyster Recruitment As A Function Of Substrate Type And Tidal Height, Fx O'Beirn, Mark Luckenbach, Ja Nestlerode, Gm Coates

VIMS Articles

Restoration of degraded oyster reef habitat generally begins with the addition of substrate that serves as a reef base and site for oyster spat attachment. Remarkably, little is known about how substrate type and reef morphology affect the development of oyster populations on restored reefs. Three-dimensional, intertidal reefs were constructed near Fisherman's Island, Virginia: two reefs in 1995 using surfclam (Spisula solidissima) shell and six reefs in 1996 using surfclam shell, oyster shell, and stabilized coal ash. We have monitored oyster recruitment and growth quarterly at three tidal heights (intertidal, mean low water, and subtidal) on each reef type ...


The Effect Of Cytochalasin B Dosage On The Survival And Ploidy Of Crassostrea Virginica (Gmelin) Larvae, Je Supan, Ce Wilson, Standish K. Allen Jr. Jan 2000

The Effect Of Cytochalasin B Dosage On The Survival And Ploidy Of Crassostrea Virginica (Gmelin) Larvae, Je Supan, Ce Wilson, Standish K. Allen Jr.

VIMS Articles

Survival and ploidy of D-stage oyster larvae (Crassostrea virginica) were determined following the rearing of embryos exposed to CB dosages of 0.5 mg/L, 0.25 mg/L, and 0.125 mg/L for 10 minutes, with 0.05% DMSO and ambient seawater as controls. The experiment was replicated three times on the same day with the same procedures and partially stripping the same male oysters; different females were used for each replicate. CB dosage treatments began when 50% of the eggs reached PBI (24-31 min). Embryos were reared for 48 h at ambient temperature and salinity. Resulting triploid ...