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Sample records for restoration oyster shell

  1. Restoration of oyster reefs in an estuarine lake: population dynamics and shell accretion

    Casas, Sandra M.; La Peyre, Jerome F.; La Peyre, Megan K.

    2015-01-01

    Restoration activities inherently depend on understanding the spatial and temporal variation in basic demographic rates of the species of interest. For species that modify and maintain their own habitat such as the eastern oyster Crassostrea virginica, understanding demographic rates and their impacts on population and habitat success are crucial to ensuring restoration success. We measured oyster recruitment, density, size distribution, biomass, mortality and Perkinsus marinus infection intensity quarterly for 3 yr on shallow intertidal reefs created with shell cultch in March 2009. All reefs were located within Sister Lake, LA. Reefs were placed in pairs at 3 different locations within the lake; pairs were placed in low and medium energy sites within each location. Restored reefs placed within close proximity (biomass (>14.6 kg m-2) at the end of 3 yr. Shell accretion, on average, exceeded estimated rates required to keep pace with local subsidence and shell loss. Variation in recruitment, growth and survival drives local site-specific population success, which highlights the need to understand local water quality, hydrodynamics, and metapopulation dynamics when planning restoration.

  2. Composted oyster shell as lime fertilizer is more effective than fresh oyster shell.

    Lee, Young Han; Islam, Shah Md Asraful; Hong, Sun Joo; Cho, Kye Man; Math, Renukaradhya K; Heo, Jae Young; Kim, Hoon; Yun, Han Dae

    2010-01-01

    Physio-chemical changes in oyster shell were examined, and fresh and composted oyster shell meals were compared as lime fertilizers in soybean cultivation. Structural changes in oyster shell were observed by AFM and FE-SEM. We found that grains of the oyster shell surface became smoother and smaller over time. FT-IR analysis indicated the degradation of a chitin-like compound of oyster shell. In chemical analysis, pH (12.3+/-0.24), electrical conductivity (4.1+/-0.24 dS m(-1)), and alkaline powder (53.3+/-1.12%) were highest in commercial lime. Besides, pH was higher in composted oyster shell meal (9.9+/-0.53) than in fresh oyster shell meal (8.4+/-0.32). The highest organic matter (1.1+/-0.08%), NaCl (0.54+/-0.03%), and moisture (15.1+/-1.95%) contents were found in fresh oyster shell meal. A significant higher yield of soybean (1.33 t ha(-1)) was obtained by applying composted oyster shell meal (a 21% higher yield than with fresh oyster shell meal). Thus composting of oyster shell increases the utility of oyster shell as a liming material for crop cultivation.

  3. Thermoluminescence analysis of irradiated oyster shells

    Cruz-Zaragoza, E.; Marcazzó, J.; Della Monaca, S.; Boniglia, C.; Gargiulo, R.; Bortolin, E.

    2012-01-01

    This paper reports the thermoluminescence (TL) analysis performed on the oyster shells powder. TL response of 60 Co gamma-rays irradiated samples were studied in the range from 80 Gy to 8 kGy doses. TL signal of irradiated shell powder was higher as compared to the unirradiated control samples, which allowed to identify the irradiated oysters. Results show that the oyster shells have good TL properties and can be useful for the identification of irradiated seafood as well as for the evaluation of the treatment dose. - Highlights: ► TL properties of irradiated oyster shell powder were studied. ► The SEM analysis shows that several elements are present in oyster shell powder. ► Calcite is the main component in the samples and β-calcite is also present. ► Following the European Standard EN 1788, the irradiated oyster can be identified. ► Determination of absorbed dose is possible by performing a preheat treatment.

  4. High pressure inactivation of HAV within oysters: comparison of shucked oysters with whole in shell meats

    High pressure inactivation of hepatitis A virus (HAV) within oysters bioaccumulated under simulated natural conditions to levels >106 PFU/oyster has been evaluated. Five min treatments at 20C were administered at 350, 375, and 400 MegaPascals (MPa). Shucked and whole-in-shell oysters were directly...

  5. A Restoration Suitability Index Model for the Eastern Oyster (Crassostrea virginica) in the Mission-Aransas Estuary, TX, USA

    Beseres Pollack, Jennifer; Cleveland, Andrew; Palmer, Terence A.; Reisinger, Anthony S.; Montagna, Paul A.

    2012-01-01

    Oyster reefs are one of the most threatened marine habitats on earth, with habitat loss resulting from water quality degradation, coastal development, destructive fishing practices, overfishing, and storm impacts. For successful and sustainable oyster reef restoration efforts, it is necessary to choose sites that support long-term growth and survival of oysters. Selection of suitable sites is critically important as it can greatly influence mortality factors and may largely determine the ultimate success of the restoration project. The application of Geographic Information Systems (GIS) provides an effective methodology for identifying suitable sites for oyster reef restoration and removes much of the uncertainty involved in the sometimes trial and error selection process. This approach also provides an objective and quantitative tool for planning future oyster reef restoration efforts. The aim of this study was to develop a restoration suitability index model and reef quality index model to characterize locations based on their potential for successful reef restoration within the Mission-Aransas Estuary, Texas, USA. The restoration suitability index model focuses on salinity, temperature, turbidity, dissolved oxygen, and depth, while the reef quality index model focuses on abundance of live oysters, dead shell, and spat. Size-specific Perkinsus marinus infection levels were mapped to illustrate general disease trends. This application was effective in identifying suitable sites for oyster reef restoration, is flexible in its use, and provides a mechanism for considering alternative approaches. The end product is a practical decision-support tool that can be used by coastal resource managers to improve oyster restoration efforts. As oyster reef restoration activities continue at small and large-scales, site selection criteria are critical for assisting stakeholders and managers and for maximizing long-term sustainability of oyster resources. PMID:22792410

  6. Flow-sediment-oyster interaction around degraded, restored, and reference oyster reefs in Florida's Indian River Lagoon

    Kitsikoudis, V.; Kibler, K. M.; Spiering, D. W.

    2017-12-01

    This study analyzes flow patterns and sediment distributions around three oyster reefs in a bar-built estuarine lagoon. We studied a degraded reef, a recently restored reef, and a reference condition reef with a healthy live oyster community. The restored reef had been regraded and restored with oyster shell mats to aid in recruitment of oyster spat, with the goal of reestablishing a healthy oyster community. Despite the fact that flow-biota-sediment interaction constitutes a blossoming research field, actual field data are sparse and current knowledge emanates from flume studies and numerical modeling. Moreover, the hydraulic effect of restored oyster reefs has not been thoroughly investigated and it is not clear if the flow field and sediment erosion/deposition are similar or diverge from natural reefs. Instantaneous three-dimensional flow velocities were collected on reefs using a Nortek Vectrino Profiler and an acoustic Doppler current profiler (Nortek Aquadopp). The former measured a 2 - 3 cm velocity profile above the oyster bed, while the latter quantified incoming velocities across the flow profile approximately 10 m from the edge of the reef. Flow measurements were conducted during rising tides and are coupled with simultaneous wind speed and direction data. In addition, 20 cm deep sediment cores were retrieved on and off the investigated reefs. Sediment grain size distributions were determined after individual cores were processed for loss on ignition. Incoming flow velocities were as high as 10 cm/s, relatively higher than those recorded close to reefs. Mean and turbulent flow velocities close to the reefs, varied among the investigated sites, despite the similar wind flow conditions offshore. For instance, the measurements at the degraded reef showed decreased wave attenuation and augmented flow velocities compared to the other sites. Boat wakes exhibited a very distinct signal in the flow velocity time-series and significantly increased the approaching

  7. Optimal Site Characterization and Selection Criteria for Oyster Restoration using Multicolinear Factorial Water Quality Approach

    Yoon, J.

    2015-12-01

    Elevated levels of nutrient loadings have enriched the Chesapeake Bay estuaries and coastal waters via point and nonpoint sources and the atmosphere. Restoring oyster beds is considered a Best Management Practice (BMP) to improve the water quality as well as provide physical aquatic habitat and a healthier estuarine system. Efforts include declaring sanctuaries for brood-stocks, supplementing hard substrate on the bottom and aiding natural populations with the addition of hatchery-reared and disease-resistant stocks. An economic assessment suggests that restoring the ecological functions will improve water quality, stabilize shorelines, and establish a habitat for breeding grounds that outweighs the value of harvestable oyster production. Parametric factorial models were developed to investigate multicolinearities among in situ water quality and oyster restoration activities to evaluate posterior success rates upon multiple substrates, and physical, chemical, hydrological and biological site characteristics to systematically identify significant factors. Findings were then further utilized to identify the optimal sites for successful oyster restoration augmentable with Total Maximum Daily Loads (TMDLs) and BMPs. Factorial models evaluate the relationship among the dependent variable, oyster biomass, and treatments of temperature, salinity, total suspended solids, E. coli/Enterococci counts, depth, dissolved oxygen, chlorophyll a, nitrogen and phosphorus, and blocks consist of alternative substrates (oyster shells versus riprap, granite, cement, cinder blocks, limestone marl or combinations). Factorial model results were then compared to identify which combination of variables produces the highest posterior biomass of oysters. Developed Factorial model can facilitate maximizing the likelihood of successful oyster reef restoration in an effort to establish a healthier ecosystem and to improve overall estuarine water quality in the Chesapeake Bay estuaries.

  8. Quantitative validation of a habitat suitability index for oyster restoration

    Seth eTheuerkauf

    2016-05-01

    Full Text Available Habitat suitability index (HSI models provide spatially explicit information on the capacity of a given habitat to support a species of interest, and their prevalence has increased dramatically in recent years. Despite caution that the reliability of HSIs must be validated using independent, quantitative data, most HSIs intended to inform terrestrial and marine species management remain unvalidated. Furthermore, of the eight HSI models developed for eastern oyster (Crassostrea virginica restoration and fishery production, none has been validated. Consequently, we developed, calibrated, and validated an HSI for the eastern oyster to identify optimal habitat for restoration in a tributary of Chesapeake Bay, the Great Wicomico River (GWR. The GWR harbors a high density, restored oyster population, and therefore serves as an excellent model system for assessing the validity of the HSI. The HSI was derived from GIS layers of bottom type, salinity, and water depth (surrogate for dissolved oxygen, and was tested using live adult oyster density data from a survey of high vertical relief reefs (HRR and low vertical relief reefs (LRR in the sanctuary network. Live adult oyster density was a statistically-significant sigmoid function of the HSI, which validates the HSI as a robust predictor of suitable oyster reef habitat for rehabilitation or restoration. In addition, HRR had on average 103-116 more adults m^−2 than LRR at a given level of the HSI. For HRR, HSI values ≥0.3 exceeded the accepted restoration target of 50 live adult oysters m^−2. For LRR, the HSI was generally able to predict live adult oyster densities that meet or exceed the target at HSI values ≥0.3. The HSI indicated that there remain large areas of suitable habitat for restoration in the GWR. This study provides a robust framework for HSI model development and validation, which can be refined and applied to other systems and previously developed HSIs to improve the efficacy of

  9. Calcium, strontium and fluorine patterns in shells of Pacific Oyster and Rock Oyster

    Coote, G.E.

    1996-01-01

    The IGNS proton microprobe has been applied in a study of the distribution of Calcium, Strontium and Fluorine in the calcite shells of Pacific Oyster (Crassostrea gigas) and the native Rock oyster (Crassostrea glomerata). The ultimate aim is to derive information which could have application in such fields as archaeology, biology, palaeontology, aquaculture and environmental studies. Calcium and strontium were determined from their emissions of K X-rays under proton bombardment, and fluorine from the 19 F (p,alpha gamma) 16 O nuclear reaction. The three elements were determined simultaneously at points no more than 20 micrometres apart. A total of 14 one and 17 two-dimensional scans were performed on sections of the shells embedded in epoxy resin. We studied shells from nine Pacific oysters (five transferred from the Marlborough Sounds to Wellington Harbour and four from the Bay of Islands). (author). 11 refs.; 5 figs

  10. Oyster Shell Recycling and Bone Waste Treatment Using Plasma Pyrolysis

    Chae, Jae Ou; Knak, S P; Knak, A N; Koo, H J; Ravi, V

    2006-01-01

    Investigations on the recycling of oyster shells and bone waste treatment using the plasma pyrolysis technique are presented in this paper. A arc based plasma torch operated at 25 kW was employed for the experiments. Fresh oyster shells were recycled using the plasma torch to convert them to a useful product such as CaO. Bone waste was treated to remove the infectious organic part and to vitrify the inorganic part. The time required for treatment in both cases was significantly short. Significant reduction in the weight of the samples was observed in both cases

  11. Oyster Shell Recycling and Bone Waste Treatment Using Plasma Pyrolysis

    Jae, Ou Chae; Knak, S. P.; Knak, A. N.; Koo, H. J.; Ravi, V.

    2006-11-01

    Investigations on the recycling of oyster shells and bone waste treatment using the plasma pyrolysis technique are presented in this paper. A arc based plasma torch operated at 25 kW was employed for the experiments. Fresh oyster shells were recycled using the plasma torch to convert them to a useful product such as CaO. Bone waste was treated to remove the infectious organic part and to vitrify the inorganic part. The time required for treatment in both cases was significantly short. Significant reduction in the weight of the samples was observed in both cases.

  12. Guidelines for evaluating performance of oyster habitat restoration

    Baggett, Lesley P.; Powers, Sean P.; Brumbaugh, Robert D.; Coen, Loren D.; DeAngelis, Bryan M.; Greene, Jennifer K.; Hancock, Boze T.; Morlock, Summer M.; Allen, Brian L.; Breitburg, Denise L.; Bushek, David; Grabowski, Jonathan H.; Grizzle, Raymond E.; Grosholz, Edwin D.; LaPeyre, Megan K.; Luckenbach, Mark W.; McGraw, Kay A.; Piehler, Michael F.; Westby, Stephanie R.; zu Ermgassen, Philine S. E.

    2015-01-01

    Restoration of degraded ecosystems is an important societal goal, yet inadequate monitoring and the absence of clear performance metrics are common criticisms of many habitat restoration projects. Funding limitations can prevent adequate monitoring, but we suggest that the lack of accepted metrics to address the diversity of restoration objectives also presents a serious challenge to the monitoring of restoration projects. A working group with experience in designing and monitoring oyster reef projects was used to develop standardized monitoring metrics, units, and performance criteria that would allow for comparison among restoration sites and projects of various construction types. A set of four universal metrics (reef areal dimensions, reef height, oyster density, and oyster size–frequency distribution) and a set of three universal environmental variables (water temperature, salinity, and dissolved oxygen) are recommended to be monitored for all oyster habitat restoration projects regardless of their goal(s). In addition, restoration goal-based metrics specific to four commonly cited ecosystem service-based restoration goals are recommended, along with an optional set of seven supplemental ancillary metrics that could provide information useful to the interpretation of prerestoration and postrestoration monitoring data. Widespread adoption of a common set of metrics with standardized techniques and units to assess well-defined goals not only allows practitioners to gauge the performance of their own projects but also allows for comparison among projects, which is both essential to the advancement of the field of oyster restoration and can provide new knowledge about the structure and ecological function of oyster reef ecosystems.

  13. Removal of Arsenic with Oyster Shell: Experimental Measurements

    Md. Atiqur Rahman, , and

    2008-12-01

    Full Text Available Oyster shell has tremendous potential as a remediation material for the removal of arsenic from groundwater. A single arsenic removal system was developed with oyster shell for tube well water containing arsenic. The system removes arsenic from water by adsorption through fine oyster shell. Various conditions that affect the adsorption/desorption of arsenic were investigated. Adsorption column methods showed the removal of As(III under the following conditions: initial As concentration, 100 µg /L; oyster shell amount, 6 g; particle size, <355µm ; treatment flow rate, 1.7 mL/min; and pH 6.5. Arsenic concentration of the treated water were below the Bangladesh drinking water standard of 50 µg/L for As. The desorption efficiencies with 2M of KOH after the treatment of groundwater were in the range of 80-83%. A combination of techniques was used to measure the pH, conductivity, cations and anions. The average concentrations of other inorganic constituents of health concern (Na, K, Ca, Mg and Fe in treated water were below their respective WHO guideline for drinking. The present study might provide new avenues to achieve the arsenic concentrations required for drinking water recommended by Bangladesh and the World Health Organization (WHO.

  14. Overcoming restoration paradigms: value of the historical record and metapopulation dynamics in native oyster restoration

    Romuald N. Lipcius

    2015-09-01

    Full Text Available Restoration strategies for native oyster populations rely on multiple sources of information, which often conflict due to time- and space-varying patterns in abundance and distribution. For instance, strategies based on population connectivity and disease resistance can differ, and extant and historical records of abundance and distribution are often at odds, such that the optimal strategy is unclear and valuable restoration sites may be excluded from consideration. This was the case for the Lynnhaven River subestuary of lower Chesapeake Bay, which was deemed unsuitable for Eastern Oyster restoration based on physical conditions, disease challenge, and extant oyster abundance. Consequently, we (i evaluated previously unknown historical data from the 1800s, (ii quantified extant oyster recruitment and abundance, physical conditions, and disease presence on constructed restoration reefs and alternative substrates, and (iii assessed simulations from biophysical models to identify potential restoration sites in the metapopulation. The collective data distinguished numerous restoration sites (i in the polyhaline zone (salinity 18.4-22.2 where disease resistance is evolving, (ii where oysters were abundant in the late 1800s-early 1900s, (iii of recent high recruitment, abundance and survival, despite consistent and elevated disease challenge, and (iv interconnected as a metapopulation via larval dispersal. Moreover, a network of constructed restoration reefs met size structure, abundance and biomass standards of restoration success. These findings demonstrate that assumptions about the suitability of sites for oyster restoration based on individual processes can be severely flawed, and that in-depth examination of multiple processes and sources of information are required for oyster reef restoration plans to maximize success. We use these findings and previous information to recommend a strategy for successful restoration of subtidal oyster reefs

  15. Photosynthetic epibionts and endobionts of Pacific oyster shells from oyster reefs in rocky versus mudflat shores.

    Laurent Barillé

    Full Text Available The Pacific oyster, Crassostrea gigas (Thunberg, is the main bivalve species cultivated in the world. With global warming enabling its reproduction and larval survival at higher latitudes, this species is now recognized as invasive and creates wild oyster reefs globally. In this study, the spatial distribution of photosynthetic assemblages colonizing the shells of wild C. gigas was investigated on both a large scale (two contrasting types of reefs found in mudflats and rocky areas and a small scale (within individual shells using a hyperspectral imager. The microspatial distribution of all phototrophs was obtained by mapping the Normalized Difference Vegetation Index (NDVI. Second derivative (δδ analyses of hyperspectral images at 462, 524, 571 and 647 nm were subsequently applied to map diatoms, cyanobacteria, rhodophytes and chlorophytes, respectively. A concomitant pigment analysis was carried out by high performance liquid chromatography and completed by taxonomic observations. This study showed that there was high microalgal diversity associated with wild oyster shells and that there were differences in the structure of the phototropic assemblages depending on the type of reef. Namely, vertically-growing oysters in mudflat areas had a higher biomass of epizoic diatoms (hyperspectral proxy at δδ462 nm and were mainly colonized by species of the genera Navicula, Nitzschia and Hippodonta, which are epipelic or motile epipsammic. The assemblages on the horizontal oysters contained more tychoplanktonic diatoms (e.g. Thalassiosira pseudonana, T. proschkinae and Plagiogrammopsis vanheurckii. Three species of boring cyanobacteria were observed for both types of reef: Mastigocoleus testarum, Leptolyngbya terrebrans, and Hyella caespistosa, but the second derivative analysis at 524 nm showed a significantly higher biomass for the horizontally-growing oysters. There was no biomass difference for the boring chlorophyte assemblages (δδ647 nm, with

  16. 3D CENTRAL LINE EXTRACTION OF FOSSIL OYSTER SHELLS

    A. Djuricic

    2016-06-01

    Full Text Available Photogrammetry provides a powerful tool to digitally document protected, inaccessible, and rare fossils. This saves manpower in relation to current documentation practice and makes the fragile specimens more available for paleontological analysis and public education. In this study, high resolution orthophoto (0.5 mm and digital surface models (1 mm are used to define fossil boundaries that are then used as an input to automatically extract fossil length information via central lines. In general, central lines are widely used in geosciences as they ease observation, monitoring and evaluation of object dimensions. Here, the 3D central lines are used in a novel paleontological context to study fossilized oyster shells with photogrammetric and LiDAR-obtained 3D point cloud data. 3D central lines of 1121 Crassostrea gryphoides oysters of various shapes and sizes were computed in the study. Central line calculation included: i Delaunay triangulation between the fossil shell boundary points and formation of the Voronoi diagram; ii extraction of Voronoi vertices and construction of a connected graph tree from them; iii reduction of the graph to the longest possible central line via Dijkstra’s algorithm; iv extension of longest central line to the shell boundary and smoothing by an adjustment of cubic spline curve; and v integration of the central line into the corresponding 3D point cloud. The resulting longest path estimate for the 3D central line is a size parameter that can be applied in oyster shell age determination both in paleontological and biological applications. Our investigation evaluates ability and performance of the central line method to measure shell sizes accurately by comparing automatically extracted central lines with manually collected reference data used in paleontological analysis. Our results show that the automatically obtained central line length overestimated the manually collected reference by 1.5% in the test set, which

  17. D Central Line Extraction of Fossil Oyster Shells

    Djuricic, A.; Puttonen, E.; Harzhauser, M.; Mandic, O.; Székely, B.; Pfeifer, N.

    2016-06-01

    Photogrammetry provides a powerful tool to digitally document protected, inaccessible, and rare fossils. This saves manpower in relation to current documentation practice and makes the fragile specimens more available for paleontological analysis and public education. In this study, high resolution orthophoto (0.5 mm) and digital surface models (1 mm) are used to define fossil boundaries that are then used as an input to automatically extract fossil length information via central lines. In general, central lines are widely used in geosciences as they ease observation, monitoring and evaluation of object dimensions. Here, the 3D central lines are used in a novel paleontological context to study fossilized oyster shells with photogrammetric and LiDAR-obtained 3D point cloud data. 3D central lines of 1121 Crassostrea gryphoides oysters of various shapes and sizes were computed in the study. Central line calculation included: i) Delaunay triangulation between the fossil shell boundary points and formation of the Voronoi diagram; ii) extraction of Voronoi vertices and construction of a connected graph tree from them; iii) reduction of the graph to the longest possible central line via Dijkstra's algorithm; iv) extension of longest central line to the shell boundary and smoothing by an adjustment of cubic spline curve; and v) integration of the central line into the corresponding 3D point cloud. The resulting longest path estimate for the 3D central line is a size parameter that can be applied in oyster shell age determination both in paleontological and biological applications. Our investigation evaluates ability and performance of the central line method to measure shell sizes accurately by comparing automatically extracted central lines with manually collected reference data used in paleontological analysis. Our results show that the automatically obtained central line length overestimated the manually collected reference by 1.5% in the test set, which is deemed

  18. Rapid detection of toxic metals in non-crushed oyster shells by portable X-ray fluorescence spectrometry

    Chou Ju, E-mail: Ju.Chou@selu.ed [Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402 (United States); Clement, Garret; Bursavich, Bradley; Elbers, Don [Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402 (United States); Cao Baobao; Zhou Weilie [Advanced Material Research Institute, University of New Orleans, New Orleans, LA 70148 (United States)

    2010-06-15

    The aim of this study was the multi-elemental detection of toxic metals such as lead (Pb) in non-crushed oyster shells by using a portable X-ray fluorescence (XRF) spectrometer. A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using a portable XRF which provides a quick, quantitative, non-destructive, and cost-effective mean for assessment of oyster shell contamination from Pb. Pb contamination in oyster shells was further confirmed by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results indicated that Pb is distributed in-homogeneously in contaminated shells. Oyster shells have a lamellar structure that could contribute to the high accumulation of Pb on oyster shells. - A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using XRF and contamination of lead on oyster shells was confirmed by XRF and SEM-EDS.

  19. Rapid detection of toxic metals in non-crushed oyster shells by portable X-ray fluorescence spectrometry

    Chou Ju; Clement, Garret; Bursavich, Bradley; Elbers, Don; Cao Baobao; Zhou Weilie

    2010-01-01

    The aim of this study was the multi-elemental detection of toxic metals such as lead (Pb) in non-crushed oyster shells by using a portable X-ray fluorescence (XRF) spectrometer. A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using a portable XRF which provides a quick, quantitative, non-destructive, and cost-effective mean for assessment of oyster shell contamination from Pb. Pb contamination in oyster shells was further confirmed by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results indicated that Pb is distributed in-homogeneously in contaminated shells. Oyster shells have a lamellar structure that could contribute to the high accumulation of Pb on oyster shells. - A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using XRF and contamination of lead on oyster shells was confirmed by XRF and SEM-EDS.

  20. A microbial spoilage profile of half shell Pacific oysters (Crassostrea gigas) and Sydney rock oysters (Saccostrea glomerata).

    Madigan, Thomas L; Bott, Nathan J; Torok, Valeria A; Percy, Nigel J; Carragher, John F; de Barros Lopes, Miguel A; Kiermeier, Andreas

    2014-04-01

    This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Identification of irradiated oysters by EPR measurements on shells

    Della Monaca, S., E-mail: sara.dellamonaca@iss.it [Istituto Superiore di Sanita, viale Regina Elena, 299 Rome (Italy); Fattibene, P.; Boniglia, C.; Gargiulo, R.; Bortolin, E. [Istituto Superiore di Sanita, viale Regina Elena, 299 Rome (Italy)

    2011-09-15

    In this paper the EPR spectra of the radicals induced in oyster shells after irradiation to (0.5-2) kGy ionizing radiation doses are analyzed. EPR spectra of irradiated shells showed the complex radical composition of biocarbonates, characterized by the presence of SO{sub 2}{sup -}, SO{sub 3}{sup -} and CO{sub 2}{sup -} radicals with different symmetries. In particular, the radiation-induced line at g = 2.0038, due to the g{sub x} component of the orthorhombic SO{sub 3}{sup -}, was well distinguishable from the rest of the spectrum. The g{sub x} component of the orthorhombic SO{sub 3}{sup -} was found to be intense and stable enough to allow the identification at least for the whole shelf life of the oyster. Furthermore, it is still well visible at low microwave powers for which the other signals are weak or non-visible and has a linear dose response in the (0.5-2) kGy range. A possible procedure protocol for the identification of irradiated oysters, can be based on acquisitions of the spectrum at low microwave power values (tenths of milliWatt) and low modulation amplitude values (0.03-0.05 mT) and on the identification of the g = 2.0038 signal as a proof of the ionizing radiation treatment performed on the sample.

  2. Identification of irradiated oysters by EPR measurements on shells

    Della Monaca, S.; Fattibene, P.; Boniglia, C.; Gargiulo, R.; Bortolin, E.

    2011-01-01

    In this paper the EPR spectra of the radicals induced in oyster shells after irradiation to (0.5-2) kGy ionizing radiation doses are analyzed. EPR spectra of irradiated shells showed the complex radical composition of biocarbonates, characterized by the presence of SO 2 - , SO 3 - and CO 2 - radicals with different symmetries. In particular, the radiation-induced line at g = 2.0038, due to the g x component of the orthorhombic SO 3 - , was well distinguishable from the rest of the spectrum. The g x component of the orthorhombic SO 3 - was found to be intense and stable enough to allow the identification at least for the whole shelf life of the oyster. Furthermore, it is still well visible at low microwave powers for which the other signals are weak or non-visible and has a linear dose response in the (0.5-2) kGy range. A possible procedure protocol for the identification of irradiated oysters, can be based on acquisitions of the spectrum at low microwave power values (tenths of milliWatt) and low modulation amplitude values (0.03-0.05 mT) and on the identification of the g = 2.0038 signal as a proof of the ionizing radiation treatment performed on the sample.

  3. OYSTER POPULATUION ESTIMATION IN SUPPORT OF THE TEN-YEAR GOAL FOR OYSTER RESOTRATION IN THE CHESAPEAKE BAY: DEVELOPING STRATEGIES FOR RESTORING AND MANAGING THE EASTERN OYSTER

    Mann, Roger, Steve Jordan, Gary Smith, Kennedy Paynter, James Wesson, Mary Christman, Jessica Vanisko, Juliana Harding, Kelly Greenhawk and Melissa Southworth. 2003. Oyster Population Estimation in Support of the Ten-Year Goal for Oyster Restoration in the Chesapeake Bay: Develop...

  4. Egg Shell and Oyster Shell Powder as Alternatives for Synthetic Phosphate: Effects on the Quality of Cooked Ground Pork Products.

    Cho, Min Guk; Bae, Su Min; Jeong, Jong Youn

    2017-01-01

    This study aimed to determine the optimal ratio of natural calcium powders (oyster shell and egg shell calcium) as synthetic phosphate replacers in pork products. Ground pork samples were subjected to six treatments, as follows: control (-) (no phosphate added), control (+) (0.3% phosphate blend added), treatment 1 (0.5% oyster shell calcium powder added), treatment 2 (0.3% oyster shell calcium powder and 0.2% egg shell calcium powder added), treatment 3 (0.2% oyster shell calcium powder and 0.3% egg shell calcium powder added), and treatment 4 (0.5% egg shell calcium powder added). The addition of natural calcium powders resulted in an increase in the pH values of meat products, regardless of whether they were used individually or mixed. The highest cooking loss was observed ( p cooking loss in samples with natural calcium powder added was similar ( p >0.05) to that in the positive control samples. CIE L* values decreased as the amount of added egg shell calcium powder increased. CIE a* values were higher ( p egg shell powder (treatment 2 or 3) was effective for the improvement of textural properties of the pork products. The findings show that the combined use of 0.2% oyster shell calcium and 0.3% egg shell calcium should enable the replacement of synthetic phosphate in the production of cooked pork products with desirable qualities.

  5. Adsorption of copper to different biogenic oyster shell structures

    Wu, Qiong; Chen, Jie [College of Materials Science and Engineering, Fuzhou University, New Campus, Minhou, Fujian Province 350108 (China); Clark, Malcolm [Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, P.O. Box 157, Lismore, NSW 2480 (Australia); Yu, Yan, E-mail: yuyan_1972@126.com [College of Materials Science and Engineering, Fuzhou University, New Campus, Minhou, Fujian Province 350108 (China)

    2014-08-30

    Graphical abstract: - Highlights: • Adsorption of copper to waste oyster shell occurs rapidly at pH 5.5. • Copper adsorbs to the different structures of oyster shell at different rates. • The prismatic layer dominates copper sorption rather than the nacreous layer. • SEM analysis shows a porous open network structure to the prismatic layer. • Surface ζ-potentials establish electrostatic attraction to drive copper sorption. - Abstract: The removal of copper from solution by oyster shell powder was investigated for potential wastewater treatment uses. In particular, adsorption behavior differences between the prismatic (PP) and nacreous (NP) shell layers, and how this affects copper removal, were investigated. Experimental results indicated that copper adsorption was highly pH-dependent with optimal copper removal at pH 5.5, where the powdered whole raw shell (RP) removed up to 99.9% of the copper within 24 h at a 10 mg/L initial copper concentration. Langmuir and Freundlich models were used to analyze the isotherm PP, NP and RP data. These results showed a strong homogeneous Langmuir model for low initial copper concentrations (5–30 mg/L) to both RP and PP layer, while strong agreement with a heterogeneous Freundlich model for high initial copper concentrations (30–200 mg/L); nevertheless, a homogeneous Langmuir model provided the best fit for the more dense NP layer across the initial concentration range (5–200 mg/L). The distribution coefficient (K{sub d}) value of PP layer for each initial concentration investigated was substantially higher than the NP layer and it was also found that the PP layer dominated the adsorption process with an adsorption capacity of 8.9 mg/g, while the adsorption capacity of the NP layer was 2.6 mg/g. These differences are believed to be because of the more porous structure of the PP layer, which was confirmed by scanning electron microscopy, infrared spectroscopy, energy-dispersive X-ray spectroscopy, and

  6. Adsorption of copper to different biogenic oyster shell structures

    Wu, Qiong; Chen, Jie; Clark, Malcolm; Yu, Yan

    2014-01-01

    Graphical abstract: - Highlights: • Adsorption of copper to waste oyster shell occurs rapidly at pH 5.5. • Copper adsorbs to the different structures of oyster shell at different rates. • The prismatic layer dominates copper sorption rather than the nacreous layer. • SEM analysis shows a porous open network structure to the prismatic layer. • Surface ζ-potentials establish electrostatic attraction to drive copper sorption. - Abstract: The removal of copper from solution by oyster shell powder was investigated for potential wastewater treatment uses. In particular, adsorption behavior differences between the prismatic (PP) and nacreous (NP) shell layers, and how this affects copper removal, were investigated. Experimental results indicated that copper adsorption was highly pH-dependent with optimal copper removal at pH 5.5, where the powdered whole raw shell (RP) removed up to 99.9% of the copper within 24 h at a 10 mg/L initial copper concentration. Langmuir and Freundlich models were used to analyze the isotherm PP, NP and RP data. These results showed a strong homogeneous Langmuir model for low initial copper concentrations (5–30 mg/L) to both RP and PP layer, while strong agreement with a heterogeneous Freundlich model for high initial copper concentrations (30–200 mg/L); nevertheless, a homogeneous Langmuir model provided the best fit for the more dense NP layer across the initial concentration range (5–200 mg/L). The distribution coefficient (K d ) value of PP layer for each initial concentration investigated was substantially higher than the NP layer and it was also found that the PP layer dominated the adsorption process with an adsorption capacity of 8.9 mg/g, while the adsorption capacity of the NP layer was 2.6 mg/g. These differences are believed to be because of the more porous structure of the PP layer, which was confirmed by scanning electron microscopy, infrared spectroscopy, energy-dispersive X-ray spectroscopy, and

  7. Calcium flouride (CaF2) from oyster shell as a raw material for thermoluminescence dosimeter

    Coloma, Lyra C.; Fanuga, Lyn N.; Ocreto, Cherries Ann; Rodriguez, Richita

    2006-03-01

    This study aims to develop a thermoluminescence dosimeter raw material made of calcium fluoride from locally available seashells that is suitable for personal radiation monitoring. Oyster shells were collected and grounded as powder samples and analyzed for calcium fluoride (CaF 2 ) content using XRF and XRD testing. Samples include pure CaF 2 , pure oyster shell, and oyster shells treated with acid. Based from the XRF results, natural oyster shell (w/ and w/o HNO 3 ) had high percentage of calcium about 49.64% and 47.45%, next to the pure calcium fluoride of 51.08%. X-ray diffractrogram shows that oyster sample had the nearest desired structure of CaF 2 compared with two seashells relative to the pure CaF 2 as standard materials. Results show that all of the natural oyster samples displayed TL emission glow curves at the temperature range 200-300 o C. It was also found that pure oyster sample has better TL response as compared to the treated ones. The researchers concluded that the calcium fluoride from oyster shells (without acid and heated) is a potentially good low-cost TLD raw material and may be used as an alternative for the much more expensive LiF dosimeters. (Authors)

  8. Characteristic crystal orientation of folia in oyster shell, Crassostrea gigas

    Lee, Seung Woo [Department of Chemical and Biomolecular Engineering, Sogang University, Seoul (Korea, Republic of); Kim, Gyeung Ho [Nano-Materials Reserch Center, Korea Institute of Science and Technology, Seoul (Korea, Republic of); Choi, Cheong Song [Department of Chemical and Biomolecular Engineering, Sogang University, Seoul (Korea, Republic of)], E-mail: cschoi@sogang.ac.kr

    2008-03-10

    The thin sheets of calcite, termed folia, that make up much of the shell of an oyster are composed of foliated lath. Folia of the giant Pacific oyster (Crassostrea gigas) were examined using TEM (transmission electron microscopy) and tested using microindentation and nanoindentation techniques. Analysis of the Kikuchi patterns obtained from the folia showed that there are two types (type I and type II) of preferred orientation, with an angle of around 70{sup o} between them. Nanoindentation tests showed that the folia exhibit a hardness of about 3 GPa and elastic modulus of about 73 GPa. Microcracks were generated using a microindenter in order to study the fracture mechanisms of the folia. Following on from these investigations, fracture mechanisms are discussed in conjunction with the correlation between preferred orientation and structural characteristics during cracking of the folia. Comparing the morphology and the polymorphism with nacre (also known as mother of pearl), the advantages of the relatively fast crystal growth and less amount of organic matrix in folia may have interesting implications for the development of sophisticated synthetic materials.

  9. A shell-neutral modeling approach yields sustainable oyster harvest estimates: a retrospective analysis of the Louisiana state primary seed grounds

    Soniat, Thomas M.; Klinck, John M.; Powell, Eric N.; Cooper, Nathan; Abdelguerfi, Mahdi; Hofmann, Eileen E.; Dahal, Janak; Tu, Shengru; Finigan, John; Eberline, Benjamin S.; La Peyre, Jerome F.; LaPeyre, Megan K.; Qaddoura, Fareed

    2012-01-01

    A numerical model is presented that defines a sustainability criterion as no net loss of shell, and calculates a sustainable harvest of seed (<75 mm) and sack or market oysters (≥75 mm). Stock assessments of the Primary State Seed Grounds conducted east of the Mississippi from 2009 to 2011 show a general trend toward decreasing abundance of sack and seed oysters. Retrospective simulations provide estimates of annual sustainable harvests. Comparisons of simulated sustainable harvests with actual harvests show a trend toward unsustainable harvests toward the end of the time series. Stock assessments combined with shell-neutral models can be used to estimate sustainable harvest and manage cultch through shell planting when actual harvest exceeds sustainable harvest. For exclusive restoration efforts (no fishing allowed), the model provides a metric for restoration success-namely, shell accretion. Oyster fisheries that remove shell versus reef restorations that promote shell accretion, although divergent in their goals, are convergent in their management; both require vigilant attention to shell budgets.

  10. Use of extracts from oyster shell and soil for cultivation of Spirulina maxima.

    Jung, Joo-Young; Kim, Sunmin; Lee, Hansol; Kim, Kyochan; Kim, Woong; Park, Min S; Kwon, Jong-Hee; Yang, Ji-Won

    2014-12-01

    Calcium ion and trace metals play important roles in various metabolisms of photosynthetic organisms. In this study, simple methods were developed to extract calcium ion and micronutrients from oyster shell and common soil, and the prepared extracts were tested as a replacement of the corresponding chemicals that are essential for growth of microalgae. The oyster shell and soil were treated with 0.1 M sodium hydroxide or with 10 % hydrogen peroxide, respectively. The potential application of these natural sources to cultivation was investigated with Spirulina maxima. When compared to standard Zarrouk medium, the Spirulina maxima cultivated in a modified Zarrouk media with elements from oyster shell and soil extract exhibited increases in biomass, chlorophyll, and phycocyanin by 17, 16, and 64 %, respectively. These results indicate that the extracts of oyster shell and soil provide sufficient amounts of calcium and trace metals for successful cultivation of Spirulina maxima.

  11. Inhibition of 4NQO-Induced Oral Carcinogenesis by Dietary Oyster Shell Calcium.

    Chen, Ying; Jiang, Yi; Liao, Liyan; Zhu, Xiaoxin; Tang, Shengan; Yang, Qing; Sun, Lihua; Li, Yujie; Gao, Shuangrong; Xie, Zhongjian

    2016-03-01

    Oyster has gained much attention recently for its anticancer activity but it is unclear whether calcium, the major antitumor ingredient in oyster shell, is responsible for the anticarcinogenic role of the oyster. To address this issue, C57BL/6 mice were fed with the carcinogen 4-nitroquinoline-1-oxide (4NQO, 50 µg/mL) and normal diet or a diet containing oyster powder, oyster calcium, or calcium depleted oyster powder. The tongue tissue specimens isolated from these mice were histologically evaluated for hyperplasia, dysplasia, and papillary lesions, and then analyzed for proliferation and differentiation markers by immunohistochemistry. The results showed that mice on the diet containing oyster calcium significantly reduced rates of tumors in the tongue and proliferation and enhanced differentiation in the oral epithelium compared with the diet containing calcium depleted oyster powder. These results suggest that calcium in oyster plays a critical role in suppressing formation of oral squamous cell carcinoma and proliferation and promoting differentiation of the oral epithelium. © The Author(s) 2015.

  12. Gear and survey efficiency of patent tongs for oyster populations on restoration reefs.

    David M Schulte

    Full Text Available Surveys of restored oyster reefs need to produce accurate population estimates to assess the efficacy of restoration. Due to the complex structure of subtidal oyster reefs, one effective and efficient means to sample is by patent tongs, rather than SCUBA, dredges, or bottom cores. Restored reefs vary in relief and oyster density, either of which could affect survey efficiency. This study is the first to evaluate gear (the first full grab and survey (which includes selecting a specific half portion of the first grab for further processing efficiencies of hand-operated patent tongs as a function of reef height and oyster density on subtidal restoration reefs. In the Great Wicomico River, a tributary of lower Chesapeake Bay, restored reefs of high- and low-relief (25-45 cm, and 8-12 cm, respectively were constructed throughout the river as the first large-scale oyster sanctuary reef restoration effort (sanctuary acreage > 20 ha at one site in Chesapeake Bay. We designed a metal frame to guide a non-hydraulic mechanical patent tong repeatedly into the same plot on a restored reef until all oysters within the grab area were captured. Full capture was verified by an underwater remotely-operated vehicle. Samples (n = 19 were taken on nine different reefs, including five low- (n = 8 and four high-relief reefs (n = 11, over a two-year period. The gear efficiency of the patent tong was estimated to be 76% (± 5% standard error, whereas survey efficiency increased to 81% (± 10% due to processing. Neither efficiency differed significantly between young-of-the-year oysters (spat and adults, high- and low-relief reefs, or years. As this type of patent tong is a common and cost-effective tool to evaluate oyster restoration projects as well as population density on fished habitat, knowing the gear and survey efficiencies allows for accurate and precise population estimates.

  13. Gear and survey efficiency of patent tongs for oyster populations on restoration reefs.

    Schulte, David M; Lipcius, Romuald N; Burke, Russell P

    2018-01-01

    Surveys of restored oyster reefs need to produce accurate population estimates to assess the efficacy of restoration. Due to the complex structure of subtidal oyster reefs, one effective and efficient means to sample is by patent tongs, rather than SCUBA, dredges, or bottom cores. Restored reefs vary in relief and oyster density, either of which could affect survey efficiency. This study is the first to evaluate gear (the first full grab) and survey (which includes selecting a specific half portion of the first grab for further processing) efficiencies of hand-operated patent tongs as a function of reef height and oyster density on subtidal restoration reefs. In the Great Wicomico River, a tributary of lower Chesapeake Bay, restored reefs of high- and low-relief (25-45 cm, and 8-12 cm, respectively) were constructed throughout the river as the first large-scale oyster sanctuary reef restoration effort (sanctuary acreage > 20 ha at one site) in Chesapeake Bay. We designed a metal frame to guide a non-hydraulic mechanical patent tong repeatedly into the same plot on a restored reef until all oysters within the grab area were captured. Full capture was verified by an underwater remotely-operated vehicle. Samples (n = 19) were taken on nine different reefs, including five low- (n = 8) and four high-relief reefs (n = 11), over a two-year period. The gear efficiency of the patent tong was estimated to be 76% (± 5% standard error), whereas survey efficiency increased to 81% (± 10%) due to processing. Neither efficiency differed significantly between young-of-the-year oysters (spat) and adults, high- and low-relief reefs, or years. As this type of patent tong is a common and cost-effective tool to evaluate oyster restoration projects as well as population density on fished habitat, knowing the gear and survey efficiencies allows for accurate and precise population estimates.

  14. Shell Games. VORTEX: Virginia's Oyster Reef Teaching EXperience.

    Harding, Juliana M.; Mann, Roger; Clark, Vicki P.

    This document introduces Virginia's Oyster Reef Teaching EXperience (VORTEX), which is an interdisciplinary program focusing on the importance of oyster reef communities in the Chesapeake Bay ecosystem. The VORTEX program uses field and laboratory experiences supported by multimedia instruction. This document presents an overview on the biology of…

  15. Temporal variation in development of ecosystem services from oyster reef restoration

    LaPeyre, Megan K.; Humphries, Austin T.; Casas, Sandra M.; La Peyre, Jerome F.

    2014-01-01

    Restoration ecology relies heavily on ecosystem development theories that generally assume development of fully functioning natural systems over time, but often fail to identify the time-frame required for provision of desired functions, or acknowledge different pathways of functional development. In estuaries, a decline of overall habitat quality and functioning has led to significant efforts to restore critical ecosystem services, recently through the creation and restoration of oyster reefs. Oyster reef restoration generally occurs with goals of (1) increasing water quality via filtration through sustainable oyster recruitment, (2) stabilizing shorelines, and (3) creating and enhancing critical estuarine habitat for fish and invertebrates. We restored over 260 m2 of oyster reef habitat in coastal Louisiana and followed the development and provision of these ecosystem services from 2009 through 2012. Oysters recruited to reefs immediately, with densities of oysters greater than 75 mm exceeding 80 ind m−2 after 3 years, and provision of filtration rates of 1002 ± 187 L h−1 m−2; shoreline stabilization effects of the created reefs were minimal over the three years of monitoring, with some evidence of positive shoreline stabilization during higher wind/energy events only; increased nekton abundance of resident, but not larger transient fish was immediately measurable at the reefs, however, this failed to increase through time. Our results provide critical insights into the development trajectories of ecosystem services provided by restored oyster reefs, as well as the mechanisms mediating these changes. This is critical both ecologically to understand how and where a reef thrives, and for policy and management to guide decision-making related to oyster reef restoration and the crediting and accounting of ecosystem services.

  16. Characterization of Dredged Oyster Shell Deposits at Mobile Bay, Alabama Using Geophysical Methods

    Stanley C. Nwokebuihe

    2016-12-01

    Full Text Available The need for disposing materials dredged from ship channels is a common problem in bays and lagoons. This study is aimed at investigating the suitability of scour features produced by dredging oyster shell deposits in Mobile Bay, Alabama, to dispose excavated channel material. A study area approximately 740 by 280 m lying about 5 km east of Gaillard Island was surveyed using underwater electrical resistivity tomography (UWERT and continuous electrical resistivity profiling (CERP tools. The geophysical survey was conducted with the intent to map scour features created by oyster shell dredging activities in the bay between 1947 and 1982. The geoelectrical surveys show that oyster beds are characterized by high resistivity values greater than 1.1 ohm.m while infilled dredge cuts show lower resistivity, generally from 0.6 to 1.1 ohm.m. The difference in resistivity mainly reflects the lithology and the consolidation of the shallow sediments: consolidated silty clay and sandy sediments rich in oyster shell deposits (with less clay content overlying unconsolidated clayey materials infilling the scours. Results show that most of the infilled dredge cuts are mostly distributed in the north-south direction. Considering that the scours are generally up to 6 m deep across the survey location, it is estimated that about 0.8 million cubic meters of oyster shells and overlying strata were dredged from the survey location.

  17. Automatic determination of 3D orientations of fossilized oyster shells from a densely packed Miocene shell bed

    Puttonen, Ana; Harzhauser, Mathias; Puttonen, Eetu; Mandic, Oleg; Székely, Balázs; Molnár, Gábor; Pfeifer, Norbert

    2018-02-01

    Shell beds represent a useful source of information on various physical processes that cause the depositional condition. We present an automated method to calculate the 3D orientations of a large number of elongate and platy objects (fossilized oyster shells) on a sedimentary bedding plane, developed to support the interpretation of possible depositional patterns, imbrications, or impact of local faults. The study focusses on more than 1900 fossil oyster shells exposed in a densely packed Miocene shell bed. 3D data were acquired by terrestrial laser scanning on an area of 459 m2 with a resolution of 1 mm. Bivalve shells were manually defined as 3D-point clouds of a digital surface model and stored in an ArcGIS database. An individual shell coordinate system (ISCS) was virtually embedded into each shell and its orientation was determined relative to the coordinate system of the entire, tectonically tilted shell bed. Orientation is described by the rotation angles roll, pitch, and yaw in a Cartesian coordinate system. This method allows an efficient measurement and analysis of the orientation of thousands of specimens and is a major advantage compared to the traditional 2D approach, which measures only the azimuth (yaw) angles. The resulting data can variously be utilized for taphonomic analyses and the reconstruction of prevailing hydrodynamic regimes and depositional environments. For the first time, the influence of possible post-sedimentary vertical displacements can be quantified with high accuracy. Here, the effect of nearby fault lines—present in the reef—was tested on strongly tilted oyster shells, but it was found out that the fault lines did not have a statistically significant effect on the large tilt angles. Aside from the high reproducibility, a further advantage of the method is its non-destructive nature, which is especially suitable for geoparks and protected sites such as the studied shell bed.

  18. RELATIONSHIP OF AMEBOCYTES AND TERRESTRIAL ELEMENTS TO ADULT SHELL DEPOSITION IN EASTERN OYSTERS

    Fisher, William S. Submitted. Relationship of Amebocytes and Terrestrial Elements to Adult Shell Deposition in Eastern Oysters. J. Shellfish Res. 30 p. (ERL,GB 1197). Freshwater runoff contains terrestrial elements from geological deposits that may be vital to eastern oys...

  19. Production of biodiesel from Chlorella sp. enriched with oyster shell extracts.

    Choi, Cheol Soon; Choi, Woon Yong; Kang, Do Hyung; Lee, Hyeon Yong

    2014-01-01

    This study investigated the cultivation of the marine microalga Chlorella sp. without supplying an inorganic carbon source, but instead with enriching the media with extracts of oyster shells pretreated by a high-pressure homogenization process. The pretreated oyster shells were extracted by a weak acid, acetic acid, that typically has harmful effects on cell growth and also poses environmental issues. The concentration of the residual dissolved carbon dioxide in the medium was sufficient to maintain cell growth at 32 ppm and pH 6.5 by only adding 5% (v/v) of oyster shell extracts. Under this condition, the maximum cell density observed was 2.74 g dry wt./L after 27 days of cultivation. The total lipid content was also measured as 18.1 (%, w/w), and this value was lower than the 23.6 (%, w/w) observed under nitrogen deficient conditions or autotrophic conditions. The fatty acid compositions of the lipids were also measured as 10.9% of C16:1 and 16.4% of C18:1 for the major fatty acids, which indicates that the biodiesel from this culture process should be a suitable biofuel. These results suggest that oyster shells, environmental waste from the food industry, can be used as a nutrient and carbon source with seawater, and this reused material should be important for easily scaling up the process for an outdoor culture system.

  20. Integrating Larval Dispersal, Permitting, and Logistical Factors Within a Validated Habitat Suitability Index for Oyster Restoration

    Brandon J. Puckett

    2018-04-01

    Full Text Available Habitat suitability index (HSI models are increasingly used to guide ecological restoration. Successful restoration is a byproduct of several factors, including physical and biological processes, as well as permitting and logistical considerations. Rarely are factors from all of these categories included in HSI models, despite their combined relevance to common restoration goals such as population persistence. We developed a Geographic Information System (GIS-based HSI for restoring persistent high-relief subtidal oyster (Crassostrea virginica reefs protected from harvest (i.e., sanctuaries in Pamlico Sound, North Carolina, USA. Expert stakeholder input identified 17 factors to include in the HSI. Factors primarily represented physical (e.g., salinity and biological (e.g., larval dispersal processes relevant to oyster restoration, but also included several relevant permitting (e.g., presence of seagrasses and logistical (e.g., distance to restoration material stockpile sites considerations. We validated the model with multiple years of oyster density data from existing sanctuaries, and compared HSI output with distributions of oyster reefs from the late 1800's. Of the 17 factors included in the model, stakeholders identified four factors—salinity, larval export from existing oyster sanctuaries, larval import to existing sanctuaries, and dissolved oxygen—most critical to oyster sanctuary site selection. The HSI model provided a quantitative scale over which a vast water body (~6,000 km2 was narrowed down by 95% to a much smaller suite of optimal (top 1% HSI and suitable (top 5% HSI locations for oyster restoration. Optimal and suitable restoration locations were clustered in northeast and southwest Pamlico Sound. Oyster density in existing sanctuaries, normalized for time since reef restoration, was a positive exponential function of HSI, providing validation for the model. Only a small portion (10–20% of historical reef locations

  1. Extreme ocean acidification reduces the susceptibility of eastern oyster shells to a polydorid parasite.

    Clements, J C; Bourque, D; McLaughlin, J; Stephenson, M; Comeau, L A

    2017-11-01

    Ocean acidification poses a threat to marine organisms. While the physiological and behavioural effects of ocean acidification have received much attention, the effects of acidification on the susceptibility of farmed shellfish to parasitic infections are poorly understood. Here we describe the effects of moderate (pH 7.5) and extreme (pH 7.0) ocean acidification on the susceptibility of Crassostrea virginica shells to infection by a parasitic polydorid, Polydora websteri. Under laboratory conditions, shells were exposed to three pH treatments (7.0, 7.5 and 8.0) for 3- and 5-week periods. Treated shells were subsequently transferred to an oyster aquaculture site (which had recently reported an outbreak of P. websteri) for 50 days to test for effects of pH and exposure time on P. websteri recruitment to oyster shells. Results indicated that pH and exposure time did not affect the length, width or weight of the shells. Interestingly, P. websteri counts were significantly lower under extreme (pH 7.0; ~50% reduction), but not moderate (pH 7.5; ~20% reduction) acidification levels; exposure time had no effect. This study suggests that extreme levels - but not current and projected near-future levels - of acidification (∆pH ~1 unit) can reduce the susceptibility of eastern oyster shells to P. websteri infections. © 2017 John Wiley & Sons Ltd.

  2. Oxygen Isotope Records in Modern Oyster Shells from Chi Ku, Tainan and Their Implication of Seasonality

    Chen, Y. C.; Mii, H. S.; Li, K. T.

    2015-12-01

    To exam whether oxygen isotope records of Crassostrea gigasoysters can be used as proxies of environment, 133 cultivated oysters and 21 water samples were collected from Chi Ku area, Tainan City, southern Taiwan in December of 2012, and from March, 2013 to July, 2014. Instrumental air and water temperatures and precipitation records were obtained from a nearest Central Weather Bureau (CWB) station roughly 16 km north of Chi Ku. The oxygen and carbon isotope values of the ligamental area of the modern oyster shells are from -6.92‰ to -0.08‰ (-3.05 ± 1.17‰, N = 2280; 1σ; VPDB) and from -5.57‰ to 0.63‰ (-1.88 ± 0.81‰), respectively. Oxygen isotope values of the water samples are mainly between -0.28‰ and 0.74‰ (0.18 ± 0.29‰, N = 20; 1σ; VSMOW). However, water oxygen isotope value of -2.75‰ was observed for the water sample collected immediately after a typhoon heavy rainfall. Seasonal temperature fluctuation pattern of estimated oxygen isotope temperatures from modern shells is similar to that of CWB instrumental records. However, the oxygen isotope temperatures are respectively about 3 °C and 10°C higher than those of instrumental records for winter and summer. Higher estimated oxygen isotope temperatures are most likely caused by underestimated fraction of freshwater. We analyzed 5 archaeological oyster shells of Siraya culture (500~250B.P.) collected from Wu Chien Tuso North (WCTN) archaeological site of Tainan branch of Southern Taiwan Science Park to infer the harvest season of mollusks. Oxygen isotope values of the ligamental area of the archaeological oyster shells are between -5.98‰ and -1.26‰ (-3.34 ± 1.37‰, N = 60; 1σ), and carbon isotope values are between -3.21‰ and 0.60‰ (-2.04‰ ± 0.55‰). The oxygen isotope records of archaeological oyster shells also showed clear seasonality. Most of the oysters were collected in autumn and winter. Oxygen isotope values of archaeological oyster shells was 1‰ greater than that

  3. Oyster reef restoration supports increased nekton biomass and potential commercial fishery value

    Austin T. Humphries

    2015-08-01

    Full Text Available Across the globe, discussions centered on the value of nature drive many conservation and restoration decisions. As a result, justification for management activities increasingly asks for two lines of evidence: (1 biological proof of augmented ecosystem function or service, and (2 monetary valuation of these services. For oyster reefs, which have seen significant global declines and increasing restoration work, the need to provide both biological and monetary evidence of reef services on a local-level has become more critical in a time of declining resources. Here, we quantified species biomass and potential commercial value of nekton collected from restored oyster (Crassostrea virginica reefs in coastal Louisiana over a 3-year period, providing multiple snapshots of biomass support over time. Overall, and with little change over time, fish and invertebrate biomass is 212% greater at restored oyster reefs than mud-bottom, or 0.12 kg m−2. The additional biomass of commercial species is equivalent to an increase of local fisheries value by 226%, or $0.09 m−2. Understanding the ecosystem value of restoration projects, and how they interact with regional management priorities, is critical to inform local decision-making and provide testable predictions. Quantitative estimates of potential commercial fisheries enhancement by oyster reef restoration such as this one can be used directly by local managers to determine the expected return on investment.

  4. Genomics on the Half Shell: So, What do Oysters Have to do with Energy? (2010 JGI User Meeting)

    Hedgecock, Dennis

    2010-03-24

    Dennis Hedgecock from the University of Southern California answers the question, "Genomics on the Half Shell: So, What Do Oysters Have to Do with Energy?" on March 24, 2010 at the 5th Annual DOE JGI User Meeting.

  5. Biomarkers of dissolved oxygen stress in oysters: a tool for restoration and management efforts.

    Patterson, Heather K; Boettcher, Anne; Carmichael, Ruth H

    2014-01-01

    The frequency and intensity of anoxic and hypoxic events are increasing worldwide, creating stress on the organisms that inhabit affected waters. To understand the effects of low dissolved oxygen stress on oysters, hatchery-reared oysters were placed in cages and deployed along with continuously recording environmental data sondes at a reef site in Mobile Bay, AL that typically experiences low oxygen conditions. To detect and measure sublethal stress, we measured growth and survival of oysters as well as expression of three biomarkers, heat shock protein 70 (HSP70), hypoxia inducible factor (HIF) and phospho-p38 MAP kinase, in tissues from juvenile and adult oysters. Survival rates were high for both juvenile and adult oysters. Expression levels of each of the 3 isoforms of HSP 70 were negatively correlated to dissolved oxygen (DO) concentrations, suggesting that HSP 70 is useful to quantify sublethal effects of DO stress. Results for HIF and phospho-p38 MAP kinase were inconclusive. Test deployments of oysters to assess expression of HSP 70 relative to environmental conditions will be useful, in addition to measuring abiotic factors, to identify appropriate sites for restoration, particularly to capture negative effects of habitat quality on biota before lethal impacts are incurred.

  6. A developmental and energetic basis linking larval oyster shell formation to acidification sensitivity

    Waldbusser, George G.; Brunner, Elizabeth L.; Haley, Brian A.; Hales, Burke; Langdon, Christopher J.; Prahl, Frederick G.

    2013-05-01

    Acidified waters are impacting commercial oyster production in the U.S. Pacific Northwest, and favorable carbonate chemistry conditions are predicted to become less frequent. Within 48 h of fertilization, unshelled Pacific oyster (Crassostrea gigas) larvae precipitate roughly 90% of their body weight as calcium carbonate. We measured stable carbon isotopes in larval shell and tissue and in algal food and seawater dissolved inorganic carbon in a longitudinal study of larval development and growth. Using these data and measured biochemical composition of larvae, we show that sensitivity of initial shell formation to ocean acidification results from diminished ability to isolate calcifying fluid from surrounding seawater, a limited energy budget and a strong kinetic demand for calcium carbonate precipitation. Our results highlight an important link between organism physiology and mineral kinetics in larval bivalves and suggest the consideration of mineral kinetics may improve understanding winners and losers in a high CO2 world.

  7. Impacts of biochar and oyster shells waste on the immobilization of arsenic in highly contaminated soils.

    Chen, Yongshan; Xu, Jinghua; Lv, Zhengyong; Xie, Ruijia; Huang, Liumei; Jiang, Jinping

    2018-07-01

    Soil contamination is a serious problem with deleterious impacts on global sustainability. Readily available, economic, and highly effective technologies are therefore urgently needed for the rehabilitation of contaminated sites. In this study, two readily available materials prepared from bio-wastes, namely biochar and oyster shell waste, were evaluated as soil amendments to immobilize arsenic in a highly As-contaminated soil (up to 15,000 mgAs/kg). Both biochar and oyster shell waste can effectively reduce arsenic leachability in acid soils. After application of the amendments (2-4% addition, w/w), the exchangeable arsenic fraction decreased from 105.8 to 54.0 mg/kg. The application of 2%biochar +2% oyster shell waste most effectively reduced As levels in the column leaching test by reducing the arsenic concentration in the porewater by 62.3% compared with the treatment without amendments. Biochar and oyster shell waste also reduced soluble As(III) from 374.9 ± 18.8 μg/L to 185.9 ± 16.8 μg/L and As(V) from 119.8 ± 13.0 μg/L to 56.4 ± 2.6 μg/L at a pH value of 4-5. The treatment using 4% (w/w) amendments did not result in sufficient As immobilization in highly contaminated soils; high soluble arsenic concentrations (upto193.0 μg/L)were found in the soil leachate, particularly in the form of As(III), indicating a significant potential to pollute shallow groundwater aquifers. This study provides valuable insights into the use of cost-effective and readily available materials for soil remediation and investigates the mechanisms underlying arsenic immobilization in acidic soils. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Differential response of oyster shell powder on enzyme profile and nutritional value of oyster mushroom Pleurotus florida PF05.

    Naraian, Ram; Narayan, Om Prakash; Srivastava, Jatin

    2014-01-01

    Oyster mushroom Pleurotus florida was cultivated on different combinations of wheat straw (WS) as basal substrate and oyster shell powder (OSP) supplement. The OSP supplementation considerably responded to different cultivation phases. The mycelium grew fast and showed rapid growth rate (8.91 mmd(-1)) in WS + OSP (97 + 3) combination while WS + OSP (92 + 8) showed maximum laccase (3.133 U/g) and Mn peroxidase (MnP) activities (0.091 U/g). The climax level of laccase (5.433 U/g) and MnP (0.097 U/g) was recorded during fruit body initiation in WS + OSP (97 + 3) and WS + OSP (98 + 2) combinations, respectively. The WS + OSP (97 + 3) combination represented the best condition for mushroom cultivation and produced the highest biological efficiency (147%). In addition, protein and lipid contents in fruit bodies were slightly improved in response to OSP. The carbohydrate was significantly increased by raising concentration of OSP. The highest values of protein, carbohydrate, and lipid noted were 31.3 μg/g, 0.0639 (g/g), and 0.373 (g/g) correspondingly. Conclusively it was evident that lower concentrations of OSP acted positively and relatively to higher concentrations and improved nutritional content which may suitably be used to enhance both yield and nutritional values of mushroom.

  9. Effects of an artificial oyster shell reef on macrobenthic communities in Rongcheng Bay, East China

    Xu, Qinzeng; Zhang, Libin; Zhang, Tao; Zhou, Yi; Xia, Sudong; Liu, Hui; Yang, Hongsheng

    2014-01-01

    An artificial oyster shell reef was deployed in Rongcheng Bay, East China. However, the effects of this reef on the surrounding macrobenthic communities were unknown. We compared sedimentary factors, macrobenthic biomass, abundance, and community composition and ecological indicators between the reef and non-reef areas over a one year period. The mean values for chlorophyll a (Chl a), total organic matter (TOM), total organic carbon (TOC), and total nitrogen (TN) content in surface sediments in the reef area were slightly higher than those in the non-reef area. The Chl a levels differed significantly between the two areas, but the TOM, TOC, and TN were not significantly different. The abundance of crustaceans was significantly different between the two areas, but the abundance and biomass of polychaetes, echinoderms, mollusk did not differ significantly. The permutational multivariate analysis of variance (PERMANOVA) revealed that the macrobenthic community differed significantly through time and analysis of similarity multivariate analyses (ANOSIM) revealed that the macrobenthic community differed significantly in some months. The ecological indicators revealed that the environmental quality of the reef area was slightly better than that of the non-reef area. Overall, our results suggest that the artificial oyster shell reef may change the macrobenthic community and the quality of the environment. Despite the lack of an effect in the short term, long-term monitoring is still needed to evaluate the effects of artificial oyster shell reefs on macrobenthic communities.

  10. Potential of Waste Oyster Shells as a Novel Biofiller for Hot-Mix Asphalt

    Nader Nciri

    2018-03-01

    Full Text Available This paper reports the use of waste oyster shells as a novel biofiller for hot-mix asphalt (HMA pavement applications. The effects of different fractions (e.g., 0, 5, 10, 15 wt % of oyster shell powder (OSP on the bitumen performance were investigated. The chemical properties of unfilled and OSP-filled asphalts were characterized by means of thin layer chromatography-ionization detection (TLC-FID, Fourier transform-infrared spectroscopy (FT-IR, X-ray diffraction (XRD, and scanning electron microscopy (SEM. Thermal characteristics were examined by thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. Physical and rheological properties were assessed through penetration, softening point, ductility, and dynamic shear rheometer (DSR tests. Results showed that OSP addition increased the resins content, as well as the stiffness of blends. No obvious reactions have occurred between the filler and the asphalt. A higher dose of OSP altered the morphology of the binder, whereas lower and intermediate doses improved its thermal stability and enhanced its low-temperature, rutting, and fatigue performances with respect to the plain asphalt. Overall, the waste oyster shells could be used as filler substitute, not only to improve the quality of road pavements but also to reduce the cost of their construction and solve the waste disposal problems.

  11. Stabilization of As-, Pb-, and Cu-contaminated soil using calcined oyster shells and steel slag.

    Moon, Deok Hyun; Wazne, Mahmoud; Cheong, Kyung Hoon; Chang, Yoon-Young; Baek, Kitae; Ok, Yong Sik; Park, Jeong-Hun

    2015-07-01

    In this study, As-, Pb-, and Cu-contaminated soil was stabilized using calcined oyster shells (COS) and steel slag (SS). The As-contaminated soil was obtained from a timber mill site where chromate copper arsenate (CCA) was used as a preservative. On the other hand, Pb- and Cu-contaminated soil was obtained from a firing range. These two soils were thoroughly mixed to represent As-, Pb-, and Cu-contaminated soil. Calcined oyster shells were obtained by treating waste oyster shells at a high temperature using the calcination process. The effectiveness of stabilization was evaluated by 1-N HCl extraction for As and 0.1-N HCl extraction for Pb and Cu. The treatment results showed that As, Pb, and Cu leachability were significantly reduced upon the combination treatment of COS and SS. The sole treatment of SS (10 wt%) did not show effective stabilization. However, the combination treatment of COS and SS showed a significant reduction in As, Pb, and Cu leachability. The best stabilization results were obtained from the combination treatment of 15 wt% COS and 10 wt% SS. The SEM-EDX results suggested that the effective stabilization of As was most probably achieved by the formation of Ca-As and Fe-As precipitates. In the case of Pb and Cu, stabilization was most probably associated with the formation of pozzolanic reaction products such as CSHs and CAHs.

  12. Characterizations of Shell and Mantle Edge Pigmentation of a Pacific Oyster, , in Korean Peninsula

    Jung-Ha Kang

    2013-12-01

    Full Text Available The objectives of this study were to investigate color patterns of shell and mantle edge pigmentation of a Pacific oyster, C. gigas, and to estimate variance components of the two colors. A sample of 240 F0 oysters was collected from six aquaculture farms in Tongyeong, Korea to measure shell color and mantle edge pigmentation. Among the F0s, male and female individuals with black (white shell and black (white mantle edge were selected and mated to generate three F1 full-sib black (white cross families (N = 265. Two and four F2 cross families (N = 286 were also produced from black and white F1 selected individuals, respectively. Variance component estimates due to residuals and families within color were obtained using SAS PROC VARCOMP procedures to estimate heritability of shell and mantle edge pigmentation. In the F0 generation, about 29% (11% had black (white color for both shell and mantle edge. However, in the F1 and F2 black (white cross families, 75% (67% and 100% (100% of oysters had black (white shell colors, and 59% (23% and 79% (55% had black (white mantle edge, respectively. Spearman correlation coefficients between shell and mantle edge color were 0.25, 0.74, and 0.92 in F0, F1, and F2 generations, respectively, indicating that, with generations of selection process, an individual with black (white shell color is more likely to have black (white mantle edge pigmentation. This suggests that shell color could be a good indicator trait for mantle edge pigmentation if selection of both the colors is implemented for a couple of generations. Estimates of heritability were 0.41 and 0.77 for shell color and 0.27 and 0.08 for mantle edge pigmentation in the F1 and F2 generations, respectively, indicating that, in general, significant proportions of phenotypic variations for the shell and mantle edge colors are explained by genetic variations between individuals. These results suggest that the two color traits are inheritable and correlated

  13. The Acoustical Properties of the Polyurethane Concrete Made of Oyster Shell Waste Comparing Other Concretes as Architectural Design Components

    Setyowati, Erni; Hardiman, Gagoek; Purwanto

    2018-02-01

    This research aims to determine the acoustical properties of concrete material made of polyurethane and oyster shell waste as both fine aggregate and coarse aggregate comparing to other concrete mortar. Architecture needs aesthetics materials, so the innovation in architectural material should be driven through the efforts of research on materials for building designs. The DOE methods was used by mixing cement, oyster shell, sands, and polyurethane by composition of 160 ml:40 ml:100 ml: 120 ml respectively. Refer to the results of previous research, then cement consumption is reduced up to 20% to keep the concept of green material. This study compared three different compositions of mortars, namely portland cement concrete with gravel (PCG), polyurethane concrete of oyster shell (PCO) and concrete with plastics aggregate (PCP). The methods of acoustical tests were conducted refer to the ASTM E413-04 standard. The research results showed that polyurethane concrete with oyster shell waste aggregate has absorption coefficient 0.52 and STL 63 dB and has a more beautiful appearance when it was pressed into moulding. It can be concluded that polyurethane concrete with oyster shell aggregate (PCO) is well implemented in architectural acoustics-components.

  14. Evaluation of buffering potency of oyster ( Crassostrea gasar ) shells ...

    ) shells on acidic borehole water for fish farming. Eighteen (18), 100-litre shaded plastic tanks (3/4- filled, pH 4.0) of three replicates per treatment of 270 g buffer agent were used. There were four trials of six treatments (T) namely control (C) ...

  15. Gene expression correlated with delay in shell formation in larval Pacific oysters (Crassostrea gigas) exposed to experimental ocean acidification provides insights into shell formation mechanisms.

    De Wit, Pierre; Durland, Evan; Ventura, Alexander; Langdon, Chris J

    2018-02-22

    Despite recent work to characterize gene expression changes associated with larval development in oysters, the mechanism by which the larval shell is first formed is still largely unknown. In Crassostrea gigas, this shell forms within the first 24 h post fertilization, and it has been demonstrated that changes in water chemistry can cause delays in shell formation, shell deformations and higher mortality rates. In this study, we use the delay in shell formation associated with exposure to CO 2 -acidified seawater to identify genes correlated with initial shell deposition. By fitting linear models to gene expression data in ambient and low aragonite saturation treatments, we are able to isolate 37 annotated genes correlated with initial larval shell formation, which can be categorized into 1) ion transporters, 2) shell matrix proteins and 3) protease inhibitors. Clustering of the gene expression data into co-expression networks further supports the result of the linear models, and also implies an important role of dynein motor proteins as transporters of cellular components during the initial shell formation process. Using an RNA-Seq approach with high temporal resolution allows us to identify a conceptual model for how oyster larval calcification is initiated. This work provides a foundation for further studies on how genetic variation in these identified genes could affect fitness of oyster populations subjected to future environmental changes, such as ocean acidification.

  16. A Preliminary Investigation of Wastewater Treatment Efficiency and Economic Cost of Subsurface Flow Oyster-Shell-Bedded Constructed Wetland Systems

    Chia-Chuan Hsu

    2013-06-01

    Full Text Available We conducted a preliminary investigation of wastewater treatment efficiency and economic cost of the oyster-shell-bedded constructed wetlands (CWs compared to the conventional gravel-bedded CW based on field monitoring data of water quality and numerical modeling. Four study subsurface (SSF CWs were built to receive wastewater from Taipei, Taiwan. Among these sites, two are vertical wetlands, filled with bagged- (VA and scattered- (VB oyster shells, and the other two horizontal wetlands were filled with scattered-oyster shells (HA and gravels (HB. The BOD, NO3−, DO and SS treatment efficiency of VA and VB were higher than HA and HB. However, VA was determined as the best option of CW design due to its highest cost-effectiveness in term of BOD removal (only 6.56 US$/kg as compared to VB, HA and HB (10.88–25.01 US$/kg. The results confirmed that oyster shells were an effective adsorption medium in CWs. Hydraulic design and arrangement of oyster shells could be important in determining their treatment efficiency and cost-effectiveness. A dynamic model was developed to simulate substance transmissions in different treatment processes in the CWS using AQUASIM 2.1 based on the water quality data. Feasible ranges of biomedical parameters involved were determined for characterizing the importance of different biochemical treatment processes in SSF CWs. Future work will involve extending the experimental period to confirm the treatment efficiency of the oyster-shell-bedded CW systems in long-term operation and provide more field data for the simulated model instead of the literature values.

  17. Stabilization of lead and copper contaminated firing range soil using calcined oyster shells and fly ash.

    Moon, Deok Hyun; Park, Jae-Woo; Cheong, Kyung Hoon; Hyun, Seunghun; Koutsospyros, Agamemnon; Park, Jeong-Hun; Ok, Yong Sik

    2013-12-01

    A stabilization/solidification treatment scheme was devised to stabilize Pb and Cu contaminated soil from a firing range using renewable waste resources as additives, namely waste oyster shells (WOS) and fly ash (FA). The WOS, serving as the primary stabilizing agent, was pre-treated at a high temperature to activate quicklime from calcite. Class C FA was used as a secondary additive along with the calcined oyster shells (COS). The effectiveness of the treatment was evaluated by means of the toxicity characteristic leaching procedure (TCLP) and the 0.1 M HCl extraction tests following a curing period of 28 days. The combined treatment with 10 wt% COS and 5 wt% FA cause a significant reduction in Pb (>98 %) and Cu (>96 %) leachability which was indicated by the results from both extraction tests (TCLP and 0.1 M HCl). Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) analyses are used to investigate the mechanism responsible for Pb and Cu stabilization. SEM-EDX results indicate that effective Pb and Cu immobilization using the combined COS-FA treatment is most probably associated with ettringite and pozzolanic reaction products. The treatment results suggest that the combined COS-FA treatment is a cost effective method for the stabilization of firing range soil.

  18. Stabilization of Pb and Cd contaminated soils and soil quality improvements using waste oyster shells.

    Ok, Yong Sik; Lim, Jung Eun; Moon, Deok Hyun

    2011-02-01

    Large amounts of oyster shells are produced as a by-product of shellfish farming in coastal regions without beneficial use options. Accordingly, this study was conducted to evaluate the potential for the use of waste oyster shells (WOS) containing a high amount of CaCO₃ to improve soil quality and to stabilize heavy metals in soil. To accomplish this, an incubation experiment was conducted to evaluate the ability of the addition of 1-5 wt% WOS to stabilize the Pb (total 1,246 mg/kg) and Cd (total 17 mg/kg) in a contaminated soil. The effectiveness of the WOS treatments was evaluated using various single extraction techniques. Soil amended with WOS was cured for 30 days complied with the Korean Standard Test method (0.1 M·HCl extraction). The Pb and Cd concentrations were less than the Korean warning and countermeasure standards following treatment with 5 wt% WOS. Moreover, the concentrations of Cd were greatly reduced in response to WOS treatment following extraction using 0.01 M·CaCl₂, which is strongly associated with phytoavailability. Furthermore, the soil pH and exchangeable Ca increased significantly in response to WOS treatment. Taken together, the results of this study indicated that WOS amendments improved soil quality and stabilized Pb and Cd in contaminated soil. However, extraction with 0.43 M·CH₃ COOH revealed that remobilization of heavy metals can occur when the soil reaches an acidic condition.

  19. D1 dopamine receptor is involved in shell formation in larvae of Pacific oyster Crassostrea gigas.

    Liu, Zhaoqun; Wang, Lingling; Yan, Yunchen; Zheng, Yan; Ge, Wenjing; Li, Meijia; Wang, Weilin; Song, Xiaorui; Song, Linsheng

    2018-07-01

    Dopamine (DA), a significant member of catecholamines, is reported to induce biomineralization of calcium carbonate vaterite microspheres via dopamine receptor (DR) in bivalves, implying the modulation of dopaminergic system on shell formation during larval development. In this research, a homologue of D1 type DR (CgD1DR-1) was identified from oyster Crassostrea gigas, whose full length cDNA was 1197 bp. It was widely expressed in various tissues of C. gigas, with the significantly higher levels in hepatopancreas, mantle, muscle and gill. During developmental stages, the mRNA transcripts of CgD1DR-1 in D-shape larvae were obviously higher (p < 0.05) than those in trochophore and umbo larvae, and CO 2 exposure could inhibit the synthesis of DA and mRNA expression of CgD1DR-1. After cell transfection and DA treatment, intracellular cAMP in cells with the expression of CgD1DR-1 increased significantly (p < 0.05). Furthermore, the incubation with SCH 23390 for the blockage of CgD1DR-1 significantly restrained the expressions of six shell formation-related genes including CgTyrosinase-1, CgTyrosinase-3, CgChitinaseLP, CgAMC, CgBMP and CgBMPR in trochophore and D-shape larvae. These results jointly suggested that DA together with its receptor CgD1DR-1 might be involved in shell formation during oyster larval development from trochophore to D-shape larvae, and CO 2 -induced ocean acidification (OA) might influence marine bivalves by inhibiting the DA-D1DR pathway to prohibit their shell formation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Effect of Oyster Shell Calcium Powder on the Quality of Restructured Pork Ham

    Choi, Jung-Seok; Lee, Hyun-Jin; Jin, Sang-Keun; Lee, Hyun-Joo; Choi, Yang-Il

    2014-01-01

    This study was conducted to evaluate the effects of oyster shell calcium powder (OSCP) as a substitute for phosphates in curing agent, on the quality of restructured pork ham. Restructured pork ham was processed under six treatment conditions: T1 (no additives), T2 (0.3% sodium tripolyphosphate), T3 (1.5% NaCl+0.5% whey protein), T4 (1.5% NaCl+0.5% whey protein+0.15% OSCP), T5 (1.5% NaCl+0.5% whey protein+0.3% OSCP), and T6 (1.5% NaCl+0.5% whey protein+0.5% OSCP). Addition of OSCP significant...

  1. Structure and expression of an unusually acidic matrix protein of pearl oyster shells

    Tsukamoto, Daiki; Sarashina, Isao; Endo, Kazuyoshi

    2004-01-01

    We report identification and characterization of the unusually acidic molluscan shell matrix protein Aspein, which may have important roles in calcium carbonate biomineralization. The Aspein gene (aspein) encodes a sequence of 413 amino acids, including a high proportion of Asp (60.4%), Gly (16.0%), and Ser (13.2%), and the predicted isoelectric point is 1.45; this is the most acidic of all the molluscan shell matrix proteins sequenced so far, or probably even of all known proteins on earth. The main body of Aspein is occupied by (Asp) 2-10 sequences punctuated with Ser-Gly dipeptides. RT-PCR demonstrated that the transcript of aspein is expressed at the outer edge of the mantle, corresponding to the calcitic prismatic layer, but not at the inner part of the mantle, corresponding to the aragonitic nacreous layer. Our findings and previous in vitro experiments taken together suggest that Aspein is responsible for directed formation of calcite in the shell of the pearl oyster Pinctada fucata

  2. Limestone and oyster shell for brown layers in their second egg production cycle

    CC Pizzolante

    2011-06-01

    Full Text Available This study aimed at evaluating the effect of dietary calcium levels and the replacement of calcium sources with different particle size compositions on the performance and egg quality of brown layers in their second egg production cycle. A randomized block experimental design was applied with 12 treatments in a 3x4 factorial arrangement: three calcium levels (2.6, 3.2, 3.8 % and four combinations of calcium sources (1- 100% fine limestone (FL, 2- 50% FL + 50% coarse limestone (CL, 3- 50% FL and 50% oyster shell (OS, 4- 50% FL and 25% CL+ 25 %OS, with six replicates of eight birds each. Calcium sources were analyzed for geometric mean diameter (GMD and in-vitro solubility. The following performance and egg quality parameters were evaluated: egg weight (EW, g, egg production (% Eggs, egg mass (EM %, feed intake (FI g, feed conversion ratio (FCR kg/dz and FCR kg/kg, mortality (% Mort., specific egg gravity (SG, percentages of yolk (Y%, albumen (Alb% and eggshell (ES%, eggshell thickness (EST, eggshell breaking strength (BS, eggshell weight per surface area (EWSA, Haugh unit (HU, yolk index (YI and yolk color. Performance and internal egg quality were not affected by the treatments (p>0.05. Blocks had a significant effect on (p<0.05 FI and FCR (kg/dz and kg/kg. Treatments significantly influenced external egg quality, which improved as dietary calcium levels increases and when up to 50% fine limestone was replaced by combinations of coarse limestone with oyster shell.

  3. Probing for heavy element impurities in the shell of the Pacific oyster, Crassostrea gigas, with nuclear microscopy

    Markwitz, A.; Barry, B.; Gauldie, R.W.; Roberts, R.D.

    2003-01-01

    Nuclear microscopy was performed on shells of the Pacific oyster, Crassostrea gigas, to probe for heavy element impurities. For the studies 14 shells from the Auckland and the Marlborough Sounds region were chosen. In sections, the shells appear as opaque with white and grey zones, which are related to alternating layers of calcite and aragonite. Raster scans with 2.5 MeV protons over the sections (scan area 5 x 5 mm) were used in the experiment to measure trace elements in the ppm region using proton induced X-ray spectroscopy. Two dimensional maps and line scans revealed the presence of bromine in all shells investigated. Bromine was found to be related with the pattern of calcium. Hot spots of iron proved to be a common feature in the shells as well. In some shells, copper and zinc were also measured in hot spots of a few micrometers in diameter. Spatially resolved results on the micrometer level indicate the usefulness of nuclear microscopy for the detection of heavy elements in shells of the Pacific oyster

  4. The Mendelian inheritance of rare flesh and shell colour variants in the black-lipped pearl oyster (Pinctada margaritifera).

    Ky, Chin-Long; Nakasai, Seiji; Pommier, Steve; Sham Koua, Manaarii; Devaux, Dominique

    2016-10-01

    Pinctada margaritifera is French Polynesia's most economically important aquaculture species. This pearl oyster has the specific ability to produce cultured pearls with a very wide range of colours, depending on the colour phenotypes of donor oysters used. Its aquaculture is still based on natural spat collection from wild stocks. We investigated three rare colour variants of P. margaritifera - orange flesh, and red and white shell colour phenotypes - in comparison with the wild-type black flesh and shell commonly found in this species. The study aimed to assess the geographic distribution and genetic basis of these colour variants. Colour frequencies were evaluated during transfer and graft processes of pearl oyster seed captured at collector stations. Among the collection locations studied, Mangareva Island showed the highest rate of the orange flesh phenotype, whereas Takaroa and Takume atolls had relatively high rates of red and white shell phenotypes respectively. Broodstocks were made of these rare colour variants, and crosses were performed to produce first- and second-generation progenies to investigate segregation. The results were consistent with Mendelian ratios and suggest a distinct model with no co-dominance: (i) a two-allele model for flesh trait, whereby the orange allele is recessive to the black fleshed type, and (ii) a three-allele model for shell trait, whereby the black wild-type allele is dominant to the red coloration, which is dominant to the white shell. Furthermore, the proposed model provides the basis for producing selected donor pearl oyster lines through hatchery propagation. © 2016 Stichting International Foundation for Animal Genetics.

  5. Rapid age determination of oysters using LA-ICP-MS line scans of shell Mg/Ca ratios

    Gillikin, D. P.; Durham, S. R.; Goodwin, D. H.

    2016-02-01

    Magnesium to calcium (Mg/Ca) ratios exhibit a strong temperature dependence in foraminifera and corals, but not in bivalve mollusks. Various studies have reported Mg/Ca-temperature relationships with R2 values ranging from 0.3 to 0.8 and significantly different relationships for bivalves growing at different salinities. However, this poor temperature correlation does not render Mg/Ca data useless. A weak temperature dependence would allow time (seasons and years) to be determined along the growth axis of shells. This would provide information about age, growth rate and also allow other proxies to be aligned with time. Typically, oxygen isotopes (δ18O) are used to age shells without clear periodic growth lines, which is time consuming and expensive. Line scans using laser ablation systems can cover several centimeters of shell in a few minutes. We test this method on the resilifer of two oyster species (Crassostrea gigas and C. virginica) using a 193 nm Laser-Ablation-ICP-MS. Living oysters were collected from San Francisco Bay, North Carolina, South Carolina, and the Gulf of Mexico; fossil shells (Pleistocene) were also collected in South Carolina. Shells were sampled for δ18O values and Mg/Ca ratios. We use annual cycles in δ18O values to confidently determine age, then apply the Mg/Ca technique. Shells of both species exhibit annual cyclicity in Mg/Ca ratios using spot and line scan laser sampling, which matche the seasonal cyclicity determined using δ18O values. Results show a good correlation between ages determined using the different methods. We conclude that LA-ICP-MS line scans offer a rapid and inexpensive technique for determining age, growth rate, and timing of shell growth in oyster reslifers.

  6. Studies on the Use of Oyster, Snail and Periwinkle Shells as Adsorbents for the Removalof Pb2+ Aqueous Solution

    Stevens A. Odoemelam

    2009-01-01

    Full Text Available In view of increasing rate of lead pollution resulting from discharge of lead containing effluents by industries into the environment, this study was carried out to investigate the removal of Pb2+ from aqueous solutions by oyster, snail and periwinkle shells. The effects of contact time and concentration on adsorption, thermodynamics of sorption and distribution coefficients of the adsorbents were examined to optimize the conditions to be utilized for decontamination of effluents containing Pb2+. The study revealed that these materials are good adsorbents that can be used for the removal of Pb2+ from aqueous solution. Adsorption of Pb2+ by oyster, snail and periwinkle shells were found to conform to the classical models of Langmuir, Freundlich and Temkin adsorption isotherms. Thermodynamic consideration revealed that adsorption of Pb2+ by these materials was spontaneous and proceeded via chemical adsorption. The use of these materials for the removal of lead ion from aqueous solution is therefore advocated

  7. Nuclear microprobe and Raman investigation of the chemistry of the shell of the pacific oyster, Crassostrea gigas

    Markwitz, A.; Gauldie, R.W.; Pithie, J.; Sharma, S.K.; Jamieson, D.J.

    1999-01-01

    High-resolution nuclear microscopy was used to study the layered structure in the shell of the pacific oyster, Crassostrea gigas. In cross section, the layers appear as opaque white zones and clearer translucent zones. Raman spectroscopy indicates that the zones consist of alternating layers of the aragonite and calcite morphs of calcium carbonate, the mineral constituent of the shell. The chemistry of the shell varies from individual to individual but generally the predominant metal ion is Ca, with varying amounts of Si, Cl, Cr, Mn, Fe, Zn, Sb, Ni, Fe, As and Sr. Two dimensional maps of these major, minor and trace elements were measured in many shells with nuclear microscopy to identify the patterns of Zn and Sr deposition reflecting the calcite and aragonite layers. The significant difference in the patterns identified by ion beam analyses are possibly a result of isostructural exclusion of these metal ions between the different aragonite and calcite polymorphic forms of calcium carbonate. (author)

  8. Remediation of muddy tidal flat sediments using hot air-dried crushed oyster shells.

    Yamamoto, Tamiji; Kondo, Shunsuke; Kim, Kyung-Hoi; Asaoka, Satoshi; Yamamoto, Hironori; Tokuoka, Makoto; Hibino, Tadashi

    2012-11-01

    In order to prove that hot air-dried crushed oyster shells (HACOS) are effective in reducing hydrogen sulfide in muddy tidal flat sediments and increasing the biomass, field experiments were carried out. The concentration of hydrogen sulfide in the interstitial water, which was 16 mg SL(-1) before the application of HACOS, decreased sharply and maintained almost zero in the experimental sites (HACOS application sites) for one year, whereas it was remained at ca. 5 mg SL(-1) in the control sites. The number of macrobenthos individuals increased to 2-4.5 times higher than that in the control site. Using a simple numerical model, the effective periods for suppression of hydrogen sulfide were estimated to be 3.2-7.6 and 6.4-15.2 years for the experimental sites with 4 and 8 tons per 10 × 10 × 0.2m area, respectively. From these results, it is concluded that HACOS is an effective material to remediate muddy tidal flats. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Effect of Oyster Shell Calcium Powder on the Quality of Restructured Pork Ham.

    Choi, Jung-Seok; Lee, Hyun-Jin; Jin, Sang-Keun; Lee, Hyun-Joo; Choi, Yang-Il

    2014-01-01

    This study was conducted to evaluate the effects of oyster shell calcium powder (OSCP) as a substitute for phosphates in curing agent, on the quality of restructured pork ham. Restructured pork ham was processed under six treatment conditions: T1 (no additives), T2 (0.3% sodium tripolyphosphate), T3 (1.5% NaCl+0.5% whey protein), T4 (1.5% NaCl+0.5% whey protein+0.15% OSCP), T5 (1.5% NaCl+0.5% whey protein+0.3% OSCP), and T6 (1.5% NaCl+0.5% whey protein+0.5% OSCP). Addition of OSCP significantly increased the ash content and pH of restructured pork ham (pham. Addition of OSCP had no effect on Hunter a and b surface color values of restructured pork ham, but did decrease the Hunter L surface color value (pham, compared with the addition of phosphates (pham.

  10. The oyster genome reveals stress adaptation and complexity of shell formation

    Zhang, Guofan; Fang, Xiaodong; Guo, Ximing

    2012-01-01

    The Pacific oyster Crassostrea gigas belongs to one of the most species-rich but genomically poorly explored phyla, the Mollusca. Here we report the sequencing and assembly of the oyster genome using short reads and a fosmid-pooling strategy, along with transcriptomes of development and stress re...

  11. UF's Lone Cabbage Oyster Reef Restoration Project: a use case in implementing a data management plan (DMP)

    Aufmuth, Joe

    2018-01-01

    Data management plans are created to satisfy funding agency proposal requirements related to the data life cycle. Once an award is made researchers must implement the plan they described. But how is this best accomplished? The presentation UF’s Lone Cabbage Oyster Reef Restoration Project: a use case in implementing a data management plan (DMP) describes how PI's for this grant funded research project are achieving its data management plan goals using an academic library's consulting team.

  12. 3D printed porous polycaprolactone/oyster shell powder (PCL/OSP) scaffolds for bone tissue engineering

    Luo, Wenfeng; Zhang, Shuangying; Lan, Yuewei; Huang, Chen; Wang, Chao; Lai, Xuexu; Chen, Hanwei; Ao, Ningjian

    2018-04-01

    In this work, oyster shell powder (OSP) was used as the bio-filler and combined with polycaprolactone (PCL) through melt blending methodology. The PCL and PCL/OSP scaffolds were prepared using additive manufacturing process. All the 3D printed scaffolds hold a highly porosity and interconnected pore structures. OSP particles are dispersed in the polymer matrix, which helped to improve the degree of crystallinity and mineralization ability of the scaffolds. There was no significant cytotoxicity of the prepared scaffolds towards MG-63 cells, and all the scaffolds showed a well ALP activity. Therefore, PCL/OSP scaffolds had a high potential to be employed in the bone tissue engineering.

  13. Production of bio-fertilizer from microwave vacuum pyrolysis of waste palm shell for cultivation of oyster mushroom (Pleurotus ostreatus

    Nam Wai Lun

    2017-01-01

    Full Text Available Microwave vacuum pyrolysis of waste palm shell (WPS was performed to produce biochar, which was then tested as bio-fertilizer in growing Oyster mushroom (Pleurotus ostreatus. The pyrolysis approach generated a biochar containing a highly porous structure with a high BET surface area (up to 1250 m2/g and a low moisture content (≤ 10 wt%, exhibiting desirable adsorption properties to be used as bio-fertilizer since it can act as a housing that provides many sites on which living microorganisms (mycelium or plant-growth promoting bacteria and organic nutrients can be attached or adsorbed onto. This could in turn stimulate plant growth by increasing the availability and supply of nutrients to the targeted host plant. The results from growing Oyster mushroom using the biochar record an impressive growth rate and a monthly production of up to about 550 g of mushroom. The shorter time for mycelium growth on whole baglog (30 days and the highest yield of Oyster mushroom (550 g was obtained from the cultivation medium added with 20 g of biochar. Our results demonstrate that the biochar-based bio-fertilizer produce from microwave vacuum pyrolysis of WPS show exceptional promise as an alternative growing substrate for mushroom cultivation.

  14. Production of bio-fertilizer from microwave vacuum pyrolysis of waste palm shell for cultivation of oyster mushroom (Pleurotus ostreatus)

    Lun Nam, Wai; Huan Su, Man; Phang, Xue Yee; Chong, Min Yee; Keey Liew, Rock; Ma, Nyuk Ling; Lam, Su Shiung

    2017-11-01

    Microwave vacuum pyrolysis of waste palm shell (WPS) was performed to produce biochar, which was then tested as bio-fertilizer in growing Oyster mushroom (Pleurotus ostreatus). The pyrolysis approach generated a biochar containing a highly porous structure with a high BET surface area (up to 1250 m2/g) and a low moisture content (≤ 10 wt%), exhibiting desirable adsorption properties to be used as bio-fertilizer since it can act as a housing that provides many sites on which living microorganisms (mycelium or plant-growth promoting bacteria) and organic nutrients can be attached or adsorbed onto. This could in turn stimulate plant growth by increasing the availability and supply of nutrients to the targeted host plant. The results from growing Oyster mushroom using the biochar record an impressive growth rate and a monthly production of up to about 550 g of mushroom. The shorter time for mycelium growth on whole baglog (30 days) and the highest yield of Oyster mushroom (550 g) was obtained from the cultivation medium added with 20 g of biochar. Our results demonstrate that the biochar-based bio-fertilizer produce from microwave vacuum pyrolysis of WPS show exceptional promise as an alternative growing substrate for mushroom cultivation.

  15. In situ distribution and characterization of the organic content of the oyster shell Crassostrea gigas (Mollusca, Bivalvia).

    Dauphin, Yannicke; Ball, Alexander D; Castillo-Michel, Hiram; Chevallard, Corinne; Cuif, Jean-Pierre; Farre, Bastien; Pouvreau, Stéphane; Salomé, Murielle

    2013-01-01

    Cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". In order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. The left and right valves of the oyster shell Crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular. The shell layers of juvenile C. gigas are studied using a variety of highly spatially resolved techniques to establish their composition and structure. Our results confirm the presence of three different calcitic structural types. The role of the lenses of chalky layers is not yet deciplered. Despite a common mineralogy, the elemental composition of the layers differs. The sulphur aminoacids and sulphated polysaccharide contents of the intracrystalline and intercrystalline matrices differ, as well as those of the structural types. The possible different sensitivity of these structures to environmental changes is still unknown. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Composite cement mortars based on marine sediments and oyster shell powder

    Ez-zaki, H.

    2016-03-01

    Full Text Available Additions of dredged marine sediments and oyster shell powder (OS as cement substitute materials in mortars are examined by several techniques. The sediments have high water and chloride contents and calcite, quartz, illite and kaolinite as principal minerals. The OS powders are entirely composed of calcium carbonate and traces of other impurities. Four mixtures of treated sediments and OS powders at 650 °C and 850 °C are added to Portland cement at 8%, 16% and 33% by weight. The hydration of composite pastes is followed by calorimetric tests, the porosity accessible to water, the bulk density, the permeability to gas, the compressive strength and the accelerated carbonation resistance are measured. In general, the increase of addition amounts reduced the performance of mortars. However, a reduction of gas permeability was observed when the addition was up to 33%. Around 16% of addition, the compressive strength and carbonation resistance were improved.En este trabajo se ha valorado la sustitución de cemento en morteros por sedimentos marinos dragados y polvo de concha de ostra (OS. Los sedimentos tienen altos contenidos de agua, cloruros, calcita, cuarzo, illita y caolinita como minerales principales. Los polvos OS están compuestos de carbonato cálcico y trazas de otras impurezas. Se añadieron a un cemento Portland, cuatro mezclas de los sedimentos y polvos de OS tratados a 650 °C y 850 °C en proporciones del 8%, 16% y 33% en peso. La hidratación de pastas se estudió a través de calorimetría. Se estudió además la porosidad accesible al agua, densidad aparente, permeabilidad al gas, resistencia a compresión y carbonatación acelerada. En general, un aumento en la adición produjo una reducción del rendimiento de los morteros. Se observó, sin embargo, una reducción de la permeabilidad a los gases con porcentajes de adición de hasta el 33%. Con valores del 16% de sustitución, mejoraron las resistencias mecánicas y la

  17. Identification two novel nacrein-like proteins involved in the shell formation of the Pacific oyster Crassostrea gigas.

    Song, Xiaorui; Wang, Xiaotong; Li, Li; Zhang, Guofan

    2014-07-01

    Nacrein-like proteins have carbonic anhydrase (CA)-like domains, but their coding regions are flanked by inserted repeat sequence, such as Gly-X-Asn. Reportedly, nacrein-like proteins show the highest similarity to human carbonic anhydrase 1(α-CA1), possess CA catalytic functions, and play a key role in shell biomineralization. In the present study, two novel nacrein-like proteins were firstly identified from the shell-forming mantle of the Pacific oyster Crassostrea gigas. With numerous analyses, it was identified and characterized that both the nacrein-like proteins F1 and F2 were secreted and most closely related to the nacrein-like protein of California mussel Mytilus californianus via phylogenetic analysis. RT-PCR analysis showed that the nacrein-like proteins F1 and F2 were expressed in multiple tissues and the expression levels remarkably rose after entering the spat stage, which were basically consistent with the increase of calcite fractions in the total shell volume. Surprisingly, the Gly-X-Asn repeat domain, which is distinctive in most nacrein-like proteins, was absent in the two newly identified nacrein-like proteins in C. gigas and replaced with a series of acidic amino acids (D/E). Regardless, nacrein-like proteins in mollusks seem to be vital to the deposition of calcium carbonate and likely perform diverse functions.

  18. Calculation of Oyster Benefits with a Bioenergetics Model of the Virginia Oyster

    2014-11-01

    soft tissue, and reproduction. Inorganic carbon incorporated into shell CaCO3 is considered separately. The organic carbon sequestered in biomass ...oyster biomass (dry tissue weight); • oyster age vs. shell length; • standing stock (population and biomass ); • shell accretion rates; • age...that found use in model parameterization and validation included: • individual oyster biomass (dry tissue weight); • oyster age vs. shell length

  19. Oyster reef restoration in controlling coastal pollution around India: A viewpoint

    Chakraborty, P.

    .G., Pirie, B.J.S., Cheyne, A.R., Coombs, T.L. and Grant, P.T., 1978. Detoxication of metals by marine bivalves: an ultrastructural study of the compartmentation of copper and zinc in the oyster Ostreaedulis. Marine Biology, 45(2), pp.147-156. Gupta, R...

  20. Isostructural exclusion of elements between aragonite and calcite layers in the shell of the Pacific oyster Crassostrea gigas

    Markwitz, A.; Gauldie, R.W.; Trompetter, W.J.; Pithie, J.; Jamieson, D.N.; Sharma, S.K.

    1999-01-01

    Sections of the shell of the farmed Pacific oyster 'Crassostrea gigas' that are available commercially in Wellington, New Zealand, showed a distinct alternating pattern in the shell mineral when observed by reflected light. The layers were identified by Raman scattering as alternating bands of the calcite and aragonite mineral forms of calcium carbonate using the micro-Raman facility at the Hawaii Institute of Geophysics and Planetology. The differences in the unit cell structure of calcite and aragonite favour different trace elements in the two minerals. Aragonite is isostructural with Strontianite SrCO 3 , and calcite is isostructural with Smithsonite ZnCO 3 . As a result, Sr deposition should be favoured in the aragonite layer and is excluded from the calcite layer; and, conversely, Zn deposition should be favoured in the calcite layer and is excluded from the aragonite layer. However, up to today, significant differences in the pattern of Sr and Zn in microprobe scans are not discovered. By ion microprobe analysis, it was shown that differences in the unit cell structure of calcite and aragonite favor different trace elements in the two minerals

  1. Recycling method of rubbish glass, wasted slate and oyster shell; Gan Ca haizai wo riyosuru kenzaiyo glass kuzu oyobi senshoseki kuzu no recycle

    Okawa, A.; Omi, M. [Tohoku University, Sendai (Japan). Institute for Advanced Materials Processing

    1996-03-29

    Examination was made about the method of recycling rubbish glass and Gensho-stone slate, left after the use of construction materials, and oyster shells. In the experiment, quartz powder having the highest softening temperature was used instead of rubbish glass powder, and H3PO4 was used as the additive agent. The Gensho-stone slate was ground in a ball mill into power smaller than 100 mesh. The main constituent of the oyster shell, CaCO3, was subjected to thermolysis for conversion into CaO; and calcium phosphate was used as animal bone powder. The above-said materials as the starting materials were subjected to pressure-forming, and heating was done in the air at 1173K for 7.2ks for the production of sintered pellets. The sintered bodies were left in the air for 30 days and examined for geometrical changes, and it was found that the Gensho-stone slate was the best specimen, with the oyster shell occupying the second place, and that the sintered bodies of bone powder and SiO2 absorbed moisture indicating they were short of serviceability. As for the use of sintered bodies, Gensho stone may be used as material for landscape building while CaO may be used as a Ca ion source in the sea for cultivating seashells. 5 refs., 5 figs., 3 tabs.

  2. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    SHEN, E.J.

    2000-10-05

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system.

  3. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    SHEN, E.J.

    2000-01-01

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system

  4. Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae).

    Christo, S W; Absher, T M; Boehs, G

    2010-08-01

    In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM). Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.

  5. Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae

    SW. Christo

    Full Text Available In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM. Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.

  6. Deep sequencing of ESTs from nacreous and prismatic layer producing tissues and a screen for novel shell formation-related genes in the pearl oyster.

    Shigeharu Kinoshita

    Full Text Available BACKGROUND: Despite its economic importance, we have a limited understanding of the molecular mechanisms underlying shell formation in pearl oysters, wherein the calcium carbonate crystals, nacre and prism, are formed in a highly controlled manner. We constructed comprehensive expressed gene profiles in the shell-forming tissues of the pearl oyster Pinctada fucata and identified novel shell formation-related genes candidates. PRINCIPAL FINDINGS: We employed the GS FLX 454 system and constructed transcriptome data sets from pallial mantle and pearl sac, which form the nacreous layer, and from the mantle edge, which forms the prismatic layer in P. fucata. We sequenced 260477 reads and obtained 29682 unique sequences. We also screened novel nacreous and prismatic gene candidates by a combined analysis of sequence and expression data sets, and identified various genes encoding lectin, protease, protease inhibitors, lysine-rich matrix protein, and secreting calcium-binding proteins. We also examined the expression of known nacreous and prismatic genes in our EST library and identified novel isoforms with tissue-specific expressions. CONCLUSIONS: We constructed EST data sets from the nacre- and prism-producing tissues in P. fucata and found 29682 unique sequences containing novel gene candidates for nacreous and prismatic layer formation. This is the first report of deep sequencing of ESTs in the shell-forming tissues of P. fucata and our data provide a powerful tool for a comprehensive understanding of the molecular mechanisms of molluscan biomineralization.

  7. Shell extracts of the edible mussel and oyster induce an enhancement of the catabolic pathway of human skin fibroblasts, in vitro.

    Latire, Thomas; Legendre, Florence; Bouyoucef, Mouloud; Marin, Frédéric; Carreiras, Franck; Rigot-Jolivet, Muriel; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

    2017-10-01

    Mollusc shells are composed of more than 95% calcium carbonate and less than 5% organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. In this study, we investigated the effects of matrix macromolecular components extracted from the shells of two edible molluscs of economic interest, i.e., the blue mussel Mytilus edulis and the Pacific oyster Crassostrea gigas. The potential biological activities of these organic molecules were analysed on human dermal fibroblasts in primary culture. Our results demonstrate that shell extracts of the two studied molluscs modulate the metabolic activities of the cells. In addition, the extracts caused a decrease of type I collagen and a concomitant increase of active MMP-1, both at the mRNA and the protein levels. Therefore, our results suggest that shell extracts from M. edulis and C. gigas contain molecules that promote the catabolic pathway of human dermal fibroblasts. This work emphasises the potential use of these shell matrices in the context of anti-fibrotic strategies, particularly against scleroderma. More generally, it stresses the usefulness to valorise bivalve shells that are coproducts of shellfish farming activity.

  8. Shells, orbit bifurcations, and symmetry restorations in Fermi systems

    Magner, A. G., E-mail: magner@kinr.kiev.ua; Koliesnik, M. V. [NASU, Institute for Nuclear Research (Ukraine); Arita, K. [Nagoya Institute of Technology, Department of Physics (Japan)

    2016-11-15

    The periodic-orbit theory based on the improved stationary-phase method within the phase-space path integral approach is presented for the semiclassical description of the nuclear shell structure, concerning themain topics of the fruitful activity ofV.G. Soloviev. We apply this theory to study bifurcations and symmetry breaking phenomena in a radial power-law potential which is close to the realistic Woods–Saxon one up to about the Fermi energy. Using the realistic parametrization of nuclear shapes we explain the origin of the double-humped fission barrier and the asymmetry in the fission isomer shapes by the bifurcations of periodic orbits. The semiclassical origin of the oblate–prolate shape asymmetry and tetrahedral shapes is also suggested within the improved periodic-orbit approach. The enhancement of shell structures at some surface diffuseness and deformation parameters of such shapes are explained by existence of the simple local bifurcations and new non-local bridge-orbit bifurcations in integrable and partially integrable Fermi-systems. We obtained good agreement between the semiclassical and quantum shell-structure components of the level density and energy for several surface diffuseness and deformation parameters of the potentials, including their symmetry breaking and bifurcation values.

  9. Post-mortem ecosystem engineering by oysters creates habitat for a rare marsh plant.

    Guo, Hongyu; Pennings, Steven C

    2012-11-01

    Oysters are ecosystem engineers in marine ecosystems, but the functions of oyster shell deposits in intertidal salt marshes are not well understood. The annual plant Suaeda linearis is associated with oyster shell deposits in Georgia salt marshes. We hypothesized that oyster shell deposits promoted the distribution of Suaeda linearis by engineering soil conditions unfavorable to dominant salt marsh plants of the region (the shrub Borrichia frutescens, the rush Juncus roemerianus, and the grass Spartina alterniflora). We tested this hypothesis using common garden pot experiments and field transplant experiments. Suaeda linearis thrived in Borrichia frutescens stands in the absence of neighbors, but was suppressed by Borrichia frutescens in the with-neighbor treatment, suggesting that Suaeda linearis was excluded from Borrichia frutescens stands by interspecific competition. Suaeda linearis plants all died in Juncus roemerianus and Spartina alterniflora stands, regardless of neighbor treatments, indicating that Suaeda linearis is excluded from these habitats by physical stress (likely water-logging). In contrast, Borrichia frutescens, Juncus roemerianus, and Spartina alterniflora all performed poorly in Suaeda linearis stands regardless of neighbor treatments, probably due to physical stresses such as low soil water content and low organic matter content. Thus, oyster shell deposits play an important ecosystem engineering role in influencing salt marsh plant communities by providing a unique niche for Suaeda linearis, which otherwise would be rare or absent in salt marshes in the southeastern US. Since the success of Suaeda linearis is linked to the success of oysters, efforts to protect and restore oyster reefs may also benefit salt marsh plant communities.

  10. Oyster Fauna of Thailand

    Bussarawit, Somchai; Cedhagen, Tomas

    2012-01-01

    Here, we describe 16 species of true oysters from Thai waters. They are widely distributed on various intertidal and subtidal substrates in the Gulf of Thailand and in the Andaman Sea. The different species were identified on the basis of their shell morphology, and their characteristic features...

  11. Stabilization of Pb²⁺ and Cu²⁺ contaminated firing range soil using calcined oyster shells and waste cow bones.

    Moon, Deok Hyun; Cheong, Kyung Hoon; Khim, Jeehyeong; Wazne, Mahmoud; Hyun, Seunghun; Park, Jeong-Hun; Chang, Yoon-Young; Ok, Yong Sik

    2013-05-01

    Pb(2+) and Cu(2+) contamination at army firing ranges poses serious environmental and health risks to nearby communities necessitating an immediate and prompt remedial action. In this study, a novel mixture of calcined oyster shells (COSs) and waste cow bones (WCBs) was utilized to immobilize Pb(2+) and Cu(2+) in army firing range soils. The effectiveness of the treatment was evaluated based on the Korean Standard leaching test. The treatment results showed that Pb(2+) and Cu(2+) immobilization in the army firing range soil was effective in significantly reducing Pb(2+) and Cu(2+) leachability upon the combined treatment with COS and WCB. A drastic reduction in Pb(2+) (99%) and Cu(2+) leachability (95%) was obtained as compared to the control sample, upon treatment with 5 wt.% COS and 5 wt.% WCB. The combination treatment of COS and WCB was more effective for Pb immobilization, than the treatment with COS or WCB alone. The 5 wt.% COS alone treatment resulted in 95% reduction in Cu(2+) leachability. The SEM-EDX results suggested that Pb(2+) and Cu(2+) immobilization was most probably associated with the formation of ettringite, pozzolanic reaction products and pyromorphite-like phases at the same time. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. NaF-loaded core-shell PAN-PMMA nanofibers as reinforcements for Bis-GMA/TEGDMA restorative resins.

    Cheng, Liyuan; Zhou, Xuegang; Zhong, Hong; Deng, Xuliang; Cai, Qing; Yang, Xiaoping

    2014-01-01

    A kind of core-shell nanofibers containing sodium fluoride (NaF) was produced and used as reinforcing materials for dimethacrylate-based dental restorative resins in this study. The core-shell nanofibers were prepared by coaxial-electrospinning with polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) solutions as core and shell fluids, respectively. The produced PAN-PMMA nanofibers varied in fiber diameter and the thickness of PMMA shell depending on electrospinning parameters. NaF-loaded nanofibers were obtained by incorporating NaF nanocrystals into the core fluid at two loadings (0.8 or 1.0wt.%). Embedment of NaF nanocrystals into the PAN core did not damage the core-shell structure. The addition of PAN-PMMA nanofibers into Bis-GMA/TEGDMA clearly showed the reinforcement due to the good interfacial adhesion between fibers and resin. The flexural strength (Fs) and flexural modulus (Ey) of the composites decreased slightly as the thickness of PMMA shell increasing. Sustained fluoride releases with minor initial burst release were achieved from NaF-loaded core-shell nanofibers and the corresponding composites, which was quite different from the case of embedding NaF nanocrystals into the dental resin directly. The study demonstrated that NaF-loaded PAN-PMMA core-shell nanofibers were not only able to improve the mechanical properties of restorative resin, but also able to provide sustained fluoride release to help in preventing secondary caries. © 2013.

  13. Length-weight relationship of Giant Oyster, Crassostrea gyphoides (Schlotheim)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Parulekar, A.H.

    Relationship between shell length and total weight, shell weight and meat weight of giant oyster, Crassostrea gryphoides revealed that the growth of these parameters is very fast and significant. It indicates the suitability of the species concerned...

  14. Oyster Shell Dredging in Atchafalaya Bay and Adjacent Waters, Louisiana. Volume 1. Final Environment Impact Statement and Appendixes.

    1987-11-01

    This force majure clause shall not apply to the annual minimum guaranty set forth in item 22 in any lease year in which any of the Purchasers dredge...the Gulf Coast Region, by Statets, 1960-1969 Table 10. Civilian Labor Force ..... ............... . EIS-80 Table 11. 1975-85 Inclusive - Clam and...within the region and are continuously reworked by erosional forces . Shell dredging operations in the recent past have been concentrated in the southern

  15. Hyperspectral remote sensing of wild oyster reefs

    Le Bris, Anthony; Rosa, Philippe; Lerouxel, Astrid; Cognie, Bruno; Gernez, Pierre; Launeau, Patrick; Robin, Marc; Barillé, Laurent

    2016-04-01

    The invasion of the wild oyster Crassostrea gigas along the western European Atlantic coast has generated changes in the structure and functioning of intertidal ecosystems. Considered as an invasive species and a trophic competitor of the cultivated conspecific oyster, it is now seen as a resource by oyster farmers following recurrent mass summer mortalities of oyster spat since 2008. Spatial distribution maps of wild oyster reefs are required by local authorities to help define management strategies. In this work, visible-near infrared (VNIR) hyperspectral and multispectral remote sensing was investigated to map two contrasted intertidal reef structures: clusters of vertical oysters building three-dimensional dense reefs in muddy areas and oysters growing horizontally creating large flat reefs in rocky areas. A spectral library, collected in situ for various conditions with an ASD spectroradiometer, was used to run Spectral Angle Mapper classifications on airborne data obtained with an HySpex sensor (160 spectral bands) and SPOT satellite HRG multispectral data (3 spectral bands). With HySpex spectral/spatial resolution, horizontal oysters in the rocky area were correctly classified but the detection was less efficient for vertical oysters in muddy areas. Poor results were obtained with the multispectral image and from spatially or spectrally degraded HySpex data, it was clear that the spectral resolution was more important than the spatial resolution. In fact, there was a systematic mud deposition on shells of vertical oyster reefs explaining the misclassification of 30% of pixels recognized as mud or microphytobenthos. Spatial distribution maps of oyster reefs were coupled with in situ biomass measurements to illustrate the interest of a remote sensing product to provide stock estimations of wild oyster reefs to be exploited by oyster producers. This work highlights the interest of developing remote sensing techniques for aquaculture applications in coastal

  16. Feeding traits of the European flat oyster, Ostrea edulis, and the invasive Pacific oyster, Crassostrea gigas

    Nielsen, Mette; Hansen, Benni Winding; Vismann, Bent

    2017-01-01

    Two oysters, the native flat oyster, Ostrea edulis, and the non-indigenous Pacific oyster, Crassostrea gigas, have partially overlapping distributions in European waters. Relatively little is known about particle selection by O. edulis, and the goal of the present study was to establish baselines...... for particle selection by both oyster species under controlled conditions in the laboratory. The study was carried out with adult oysters of similar shell size collected in the Limfjord estuary, Denmark (56°47′N, 08°51′E), in November 2011. The feeding traits of both species [clearance rate (CR), retention...... efficiency (RE) and lower threshold for clearance (LTC)] were compared using five algal species with different cell sizes (5−32 µm ESD) (Isochrysis galbana, Rhodomonas salina, Thalassiosira weissflogii, Prorocentrum micans and Akashiwo sanguinea). Oysters were acclimated to an experimental temperature of 22...

  17. Economic Values Associated With Construction of Oyster Reefs by the Corps of Engineers

    Henderson, Jim

    2003-01-01

    .... That template includes a community model for the American oyster (Crassostrea virginica) which can be used to quantify the ecological benefits of an oyster reef in an ecosystem restoration project...

  18. Japanese oysters in Dutch waters

    Berg, van den J.B.; Kozyreff, G.; Lin, H.X.; McDarby, J.; Peletier, M.A.; Planqué, R.; Wilson, P.L.

    2005-01-01

    Since the introduction of the Japanese oyster in the Eastern Scheldt it has spread into the Wadden Sea. This growth has a negative impact on the life of various other species in the sea. Seen from a mathematical viewpoint, the biological problem of how to restore the disturbed natural equilibrium

  19. Bioimmuring late Cretaceous and Recent oysters : 'A view from within'

    Jagt, John W M; Neumann, Christian; Schulp, Anne S.

    2007-01-01

    Being obligate cementers, oysters (Ostreoidea), both fossil and Recent, often yield valuable information on their substrates, whether biotic/ abiotic, perishable or inert. By a process called bioimmuration, oyster shells may preserve lightly or non-calcified sessile organisms already present on the

  20. Collapse of a historic oyster fishery: diagnosing causes and identifying paths toward increased resilience

    Edward V. Camp

    2015-09-01

    Full Text Available Diagnosing causal factors of change at the ecosystem level is challenging because multiple drivers often interact at various spatial and temporal scales. We employ an integrated natural and social science approach to assess potential mechanisms leading to the collapse of an estuarine social-ecological system, and recommend future paths to increased system resilience. Our case study is the collapse of the eastern oyster (Crassostrea virginica fishery in Apalachicola Bay, Florida, USA, and the associated impacts on local resource dependent communities. The oyster fishery collapse is the most recent in a series of environmental stressors to this region, which have included hurricanes and tropical storms, drought, and the Deepwater Horizon oil spill. We found it likely that the oyster collapse was not related to contamination from the recent oil spill, but rather to factors affecting oyster recruitment and survival, which may have been mediated by both human, e.g., fishing-related habitat alteration, and environmental, e.g., increased natural mortality from predators and disease, factors. The relative impact of each of these factors is likely to increase in the future because of changing climate and increased demand for fishery, water, and petroleum resources. Successful restoration and persistence of a viable oyster fishery will depend on: (1 implementation of some minimal best management practices, e.g., extensive habitat restoration via shell addition, and some spatial closures to harvest, (2 improving environmental knowledge and promoting episodic learning through enhanced monitoring and experimental management, and (3 continued community engagement necessary to produce adaptable governance suitable to responding to future unexpected challenges.

  1. Oysters and Oyster Reef Communities in Florida.

    Knight, Jean; Bly, Joe

    1989-01-01

    The habitat, life history, feeding, classification, anatomy and pearl production of the American oyster (Crassostrea virginica) are presented. A list of other oyster reef inhabitants and predators is provided. Harvest and habitat loss are discussed. (CW)

  2. Water quality parameters and total aerobic bacterial and vibrionaceae loads in eastern oysters (Crassostrea virginica) from oyster gardening sites

    Oyster gardening is a practice designed to restore habitat for marine life and to improve water quality. This study determined physical and chemical water quality parameters at two oyster gardening sites in the Delaware Inland Bays and compared them with total aerobic bacteria and Vibrionaceae conc...

  3. Project ash cultch: A report on optimal oyster cultch based on a prepared fly ash substratum

    Price, K.S.; Hansen, K.M.; Schlekat, C.E.

    1991-01-01

    Based on a three year study involving setting, growth, mortality, oyster condition, and metals accumulation, the evidence is extensive and convincing that stabilized coal ash is an acceptable oyster growing cultch (substratum). Oyster larvae are attracted to set on coal ash cultch at commercial fishery densities, tend to grow as well as on natural substrata (oyster shell), and are moderately more exposed to predators on the puck shaped ash materials as produced for this study. Oysters grown for one to two years on coal ash do not accumulate heavy metals and generally are in good health as measured by several biological condition indexes

  4. Oysters and Vibriosis

    ... this? Submit What's this? Submit Button Past Emails Oysters and Vibriosis Language: English (US) Español (Spanish) Recommend ... is to cook them properly. Tips for Cooking Oysters & Other Shellfish Before cooking, throw out any shellfish ...

  5. Growth and reproductive investment of introduced Pacific oysters

    Cardoso, J.F.M.F.; Peralta, N.R.E.; Machado, J.P.; van der Veer, H.W.

    2013-01-01

    Growth and reproductive investment of cultured Pacific oysters Crassostrea gigas were studied in two south-western European estuaries: the Ria de Ribadeo in Spain and the Ria Formosa in Portugal. Developing gonads were found in individuals >23.5 mm shell length in the Ria Formosa and >27.5 mm shell

  6. Are oysters being bored to death? Influence of Cliona celata on Crassostrea virginica condition, growth and survival.

    Carroll, John M; O'Shaughnessy, Kathryn A; Diedrich, Grant A; Finelli, Christopher M

    2015-11-17

    The boring sponge Cliona celata is a nuisance species that can have deleterious effects on eastern oyster Crassostrea virginica growth, condition, and survival. Surprisingly, however, these effects have not been well documented and when examined, results have been equi-vocal. In this study, we provide a direct comparison of growth, condition, and survival of sponge-colonized and uncolonized oysters in southeast North Carolina in 2 separate experiments. In the first experiment, sponge-colonized oysters exhibited significantly slower growth rates, reduced condition, and lower survival relative to uncolonized oysters, although results may have been confounded by oyster source. In the second experiment, using smaller oysters from the same source population, growth rate was again significantly reduced in colonized oysters relative to uncolonized oysters, however neither condition nor survival differed. In field surveys of the same population, colonized individuals across a range of sizes demonstrated significantly reduced condition. Further, condition index was negatively correlated with sponge biomass, which was positively correlated with oyster size, suggesting that the impact of the sponge changes with ontogeny. By investigating clearance rates, tissue isotopic and nutrient content, as well as caloric value, this study provides further evidence that sponge presence causes the oysters to divert energy into costly shell maintenance and repair at the expense of shell and somatic growth. Thus, although variable, our results demonstrate negative impacts of sponge infestation on oyster demographics, particularly as oysters grow larger.

  7. Predicting the effects of proposed Mississippi River diversions on oyster habitat quality; application of an oyster habitat suitability index model

    Soniat, Thomas M.; Conzelmann, Craig P.; Byrd, Jason D.; Roszell, Dustin P.; Bridevaux, Joshua L.; Suir, Kevin J.; Colley, Susan B.

    2013-01-01

    In an attempt to decelerate the rate of coastal erosion and wetland loss, and protect human communities, the state of Louisiana developed its Comprehensive Master Plan for a Sustainable Coast. The master plan proposes a combination of restoration efforts including shoreline protection, marsh creation, sediment diversions, and ridge, barrier island, and hydrological restoration. Coastal restoration projects, particularly the large-scale diversions of fresh water from the Mississippi River, needed to supply sediment to an eroding coast potentially impact oyster populations and oyster habitat. An oyster habitat suitability index model is presented that evaluates the effects of a proposed sediment and freshwater diversion into Lower Breton Sound. Voluminous freshwater, needed to suspend and broadly distribute river sediment, will push optimal salinities for oysters seaward and beyond many of the existing reefs. Implementation and operation of the Lower Breton Sound diversion structure as proposed would render about 6,173 ha of hard bottom immediately east of the Mississippi River unsuitable for the sustained cultivation of oysters. If historical harvests are to be maintained in this region, a massive and unprecedented effort to relocate private leases and restore oyster bottoms would be required. Habitat suitability index model results indicate that the appropriate location for such efforts are to the east and north of the Mississippi River Gulf Outlet.

  8. 78 FR 62293 - Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY

    2013-10-15

    ... Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY AGENCY: Coast... zone on the navigable waters of Oyster Bay near Oyster Bay, NY for the Oyster Festival 30th Anniversary... Oyster Festival 30th Anniversary Fireworks Display is scheduled for October 19, 2013 and is one of...

  9. Characterization of adhesive from oysters: A structural and compositional study

    Alberts, Erik

    The inability for man-made adhesives to set in wet or humid environments is an ongoing challenging the design of biomedical and marine adhesive materials. However, we see that nature has already overcome this challenge. Mussels, barnacles, oysters and sandcastle worms all have unique mechanisms by which they attach themselves to surfaces. By understanding what evolution has already spent millions of years perfecting, we can design novel adhesive materials inspired by nature's elegant designs. The well-studied mussel is currently the standard for design of marine inspired biomimetic polymers. In the work presented here, we aim to provide new insights into the adhesive produced by the eastern oyster, Crassostrea virginica. Unlike the mussel, which produces thread-like plaques comprised of DOPA containing-protein, the oyster secretes an organic-inorganic hybrid adhesive as it settles and grows onto a surface. This form of adhesion renders the oyster to be permanently fixed in place. Over time, hundreds of thousands of oyster grow and agglomerate to form extensive reef structures. These reefs are not only essential to survival of the oyster, but are also vital to intertidal ecosystems. While the shell of the oyster has been extensively studied, curiously, only a few conflicting insights have been made into the nature of the adhesive and contact zone between shell and substrate, and even lesfs information has been ascertained on organic and inorganic composition. In this work, we provide microscopy and histochemical studies to characterize the structure and composition of the adhesive, using oyster in the adult and juvenile stages of life. Preliminary work on extracting and characterizing organic components through collaborative help with solid-state NMR (SSNMR) and proteomics are also detailed here. We aim to provide a full, comprehensive characterization of oyster adhesive so that in the future, we may apply what we learn to the design of new materials.

  10. Kinds of nucleus for effective pearl cultivation of the pearl oysters, Pinctada fucata

    Kanjanachatree, K.; Piyathamrongrut, K.; Inthoncharoen, J.

    2007-01-01

    Seeding is the most important aspect of pearl cultivation, and appropriate nucleus can determine the quality of a pearl : nacre secretion and accumulation around the nucleus. This affects harvest time, nucleus extrusion, survival rate of the pearl oysters and the production cost. In order to provide nuclei to substitute for those imported from China which are made from freshwater pearl oyster-shells, 3 kinds of the local shells of Pinctada fucata, Pteria penguin and Pinctada maxima were selec...

  11. Ocean acidification increases the vulnerability of native oysters to predation by invasive snails.

    Sanford, Eric; Gaylord, Brian; Hettinger, Annaliese; Lenz, Elizabeth A; Meyer, Kirstin; Hill, Tessa M

    2014-03-07

    There is growing concern that global environmental change might exacerbate the ecological impacts of invasive species by increasing their per capita effects on native species. However, the mechanisms underlying such shifts in interaction strength are poorly understood. Here, we test whether ocean acidification, driven by elevated seawater pCO₂, increases the susceptibility of native Olympia oysters to predation by invasive snails. Oysters raised under elevated pCO₂ experienced a 20% increase in drilling predation. When presented alongside control oysters in a choice experiment, 48% more high-CO₂ oysters were consumed. The invasive snails were tolerant of elevated CO₂ with no change in feeding behaviour. Oysters raised under acidified conditions did not have thinner shells, but were 29-40% smaller than control oysters, and these smaller individuals were consumed at disproportionately greater rates. Reduction in prey size is a common response to environmental stress that may drive increasing per capita effects of stress-tolerant invasive predators.

  12. Role of dissolved and particulate cadmium in the accumulation of cadmium in cultured oysters (Crassostrea gigas)

    Lekhi, Priyanka [Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)], E-mail: anka.lekhi@ubc.ca; Cassis, D. [Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Pearce, C.M. [Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7 (Canada); Ebell, N. [Odyssey Shellfish Ltd., Nanoose Bay, BC V0R 9G0 (Canada); Maldonado, M.T. [Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Orians, K.J. [Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)

    2008-04-15

    Pacific oysters (Crassostrea gigas) collected on the coast of British Columbia, Canada have occasionally shown cadmium (Cd) concentrations at or above 2 {mu}g g{sup -1} (wet weight), which has resulted in the loss of some international markets. This study investigated the source and transfer of Cd to oysters by focusing on the role of dissolved and particulate Cd in seawater. Parameters monitored for 1 year at two oyster farm sites on Vancouver Island included: oyster tissue mass and shell length, Cd in oysters, dissolved Cd, particulate Cd, temperature and salinity. Results show that dissolved Cd was the main source of Cd to the oysters and that Cd was mainly concentrated in the gut tissues. A seasonal trend was observed in Cd in oysters, in which levels were lowest during periods of higher temperatures. Results also indicate that the local oceanographic inputs and sediment diagenesis directly affect dissolved Cd and thereby influence the Cd levels in oysters. Particulate matter was not found to be a source of Cd in oysters, and was actually negatively correlated. This was likely due to the uptake of dissolved Cd by phytoplankton and the effect of phytoplankton on oyster tissue mass.

  13. Role of dissolved and particulate cadmium in the accumulation of cadmium in cultured oysters (Crassostrea gigas)

    Lekhi, Priyanka; Cassis, D.; Pearce, C.M.; Ebell, N.; Maldonado, M.T.; Orians, K.J.

    2008-01-01

    Pacific oysters (Crassostrea gigas) collected on the coast of British Columbia, Canada have occasionally shown cadmium (Cd) concentrations at or above 2 μg g -1 (wet weight), which has resulted in the loss of some international markets. This study investigated the source and transfer of Cd to oysters by focusing on the role of dissolved and particulate Cd in seawater. Parameters monitored for 1 year at two oyster farm sites on Vancouver Island included: oyster tissue mass and shell length, Cd in oysters, dissolved Cd, particulate Cd, temperature and salinity. Results show that dissolved Cd was the main source of Cd to the oysters and that Cd was mainly concentrated in the gut tissues. A seasonal trend was observed in Cd in oysters, in which levels were lowest during periods of higher temperatures. Results also indicate that the local oceanographic inputs and sediment diagenesis directly affect dissolved Cd and thereby influence the Cd levels in oysters. Particulate matter was not found to be a source of Cd in oysters, and was actually negatively correlated. This was likely due to the uptake of dissolved Cd by phytoplankton and the effect of phytoplankton on oyster tissue mass

  14. Trade-off between increased survival and reduced growth for blue mussels living on Pacific oyster reefs

    Eschweiler, Nina; Christensen, Helle Torp

    2011-01-01

    Pacific oysters Crassostrea gigas (Thunberg 1793) have been introduced into the Wadden Sea (North Sea, Germany) in the mid of the 1980s and have invaded native blue mussel Mytilus edulis (L.) beds. The latter turned into oyster reefs where mussels seem to be relegated to the bottom in between...... the much larger oysters. By combining field and laboratory experiments, we reveal how mussels react to cohabitation with the invasive oysters. Mussels subjected to direct contact with crabs Carcinus maenas migrate from top to bottom positions between oysters in both field and laboratory experiments within...... 22days. Shell growth was significantly reduced for mussels placed on the bottom compared to mussels at the top of an oyster reef. Condition index was lower for mussels on the bottom of the reef irrespective of whether placed between dead or living oysters. We conclude that mussels experience a trade...

  15. Sistemas de alimentação e suplementação de farinha de casca de ostras sobre o desempenho e a qualidade da casca dos ovos de poedeiras comerciais Feeding systems and oyster shell meal supplementation on the performance and eggshell quality of laying hens

    Douglas Emygdio de Faria

    2000-10-01

    Full Text Available O objetivo desta pesquisa foi avaliar diferentes sistemas de alimentação e suplementação de farinha de casca de ostras sobre o desempenho e a qualidade da casca dos ovos, determinados constituintes sangüíneos, e sobre a disponibilidade aparente do cálcio e fósforo dietéticos, em 120 galinhas Lohmann LSL, com 70 semanas de idade, distribuídas em 20 unidades experimentais com seis aves cada. O delineamento utilizado foi o inteiramente ao acaso em arranjo fatorial 2 x 2: sistemas de alimentação (ad libitum e jejum das 7 às 18 h e suplementação de farinha de casca de ostras (0 e 6,5 g/ave/dia, totalizando quatro tratamentos com cinco repetições cada. Os resultados mostraram menor consumo de ração para as galinhas submetidas à restrição alimentar. Produção, peso e massa de ovos, conversão alimentar, porcentagem de casca, espessura de casca, densidade aparente dos ovos e os coeficientes de disponibilidade aparente do cálcio e fósforo não foram afetados pelos tratamentos. Concluiu-se que o fornecimento de ração após às 18 h e a suplementação de casca de ostras não se mostraram vantajosos para o desempenho e a qualidade da casca dos ovos de poedeiras comerciais.The objective of this experiment was to evaluate different feeding schedule and oyster shell supplementation on the performance and eggshell quality, determined blood constituents, and on the calcium and phosphorus apparent availability using 120 laying hens Lohmann LSL, aged 70 weeks, distributed in 20 experimental units with six hens each. A completely randomized experimental design was used in a factorial arrangement 2 x 2: feeding systems (ad libitum and fasting from 7 a.m. to 6 p.m. and oyster shell meal supplementation (0 and 6.5 g/hen/day, totalizing four treatments with five replicates each. The results showed smaller feed intake with fasting. The characteristics egg production, egg weight, egg mass, feed:gain ratio, shell percent, shell thickness, egg

  16. Kinds of nucleus for effective pearl cultivation of the pearl oysters, Pinctada fucata

    Kanjanachatree, K.

    2007-07-01

    Full Text Available Seeding is the most important aspect of pearl cultivation, and appropriate nucleus can determine the quality of a pearl : nacre secretion and accumulation around the nucleus. This affects harvest time, nucleus extrusion, survival rate of the pearl oysters and the production cost. In order to provide nuclei to substitute for those imported from China which are made from freshwater pearl oyster-shells, 3 kinds of the local shells of Pinctada fucata, Pteria penguin and Pinctada maxima were selected for seed production. The obtained nuclei have various diameters depend on the shell width at the hinge region. The average diameters are 5.44, 6.78, 7.54 and 6.10 mm, while their production costs are 5, 7.7, 18.5 and 7.5 baht per 1 nucleus, respectively, for Pinctada fucata, Pteria penguin, Pinctada maxima and freshwater pearl oysters (control group. After nucleus implantation into the gonad of culture pearl oysters, Pinctada fucata, and rearing in the sea, the obtained pearls using nuclei made from the shells of Pinctada fucata and Pinctada maxima (both belong to the same genus as the implanted culture pearl oysters have as good nacre formation as that from freshwater pearl oysters. In contrast, the pearl production using nuclei made from Pteria penguin-shells have significantly worse nacre formation. Survival rate of the culture oysters seeded with nuclei made from Pinctada fucata-shells is highest at 47%, nucleus extrusion 8% only, and harvest rate 31%; while with Pinctada maxima-shells, these values are 38%, 17.5% and 14%, respectively. So the nuclei made from local Pinctada fucata-shells are appropriate for pearl cultivation and are comparable to imported nuclei. Although the obtained pearls are small, the nuclei made from Pinctada fucata-shells have low cost, low nucleus extrusion and high productivity.

  17. Oxygen isotope fluctuations in a modern North Sea oyster (Crassostrea gigas) compared with annual variations in seawater temperature

    Ullmann, Clemens Vinzenz; Wiechert, Uwe; Korte, Christoph

    2010-01-01

    A total of 181 oxygen isotope values from sequential samples of the left shell of a modern Pacific Oyster (Crassostrea gigas) that lived on a sub-tidal oyster bank in the List Basin (North Sea, Germany) shows periodically varying values between + 1.3‰ and -2.5‰. In order to test whether these d18O...... fluctuations reflect seawater temperature changes, the isotope values of the shell were compared to actual seawater temperature variations from the region. C. gigas serves as an excellent proxy for temperature of palaeoseawater and the results show that the examined oyster precipitated its shell in d18O...... equilibrium with the ambient seawater. A cessation of the oyster shell calcification starts at water temperatures below 6 °C, at lower temperatures than previously thought for Crassostrea. For palaeoclimate investigations the termination of shell production is important because the lowest temperatures might...

  18. Millennial-scale sustainability of the Chesapeake Bay Native American oyster fishery.

    Rick, Torben C; Reeder-Myers, Leslie A; Hofman, Courtney A; Breitburg, Denise; Lockwood, Rowan; Henkes, Gregory; Kellogg, Lisa; Lowery, Darrin; Luckenbach, Mark W; Mann, Roger; Ogburn, Matthew B; Southworth, Melissa; Wah, John; Wesson, James; Hines, Anson H

    2016-06-07

    Estuaries around the world are in a state of decline following decades or more of overfishing, pollution, and climate change. Oysters (Ostreidae), ecosystem engineers in many estuaries, influence water quality, construct habitat, and provide food for humans and wildlife. In North America's Chesapeake Bay, once-thriving eastern oyster (Crassostrea virginica) populations have declined dramatically, making their restoration and conservation extremely challenging. Here we present data on oyster size and human harvest from Chesapeake Bay archaeological sites spanning ∼3,500 y of Native American, colonial, and historical occupation. We compare oysters from archaeological sites with Pleistocene oyster reefs that existed before human harvest, modern oyster reefs, and other records of human oyster harvest from around the world. Native American fisheries were focused on nearshore oysters and were likely harvested at a rate that was sustainable over centuries to millennia, despite changing Holocene climatic conditions and sea-level rise. These data document resilience in oyster populations under long-term Native American harvest, sea-level rise, and climate change; provide context for managing modern oyster fisheries in the Chesapeake Bay and elsewhere around the world; and demonstrate an interdisciplinary approach that can be applied broadly to other fisheries.

  19. 21 CFR 161.136 - Olympia oysters.

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Olympia oysters. 161.136 Section 161.136 Food and... oysters. Olympia oysters, raw Olympia oysters, shucked Olympia oysters, are of the species Ostrea lurida and conform to the definition and standard of identity prescribed for oysters in § 161.130. ...

  20. Growth, mortality and susceptibility of oyster Crassostrea spp. to Perkinsus spp. infection during on growing in northeast Brazil

    Marcos Paiva Scardua

    2017-11-01

    Full Text Available Abstract Crassostrea rhizophorae and C. gasar oysters are cultivated in the northeast region. Perkinsus parasites infect bivalves, and their effects on oysters from tropical regions are poorly understood. This study evaluated the impact of Perkinsus infection on the productive traits of native oysters. Oysters were sampled bimonthly during 7 months, from July 2010 to February 2011, to evaluate growth rate, mortality and shell color patterns (white and dark-gray (n = 500, and to determine the prevalence and intensity of Perkinsus (n = 152. Perkinsus and Crassostrea species were determined using molecular tools. Results showed that most dark-gray (90%, n = 20 and white (67%, n = 18 oysters were C. gasar and C. rhizophorae, respectively. Oysters showed a high growth rate and moderate cumulative mortality (44%. C. gasar oysters grew better and showed lower mortality and lower incidence of Perkinsus compared to C. rhizophorae. The mean prevalence of Perkinsus was moderate (48%, but the infection intensity was light (2.2. Perkinsosis affected very small oysters (19.4 mm. In conclusion, native oysters, especially C. gasar, have a great potential for culture, mortality is not associated with perkinsosis, and the shell color of oysters can be used to improve selection for spats with better performance.

  1. Oyster radiation sensitivity

    Marchese, Sandra R.M.; Mastro, Nelida L. del

    1996-01-01

    Various food products like oysters, crabs and shrimps have been described as possible Vibrio spp. transmitting agents. Seafood irradiation is been presented as an alternative among the different public health intervention measures to control food borne diseases. The objective of this work was to establish, firstly, the radioresistance of Crassostrea brasiliana oysters. The oysters were irradiated with Co-60 radiation with doses of 0, 1.5,3 and 6 kGy. Survival curves a function of time showed that 100% of samples irradiated with 3 kGy survived at least 6 days; among those irradiated with 6 kGy, 100% survived 3 days. These results are encouraging since a dose of 2 kGy is already effective in diminishing oyster bioburden. (author)

  2. Molecular Cloning and Characterization of Full-Length cDNA of Calmodulin Gene from Pacific Oyster Crassostrea gigas.

    Li, Xing-Xia; Yu, Wen-Chao; Cai, Zhong-Qiang; He, Cheng; Wei, Na; Wang, Xiao-Tong; Yue, Xi-Qing

    2016-01-01

    The shell of the pearl oyster ( Pinctada fucata ) mainly comprises aragonite whereas that of the Pacific oyster ( Crassostrea gigas ) is mainly calcite, thereby suggesting the different mechanisms of shell formation between above two mollusks. Calmodulin (CaM) is an important gene for regulating the uptake, transport, and secretion of calcium during the process of shell formation in pearl oyster. It is interesting to characterize the CaM in oysters, which could facilitate the understanding of the different shell formation mechanisms among mollusks. We cloned the full-length cDNA of Pacific oyster CaM (cgCaM) and found that the cgCaM ORF encoded a peptide of 113 amino acids containing three EF-hand calcium-binding domains, its expression level was highest in the mantle, hinting that the cgCaM gene is probably involved in shell formation of Pacific oyster, and the common ancestor of Gastropoda and Bivalvia may possess at least three CaM genes. We also found that the numbers of some EF hand family members in highly calcified species were higher than those in lowly calcified species and the numbers of these motifs in oyster genome were the highest among the mollusk species with whole genome sequence, further hinting the correlation between CaM and biomineralization.

  3. Molecular Cloning and Characterization of Full-Length cDNA of Calmodulin Gene from Pacific Oyster Crassostrea gigas

    Xing-Xia Li

    2016-01-01

    Full Text Available The shell of the pearl oyster (Pinctada fucata mainly comprises aragonite whereas that of the Pacific oyster (Crassostrea gigas is mainly calcite, thereby suggesting the different mechanisms of shell formation between above two mollusks. Calmodulin (CaM is an important gene for regulating the uptake, transport, and secretion of calcium during the process of shell formation in pearl oyster. It is interesting to characterize the CaM in oysters, which could facilitate the understanding of the different shell formation mechanisms among mollusks. We cloned the full-length cDNA of Pacific oyster CaM (cgCaM and found that the cgCaM ORF encoded a peptide of 113 amino acids containing three EF-hand calcium-binding domains, its expression level was highest in the mantle, hinting that the cgCaM gene is probably involved in shell formation of Pacific oyster, and the common ancestor of Gastropoda and Bivalvia may possess at least three CaM genes. We also found that the numbers of some EF hand family members in highly calcified species were higher than those in lowly calcified species and the numbers of these motifs in oyster genome were the highest among the mollusk species with whole genome sequence, further hinting the correlation between CaM and biomineralization.

  4. Obtenção de comprimidos contendo cálcio de conchas de ostras: pré-formulação e liodisponibilidade comparativa - DOI: 10.4025/actascihealthsci.v28i1.1116 Obtaining tablets with calcium from oyster shells: preformulation and comparative lyoavailability - DOI: 10.4025/actascihealthsci.v28i1.1116

    Ednaldo Queiroga de Lima

    2006-03-01

    Full Text Available A osteoporose é uma doença que afeta um número significativo de pessoas no mundo todo, em especial nos países subdesenvolvidos. Nesse contexto, o pó de concha de ostra, que constitui uma fonte de cálcio, aparece como uma oportunidade de utilizar os recursos naturais da região litorânea brasileira, na suplementação alimentar de sua população. O estudo se propôs a aproveitar essa fonte natural de cálcio, incorporando-a na forma farmacêutica comprimido. O estudo foi desenvolvido em duas etapas, a primeira com a otimização da matéria-prima a partir de conchas de ostra, desde o processo de seleção até a transformação da concha de ostra em pó, com caracterização físico-química e pré-formulação desse pó. A segunda etapa foi a obtenção dos comprimidos desde o desenvolvimento até os ensaios de liodisponibilidade comparativa. Os estudos de pré-formulação e o planejamento fatorial dos excipientes (aglutinante, lubrificante e desintegrante permitiram obter com economia e performance comprimidos com liodisponibilidade semelhante à referência Os-cal®Osteoporosis is a disease that affects a significant number of people in the world, particularly in developing countries. In this context, the powder of oyster shells, found to be a calcium source, emerges as one opportunity to use the natural resources from the Brazilian coast region for alimentary supplementation. This study proposes the use of this natural source of calcium, incorporated in tablets. The study was developed in two parts. The first was concerned with optimizing the raw material from oyster shells, from the selection process until the transformation of de oyster shell into dust; and with the physicochemical evaluation and preformulation of this dust. The second part consisted of obtaining tablets, from the development until the comparative evaluation of lyoavailability. The studies on preformulation and factorial planning of the excipients (binging agent

  5. Obtenção de comprimidos contendo cálcio de btenção conchas de ostras: pré-formulação e liodisponibilidade comparativa = Obtaining tablets with calcium from oyster shells: preformulation and comparative lyoavailability

    Lívio César Cunha Nunes

    2006-01-01

    Full Text Available A osteoporose é uma doença que afeta um número significativo de pessoas no mundo todo, em especial nos países subdesenvolvidos. Nesse contexto, o pó de concha de ostra, que constitui uma fonte de cálcio, aparece como uma oportunidade de utilizar os recursos naturais da região litorânea brasileira, na suplementação alimentar de suapopulação. O estudo se propôs a aproveitar essa fonte natural de cálcio, incorporando-a na forma farmacêutica comprimido. O estudo foi desenvolvido em duas etapas, a primeira com a otimização da matéria-prima a partir de conchas de ostra, desde o processo de seleção até a transformação da concha de ostra em pó, com caracterização físico-química e préformulação desse pó. A segunda etapa foi a obtenção dos comprimidos desde o desenvolvimento até os ensaios de liodisponibilidade comparativa. Os estudos de préformulaçãoe o planejamento fatorial dos excipientes (aglutinante, lubrificante edesintegrante permitiram obter com economia e performance comprimidos com liodisponibilidade semelhante à referência Os-cal.Osteoporosis is a disease that affects a significant number of people in the world, particularly in developing countries. In this context, the powder of oyster shells, found to be a calcium source, emerges as one opportunity to use the natural resources from the Brazilian coast region for alimentary supplementation. This study proposes the use of this natural source of calcium, incorporated in tablets. The studywas developed in two parts. The first was concerned with optimizing the raw material from oyster shells, from the selection process until the transformation of de oyster shell into dust; and with the physicochemical evaluation and preformulation of this dust. The second part consisted of obtaining tablets, from the development until the comparative evaluation of lyoavailability. The studies on preformulation and factorial planning of the excipients (bingingagent

  6. Structural and compositional characterization of the adhesive produced by reef building oysters.

    Alberts, Erik M; Taylor, Stephen D; Edwards, Stephanie L; Sherman, Debra M; Huang, Chia-Ping; Kenny, Paul; Wilker, Jonathan J

    2015-04-29

    Oysters have an impressive ability to overcome difficulties of life within the stressful intertidal zone. These shellfish produce an adhesive for attaching to each other and building protective reef communities. With their reefs often exceeding kilometers in length, oysters play a major role in balancing the health of coastal marine ecosystems. Few details are available to describe oyster adhesive composition or structure. Here several characterization methods were applied to describe the nature of this material. Microscopy studies indicated that the glue is comprised of organic fiber-like and sheet-like structures surrounded by an inorganic matrix. Phospholipids, cross-linking chemistry, and conjugated organics were found to differentiate this adhesive from the shell. Symbiosis in material synthesis could also be present, with oysters incorporating bacterial polysaccharides into their adhesive. Oyster glue shows that an organic-inorganic composite material can provide adhesion, a property especially important when constructing a marine ecosystem.

  7. Top-down control of phytoplankton by oysters in Chesapeake Bay, USA: Comment on Pomeroy et al. (2006)

    Pomeroy et al. (2006) proposed that temporal and spatial mismatches between eastern oyster filtration and phytoplankton abundance will preclude restored stocks of eastern oysters from reducing the severity of hypoxia in the deep channel of central Chesapeake Bay. We refute this c...

  8. Baseline data for evaluating development trajectory and provision of ecosystem services of created fringing oyster reefs in Vermilion Bay, Louisiana

    La Peyre, Megan K.; Schwarting, Lindsay; Miller, Shea

    2013-01-01

    Understanding the time frame in which ecosystem services (that is, water quality maintenance, shoreline protection, habitat provision) are expected to be provided is important when restoration projects are being designed and implemented. Restoration of three-dimensional shell habitats in coastal Louisiana and elsewhere presents a valuable and potentially self-sustaining approach to providing shoreline protection, enhancing nekton habitat, and providing water quality maintenance. As with most restoration projects, the development of expected different ecosystem services often occurs over varying time frames, with some services provided immediately and others taking longer to develop. This project was designed initially to compare the provision and development of ecosystem services by created fringing shoreline reefs in subtidal and intertidal environments in Vermilion Bay, Louisiana. Specifically, the goal was to test the null hypothesis that over time, the oyster recruitment and development of a sustainable oyster reef community would be similar at both intertidal and subtidal reef bases, and these sustainable reefs would in time provide similar shoreline stabilization, nekton habitat, and water quality services over similar time frames. Because the ecosystem services hypothesized to be provided by oyster reefs reflect long-term processes, fully testing the above-stated null hypothesis requires a longer-time frame than this project allowed. As such, this project was designed to provide the initial data on reef development and provision of ecosystem services, to identify services that may develop immediately, and to provide baseline data to allow for longer-term follow up studies tracking reef development over time. Unfortunately, these initially created reef bases (subtidal, intertidal) were not constructed as planned because of the Deepwater Horizon oil spill in April 2010, which resulted in reef duplicates being created 6 months apart. Further confounding the

  9. Predatory blue crabs induce stronger nonconsumptive effects in eastern oysters Crassostrea virginica than scavenging blue crabs

    Avery E. Scherer

    2017-02-01

    Full Text Available By influencing critical prey traits such as foraging or habitat selection, predators can affect entire ecosystems, but the nature of cues that trigger prey reactions to predators are not well understood. Predators may scavenge to supplement their energetic needs and scavenging frequency may vary among individuals within a species due to preferences and prey availability. Yet prey reactions to consumers that are primarily scavengers versus those that are active foragers have not been investigated, even though variation in prey reactions to scavengers or predators might influence cascading nonconsumptive effects in food webs. Oysters Crassostrea virginica react to crab predators by growing stronger shells. We exposed oysters to exudates from crabs fed live oysters or fed aged oyster tissue to simulate scavenging, and to controls without crab cues. Oysters grew stronger shells when exposed to either crab exudate, but their shells were significantly stronger when crabs were fed live oysters. The stronger response to predators than scavengers could be due to inherent differences in diet cues representative of reduced risk in the presence of scavengers or to degradation of conspecific alarm cues in aged treatments, which may mask risk from potential predators subsisting by scavenging.

  10. Investigating the Role of Oysters in Altering Net N2 Fluxes Using Novel In-Situ Experimental Design

    Coastal nutrient over-enrichment represents one of the most pressing environmental management issues faced worldwide. Oyster aquaculture and restoration are hypothesized to mitigate excessive nitrogen (N) loads via increasing benthic denitrification rates in coastal systems. Howe...

  11. The American Oyster.

    Thompson, Nancy E.

    The Maryland Marine Science Education Project has produced a series of mini-units in marine science education for the junior high/middle school classroom. This unit focuses on the American oyster. Although the unit specifically treats the Chesapeake Bay, it may be adapted for use with similar estuarine systems. In addition, the unit may be…

  12. Putting oysters under pressure

    High pressure processing (HPP) is the most commercially important food processing technology in use now and is anticipated to remain of equal or greater importance during the next five to 10 years. This month’s column reviews the theory and current applications of HPP for oysters to improve their sa...

  13. Dangerous Raw Oysters

    2013-08-05

    Dr. Duc Vugia, chief of the Infectious Diseases Branch at the California Department of Public Health, discusses the dangers of eating raw oysters.  Created: 8/5/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/7/2013.

  14. High pressure treatment changes spoilage characteristics and shelf life of Pacific oysters ( Crassostrea gigas) during refrigerated storage

    Cao, Rong; Zhao, Ling; Liu, Qi

    2017-04-01

    The effects of high pressure (HP) treatment on spoilage characteristic and shelf life extension of Pacific oysters ( Crassostrea gigas) during refrigerated storage were studied. Results showed that HP treatment of 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle, pressures higher than 350 MPa caused excessive release as the shells of oysters were broken, thus use of higher pressures should be cautious in oyster processing industry because of its adverse impact on the appearance of shells. HP treatment (300 MPa, 2 min) was proper for the shucking of Pacific oyster ( Crassostrea gigas) in China. This treatment caused no organoleptic disadvantage. Moreover, HP treatment resulted in obvious differences in biochemical spoilage indicators (pH, TVB-N and TBARS) changes and volatile compounds profile determined by electronic nose during storage. HP treatment (300 MPa, 2 min) also led to a reduction of aerobic bacterial count (APC) by 1.27 log cycles. Furthermore, the APC values of oysters treated by HP were always lower than those of the control samples during storage. Based on the organoleptic, biochemical and microbiological indicators, shelf life of 6-8 d for control and 12 d for HP-treated oysters could be expected. HP treatment showed great potential in oyster processing and preservation.

  15. Nutrient bioassimilation capacity of aquacultured oysters: quantification of an ecosystem service.

    Higgins, Colleen B; Stephenson, Kurt; Brown, Bonnie L

    2011-01-01

    Like many coastal zones and estuaries, the Chesapeake Bay has been severely degraded by cultural eutrophication. Rising implementation costs and difficulty achieving nutrient reduction goals associated with point and nonpoint sources suggests that approaches supplemental to source reductions may prove useful in the future. Enhanced oyster aquaculture has been suggested as one potential policy initiative to help rid the Bay waters of excess nutrients via harvest of bioassimilated nutrients. To assess this potential, total nitrogen (TN), total phosphorous (TP), and total carbon (TC) content were measured in oyster tissue and shell at two floating-raft cultivation sites in the Chesapeake Bay. Models were developed based on the common market measurement of total length (TL) for aquacultured oysters, which was strongly correlated to the TN (R2 = 0.76), TP (R2 = 0.78), and TC (R2 = 0.76) content per oyster tissue and shell. These models provide resource managers with a tool to quantify net nutrient removal. Based on model estimates, 10(6) harvest-sized oysters (76 mm TL) remove 132 kg TN, 19 kg TP, and 3823 kg TC. In terms of nutrients removed per unit area, oyster harvest is an effective means of nutrient removal compared with other nonpoint source reduction strategies. At a density of 286 oysters m(-2), assuming no mortality, harvest size nutrient removal rates can be as high as 378 kg TN ha(-1), 54 kg TP ha(-1), and 10,934 kg TC ha(-1) for 76-mm oysters. Removing 1 t N from the Bay would require harvesting 7.7 million 76-mm TL cultivated oysters.

  16. Satellite remote sensing reveals a positive impact of living oyster reefs on microalgal biofilm development

    C. Echappé

    2018-02-01

    Full Text Available Satellite remote sensing (RS is routinely used for the large-scale monitoring of microphytobenthos (MPB biomass in intertidal mudflats and has greatly improved our knowledge of MPB spatio-temporal variability and its potential drivers. Processes operating on smaller scales however, such as the impact of benthic macrofauna on MPB development, to date remain underinvestigated. In this study, we analysed the influence of wild Crassostrea gigas oyster reefs on MPB biofilm development using multispectral RS. A 30-year time series (1985–2015 combining high-resolution (30 m Landsat and SPOT data was built in order to explore the relationship between C. gigas reefs and MPB spatial distribution and seasonal dynamics, using the normalized difference vegetation index (NDVI. Emphasis was placed on the analysis of a before–after control-impact (BACI experiment designed to assess the effect of oyster killing on the surrounding MPB biofilms. Our RS data reveal that the presence of oyster reefs positively affects MPB biofilm development. Analysis of the historical time series first showed the presence of persistent, highly concentrated MPB patches around oyster reefs. This observation was supported by the BACI experiment which showed that killing the oysters (while leaving the physical reef structure, i.e. oyster shells, intact negatively affected both MPB biofilm biomass and spatial stability around the reef. As such, our results are consistent with the hypothesis of nutrient input as an explanation for the MPB growth-promoting effect of oysters, whereby organic and inorganic matter released through oyster excretion and biodeposition stimulates MPB biomass accumulation. MPB also showed marked seasonal variations in biomass and patch shape, size and degree of aggregation around the oyster reefs. Seasonal variations in biomass, with higher NDVI during spring and autumn, were consistent with those observed on broader scales in other European mudflats. Our

  17. Satellite remote sensing reveals a positive impact of living oyster reefs on microalgal biofilm development

    Echappé, Caroline; Gernez, Pierre; Méléder, Vona; Jesus, Bruno; Cognie, Bruno; Decottignies, Priscilla; Sabbe, Koen; Barillé, Laurent

    2018-02-01

    Satellite remote sensing (RS) is routinely used for the large-scale monitoring of microphytobenthos (MPB) biomass in intertidal mudflats and has greatly improved our knowledge of MPB spatio-temporal variability and its potential drivers. Processes operating on smaller scales however, such as the impact of benthic macrofauna on MPB development, to date remain underinvestigated. In this study, we analysed the influence of wild Crassostrea gigas oyster reefs on MPB biofilm development using multispectral RS. A 30-year time series (1985-2015) combining high-resolution (30 m) Landsat and SPOT data was built in order to explore the relationship between C. gigas reefs and MPB spatial distribution and seasonal dynamics, using the normalized difference vegetation index (NDVI). Emphasis was placed on the analysis of a before-after control-impact (BACI) experiment designed to assess the effect of oyster killing on the surrounding MPB biofilms. Our RS data reveal that the presence of oyster reefs positively affects MPB biofilm development. Analysis of the historical time series first showed the presence of persistent, highly concentrated MPB patches around oyster reefs. This observation was supported by the BACI experiment which showed that killing the oysters (while leaving the physical reef structure, i.e. oyster shells, intact) negatively affected both MPB biofilm biomass and spatial stability around the reef. As such, our results are consistent with the hypothesis of nutrient input as an explanation for the MPB growth-promoting effect of oysters, whereby organic and inorganic matter released through oyster excretion and biodeposition stimulates MPB biomass accumulation. MPB also showed marked seasonal variations in biomass and patch shape, size and degree of aggregation around the oyster reefs. Seasonal variations in biomass, with higher NDVI during spring and autumn, were consistent with those observed on broader scales in other European mudflats. Our study provides the

  18. Preliminary Evaluation of Microbial Communities Isolated from the Calcifying Fluid of Oysters

    Banker, R.

    2016-02-01

    The process of biomineralization is defined as the selective uptake of elements that are incorporated into a defined mineral structure under strict biological control. For bivalve molluscs, such as clams, oysters, and mussels, the mantle is the primary organ in control of shell deposition. Alternatively, remote calcification takes place when carbonate-precipitating microbes (e.g. sulfate reducers) colonize a shell-secreting organism and enhance the ability of the host to build shell material. The oyster syndrome is a term that describes bivalves that possess an unusual shell morphology characterized by exceptionally thick valves containing numerous chambers filled with chalky calcite. Although remote calcification via microbial metabolism has been proposed as a mechanism of chalky deposit formation in oysters, this hypothesis has not yet been rigorously investigated. Here I present data on the microbial communities found in the calcifying fluid of two oyster species; Crassostrea gigas and Ostrea lurida are examples of oysters that do and do not exhibit the oyster syndrome, respectively. Comparison of the microbiomes of these two morphological end members may provide insight into the role of microbes in the formation of chalky deposits. Results indicate that the microbial community in the surrounding water is the dominant source for bacterial taxa found in the calcifying fluid of both oyster species. Also, it appears as though C. gigas maintains a microbial community that is more similar to its ambient environment than O. lurida. These results demonstrate that the ambient aquatic environment has a guiding influence on the microbiome found in the calcifying fluid of bivalve molluscs. However, the magnitude of this effect varies among organisms, even those that are closely related.

  19. Preliminary study of transplanting as a process for reducing levels of Vibrio vulnificus and Vibrio parahaemolyticus in shellstock oysters.

    Walton, William C; Nelson, Chris; Hochman, Mona; Schwarz, John

    2013-01-01

    Increasingly strict standards for harvest of oysters for the raw, half-shell market (designated as "white tag") should increase the proportion of oysters not meeting these standards (designated as "green tag"). Transplanting of green tag oysters into highsalinity waters (>20 practical salinity units) was explored as a means of returning Vibrio vulnificus and Vibrio parahaemolyticus levels to levels present on initial harvest. In summer 2011, oysters originally harvested in Louisiana were transplanted on two separate occasions (n = 2) to two sites in Mississippi Sound, AL: Sandy Bay and Dauphin Island. Oysters were tested for V. vulnificus and V. parahaemolyticus densities (by using the U.S. Food and Drug Administration enrichment method) after 2, 7, and 14 days deployed, with baseline samples taken (i) at the time of original harvest and iced, (ii) from oysters refrigerated within 1 h of harvest at oysters not refrigerated during the harvest trip (green tag) but refrigerated after an 8-h trip. White and green tag oysters were sampled ∼24 h on arrival in Bon Secour, AL, put on ice, and shipped for analysis. Among baseline samples, there were no significant differences in V. vulnificus and V. parahaemolyticus densities, although the densities in the green tag oysters tended to be highest. After transplanting, V. vulnificus densities were significantly highest on day 2, with no significant differences among any of the other days within a site. On day 2, Sandy Bay had significantly greater densities of V. vulnificus than the Dauphin Island site, but no other days differed from time zero. For Vibrio parahaemolyticus, densities were greatest on day 2 and lowest at time zero, but this did not differ significantly from abundance on day 14. Average survival was 83.4% (± 3.13 SD), with no differences between sites. These preliminary results indicate that high-salinity transplanting could be an effective method of converting green tag oysters to oysters suitable for

  20. Spatial and temporal variations in cadmium concentrations and burdens in the Pacific oyster (Crassostrea gigas) sampled from the Pacific north-west.

    Bendell, Leah I; Feng, Cindy

    2009-08-01

    Oysters from the north-west coast of Canada contain high levels of cadmium, a toxic metal, in amounts that exceed food safety guidelines for international markets. A first required step to determine the sources of cadmium is to identify possible spatial and temporal trends in the accumulation of cadmium by the oyster. To meet this objective, rather than sample wild and cultured oysters of unknown age and origin, an oyster "grow-out" experiment was initiated. Cultured oyster seed was suspended in the water column up to a depth of 7 m and the oyster seed allowed to mature a period of 3 years until market size. Oysters were sampled bimonthly and at time of sampling, temperature, chlorophyll-a, turbidity and salinity were measured. Oyster total shell length, dry tissue weights, cadmium concentrations (microg g(-1)) and burdens (microg of cadmium oyster(-1)) were determined. Oyster cadmium concentrations and burdens were then interpreted with respect to the spatial and temporal sampling design as well as to the measured physio-chemical and biotic variables. When expressed as a concentration, there was a marked seasonality with concentrations being greater in winter as compared in summer; however no spatial trend was evident. When expressed as a burden which corrects for differences in tissue mass, there was no seasonality, however cadmium oyster burdens increased from south to north. Comparison of cadmium accumulation rates oyster(-1) among sites indicated three locations, Webster Island, on the west side of Vancouver Island, and two within Desolation Sound, Teakerne Arm and Redonda Bay, where point sources of cadmium which are not present at all other sampling locations may be contributing to overall oyster cadmium burdens. Of the four physio-chemical factors measured only temperature and turbidity weakly correlated with tissue cadmium concentrations (r(2)=-0.13; p<0.05). By expressing oyster cadmium both as concentration and burden, regional and temporal patterns were

  1. Larvae of commercial  and other oyster species in Thailand (Andaman Sea and Gulf of Thailand)

    Bussarawit, Somchai; Cedhagen, Tomas

    2012-01-01

    The development of larvae of some Thai commercial oyster species (Crassostrea belcheri (Sowerby, 1871), Crassostrea bilineata (Röding, 1798), Saccostrea forskali (Gmelin, 1791) and Dendrostrea folium (Linnaeus, 1758)) is described from newly hatched to the settlement stage with particular...... reference to changes in shell morphology. Planktonic oyster larvae were collected in the Andaman Sea and the Gulf of Thailand. Different species of oyster larvae were found in the genera Crassostrea, Saccostrea, Ostrea, Dendrostrea, Nanostrea, Planostrea, Lopha, and Hyotissa. Detailed morphological...... descriptions and measurements are provided. Diagnostic features of the larval shape, hinge teeth, and prodissoconch sizes were identified in order to allow separation of commercial oyster larvae from other oyster species in Thai waters. Brooding species (incubatory) of the subfamilies Ostreinae (Ostrea...

  2. Determination of the optimum commercial size for the mangrove oyster (Crassostrea rhizophorae) in Todos os Santos Bay, Brazil

    Nascimento, Iracema Andrade; Pereira, Solange Andrade; Souza, Raymundo Costa e

    1980-01-01

    Texto completo. Acesso restrito. p. 1 – 8 Pilot studies were conducted in 1977-1978 on the cultivation of mangrove oysters in the Jacuruna River estuary at Todos OS Santos Bay, Salvador, Brazil. Growth characteristics were studied by comparing the relationships between total live weight, volume of the shell cavity fluid and yield of meat, and dry body weight to size (height). The most economically feasible proposition was production of approximately 7 cm high oysters for the sh...

  3. Perception of oyster-based products by French consumers. The effect of processing and role of social representations.

    Debucquet, Gervaise; Cornet, Josiane; Adam, Isabelle; Cardinal, Mireille

    2012-12-01

    The search for new markets in the seafood sector, associated with the question of the continuity of raw oyster consumption over generations can be an opportunity for processors to extend their ranges with oyster-based products. The twofold aim of this study was to evaluate the impact of processing and social representation on perception of oyster-based products by French consumers and to identify the best means of development in order to avoid possible failure in the market. Five products with different degrees of processing (cooked oysters in a half-shell, hot preparation for toast, potted oyster, oyster butter and oyster-based soup) were presented within focus groups and consumer tests, at home and in canteens with the staff of several companies in order to reach consumers with different ages and professional activities. The results showed that social representation had a strong impact and that behaviours were contrasted according to the initial profile of the consumer (traditional raw oyster consumers or non-consumers) and their age distribution (younger and older people). The degree of processing has to be adapted to each segment. It is suggested to develop early exposure to influence the food choices and preferences of the youngest consumers on a long-term basis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Developing tools for the study of molluscan immunity: The sequencing of the genome of the eastern oyster, Crassostrea virginica.

    Gómez-Chiarri, Marta; Warren, Wesley C; Guo, Ximing; Proestou, Dina

    2015-09-01

    The eastern oyster, Crassostrea virginica, provides important ecological and economical services, making it the target of restoration projects and supporting a significant fishery/aquaculture industry with landings valued at more than $100 million in 2012 in the United States of America. Due to the impact of infectious diseases on wild, restored, and cultured populations, the eastern oyster has been the focus of studies on host-pathogen interactions and immunity, as well as the target of selective breeding efforts for disease resistant oyster lines. Despite these efforts, relatively little is known about the genetic basis of resistance to diseases or environmental stress, not only in eastern oyster, but also in other molluscan species of commercial interest worldwide. In order to develop tools and resources to assist in the elucidation of the genomic basis of traits of commercial, biological, and ecological interest in oysters, a team of genome and bioinformatics experts, in collaboration with the oyster research community, is sequencing, assembling, and annotating the first reference genome for the eastern oyster and producing an exhaustive transcriptome from a variety of oyster developmental stages and tissues in response to a diverse set of environmentally-relevant stimuli. These transcriptomes and reference genome for the eastern oyster, added to the already available genome and transcriptomes for the Pacific oyster (Crassostrea gigas) and other bivalve species, will be an essential resource for the discovery of candidate genes and markers associated with traits of commercial, biological, and ecologic importance in bivalve molluscs, including those related to host-pathogen interactions and immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Niche dimension differs among life-history stages of Pacific oysters in intertidal environments

    Walles, B.; Smaal, A.C.; Herman, P.M.J.; Ysebaert, T.

    2016-01-01

    Structure-building, autogenic ecosystem engineers are recognized worldwide as potential tools for coastal protection, which depends on long-term sustainability and persistence of their structures. For reef-building oysters, reefs are maintained through accumulation of shell material, which depends

  6. Niche dimension differs among life-history stages of Pacific oysters in intertidal environments

    Walles, Brenda; Smaal, Aad C.; Herman, Peter M.J.; Ysebaert, Tom

    2016-01-01

    Structure-building, autogenic ecosystem engineers are recognized worldwide as potential tools for coastal protection, which depends on long-term sustainability and persistence of their structures. For reef-building oysters, reefs are maintained through accumulation of shell material, which

  7. Effects of pre- or post-processing storage conditions on high-hydrostatic pressure inactivation of Vibrio parahaemolyticus and V. vulnificus in oysters.

    Ye, Mu; Huang, Yaoxin; Gurtler, Joshua B; Niemira, Brendan A; Sites, Joseph E; Chen, Haiqiang

    2013-05-15

    The effects of storage conditions on subsequent high-hydrostatic pressure (HHP) inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in oysters were investigated. Live oysters were inoculated with V. parahaemolyticus or V. vulnificus to ca. 7-8 log MPN/g by feeding and stored at varying conditions (i.e., 21 or 35 °C for 5h, 4 or 10 °C for 1 and 2 days and -18 °C for 2 weeks). Oyster meats were then treated at 225-300 MPa for 2 min at 4, 21 or 35 °C. HHP at 300 MPa for 2 min achieved a >5-log MPN/g reduction of V. parahaemolyticus, completely inactivating V. vulnificus (negative by enrichment) in oysters. Treatment temperatures of 4, 21 and 35 °C did not significantly affect pressure inactivation of V. parahaemolyticus or V. vulnificus (P>0.05). Cold storage at -18, 4 and 10 °C, prior to HHP, decreased V. parahaemolyticus or V. vulnificus populations by 1.5-3.0 log MPN/g, but did not increase their sensitivity to subsequent HHP treatments. The effects of cold storage after HHP on inactivation of V. parahaemolyticus in oysters were also determined. Oysters were inoculated with V. parahaemolyticus and stored at 21 °C for 5h or 4 °C for 1 day. Oyster meats were then treated at 250-300 MPa for 2 min at 21 or 35 °C and stored for 15 days in ice or in a freezer. V. parahaemolyticus populations in HHP-treated oysters gradually decreased during post-HHP ice or frozen storage. A validation study using whole-shell oysters was conducted to determine whether the presence of oyster shells influenced HHP inactivation of V. parahaemolyticus. No appreciable differences in inactivation between shucked oyster meat and whole-shell oysters were observed. HPP at 300 MPa for 2 min at 21 °C, followed by 5-day ice storage or 7-day frozen storage, and HPP at 250 MPa for 2 min at 21 °C, followed by 10-day ice or 7-day frozen storage, completely inactivated V. parahaemolyticus in whole-shell oysters (>7 log reductions). The combination of HHP at a relatively low pressure

  8. Distribution of Georgia Oyster Reefs

    National Oceanic and Atmospheric Administration, Department of Commerce — The feature class in this ESRI Geodatabase contains polygons representing oyster reefs along the Georgia coastal waterways from Chatham County south to Glynn County....

  9. Investigation of coal combustion by-product utilization for oyster reef development in Texas bay waters

    Baker, W.B. Jr.; Ray, S.M.; Landry, A.M. Jr.

    1991-01-01

    Houston Lighting and Power Company (HL and P), Texas A and M University at Galveston and JTM Industries, Inc. initiated research in May 1988 and coordinated it with state and federal resource protection agencies to investigate the use of certain HL and P coal combustion by-products (CCBP) for enhancing and creating oyster reefs. Initial research involved determining and optimum mix design based on compressive strength, leaching potential, biofouling success, and cost. CCBP material was found to exceed compressive strength criterion (300 psi for at sign 14 days) and was not a significant leaching source. Candidate mix designs and oyster shell controls were exposed to hatchery-reared oyster larvae to determine spat setability and biofouling success. Larvae setting on CCBP substrate developed into spat and grew at a rate comparable to that for larvae on controls. Since all candidate mix designs exhibited excellent biofouling, an optimum design was chosen based on strength and material cost factors. Chemical analyses conducted to determine materials did not significantly contribute to the trace element load in oysters. Development of oyster cultch material was initiated with input from commercial 2.5 to 7.6 cm (1 to 3 inch) diameter pellets which are irregularly shaped and rough textured. These pellets greatly enhance water circulation, provide maximum setting potential for oyster larvae, and maximize the surface area to volume potential of the CCBP material

  10. Refining the tethering of American oysters (Crassostrea virginica) to measure the effects of two environmental stressors.

    Poirier, Luke A; Gilbert, Shane T C; St-Hilaire, Sophie; Davidson, Jeff; Cox, Ruth; Quijón, Pedro A

    2018-02-01

    Tethering assays, or the physical restraint of test organisms, has been used in the past to measure selected organisms' response to stressors while removing the observer from the experimental setting. Although informative for monitoring and hypothesis testing, these assays often used microfilaments that have been found to be too invasive or prone to biases given their effects on test organisms' behavior. Here, we describe a new variation of tethering using American oysters (Crassostrea virginica) and illustrate its use in the study of their mortality rates as a result of two stressors: siltation and predation by a non-indigenous species. Our protocol identified a resistant (non-toxic) glue that could be used to attach oysters to stone slabs, thus partially mimicking the natural cementation of the shell to natural substrates. This variation of tethering was harmless and maintained oysters' body position and natural ability to filter feed. Using tethered oysters in separate two-week field cage experiments, we also show how siltation and predation by a non-indigenous species (the European green crab, Carcinus maenas), caused a gradual, easily measurable increase in oyster mortality rates. We argue that this variation of tethering is a cost-effective and advantageous way to monitor or test the effects of these and other stressors on oysters and similar species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Growth history of cultured pearl oysters based on stable oxygen isotope analysis

    Nakashima, R.; Furuta, N.; Suzuki, A.; Kawahata, H.; Shikazono, N.

    2007-12-01

    We investigated the oxygen isotopic ratio in shells of the pearl oyster Pinctada martensii cultivated in embayments in Mie Prefecture, central Japan, to evaluate the biomineralization of shell structures of the species and its pearls in response to environmental change. Microsamples for oxygen isotope analysis were collected from the surfaces of shells (outer, middle, and inner shell layers) and pearls. Water temperature variations were estimated from the oxygen isotope values of the carbonate. Oxygen isotope profiles of the prismatic calcite of the outer shell layer reflected seasonal variations of water temperature, whereas those of nacreous aragonites of the middle and inner shell layers and pearls recorded temperatures from April to November, June to September, and July to September, respectively. Lower temperatures in autumn and winter might slow the growth of nacreous aragonites. The oxygen isotope values are controlled by both variations of water temperature and shell structures; the prismatic calcite of this species is useful for reconstructing seasonal changes of calcification temperature.

  12. The Giant Pacific Oyster (Crassostrea gigas) as a modern analogue for fossil ostreoids

    Ullmann, Clemens Vinzenz; Böhm, Florian; Rickaby, Rosalind E.M.

    2013-01-01

    carbon isotope values of different oysters agree within 0.1 ‰, but ontogenic variability is complicated by shell growth patterns and potential small vital effects. The calcium isotope ratios are found to be constant throughout ontogeny within analytical precision at a value of δ44/40Ca = 0.68 ± 0.16 ‰ (2...... sd) SRM 915a which is consistent with other bivalve species. Calcium isotope ratios in oyster shell material might thus be a possible proxy for palaeo seawater calcium isotope ratios. Element/Ca ratios are significantly higher in the chalky substance than in the foliate layers and especially high Sr...

  13. Biological and chemical data of oil-derived elements being assimilated by oysters due to the Deepwater Horizon Oil Spill collected in Alabama and Mississippi coastal waters (NODC Accession 0118498)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains stable isotope ratios of carbon and nitrogen in oyster shell, suspended particulate matter (SPM), and oil from the Deepwater Horizon oil spill....

  14. 7 CFR 701.54 - Oysters.

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Oysters. 701.54 Section 701.54 Agriculture Regulations... ADMINISTERED UNDER THIS PART § 701.54 Oysters. (a) Notwithstanding § 701.5(b), but otherwise subject to the... be made available under this section for the eligible cost of refurbishing public or private oyster...

  15. USING RESPONSES OF OYSTERS IN ESTABLISHING MINIMUM FLOWS AND LEVELS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA

    Volety, Aswani K., S. Gregory Tolley and James T. Winstead. 2002. Using Responses of Oysters in Establishing Minimum Flows and Levels in the Caloosahatchee Estuary, Florida (Abstract). Presented at the 6th International Conference on Shellfish Restoration, 20-24 November 2002, Ch...

  16. Effect of branding Gulf oysters on consumers willingness to pay

    Acquah, Sarah; Petrolia, Daniel

    2014-01-01

    Using a choice experiment this study found that raw oyster consumers are more likely to buy oysters harvested from their region over those harvested outside the region. Consumers are more likely to buy wild-caught oysters over cultivated oysters. Non-Gulf consumers are more likely to buy medium or large size oysters over small size.

  17. Persistence of Caliciviruses in Artificially Contaminated Oysters during Depuration▿

    Ueki, You; Shoji, Mika; Suto, Atsushi; Tanabe, Toru; Okimura, Yoko; Kikuchi, Yoshihiko; Saito, Noriyuki; Sano, Daisuke; Omura, Tatsuo

    2007-01-01

    The fate of calicivirus in oysters in a 10-day depuration was assessed. The norovirus gene was persistently detected from artificially contaminated oysters during the depuration, whereas feline calicivirus in oysters was promptly eliminated. The prolonged observation of norovirus in oysters implies the existence of a selective retention mechanism for norovirus within oysters.

  18. Oyster-bioimmured ammonites from the Upper Albian of Annopol, Poland: stratigraphic and palaeobiogeographic implications

    Machalski, Marcin; Kennedy, William J.

    2013-12-01

    Machalski, M. and Kennedy, W.J. 2013. Oyster-bioimmured ammonites from the Upper Albian of Annopol, Poland: stratigraphic and palaeobiogeographic implications. Acta Geologica Polonica, 63 (4), 545-554. Warszawa. Ammonites Mortoniceras (Subschloenbachia) sp. are preserved as attachment scars on the oyster shells from the topmost portion of the Albian succession at Annopol, Poland. These oyster-bioimmured ammonites show a closest affinity to the representatives of Mortoniceras (Subschloenbachia) characteristic of the upper Upper Albian Mortoniceras perinflatum Zone. No ammonites indicative of the uppermost Albian-lowermost Cenomanian Praeschloenbachia briacensis Zone are recorded. Thus, the hiatus at the Albian-Cenomanian boundary at Annopol embraces the latter zone. The presence (and dominance) of Mortoniceras in the upper Upper Albian ammonite assemblage of Annopol suggests that the representatives of this Tethyan genus could migrate into the epicratonic areas of Poland directly from the Tethyan Realm, via the Lwow (Lviv) region.

  19. The impact of suspended oyster farming on nitrogen cycling and nitrous oxide production in a sub-tropical Australian estuary

    Erler, Dirk V.; Welsh, David T.; Bennet, William W.; Meziane, Tarik; Hubas, Cédric; Nizzoli, Daniele; Ferguson, Angus J. P.

    2017-06-01

    In this study we quantified nitrate (NO3-) reduction (denitrification, anammox and DNRA) and N2O production in sediments and epibiont communities associated with Sydney Rock Oyster (Saccostrea glomerata) farming. In sediments beneath an active suspended oyster farm, DNRA accounted for 98% of NO3- reduction with rates of up to 169 ± 45 μmol N m-2 h-1. Much of this DNRA was fuelled by NO3- derived from nitrification. Reference sediments had significantly lower DNRA rates of 83.8 ± 28.2 μmol N m-2 h-1, however this constituted 96% of the sites total NO3- reduction. Fatty acid analysis showed that sediment organic matter was more labile in the oyster impacted sediments, facilitating subtle shifts in sediment oxygen demand which increased the Fe2+ availability with respect to the reference sediments. The difference in DNRA rate between the sites was attributed to autotrophic oxidation of soluble Fe2+ in sediments underlying the oyster cultures. DNRA was absent in the oyster shell epibiont communities and rates of anammox and denitrification were lower than in the sediments. Production of NH4+ from the oysters and their associated epibionts was larger than DNRA and reached a rate of 206.2 μmol N m-2 h-1. Nitrous oxide production rates were generally low compared to other aquaculture systems and the net flux of N2O for the combined oyster cultivation system (i.e. sediments plus epibionts) was negative, i.e. there was N2O consumption in the sediments beneath the oysters. Overall, subtropical suspended oyster farming systems favour inorganic N retention over N loss.

  20. Shell Venster

    De Wit, P.; Looijesteijn, B.; Regeer, B.; Stip, B.

    1995-03-01

    In the bi-monthly issues of 'Shell Venster' (window on Shell) attention is paid to the activities of the multinational petroleum company Shell Nederland and the Koninklijke/Shell Groep by means of non-specialist articles

  1. PARASITIC AND SYMBIOTIC FAUNA IN OYSTERS (CRASSOSTREA VIRGINICA) AND MUD CRABS (PANOPEUS SPP.) FROM THE CALOOSAHATCHEE ESTUARY, FLORIDA, USA.

    Volety, Aswani K., S. Greg Tolley and James T. Winstead. 2002. Parasitic and Symbiotic Fauna in Oysters (Crassostrea virginica) and Mud Crabs (Panopeus spp.) from the Caloosahatchee Estuary, Florida, USA (Abstract). Presented at the 4th International Conference on Molluscan Shell...

  2. Japanese oysters in Dutch waters

    Berg, van den J.B.; Kozyreff, G.; Lin, H.X.; McDarby, J.; Peletier, M.A.; Planqué, R.; Wilson, P.L.; Pik, D.; Rottschäfer, V.

    2004-01-01

    We study a number of aspects of the colonisation of the Eastern Scheldt by the Japanese Oyster. We formulate and analyse some simple models of the spatial spreading, and determine a rough dependence of the spreading behaviour on parameters. We examine the suggestion of reducing salinity by opening

  3. Noroviruses in oysters from local markets and oyster farms in southern Thailand.

    Kittigul, Leera; Pombubpa, Kannika; Sukonthalux, Suntharee; Rattanatham, Tippawan; Utrarachkij, Fuangfa

    2011-01-01

    One hundred and eighteen oyster samples collected from local markets and oyster farms in southern Thailand were examined for noroviruses (NoVs) and bacterial indicators of fecal contamination (fecal coliforms and Escherichia coli). Using a virus concentration procedure followed by RT-nested PCR, NoVs were detected in 38% of the samples. Oysters collected from oyster farms were found with NoVs at a higher detection rate (25/53 samples) than oysters from local markets (20/65 samples). Of the 45 NoV-positive oyster samples, 67% belonged to NoV genogroup I (GI), 15% to GII, and 18% to both GI and GII. DNA sequencing showed that 2 NoVs belonged to NoV GI-2 genotype. Fecal coliforms in NoV-positive oyster samples were in the range of oyster samples contained fecal coliforms within the standard acceptable level of raw shellfish (oyster samples were within acceptable levels of E. coli contamination (oysters obtained from both markets and oyster farms might pose a potential risk of acute gastroenteritis associated with raw oyster consumption. Examination for both fecal bacterial indicators and enteric viruses should be conducted for microbiological food safety of shellfish.

  4. Evolution and functional analysis of the Pif97 gene of the Pacific oyster Crassostrea gigas

    Xiaotong WANG, Xiaorui SONG, Tong WANG, Qihui ZHU, Guoying MIAO, Yuanxin CHEN, Xiaodong FANG, Huayong QUE, Li LI, Guofan ZHANG

    2013-02-01

    Full Text Available Mollusc shell matrix proteins (SMPs are important functional components embedded in the shell and play a role in shell formation. A SMP (Pif177 was identified previously from the nacreous layer of the Japanese pearl oyster Pinctada fucata, and its cleavage products (named pfPif97 and pfPif80 proteins were found to bind to the chitin framework and induce aragonite crystal formation and orient the c axis. In this study, a homologue of pfPif177 was cloned from the mantle of the Pacific oyster Crassostrea gigas, containing the homologue of pfPif97 only and not pfPif80. This finding hints at the large divergence in gene structure between the two species. This homologue (cgPif97 shares characteristics with pfPif97, and suggests that the biological functions of these two proteins may be similar. The expression pattern of cgPif97 in different tissues and development stages indicates that it may play an important role in shell formation of the adult oyster. The morphology of the inner shell surface was affected by injected siRNA of cgPif97 and the calcite laths of the shell became thinner and narrower when the siRNA dose increased, suggesting that the cgPif97 gene plays an important role in calcite shell formation in C. gigas. In conclusion, we found evidence that the Pif177 gene evolved very fast but still retains a similar function among species [Current Zoology 59 (1: 109–115, 2013].

  5. Measuring Macrobenthos Biodiversity at Oyster Aquaculture Sites in the Delaware Inland Bays

    Fuoco, M. J.; Ozbay, G.

    2016-12-01

    The Delaware Inland Bays consists of three shallow coastal bays located in the southern portion of Delaware. Anthropogenic activities have led to the degradation of water quality, because the bays are surrounded by highly developed areas and have low flushing rates. This results in loss of biodiversity and abundance of organisms. Ongoing degradation of the bays has led to a dramatic decline in local oyster populations since the late 1800s. Oysters are keystone species, which provide habitats for organisms and help to improve water quality. This study aims to find if the introduction of oyster aquaculture improves local biodiversity and abundance of macrobenthos. The study was conducted in Rehoboth Bay, Indian River Bay and Little Assawoman Bay. Aquaculture gear was placed at one location in each of the bays and 24 sediment core samples were taken once a month. From these core samples all worms were fixed and stained in a 10% Formalin Rose Bengal solution and preserved in 70% Ethanol for later identification. Stable carbon and nitrogen isotope analysis of oyster tissue will also be performed to assess the health of the bay. The goals of this research are to better understand the role of oyster aquaculture in restoring the viability and health of the Delaware Inland Bays.

  6. Dose characterization of the rad sourceTM 2400 X-ray irradiator for oyster pasteurization

    Wagner, Jennifer Koop; Dillon, Jeff A.; Blythe, Eugene K.; Ford, John R.

    2009-01-01

    The RS 2400's cylindrical X-ray source yields dose rates high enough to allow the irradiator to replace widely used gamma irradiators. Except for the leftmost 5 cm, beam uniformity is within 10% at the tube surface. At maximum operating parameters, the beam has HVL 1 =13.66 mm aluminum, HC=0.47, and hν eq =88.5 keV. Maximum dose rates to tissue are 65 Gy min -1 ±3.1% at tube surface, 37 Gy min -1 ±3.1% at center of canisters, 14.1 Gy min -1 ±6.5% for thin-shelled oysters, and 12.3 Gy min -1 ±6.2% for thick-shelled oysters

  7. Pacific oyster culture in British Columbia

    Quayle, D. B; Quayle, Daniel Branch

    1988-01-01

    .... Harvesting, processing, and storage methods are described. The problems of Pacific oyster culture include industrial and sewage pollution, paralytic shellfish poisoning along with predators and disease...

  8. Obtainment of calcium carbonate from mussels shell

    Hamester, M.R.R.; Becker, D.

    2010-01-01

    The mussels and oyster shell are discarded at environment, and this accumulation is causing negative consequences to ecosystem. Calcium carbonate is main constituent of the shell chemical composition. Aiming to reduce environmental aggression and generate income to shellfish producer, there was the possibility of using these shells as an alternative to commercial calcium carbonate. For this physics, chemicals and thermal properties were evaluated, using X-ray fluorescence, thermogravimetric analysis, size distribution, abrasiveness and scanning electronic microscopy. The results indicate that mussels shells have an initial degradation temperature higher than commercial calcium carbonate e same lost weight behavior and 95% of shell chemical composition is calcium carbonate. The sample size distribution was influenced by grinding condition and time as well as its abrasiveness. (author)

  9. Reducing oyster-associated bacteria levels using supercritical fluid CO2 as an agent of warm pasteurization.

    Meujo, Damaris A F; Kevin, Dion A; Peng, Jiangnan; Bowling, John J; Liu, Jianping; Hamann, Mark T

    2010-03-31

    An innovative approach to Post-Harvest Processing (PHP) of oysters is introduced focusing on the effects of supercritical carbon dioxide (scCO(2)) on bacterial contaminants trapped in the digestive system of oysters. Oysters were exposed to scCO(2) under two conditions: (1) 100 bar and 37 degrees C for 30 min and (2) 172 bar and 60 degrees C for 60 min. Using FDA standard guidelines for food analysis, variations in the Aerobic Plate Count (APC) were assessed. It was established that exposing oysters to CO(2) at 100 bar and 37 degrees C for 30 min and at 172 bar and 60 degrees C for 60 min induced 2-log and 3-log reductions in the APC respectively. The decrease in the microbial load as a result of treatment with scCO(2) was found to be significant (P=0.002). A release of adductor muscles from the shell was noted in oysters treated at 172 bar and 60 degrees C for 60 min; this was not the case for oysters treated at 100 bar and 37 degrees C for 30 min. A blind study allowing sensory analysis of treated vs. untreated oysters was also completed and no significant change in the physical appearance, smell, or texture was recorded. In this paper, we also report the effect of scCO(2) on several bacterial isolates, including a referenced ATCC strain of a non-pathogenic Vibrio (Vibrio fischeri) as well as several other bacterial isolates cultured from oyster' tissues and found to share biochemical features common to pathogenic Vibrio strains. A complete inactivation (minimum 7-log reduction) was achieved with these latter bacterial isolates. A 6-log reduction was observed with V. fischeri. Copyright 2009 Elsevier B.V. All rights reserved.

  10. Spatial and temporal variations in cadmium concentrations and burdens in the Pacific oyster (Crassostrea gigas) sampled from the Pacific north-west

    Bendell, Leah I.; Feng, Cindy

    2009-01-01

    Oysters from the north-west coast of Canada contain high levels of cadmium, a toxic metal, in amounts that exceed food safety guidelines for international markets. A first required step to determine the sources of cadmium is to identify possible spatial and temporal trends in the accumulation of cadmium by the oyster. To meet this objective, rather than sample wild and cultured oysters of unknown age and origin, an oyster 'grow-out' experiment was initiated. Cultured oyster seed was suspended in the water column up to a depth of 7 m and the oyster seed allowed to mature a period of 3 years until market size. Oysters were sampled bimonthly and at time of sampling, temperature, chlorophyll-a, turbidity and salinity were measured. Oyster total shell length, dry tissue weights, cadmium concentrations (μg g -1 ) and burdens (μg of cadmium oyster -1 ) were determined. Oyster cadmium concentrations and burdens were then interpreted with respect to the spatial and temporal sampling design as well as to the measured physio-chemical and biotic variables. When expressed as a concentration, there was a marked seasonality with concentrations being greater in winter as compared in summer; however no spatial trend was evident. When expressed as a burden which corrects for differences in tissue mass, there was no seasonality, however cadmium oyster burdens increased from south to north. Comparison of cadmium accumulation rates oyster -1 among sites indicated three locations, Webster Island, on the west side of Vancouver Island, and two within Desolation Sound, Teakerne Arm and Redonda Bay, where point sources of cadmium which are not present at all other sampling locations may be contributing to overall oyster cadmium burdens. Of the four physio-chemical factors measured only temperature and turbidity weakly correlated with tissue cadmium concentrations (r 2 = -0.13; p < 0.05). By expressing oyster cadmium both as concentration and burden, regional and temporal patterns were

  11. The hot oyster: levels of virulent Vibrio parahaemolyticus strains in individual oysters.

    Klein, Savannah L; Lovell, Charles R

    2017-02-01

    Vibrio parahaemolyticus is the leading cause of seafood-associated gastroenteritis and is most commonly transmitted by raw oysters. Consequently, detection of virulent strains of this organism in oysters is a primary concern for seafood safety. Vibrio parahaemolyticus levels were determined in 110 individual oysters harvested from two sampling sites in SC, USA. The majority of oysters (98%) contained low levels of presumptive V. parahaemolyticus However, two healthy oysters contained presumptive V. parahaemolyticus numbers that were unusually high. These two 'hot' oysters contained levels of presumptive V. parahaemolyticus within the gills that were ∼100-fold higher than the average for other oysters collected at the same date and location. Current V. parahaemolyticus detection practices require homogenizing a dozen oysters pooled together to determine V. parahaemolyticus numbers, a procedure that would dilute out V. parahaemolyticus in these 'hot' oysters. This study demonstrates the variability of V. parahaemolyticus densities taken from healthy, neighboring individual oysters in the environment. Additionally, environmental V parahaemolyticus isolates were screened for the virulence-related genes, tdh and trh, using improved polymerase chain reaction primers and protocols. We detected these genes, previously thought to be rare in environmental isolates, in approximately half of the oyster isolates. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Mapping Oyster Reef Habitats in Mobile Bay

    Bolte, Danielle

    2011-01-01

    Oyster reefs around the world are declining rapidly, and although they haven t received as much attention as coral reefs, they are just as important to their local ecosystems and economies. Oyster reefs provide habitats for many species of fish, invertebrates, and crustaceans, as well as the next generations of oysters. Oysters are also harvested from many of these reefs and are an important segment of many local economies, including that of Mobile Bay, where oysters rank in the top five commercial marine species both by landed weight and by dollar value. Although the remaining Mobile Bay oyster reefs are some of the least degraded in the world, projected climate change could have dramatic effects on the health of these important ecosystems. The viability of oyster reefs depends on water depth and temperature, appropriate pH and salinity levels, and the amount of dissolved oxygen in the water. Projected increases in sea level, changes in precipitation and runoff patterns, and changes in pH resulting from increases in the amount of carbon dioxide dissolved in the oceans could all affect the viability of oyster reefs in the future. Human activities such as dredging and unsustainable harvesting practices are also adversely impacting the oyster reefs. Fortunately, several projects are already under way to help rebuild or support existing or previously existing oyster reefs. The success of these projects will depend on the local effects of climate change on the current and potential habitats and man s ability to recognize and halt unsustainable harvesting practices. As the extent and health of the reefs changes, it will have impacts on the Mobile Bay ecosystem and economy, changing the resources available to the people who live there and to the rest of the country, since Mobile Bay is an important national source of seafood. This project identified potential climate change impacts on the oyster reefs of Mobile Bay, including the possible addition of newly viable

  13. Oyster reefs as natural breakwaters mitigate shoreline loss and facilitate fisheries.

    Steven B Scyphers

    Full Text Available Shorelines at the interface of marine, estuarine and terrestrial biomes are among the most degraded and threatened habitats in the coastal zone because of their sensitivity to sea level rise, storms and increased human utilization. Previous efforts to protect shorelines have largely involved constructing bulkheads and seawalls which can detrimentally affect nearshore habitats. Recently, efforts have shifted towards "living shoreline" approaches that include biogenic breakwater reefs. Our study experimentally tested the efficacy of breakwater reefs constructed of oyster shell for protecting eroding coastal shorelines and their effect on nearshore fish and shellfish communities. Along two different stretches of eroding shoreline, we created replicated pairs of subtidal breakwater reefs and established unaltered reference areas as controls. At both sites we measured shoreline and bathymetric change and quantified oyster recruitment, fish and mobile macro-invertebrate abundances. Breakwater reef treatments mitigated shoreline retreat by more than 40% at one site, but overall vegetation retreat and erosion rates were high across all treatments and at both sites. Oyster settlement and subsequent survival were observed at both sites, with mean adult densities reaching more than eighty oysters m(-2 at one site. We found the corridor between intertidal marsh and oyster reef breakwaters supported higher abundances and different communities of fishes than control plots without oyster reef habitat. Among the fishes and mobile invertebrates that appeared to be strongly enhanced were several economically-important species. Blue crabs (Callinectes sapidus were the most clearly enhanced (+297% by the presence of breakwater reefs, while red drum (Sciaenops ocellatus (+108%, spotted seatrout (Cynoscion nebulosus (+88% and flounder (Paralichthys sp. (+79% also benefited. Although the vertical relief of the breakwater reefs was reduced over the course of our study

  14. 21 CFR 161.130 - Oysters.

    2010-04-01

    ... water. Before packing into the containers for shipment or other delivery for consumption the oysters are... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FISH AND SHELLFISH Requirements for Specific Standardized Fish and Shellfish § 161.130 Oysters. (a...

  15. Study of characterization of trace elements in marine shells of Sambaqui: correlation between recent and old shells

    Gomez, Mauro Roger Batista Pousada; Rocha, Flavio Roberto; Silva, Paulo Sergio Cardoso da

    2013-01-01

    Calcium carbonate of recent and ancient C. rhizophorae oyster shells was analyzed for the determination of trace elements by instrumental neutron activation analysis. The ancient shells belong to a Sambaqui located in Cananeia region, South of Sao Paulo state and the recent ones are from an oyster production farm in the same region Studies related to the element concentrations in molluscs shell has been done as a tentative of establishing the element concentrations with palio-environmental factor. In this study it was aimed to verify differences in the elemental constitution of recent and ancient oyster shells that present potential for being used as indicator of marine changes. Results indicated that the elements Br, Ce, La, Na, Sm and An are higher in recent shells and the elements Cr, Fe Sc and Th are higher in ancient shells. Statistical analyses performed indicated that the enrichment of the light rare earth elements related to Ca are possibly good candidates for these palio-environmental studies. (author)

  16. Thresholds of motion of shell debris under unidirectional flow: influence of faunal composition

    Rieux, A.; Weill, P.; Mouazé, D.; Poirier, C.; Tessier, B.

    2017-12-01

    Quantifying bottom sediment erodibility is necessary to refine understanding of coastal processes and fossil records. Coastal sediments are partly composed of biogenic particles, which shape and density differ from rounded quartz grain and vary between species. Numerous studies have investigated the hydrodynamic behaviour of bioclastic sediments derived from reef-dwelling organisms, but research focusing on "cool-water carbonate" bioclastic particles (i.e. mollusc shell debris, calcareous algae, …) are rare. The present study aims in characterizing the influence of faunal composition on the entrainment threshold of mollusc shell debris from temperate regions. Shells have been sampled on shelly ridges in the southern coast of the Mont-Saint-Michel bay (NW France), before being ground and separated into individual sieve fractions. Eight species, representative of the local faunal composition, have been studied: four wild (cockle, furrow shell, saddle oyster, flat oyster), three reared (japanese oyster, mussel, manila clam) and one introduced (slipper limpet) species. Experiments for defining the threshold of motion of all samples were conducted in a small recirculating flume, under unidirectional current, and using an Acoustic Doppler Velocimeter Profiler. Critical bed shear stress values (τcr) were derived from velocity profiles in the boundary layer, by a logarithmic regression of the "law of the wall". Depending on the species, the evolution of τcr with increasing grain diameters follows either an asymptotic or a more linear trend. Differences between species can be discerned: saddle oyster, japanese oyster and flat oyster show the smallest τcr, slipper limpet, furrow shell and mussel have an intermediate τcr and cockle and manila clam the highest τcr. For the 2-3.15 mm fraction, τcr ranges from 0.38 N.m-2 (saddle oyster) to 2.13 N.m-2 (cockle). Oyster shells (japanese and flat oysters) are composed of foliated sheets of calcite, interbedded with soft

  17. Sensitivity of oysters (Crassostrea Brasiliana) to radiation

    Mattiolo Marchese, S.R.; Mastro, N.L. del

    1997-01-01

    Various foods including oysters, crabs and shrimps have been shown to be possible transmitters of Vibrio ssp. Irradiation of sea-foods is being considered an alternative to intervention measures in Public Health against food borne diseases. The aim of this work was to establish, the radiation resistance of the oysters Crassostrea brasiliana. The oysters were irradiated with Co-60 radiation with doses of 0, 1.5, 3 and 6 kGy. Survival curves as a function of time showed that 100% of the oysters irradiated with doses of 3 kGy survived at least 6 days. 100% those irradiated with 6 kGy survived 3 days. The obtained results are auspicious considering that a dose of 2 kGy is already effective in the diminishing of the microbial load on oysters. (author)

  18. Surveying a fossil oyster reef using terrestrial laser scanning

    Haring, A.; Exner, U.; Harzhauser, M.

    2009-04-01

    The Korneuburg Basin, situated north-west of Vienna, is well known to contain a rich variety of fossils from the Early Miocene (16.5 ma) and therefore has been investigated extensively by scientists in the past decades. An exceptional discovery was made in 2005: a large fossil oyster reef has been excavated and documented carefully during the last years. Aside from the giant-sized oyster (Crassostrea gryphoides), the excavation site contains numerous species of molluscs along with teeth of sharks and rays and even isolated bones of sea cows. The oysters, having lengths of up to 80 cm, are protruding from the ground surface, which is more or less a tilted plane (25˚ ) with a size of about 300 m2. The entire site is crosscut by a network of geological faults, often also offsetting individual oyster shells. Displacements along the normal faults do not exceed ~ 15 cm. The faulted fossils offer a unique opportunity to measure displacement distribution along the faults in great detail and provide insight in deformation mechanisms in porous, barely lithified sediments. In order to get a precise 3D model of the oyster reef, the terrestrial laser scanner system Leica HDS 6000 is used. It is a phase-based laser scanner, i.e. the distance measurement is performed using the phase-shift principle. Compared to the time-of-flight principle, this method is generally more appropriate to projects like this one, where the distances to be measured are relatively small (< 35 m) and where a high point density (point spacing of about 1 cm) and precision (some mm) is required for capturing the oysters adequately. However, due to fact that they occlude each other, one single scan is not sufficient to get all sides of their surface. Therefore, scans from different positions had to be acquired. These scans have to be merged, which involves the problem of sensor orientation as well as sampling of the entire 3D point cloud. Furthermore, a representation of the surface data is required that

  19. Sensory and Chemical Characteristics of Eastern Oysters(Crassostrea virginica)

    Chen, Luman

    2011-01-01

    Eastern Oysters, or Crassostrea virginica, are an important dietary component in the Chesapeake region and have supported a major fishery in the Chesapeake for more than 100 years. Virginia oysters do not always receive attention in up-scale markets. It is possible that the lack of information on sensory characteristics of Chesapeake oysters may contribute to this problem. In order to differentiate Chesapeake oysters from other oysters, a descriptive sensory test (n=8) was conducted and chemi...

  20. Uptake of cadmium from Pacific oysters (Crassostrea gigas) in British Columbia oyster growers

    Copes, Ray; Clark, Nina Annika; Rideout, Karen; Palaty, Jan; Teschke, Kay

    2008-01-01

    Background: Pacific oysters along the North American coast from Washington to Alaska contain concentrations of cadmium (Cd) that are high by comparison with Atlantic oysters, frequently exceeding 2 μg/g wet weight, but it is unclear whether this Cd is absorbed by consumers. Objectives: To determine the effect of oyster consumption on Cd in blood and urine among a group with high oyster consumption. Methods: Sixty-one non-smoking oyster growers and family members with a mean age of 47.3±7.6 years (range 33-64) were interviewed by telephone to assess their oyster consumption and other sources of Cd exposure at present and 5 years prior to the start of oyster farming. Their blood and urine Cd concentrations were measured. Results: The geometric mean Cd concentration in blood was 0.83 μg/L and in urine was 0.76 μg/g creatinine. Thirty-six percent of participants had urinary Cd levels above 1 μg/g creatinine and 5% were above 2 μg/g creatinine. Recent (last 12 months) and long-term oyster consumptions were positive predictors of blood Cd but did not directly predict urinary Cd. The optimal model for predicting the variance in blood Cd included recent intake of oyster-derived Cd, serum iron concentration and recent ketchup consumption (R 2 =0.34, p=0.00004), with the latter two variables showing a protective effect. The factors found to predict urinary Cd were blood Cd concentration and duration of oyster farming. A rise in blood Cd was observed after 12 years of farming oysters, likely caused by higher consumption of oysters during this period. Conclusions: Oyster-derived Cd is bioavailable and affects body stores of the metal

  1. Oyster condition index in Crassostrea rhizophorae (Guilding, 1828 from a heavy-metal polluted coastal lagoon

    M. F. Rebelo

    Full Text Available The condition index (CI of oysters represents an ecophysiological approach to estimate meat quality and yield in cultured bivalve mollusks. In the present study, the CI of oysters from a heavy-metal polluted bay was analyzed with respect to Zn and Cd contamination in soft tissues, spawning, and polychaete infestation. The CI was calculated through a new technique based on molds made to measure the volume of oyster-shell internal cavities. The higher CI values (over 9 in the dry season were probably related availability of suspended particles rich in organic matter in the bay, while the rapid reduction in the CI from one season to the next at some stations suggests the effect of spawning. Polychaete infestation was considered low (18.7% and produced no clear CI effects. The Cd in the oyster tissue collected during the rainy season was weak, although still significantly correlated with the CI (r = -0.36; p < 0.05. All other comparisons of CI and metal concentrations demonstrated a non-significant correlation. The CI variations observed on the temporal and spatial scale were likely to have been caused by availability of organic matter and spawning, rather than spionid infestation or metal body burdens.

  2. Review of the histopathological effects of ionizing radiation on the Pacific oyster, Crassostrea gigas

    Mix, M.C.

    1976-01-01

    Oysters were exposed to various doses of gamma radiation up to 400 k rads and maintained in a flow-through seawater system. They were sampled at intervals and histological analyses were made. Chronic degeneration was observed in all tissues dependent on a cell renewal system for their integrity. Results indicated that mortality was related to the failure of the cell renewal system to restore depleted cell populations and that the LD 50 concept has little practical value in studies on invertebrates

  3. Predicting the impacts of Mississippi River diversions and sea-level rise on spatial patterns of eastern oyster growth rate and production

    Wang, Hongqing; Chen, Qin; La Peyre, Megan K.; Hu, Kelin; La Peyre, Jerome F.

    2017-01-01

    There remains much debate regarding the perceived tradeoffs of using freshwater and sediment diversions for coastal restoration in terms of balancing the need for wetland restoration versus preserving eastern oyster (Crassostrea virginica) production. Further complicating the issue, climate change-induced sea-level rise (SLR) and land subsidence are also expected to affect estuarine water quality. In this study, we developed a process-based numerical modeling system that couples hydrodynamic, water quality, and oyster population dynamics. We selected Breton Sound Estuary (BSE) (∼2740 km2) in the eastern Mississippi River Deltaic Plain since it is home to several of the largest public oyster seed grounds and private leases for the Gulf coast. The coupled oyster population model was calibrated and validated against field observed oyster growth data. We predicted the responses of oyster population in BSE to small- (142 m3 s−1) and large-scale (7080 m3 s−1) river diversions at the Caernarvon Freshwater Diversion structure planned in the 2012 Coastal Master Plan (Louisiana) under low (0.38 m) and high (1.44 m) relative sea-level rise (RSLR = eustatic SLR + subsidence) compared to a baseline condition (Year 2009). Model results showed that the large-scale diversion had a stronger negative impact on oyster population dynamics via freshening of the entire estuary, resulting in reduced oyster growth rate and production than RSLR. Under the large-scale diversion, areas with optimal oyster growth rates (>15 mg ash-free dry weight (AFDW) oyster−1 wk−1) and production (>500 g AFDW m−2 yr−1) would shift seaward to the southeastern edge of the estuary, turning the estuary into a very low oyster production system. RSLR however played a greater role than the small-scale diversion on the magnitude and spatial pattern of oyster growth rate and production. RSLR would result in an overall estuary-wide decrease in oyster growth rate and production as a

  4. Effect of ocean acidification on growth, calcification, and gene expression in the pearl oyster, Pinctada fucata.

    Liu, Wenguang; Yu, Zonghe; Huang, Xiande; Shi, Yu; Lin, Jianshi; Zhang, Hua; Yi, Xuejie; He, Maoxian

    2017-09-01

    In this study, shell growth, shell microstructure, and expression levels of shell matrix protein genes (aspein, n16, and nacrein) that play a key role in the CaCO 3 crystal polymorphism (calcite and aragonite) of the shell were investigated in the pearl oyster Pinctada fucata at pH 8.10, 7.70, and 7.40. We found that the shell length and total weight index did not vary significantly between oysters reared at pH 8.10 and 7.70, but was significantly lower at pH 7.40. Calcium content and shell hardness were not significantly different between pH 8.10 and 7.70, but were significantly different at pH 7.40. At pH 7.40, the shell exhibited a poorly organized nacreous microstructure, and showed an apparent loss of structural integrity in the nacreous layer. The prismatic layer appeared morphologically dissimilar from the samples at pH 8.10 and 7.70. The internal layer was corroded and had dissolved. At pH 7.40, the expression levels of nacrein, aspein, and n16 decreased on day 1, and remained low between days 2 and 42. The expression levels of these genes were significantly lower at pH 7.40 than at pH 8.10 and 7.70 during days 2-42. These results suggest that ocean acidification will have a limited impact on shell growth, calcification, and associated gene expression levels at a pH of 7.70, which is projected to be reached by the end of the century. The negative effects were found on calcification and gene expression occurred at the lowest experimental pH (7.40). Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Characterisation of Oyster Shell for Neutralisation of Bio- Leached ...

    Michael

    2016-12-02

    Dec 2, 2016 ... (Goodall et al., 2005; O'Connor and Dunne, 1994;. Kydros et al. ... while the gold is concentrated in the iron oxide (hemaetite) residue ..... leaching in the characterisation of complex gold ores” ... Australia, 413 pp. O'Connor ...

  6. [Estimation and experiment of carbon sequestration by oysters attached to the enhancement artificial reefs in Laizhou Bay, Shandong, China].

    Gong, Pi-Hai; Li, Jiao; Guan, Chang-Tao; Li, Meng-Jie; Liu, Chao

    2014-10-01

    Through sampling investigation of fouling organisms on the enhancement artificial reefs set up in Laizhou Bay, it was proved that oyster (Ostrea plicatula) was the dominant fouling species. Therefore the dry mass of shell (Ms), total fresh mass (Mt) and thickness (T) of oyster attached on the reefs were analyzed. The results showed that the Mt and Ms presented seasonal variation (P oysters attaching to the tube enhancement reefs constructed in 2009, 2010 and 2011 in Laizhou Bay were 17.61, 16.33 and 10.45 kg · m(-3), respectively. The oysters on the enhancement reefs of Jincheng marine ranch with an area of 64.25 hm2 had fixed carbon of 297.5 t C (equivalent to 1071 t of CO2) from 2009 to 2013 in Laizhou Bay. To capture and store the same amount of CO2 would cost about 1.6 x 10(5)-6.4 x 10(5) US dollars. Therefore, oysters attaching to the enhancement reefs bring about remarkable ecological benefits.

  7. Sub-chronic exposure to fluoxetine in juvenile oysters (Crassostrea gigas): uptake and biological effects.

    Di Poi, Carole; Evariste, Lauris; Séguin, Alexis; Mottier, Antoine; Pedelucq, Julie; Lebel, Jean-Marc; Serpentini, Antoine; Budzinski, Hélène; Costil, Katherine

    2016-03-01

    The bioconcentration potential of fluoxetine (FLX) and its biological effects were investigated in juvenile Pacific oyster exposed for 28 days to environmentally relevant concentrations of FLX (1 ng L(-1), 100 ng L(-1) and up to 10 μg L(-1)). FLX bioaccumulated in oyster flesh resulting in 28-day bioconcentration factors greater than 2,000 and 10,000 by referring to wet and dry weights, respectively. Nevertheless, FLX did not induce oyster mortality, delayed gametogenesis, or lead to adverse histopathological alterations. At the two highest concentrations, despite non-optimal trophic conditions, FLX stimulated shell growth but only in a transient manner, suggesting a role of serotonin in the regulation of feeding and metabolism in bivalves. Those high concentrations seemed to drive bell-shaped responses of catalase and glutathione S-transferase activities throughout the exposure period, which may indicate the activation of antioxidant enzyme synthesis and then an enhanced catabolic rate or direct inhibition of those enzymes. However, no clear oxidative stress was detected because no strong differences in thiobarbituric acid-reactive substance (TBARS) content (i.e. lipid peroxidation) were observed between oyster groups, suggesting that cellular defence mechanisms were effective. These results demonstrate the importance of considering additional biomarkers of oxidative stress to obtain a comprehensive overview of the FLX-induced changes in marine bivalves exposed under realistic conditions. Considering the battery of biomarkers used, FLX appears to induce little or no effects on oyster physiology even at a concentration of 10 μg L(-1). These results do not confirm the lowest observed effect concentration (LOEC) values reported by some authors in other mollusc species.

  8. Ocean acidification but not warming alters sex determination in the Sydney rock oyster, Saccostrea glomerata.

    Parker, Laura M; O'Connor, Wayne A; Byrne, Maria; Dove, Michael; Coleman, Ross A; Pörtner, Hans-O; Scanes, Elliot; Virtue, Patti; Gibbs, Mitchell; Ross, Pauline M

    2018-02-14

    Whether sex determination of marine organisms can be altered by ocean acidification and warming during this century remains a significant, unanswered question. Here, we show that exposure of the protandric hermaphrodite oyster, Saccostrea glomerata to ocean acidification, but not warming, alters sex determination resulting in changes in sex ratios. After just one reproductive cycle there were 16% more females than males. The rate of gametogenesis, gonad area, fecundity, shell length, extracellular pH and survival decreased in response to ocean acidification. Warming as a sole stressor slightly increased the rate of gametogenesis, gonad area and fecundity, but this increase was masked by the impact of ocean acidification at a level predicted for this century. Alterations to sex determination, sex ratios and reproductive capacity will have flow on effects to reduce larval supply and population size of oysters and potentially other marine organisms. © 2018 The Author(s).

  9. Oyster Reef Projects 1997-2001

    National Oceanic and Atmospheric Administration, Department of Commerce — We used a quantitative sampling device to compare nekton use among high-relief live oyster reef, vegetated marsh edge Spartina alterniflora, and nonvegetated bottom...

  10. Norwalk virus gastroenteritis following raw oyster consumption.

    Gunn, R A; Janowski, H T; Lieb, S; Prather, E C; Greenberg, H B

    1982-03-01

    In January, 1980, six out of 13 persons (46%) attending a party in a small northwest Florida town near the Gulf of Mexico became ill with Norwalk virus gastroenteritis after eating raw oysters. Symptoms experienced by the ill persons were principally nausea (100%), vomiting (83%) and diarrhea (50%) and were of brief duration. The symptom complex and epidemiology of Norwalk virus infection closely resemble the gastrointestinal illness commonly referred to as the 24-hour intestinal flu or "stomach flu." Norwalk virus infection was identified in this outbreak by application of a recently developed sensitive and specific serologic radioimmunoassay. Oysters from the incriminated batch had fecal coliform levels above recommended standards; however, recent studies of oyster-harvesting waters have shown only a weak correlation between fecal coliforms and the presence of enteric viruses. Further studies are needed to determine whether modifications of monitoring modalities for oyster-harvesting waters are needed.

  11. Hemocyte parameters of the Pacific oyster Crassostrea gigas a year after the Hebei Spirit oil spill off the west coast of Korea

    Donaghy, Ludovic; Hong, Hyun-Ki; Lee, Hee-Jung; Jun, Je-Cheon; Park, Young-Je; Choi, Kwang-Sik

    2010-12-01

    In marine bivalves, hemocytes support various physiological functions, including immune defense, nutrient transport, shell repair, and homeostatic maintenance. Although the effects of marine contaminants on the immunological functions of bivalves have been extensively investigated, the impacts of oil spills are not well understood. Therefore, we investigated hemocyte parameters in the Pacific oyster Crassostrea gigas 13 months after the Hebei Spirit oil spill (December 2007) off the west coast of Korea. The parameters studied included hemocyte concentration and mortality, relative proportion of hemocyte populations, and immunological functions such as phagocytosis and oxidative activity using flow cytometry. These immune-related parameters in oysters damaged by the oil spill were also compared to control oysters that were collected from an area unaffected by the spill. The flow cytometry study indicated that granulocyte population, phagocytic capacity, and reactive oxygen species production in oysters exposed to crude oil 13 months prior were depressed compared to the unexposed control oysters. Our data suggest that immunocompetence in oysters affected by the oil spill had not fully recovered 1 year after the accident, although more detailed studies on the physiology and disease resistance should be performed.

  12. Survival of Salmonella Newport in oysters.

    Morrison, Christopher M; Armstrong, Alexandra E; Evans, Sanford; Mild, Rita M; Langdon, Christopher J; Joens, Lynn A

    2011-08-02

    Salmonella enterica is the leading cause of laboratory-confirmed foodborne illness in the United States and raw shellfish consumption is a commonly implicated source of gastrointestinal pathogens. A 2005 epidemiological study done in our laboratory by Brands et al., showed that oysters in the United States are contaminated with Salmonella, and in particular, a specific strain of the Newport serovar. This work sought to further investigate the host-microbe interactions between Salmonella Newport and oysters. A procedure was developed to reliably and repeatedly expose oysters to enteric bacteria and quantify the subsequent levels of bacterial survival. The results show that 10 days after an exposure to Salmonella Newport, an average concentration of 3.7 × 10(3)CFU/g remains within the oyster meat, and even after 60 days there still can be more than 10(2)CFU/g remaining. However, the strain of Newport that predominated in the market survey done by Brands et al. does not survive within oysters or the estuarine environment better than any other strains of Salmonella we tested. Using this same methodology, we compared Salmonella Newport's ability to survive within oysters to a non-pathogenic strain of E. coli and found that after 10 days the concentration of Salmonella was 200-times greater than that of E. coli. We also compared those same strains of Salmonella and E. coli in a depuration process to determine if a constant 120 L/h flux of clean seawater could significantly reduce the concentration of bacteria within oysters and found that after 3 days the oysters retained over 10(4)CFU/g of Salmonella while the oysters exposed to the non-pathogenic strain of E. coli contained 100-times less bacteria. Overall, the results of this study demonstrate that any of the clinically relevant serovars of Salmonella can survive within oysters for significant periods of time after just one exposure event. Based on the drastic differences in survivability between Salmonella and a non

  13. Collaborative evaluation of commercial irradiation for Vibrio vulnificus control in Louisiana oysters

    Kilgen, M.B.; Hemard, M.T.; Duet, D.; Rabalais, S.

    2001-01-01

    Oysters commercially harvested September 1994 and April 1995 from Black Bay, Louisiana were processed by industry collaborators as: 1) live shellstock boxed 200 per 60 lb (27 kg) box in Florida; 2) shucked 12 oz (310 g) containers in Florida; and 3) frozen half-shell in Virginia. The oysters were then shipped by each processor in commercial refrigerated trucks to Food Technology Services, Inc. in Mulberry, Florida for commercial irradiation processing. Live shellstock were held at a temperature of about 7 deg. C from harvest through sampling. Ambient levels of Vibrio vulnificus in the oysters were 4.6x10 5 MPN/g in September 1994 (harvest water 29 deg. C) and 1.5x10 2 MPN/g in April 1995 (harvest water 20 deg. C). Two 60-lb (27 kg) boxes of live oysters were each treated at minimum levels of 0.0 controls). 0.5, 1.0, 1.5, and 2.0 kGy, 400 oysters per dose. The dose ratios were calculated to be about 2:1 in the commercial box packaging. Levels of V. vulnificus, total aerobic plate counts, and percent cumulative mortality were enumerated every three days through day 14 post-harvest for the September 1994 samples, and through day 28 post-harvest for the April 1995 samples. September 1994 live shellstock oysters treated with doses of 0.5 kGy an 1.0 kGy had a very significant 4-log 10 reduction in levels of V. vulnificus at 0.5 kGy, and a 5-log 10 reduction at 1.0 kGy 2 days post-irradiation (4 days post-harvest), without a significant difference in mortality from the non-irradiated control group, which lost 1 log 10 after storage at 3 deg. C for 4 days. The April 1995 samples were reduced to below detectable levels of V. vulnificus at all doses. Commercial shucking and washing of fresh product, and freezing in the half-shell, also reduced number of V. vulnificus 4-5 log 10 by day 14 post-harvest. Additional irradiation processing of these products reduced V. vulnificus to below detectable levels at the lowest dose of 1.0 kGy. (author

  14. Dose characterization of the rad source{sup TM} 2400 X-ray irradiator for oyster pasteurization

    Wagner, Jennifer Koop [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843-3133 (United States)], E-mail: jenkoop@gmail.com; Dillon, Jeff A. [Experimental Seafood Processing Laboratory, Mississippi State University, Pascagoula, MS 39567 (United States); Blythe, Eugene K. [Coastal Research and Extension Center, Mississippi State University, South Mississippi Branch Experiment Station, Poplarville, MS 39470 (United States); Ford, John R. [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843-3133 (United States)

    2009-02-15

    The RS 2400's cylindrical X-ray source yields dose rates high enough to allow the irradiator to replace widely used gamma irradiators. Except for the leftmost 5 cm, beam uniformity is within 10% at the tube surface. At maximum operating parameters, the beam has HVL{sub 1}=13.66 mm aluminum, HC=0.47, and h{nu}{sub eq}=88.5 keV. Maximum dose rates to tissue are 65 Gy min{sup -1}{+-}3.1% at tube surface, 37 Gy min{sup -1}{+-}3.1% at center of canisters, 14.1 Gy min{sup -1}{+-}6.5% for thin-shelled oysters, and 12.3 Gy min{sup -1}{+-}6.2% for thick-shelled oysters.

  15. Immunochromatographic assay of cadmium levels in oysters.

    Nishi, Kosuke; Kim, In-Hae; Itai, Takaaki; Sugahara, Takuya; Takeyama, Haruko; Ohkawa, Hideo

    2012-08-15

    Oysters are one of foodstuffs containing a relatively high amount of cadmium. Here we report on establishment of an immunochromatographic assay (ICA) method of cadmium levels in oysters. Cadmium was extracted with 0.l mol L(-1) HCl from oysters and cleaned up from other metals by the use of an anion-exchange column. The behavior of five metals Mn, Fe, Cu, Zn, and Cd was monitored at each step of extraction and clean-up procedure for the ICA method in an inductively coupled plasma-mass spectrometry (ICP-MS) analysis. The results revealed that a simple extraction method with the HCl solution was efficient enough to extract almost all of cadmium from oysters. Clean-up with an anion-exchange column presented almost no loss of cadmium adsorbed on the column and an efficient removal of metals other than cadmium. When a spiked recovery test was performed in the ICA method, the recovery ranged from 98% to 112% with relative standard deviations between 5.9% and 9.2%. The measured values of cadmium in various oyster samples in the ICA method were favorably correlated with those in ICP-MS analysis (r(2)=0.97). Overall results indicate that the ICA method established in the present study is an adequate and reliable detection method for cadmium levels in oysters. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Oyster Reef Communities in the Chesapeake Bay: A Brief Primer. VORTEX: Virginia's Oyster Reef Teaching EXperience.

    Harding, Juliana M.; Mann, Roger; Clark, Vicki P.

    This document introduces Virginia's Oyster Reef Teaching EXperience (VORTEX), which is an interdisciplinary program focusing on the importance of oyster reef communities in the Chesapeake Bay ecosystem. The VORTEX program uses field and laboratory experience supported by multimedia instruction. This document presents an overview on the biology of…

  17. Effect of oyster mushroom ( Pleurotus ostreatus ) mycelia on ...

    Effect of oyster mushroom ( Pleurotus ostreatus ) mycelia on petroleum ... of chains of hydrocarbon in a petroleum-hydrocarbon-contaminated substrate over time. ... Keywords: Mycoremediation, Mycelia, Contaminated Soil, Oyster Mushroom ...

  18. INFLUENCE OF ALTERED FRESHWATER FLOWS ON EASTERN OYSTERS

    Abstract for National Shellfisheries AssociationEastern oysters Crassostrea virginica are prominent in Gulf of Mexico estuaries. Valued both commercially and ecologically, oyster populations are threatened by human activity, including dredging, harvesting, and upstream al...

  19. Oyster mushroom (Pleurotus spp.) cultivation technique using re ...

    SARAH

    2014-08-31

    Aug 31, 2014 ... using re-usable substrate containers and comparison of ... oyster mushrooms in combination with other vegetables complements availability of various essential ..... higher than from oyster mushrooms produced from any.

  20. Flat oysters in the Eierlandse Gat, Wadden Sea

    Have, van der T.M.; Kamermans, P.; Zee, van der E.M.

    2018-01-01

    This report presents the results of a short survey of flat oysters (Ostrea edulis) in the Western Wadden Sea. Ten sites were visited and flat oysters were found on nine locations in the Eijerlandse gat. Empty cockleshells and live and dead Pacific oysters provided the main settlement substrate. The

  1. Caracterização físico-química e microestrutural de conchas de moluscos bivalves provenientes de cultivos da região litorânea da ilha de Santa Catarina Physical chemistry and micro structural characterization of shells of bivalve mollusks from sea farmer around the Santa Catarina island

    Denyo Silva

    2010-01-01

    Full Text Available Samples of shells of oysters and mussels from sea farm around the Santa Catarina Island in south Brazil were collected and analyzed by DRX, FRX, SEM, CHN-S, FTIR, TG, AAS/Flame and AAS /GF. The results showed that the crystalline structure of mussel's shells is mainly formed by aragonite and the oyster's shells by calcite. The calcium percentage in both shells species was in the range of 33 to 35% and also 850 and 1200 mg/kg of strontium was detected in the shells of oysters and mussels, respectively. The content of organic matter was larger in the mussel's shells and the thermal degradation of both shells species occurred by three events at different temperatures from 250 to 830 ºC.

  2. Pyrosequencing Analysis of Norovirus Genogroup II Distribution in Sewage and Oysters: First Detection of GII.17 Kawasaki 2014 in Oysters.

    Pu, Jian; Kazama, Shinobu; Miura, Takayuki; Azraini, Nabila Dhyan; Konta, Yoshimitsu; Ito, Hiroaki; Ueki, You; Cahyaningrum, Ermaya Eka; Omura, Tatsuo; Watanabe, Toru

    2016-12-01

    Norovirus GII.3, GII.4, and GII.17 were detected using pyrosequencing in sewage and oysters in January and February 2015, in Japan. The strains in sewage and oyster samples were genetically identical or similar, predominant strains belonging to GII.17 Kawasaki 2014 lineage. This is the first report of GII.17 Kawasaki 2014 in oysters.

  3. Cretaceous honeycomb oysters (Pycnodonte vesicularis) as palaeoseasonality records: A multi-proxy study

    de Winter, Niels J.; Vellekoop, Johan; Vorsselmans, Robin; Golreihan, Asefeh; Petersen, Sierra V.; Meyer, Kyle W.; Speijer, Robert P.; Claeys, Philippe

    2017-04-01

    Pycnodonte or "honeycomb-oysters" (Bivalvia: Gryphaeidea) is an extinct genus of calcite-producing bivalves which is found in abundance in Cretaceous to Pleistocene fossil beds worldwide. As such, Pycnodonte shells could be ideal tracers of palaeoclimate through time, with the capability to reconstruct sea water conditions and palaeotemperatures in a range of palaeoenvironmental settings. Only few studies have attempted to reconstruct palaeoclimate based on Pycnodonte shells and with variable degrees of success (e.g. Videt, 2003; Huyge et al., 2015). Our study investigates the shell growth, structure and chemical characteristics of Maastrichtian Pycnodonte vesicularis from Bajada de Jaguel in Argentina and aims to rigorously test the application of multiple palaeoenvironmental proxies on the shells of several Maastrichtian Pycnodonte oysters for palaeoclimate reconstruction. The preservation state of four calcite shells was assessed by fluorescence microscopy, cathodoluminescence and micro X-Ray Fluorescence (XRF) mapping. Their shell structure was investigated using a combination of XRF mapping, high-resolution color scanning and microCT scanning. Long integration time point-by-point XRF line scanning yielded high-resolution trace element profiles through the hinge of all shells. Microdrilled samples from the same locations on the shell were analyzed for trace element composition by ICP-MS and for stable carbon and oxygen isotopes by IRMS. Preservation of the calcite microstructure was found to be of sufficient quality to allow discussion of original shell porosity, annual growth increments and pristine chemical signatures of the bivalves. The combination of fluorescence and cathodoluminescence microscopy with XRF mapping and microCT scanning sheds light on the characteristic internal "honeycomb" structure of these extinct bivalves and allows comparison with that of the related extant Neopycnodonte bivalves (Wisshak et al., 2009). Furthermore, high resolution

  4. Prevalence of Salmonella spp. in Oysters in the United States

    Brands, Danielle A.; Inman, Allison E.; Gerba, Charles P.; Maré, C. John; Billington, Stephen J.; Saif, Linda A.; Levine, Jay F.; Joens, Lynn A.

    2005-01-01

    Food-borne diseases such as salmonellosis can be attributed, in part, to the consumption of raw oysters. To determine the prevalence of Salmonella spp. in oysters, oysters harvested from 36 U.S. bays (12 each from the West, East, and Gulf coasts in the summer of 2002, and 12 bays, four per coast, in the winter of 2002-2003) were tested. Salmonella was isolated from oysters from each coast of the United States, and 7.4% of all oysters tested contained Salmonella. Isolation tended to be bay spe...

  5. The use of chicken egg shell as an alternative source of calcium in ...

    The study was conducted to determine the effect of replacing oyster shell fraction in the diet of growing-finishing cockerel chickens partially or wholly with eggshell. A total of one hundred and twenty (120) 8 weeks old Harco cockerel chicken of mean weight 515.78 ± 3. 8g were used for the feeding trial that lasted for ten ...

  6. Oyster leases in Louisiana, Geographic NAD83, LOSCO (1997) [oyster_leases_USACE_1997

    Louisiana Geographic Information Center — This data set indicates the locations of oyster leases in Louisiana. The lease areas should be polygons, however, the source data has very poor topology including...

  7. Application of chitosan microparticles for reduction of vibrio species in seawater and live oysters (Crassostrea virginica).

    Fang, Lei; Wolmarans, Bernhard; Kang, Minyoung; Jeong, Kwang C; Wright, Anita C

    2015-01-01

    Human Vibrio infections associated with consumption of raw shellfish greatly impact the seafood industry. Vibrio cholerae-related disease is occasionally attributed to seafood, but V. vulnificus and V. parahaemolyticus are the primary targets of postharvest processing (PHP) efforts in the United States, as they pose the greatest threat to the industry. Most successful PHP treatments for Vibrio reduction also kill the molluscs and are not suitable for the lucrative half-shell market, while nonlethal practices are generally less effective. Therefore, novel intervention strategies for Vibrio reduction are needed for live oyster products. Chitosan is a bioactive derivative of chitin that is generally recognized as safe as a food additive by the FDA, and chitosan microparticles (CMs) were investigated in the present study as a potential PHP treatment for live oyster applications. Treatment of broth cultures with 0.5% (wt/vol) CMs resulted in growth cessation of V. cholerae, V. vulnificus, and V. parahaemolyticus, reducing culturable levels to nondetectable amounts after 3 h in three independent experiments. Furthermore, a similar treatment in artificial seawater at 4, 25, and 37°C reduced V. vulnificus levels by ca. 7 log CFU/ml after 24 h of exposure, but 48 h of exposure and elevated temperature were required to achieve similar results for V. parahaemolyticus and V. cholerae. Live oysters that either were artificially inoculated or contained natural populations of V. vulnificus and V. parahaemolyticus showed significant and consistent reductions following CM treatment (5%) compared to the amounts in the untreated controls. Thus, the results strongly support the promising potential for the application of CMs as a PHP treatment to reduce Vibrio spp. in intact live oysters. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Neutron activation and PIXE analysis of oyster tissues cultivated at different ocean depths for trace elements

    Fukushima, M.; Nakano, Y.; Chatt, A.

    2005-01-01

    Difference in trace element concentrations in oyster tissues cultivated in Japan on hanging ropes at different sea depths were investigated using INAA and PIXE. Three groups of oyster were collected from a single rope at 1 m, 6 m, and 11 m depths. From each group, five oysters were chosen and removed from the shell after washing in tap water. Two groups of organ, namely hepatopancreas and muscle, and gill and mantle were separated from soft tissues, freeze-dried, and pulverized. One portion of the powdered samples was irradiated for a short time at the Dalhousie University SLOWPOKE-2 reactor in Canada for Ag and Se analysis. Another portion was irradiated for one hour in Kyoto University Reactor in Osaka, Japan for Fe, Rb, Sc, and Zn analysis. The third portion was digested in a microwave oven after the addition of an indium solution (as an internal standard) and concentrated nitric acid for analysis by PIXE. More than twenty elements were determined by PIXE. The organs in oysters have different roles. For example, hepatopancreas and muscle are thought to accumulate elements after ingestion of plankton from sea water while gill and mantle are always in contact with sea water. As a result, there were differences in levels of some elements between the two groups of organ. In addition, levels of most elements were found to be depth dependent. The variations in Fe and Zn concentrations of the two organ groups at 3 different depths are shown in Table 1. Details of the method and results will be presented.

  9. Are mangroves as tough as a seawall? Flow-vegetation interaction in a living shoreline restoration

    Kibler, K. M.; Kitsikoudis, V.; Spiering, D. W.

    2017-12-01

    This study aims to assess the impact of an established living shoreline restoration on near-shore hydraulics, shoreline slope, and sediment texture and organic matter content. We collected data from three 100 m shoreline sites within an estuarine lagoon in Canaveral National Seashore: one restored; one that had been stabilized by a seawall; and one in a reference condition stabilized by mature mangrove vegetation. The living shoreline site was restored five years prior with a breakwater of oyster shell bags, emergent marsh grasses (Spartina alterniflora), and mangroves (Rhizophora mangle and Avicennia germinans). We sampled water depth and incoming velocity profiles of the full water column at 2 Hz using a 2 MHz Acoustic Doppler Current Profiler (ADCP, Nortek), stationed down-looking, approximately 10 m offshore. A 2 - 3 cm velocity profile above the bed was sampled on the shoreline at 100 Hz, using a Nortek Vectrino profiler. In restored and reference sites, the onshore probe was placed within vegetation. We surveyed vegetation upstream of the probe for species and diameter at water level. Windspeed and direction were collected 2 m above the water surface. Shorelines were surveyed in transects using GPS survey equipment. Five sediment cores were collected to 20 cm depth from both onshore and offshore of each site. Individual cores were processed for loss on ignition before being pooled by site for analysis of grain size distribution. While incoming velocity profiles were similar between sites, hydraulic conditions onshore within the vegetated sites deviated from the seawall site, which was devoid of vegetation. Offshore to onshore gradients in shear stress, mean velocity, and turbulent kinetic energy differed widely between sites, despite similar wind and tidal conditions. Sediment grain sizes were finer and contained more organic matter in the restored and reference sites than in the seawall site. Profiles of the restored and seawall sites were similar, though

  10. The effects of x-ray treatments on bioaccumulated murine norovirus-1 (MNV-1) and survivability, inherent microbiota, color, and firmness of Atlantic oysters (Crassostrea virginica) during storage at 5°C for 20 days

    In this study, we investigated the inactivation of human norovirus (HuNoV) surrogate Murine norovirus (MNV-1) by X-ray in whole-shell Atlantic oysters (Crassostrea virginica). We also investigated the effects of X-ray treatments on the survivability, inherent microbiota, color, and firmness of treat...

  11. The taxonomic status, and isotopic evidence for paleoenvironments, of giant oysters from the Oligocene Te Kuiti Group, South Auckland, New Zealand

    Nelson, C.S.; Burns, D.A.; Rodgers, K.A.

    1983-01-01

    Close inspection of the morphologic characteristics of giant oysters from the Oligocene Te Kuiti Group indicates that they do not belong in any of the several genera so far assigned them in the literature, including the estuarine genus Crassostrea. They are most typical of the tribe Flemingostreini Stenzel, but without more extensive and specialist study it is premature to give them generic status, which might only perpetrate further taxonomic confusion. Carbon and oxygen isotopic analyses of the oyster shells, as well as independent evidence, suggest that oysters in: (1) the Mangakotuku Siltstone formed in a protected, shallow marine embayment, open only to the north, having locally restricted circulation, but mainly normal to only slightly reduced salinites, the light carbon in shells being derived more from the reaction with seawater of locally produced CO 2 from decomposition of abundant organic debris in the bottom sediments than from widespread dilution of seawater by freshwater; (2) the Whaingaroa Siltstone formed in open, shallow shelf waters of normal marine salinity; and (3) the prominent oyster beds in the Orahiri Limestone developed in a fully marine, tideswept strait, in water depths of 25-50 m and bottom temperatures of possibly c. 14 0 C. (auths)

  12. Drywell corrosion stopped at Oyster Creek

    Lipford, B.L.; Flynn, J.C.

    1993-01-01

    This article describes the detection of corrosion on the drywell containment vessel of Oyster Creek Nuclear Plant and the application of a protective coating to repair the drywell. The topics of the article include drywell design features, identification of the problem, initial action, drywell corrosion, failure of cathodic protection, long-term repair, and repair results

  13. INORGANIC ELEMENTS AND DISTRIBUTION OF EASTERN OYSTERS.

    Fisher, William S. In press. Inorganic Elements and Distribution of Eastern Oysters (Abstract). To be presented at the 96th Annual Meeting (Aquaculture 2004) of the National Shellfisheries Association, 1-5 March 2004, Honolulu, HI. 1 p. (ERL,GB R962). For over a century w...

  14. Oyster mycelium on the liquid medium

    Mariusz Gapiński

    2013-12-01

    Full Text Available The research presents the results of oyster mycelium growth on the liquid medium. The growth of 4-mycelium genius: Pleurotus citrinopileatus Singer, Pleurotus djamor Fries, Boedjin, Pleurotus erynii Fr. Kumm. and Pleurotus precoce Fr. Quel was tested. The quality and quantity of mycelium was assumed.

  15. Precipitation of iron in windopane oyster shells by marine shell-boring cyanobacteria

    Raghukumar, C.; Rao, V.P.; Iyer, S.D.

    filaments encrusted with black precipitate. Microchemical test (Prussian blue reaction) and wavelength dispersive x-ray analysis confirmed this precipitate to be of iron. Mineralogical studies of this black precipitate, using x-ray diffraction and scanning...

  16. Shell supports

    Almegaard, Henrik

    2004-01-01

    A new statical and conceptual model for membrane shell structures - the stringer system - has been found. The principle was first published at the IASS conference in Copenhagen (OHL91), and later the theory has been further developed (ALMO3)(ALMO4). From the analysis of the stringer model it can...... be concluded that all membrane shells can be described by a limited number of basic configurations of which quite a few have free edges....

  17. Deeply hidden inside introduced biogenic structures - Pacific oyster reefs reduce detrimental barnacle overgrowth on native blue mussels

    Buschbaum, Christian; Cornelius, Annika; Goedknegt, M. Anouk

    2016-11-01

    In sedimentary coastal ecosystems shells of epibenthic organisms such as blue mussels (Mytilus edulis) provide the only major attachment surface for barnacle epibionts, which may cause detrimental effects on their mussel basibionts by e.g. reducing growth rate. In the European Wadden Sea, beds of native blue mussels have been invaded by Pacific oysters Crassostrea gigas, which transformed these beds into mixed reefs of oysters with mussels. In this study, we determined the spatial distribution of M. edulis and their barnacle epibionts (Semibalanus balanoides) within the reef matrix. Mean mussel density near the bottom was about twice as high compared to the mussel density near the top of an oyster reef, whereas barnacles on mussels showed a reversed pattern. Barnacle dry weight per mussel was on average 14 times higher near the top than at the bottom. This pattern was confirmed by experimentally placing clean M. edulis at the top and on the bottom of oyster reefs at two sites in the Wadden Sea (island of Texel, The Netherlands; island of Sylt, Germany). After an experimental period of five weeks (April and May 2015, the main settlement period of S. balanoides), the number of barnacles per mussel was at both sites significantly higher on mussels near the top compared to near the bottom. We conclude that the oyster reef matrix offers a refuge for M. edulis: inside reefs they are not only better protected against predators but also against detrimental barnacle overgrowth. This study shows that alien species can cause beneficial effects for native organisms and should not be generally considered as a risk for the recipient marine ecosystems.

  18. Immune and stress responses in oysters with insights on adaptation.

    Guo, Ximing; He, Yan; Zhang, Linlin; Lelong, Christophe; Jouaux, Aude

    2015-09-01

    Oysters are representative bivalve molluscs that are widely distributed in world oceans. As successful colonizers of estuaries and intertidal zones, oysters are remarkably resilient against harsh environmental conditions including wide fluctuations in temperature and salinity as well as prolonged air exposure. Oysters have no adaptive immunity but can thrive in microbe-rich estuaries as filter-feeders. These unique adaptations make oysters interesting models to study the evolution of host-defense systems. Recent advances in genomic studies including sequencing of the oyster genome have provided insights into oyster's immune and stress responses underlying their amazing resilience. Studies show that the oyster genomes are highly polymorphic and complex, which may be key to their resilience. The oyster genome has a large gene repertoire that is enriched for immune and stress response genes. Thousands of genes are involved in oyster's immune and stress responses, through complex interactions, with many gene families expanded showing high sequence, structural and functional diversity. The high diversity of immune receptors and effectors may provide oysters with enhanced specificity in immune recognition and response to cope with diverse pathogens in the absence of adaptive immunity. Some members of expanded immune gene families have diverged to function at different temperatures and salinities or assumed new roles in abiotic stress response. Most canonical innate immunity pathways are conserved in oysters and supported by a large number of diverse and often novel genes. The great diversity in immune and stress response genes exhibited by expanded gene families as well as high sequence and structural polymorphisms may be central to oyster's adaptation to highly stressful and widely changing environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Exploring Proteomic Variation in Pacific Oysters (Crassostrea gigas)

    Venkataraman, Yaamini

    2017-01-01

    150 sibling Pacific oysters (Crassostrea gigas) were outplanted at five different sites around Puget Sound. Oysters were placed in exclusion cages either inside or outside of eelgrass beds. After a month of environmental exposure, gill tissue samples were collected for proteomic analyses. Initial DIA mass spectrometry methods on a subset of oysters (one per site and eelgrass condition, 10 total) provide data for upwards of 6,000 proteins. A subset of stress-related proteins reveal site-specif...

  20. Prevalence of Salmonella spp. in oysters in the United States.

    Brands, Danielle A; Inman, Allison E; Gerba, Charles P; Maré, C John; Billington, Stephen J; Saif, Linda A; Levine, Jay F; Joens, Lynn A

    2005-02-01

    Food-borne diseases such as salmonellosis can be attributed, in part, to the consumption of raw oysters. To determine the prevalence of Salmonella spp. in oysters, oysters harvested from 36 U.S. bays (12 each from the West, East, and Gulf coasts in the summer of 2002, and 12 bays, four per coast, in the winter of 2002-2003) were tested. Salmonella was isolated from oysters from each coast of the United States, and 7.4% of all oysters tested contained Salmonella. Isolation tended to be bay specific, with some bays having a high prevalence of Salmonella, while other bays had none. Differences in the percentage of oysters from which Salmonella was isolated were observed between the summer and winter months, with winter numbers much lower probably due to a variety of weather-related events. The vast majority (78/101) of Salmonella isolates from oysters were Salmonella enterica serovar Newport, a major human pathogen, confirming the human health hazard of raw oyster consumption. Contrary to previous findings, no relationship was found between the isolation of fecal coliforms and Salmonella from oysters, indicating a necessity for specific monitoring for Salmonella and other pathogens rather than the current reliance on fecal coliform testing.

  1. Temperature-dependent stress response in oysters, Crassostrea virginica: Pollution reduces temperature tolerance in oysters

    Lannig, Gisela; Flores, Jason F.; Sokolova, Inna M.

    2006-01-01

    Combined effects of temperature and a toxic metal, cadmium (Cd), on energy metabolism were studied in a model marine bivalve, the eastern oyster Crassostrea virginica, acclimated at 20, 24 and 28 deg. C and exposed to 50 μg l -1 of Cd. Both increasing temperature and Cd exposure led to a rise in standard metabolic rates, and combined stressors appeared to override the capability for aerobic energy production resulting in impaired stress tolerance. Oysters exposed to elevated temperature but not Cd showed no significant change in condition, survival rate and lipid peroxidation, whereas those exposed to both Cd and temperature stress suffered high mortality accompanied by low condition index and elevated lipid peroxidation. Furthermore, RNA/DNA ratios indicative of protein synthesis rate, and levels of glutathione, which is involved in metal detoxification, increased in Cd-exposed oysters at 20 deg. C but not at 28 deg. C. Implications of the synergism between elevated temperatures and cadmium stress on energy metabolism of oysters are discussed in the light of the potential effects of climate change on oyster populations in polluted areas

  2. Insights from the Shell Proteome: Biomineralization to Adaptation.

    Arivalagan, Jaison; Yarra, Tejaswi; Marie, Benjamin; Sleight, Victoria A; Duvernois-Berthet, Evelyne; Clark, Melody S; Marie, Arul; Berland, Sophie

    2017-01-01

    Bivalves have evolved a range of complex shell forming mechanisms that are reflected by their incredible diversity in shell mineralogy and microstructures. A suite of proteins exported to the shell matrix space plays a significant role in controlling these features, in addition to underpinning some of the physical properties of the shell itself. Although, there is a general consensus that a minimum basic protein tool kit is required for shell construction, to date, this remains undefined. In this study, the shell matrix proteins (SMPs) of four highly divergent bivalves (The Pacific oyster, Crassostrea gigas; the blue mussel, Mytilus edulis; the clam, Mya truncata, and the king scallop, Pecten maximus) were analyzed in an identical fashion using proteomics pipeline. This enabled us to identify the critical elements of a "basic tool kit" for calcification processes, which were conserved across the taxa irrespective of the shell morphology and arrangement of the crystal surfaces. In addition, protein domains controlling the crystal layers specific to aragonite and calcite were also identified. Intriguingly, a significant number of the identified SMPs contained domains related to immune functions. These were often are unique to each species implying their involvement not only in immunity, but also environmental adaptation. This suggests that the SMPs are selectively exported in a complex mix to endow the shell with both mechanical protection and biochemical defense. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. Eating oysters without risk of vibriosis: application of a bacteriophage against Vibrio parahaemolyticus in oysters.

    Jun, Jin Woo; Kim, Hyoun Joong; Yun, Sae Kil; Chai, Ji Young; Park, Se Chang

    2014-10-01

    Vibrio parahaemolyticus is a major cause of foodborne illness and related with the consumption of raw contaminated seafood, especially oysters. To evaluate the effectiveness of various applications of a bacteriophage (phage), pVp-1, against a multiple-antibiotic-resistant V. parahaemolyticus pandemic strain (CRS 09-17), we designed artificial contamination models that are most likely to be encountered during oyster processing. When live oysters were treated with bath immersion with pVp-1 after CRS 09-17 challenge, the growth of bacterial strain was significantly reduced. After 72h of phage application with bath immersion, bacterial growth reduction was observed to be 8.9×10(6)CFU/ml (control group) to 1.4×10CFU/ml (treatment group). When pVp-1 was surface-applied on the flesh of oysters after CRS 09-17 inoculation, bacterial growth was properly inhibited. After 12h of phage application on the surface of oysters, bacterial growth inhibition was revealed to be 1.44×10(6)CFU/ml (control group) to 1.94CFU/ml (treatment group). This is the first report, to the best of our knowledge, of oyster surface-application of a phage against a multiple-antibiotic-resistant V. parahaemolyticus pandemic strain, and our successful phage application to various situations emphasizes the potential use of the phage to avoid V. parahaemolyticus infection from aquaculture to consumption. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Response of an estuarine benthic community to application of the pesticide carbaryl and cultivation of Pacific oysters (Crassostrea gigas) in Willapa Bay, Washington.

    Dumbauld, B R; Brooks, K M; Posey, M H

    2001-10-01

    Oyster culture operations on the West coast of North America have developed into complete farming operations for the introduced Japanese oyster, Crassostrea gigas, which now covers vast areas of the intertidal landscape, particularly in Washington State where the pesticide carbaryl has also been used to control burrowing thalassinid shrimp for more than 30 years. Field experiments were conducted to examine the effects of these habitat modifications on the benthic community in Willapa, Bay Washington (124 degrees 06'W,46 degrees 24'N) where 50% of the state's oyster production occurs. Results indicated that the primary long-term effect of carbaryl application was removal of the two species of thalassinid shrimp (Neotrypaea californiensis and Upogebia pugettensis), which dominated the community at the start of the experiment and clearly influenced community composition themselves. Small peracarid crustaceans like the amphipods Corophium acherusicum and Eohaustorius estuarius experienced the most significant short-term mortalities, but generally recruited back to treated sites within 3 months, and were often more abundant on treated than untreated sites 1 year after carbaryl application. Results for molluscs were mixed, with no significant effect on Macoma spp, but a significant effect on the commensal clam Crytomya californica and mixed results for the cockle Clinocardium nutalli. Polychaetes were the least susceptible to carbaryl and with the exception of a short-term effect on oligochaetes, no significant negative effects were observed. The addition of oysters did not affect the infaunal community in this study, however greater abundance of epifaunal organisms like mussels, scaleworms, and the amphipod Amphithoe valida, which builds tubes in algae attached to shells, was observed. Carbaryl, which is currently applied to roughly 242 ha (oyster culture operations like the addition of oysters themselves to a community often dominated by burrowing thalassinid shrimp

  5. Study of characterization of trace elements in marine shells of Sambaqui: correlation between recent and old shells; Estudo de caracterizacao de elementos tracos em conchas marinhas de Sambaqui: correlacao entre conchas recentes e antigas

    Gomez, Mauro Roger Batista Pousada; Rocha, Flavio Roberto; Silva, Paulo Sergio Cardoso da, E-mail: mauro_bpgomez@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Calcium carbonate of recent and ancient C. rhizophorae oyster shells was analyzed for the determination of trace elements by instrumental neutron activation analysis. The ancient shells belong to a Sambaqui located in Cananeia region, South of Sao Paulo state and the recent ones are from an oyster production farm in the same region Studies related to the element concentrations in molluscs shell has been done as a tentative of establishing the element concentrations with palio-environmental factor. In this study it was aimed to verify differences in the elemental constitution of recent and ancient oyster shells that present potential for being used as indicator of marine changes. Results indicated that the elements Br, Ce, La, Na, Sm and An are higher in recent shells and the elements Cr, Fe Sc and Th are higher in ancient shells. Statistical analyses performed indicated that the enrichment of the light rare earth elements related to Ca are possibly good candidates for these palio-environmental studies. (author)

  6. Decontamination of Cuban oysters using irradiation

    Cisneros Despaigne, E; Leyva Castillo, V; Martinez, L L; Lara Ortiz, C [Instituto de Nutricion e Higiene de los Alimentos (Cuba); Castillo Rodriguez, E [Centro Nacional de Salud Animal (Cuba)

    2001-04-01

    Oysters (Crassostrea virginica) collected on the Cuban coast near Havana were examined for contamination with Vibrio cholerae and other potentially pathogenic Vibrio species. The strains thus isolated were characterized and identified to species following standard methods, and their radiation resistance (D{sub 10}) was determined in pure culture. The Vibrio species most often isolated were V. cholerae, V. parahaemolyticus and V. Alginolyticus. Representative cultures from each species were later used to inoculate shucked oysters to determine the optimal radiation dose that would ensure elimination of 10{sup 8} colony forming units (CFU)/g. The highest proportion of isolates were identified as Vibrio parahaemolyticus and V. algynoliticus. Non-O1 strains of Vibrio cholerae were isolated from 50% of samples, but no V. cholerae O1 was identified. D{sub 10} values calculated for the various strains were low in relation to those in the literature. The radiation dose for decontaminating heavily inoculated (10{sup 8} CFU/g) oysters was 1.2 kGy. (author)

  7. Decontamination of Cuban oysters using irradiation

    Cisneros Despaigne, E.; Leyva Castillo, V.; Martinez, L.L.; Lara Ortiz, C.; Castillo Rodriguez, E.

    2001-01-01

    Oysters (Crassostrea virginica) collected on the Cuban coast near Havana were examined for contamination with Vibrio cholerae and other potentially pathogenic Vibrio species. The strains thus isolated were characterized and identified to species following standard methods, and their radiation resistance (D 10 ) was determined in pure culture. The Vibrio species most often isolated were V. cholerae, V. parahaemolyticus and V. Alginolyticus. Representative cultures from each species were later used to inoculate shucked oysters to determine the optimal radiation dose that would ensure elimination of 10 8 colony forming units (CFU)/g. The highest proportion of isolates were identified as Vibrio parahaemolyticus and V. algynoliticus. Non-O1 strains of Vibrio cholerae were isolated from 50% of samples, but no V. cholerae O1 was identified. D 10 values calculated for the various strains were low in relation to those in the literature. The radiation dose for decontaminating heavily inoculated (10 8 CFU/g) oysters was 1.2 kGy. (author)

  8. The potential of aerial photography for estimating surface areas of intertidal Pacific oyster beds (Crassostrea gigas)

    Kater, B.J.; Baars, J.M.D.D.

    2004-01-01

    Pacific oysters were introduced into the Eastern Scheldt in 1964 for breeding purposes. The first spatfall of wild Pacific oysters was recorded in 1976, and a second larval outburst in 1982 definitely settled wild Pacific oysters in the Eastern Scheldt waters. Oyster beds on intertidal and subtidal

  9. Shellfish face uncertain future in high CO2 world: influence of acidification on oyster larvae calcification and growth in estuaries.

    A Whitman Miller

    Full Text Available BACKGROUND: Human activities have increased atmospheric concentrations of carbon dioxide by 36% during the past 200 years. One third of all anthropogenic CO(2 has been absorbed by the oceans, reducing pH by about 0.1 of a unit and significantly altering their carbonate chemistry. There is widespread concern that these changes are altering marine habitats severely, but little or no attention has been given to the biota of estuarine and coastal settings, ecosystems that are less pH buffered because of naturally reduced alkalinity. METHODOLOGY/PRINCIPAL FINDINGS: To address CO(2-induced changes to estuarine calcification, veliger larvae of two oyster species, the Eastern oyster (Crassostrea virginica, and the Suminoe oyster (Crassostrea ariakensis were grown in estuarine water under four pCO(2 regimes, 280, 380, 560 and 800 microatm, to simulate atmospheric conditions in the pre-industrial era, present, and projected future concentrations in 50 and 100 years respectively. CO(2 manipulations were made using an automated negative feedback control system that allowed continuous and precise control over the pCO(2 in experimental aquaria. Larval growth was measured using image analysis, and calcification was measured by chemical analysis of calcium in their shells. C. virginica experienced a 16% decrease in shell area and a 42% reduction in calcium content when pre-industrial and end of 21(st century pCO(2 treatments were compared. C. ariakensis showed no change to either growth or calcification. Both species demonstrated net calcification and growth, even when aragonite was undersaturated, a result that runs counter to previous expectations for invertebrate larvae that produce aragonite shells. CONCLUSIONS AND SIGNIFICANCE: Our results suggest that temperate estuarine and coastal ecosystems are vulnerable to the expected changes in water chemistry due to elevated atmospheric CO(2 and that biological responses to acidification, especially calcifying

  10. Markers associated with disease resistance in Eastern oysters, Crassostrea virginica

    Eastern oyster, Crassostrea viginica, is an economically important aquaculture species in the USA, but production has been impacted by diseases such as dermo and MSX. Efforts have been put into the development of disease-resistant oyster lines using selective breeding techniques. However, these met...

  11. CAN OYSTERS PLAY A ROLE IN ENVIRONMENTAL MANAGEMENT?

    The culinary and commercial value of oysters is widely recognized but, until recently, their ecological importance has been largely overlooked. Field and laboratory studies have begun to explore how filter-feeding and reef building by oysters can influence nutrient cycling, biodi...

  12. Cultivation of oyster mushroom ( Pleurotus spp.) on palm oil ...

    Oyster mushroom is a popular mushroom due to its nutritional, medicinal and potential commercial value. In Malaysia, the fungus is currently cultivated on sawdust and rice husk. In this study, the efficiency of cultivating oyster mushroom was assessed using palm oil mesocarp fibre as a substrate. The experiment consisted ...

  13. Resource potential and status of pearl oyster fishery in India

    Ingole, B.S.; Parulekar, A.H.

    Many cultivable species of pearl oysters are known to occur in the Indo-Australian Archipelago which is an important region in the world distribution of pearl oysters. An account of the development of Indian pearl fisheries that took place over...

  14. Seasonal dynamics and diversity of bacteria in retail oyster tissues.

    Wang, Dapeng; Zhang, Qian; Cui, Yan; Shi, Xianming

    2014-03-03

    Oysters are one of the important vehicles for the transfer of foodborne pathogens. It was reported that bacteria could be bio-accumulated mainly in the gills and digestive glands. In artificially treated oysters, bacterial communities have been investigated by culture-independent methods after harvest. However, little information is available on the seasonal dynamics of bacterial accumulation in retail oyster tissues. In this study, retail oysters were collected from local market in different seasons. The seasonal dynamics and diversity of bacteria in oyster tissues, including the gills, digestive glands and residual tissues, were analyzed by denaturing gradient gel electrophoresis (DGGE). It was interesting that the highest bacterial diversity appeared in the Fall season, not in summer. Our results indicated that Proteobacteria was the predominant member (23/46) in oyster tissues. Our results also suggested that bacterial diversity in gills was higher than that in digestive glands and other tissues. In addition, not all the bacteria collected from surrounding water by gills were transferred to digestive glands. On the other hand, few bacteria were found in oyster tissues except in the gills. Therefore, the gills could be the best candidate target tissue for monitoring of pathogenic bacteria either to human or to oyster. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Macrofauna Settlement on Pearl Oyster Collectors in Kenya ...

    Key words: Pearl oysters, seed collection, macrofauna, bivalves, settlement, monsoon seasons,. Kenya .... have shown that pearl oyster settlement is higher within calm ...... collectors in the Timor Sea, Northern Australia. J. Shellfish ... systems. Aquaculture, 189: 375-388. Urban, H.J. (2000b): Culture potential of the pearl.

  16. Microcontroller based automatic temperature control for oyster mushroom plants

    Sihombing, P.; Astuti, T. P.; Herriyance; Sitompul, D.

    2018-03-01

    In the cultivation of Oyster Mushrooms need special treatment because oyster mushrooms are susceptible to disease. Mushroom growth will be inhibited if the temperature and humidity are not well controlled because temperature and inertia can affect mold growth. Oyster mushroom growth usually will be optimal at temperatures around 22-28°C and humidity around 70-90%. This problem is often encountered in the cultivation of oyster mushrooms. Therefore it is very important to control the temperature and humidity of the room of oyster mushroom cultivation. In this paper, we developed an automatic temperature monitoring tool in the cultivation of oyster mushroom-based Arduino Uno microcontroller. We have designed a tool that will control the temperature and humidity automatically by Android Smartphone. If the temperature increased more than 28°C in the room of mushroom plants, then this tool will turn on the pump automatically to run water in order to lower the room temperature. And if the room temperature of mushroom plants below of 22°C, then the light will be turned on in order to heat the room. Thus the temperature in the room oyster mushrooms will remain stable so that the growth of oyster mushrooms can grow with good quality.

  17. Utilization of detrital complexes by the oyster, Crassostrea virginica (Gmelin)

    Crosby, M.P.

    1987-01-01

    The contribution of bacteria and nonliving particulate organic matter of detrital complexes to the nutrition of the American oyster, Crassostrea virginica, was investigated in the laboratory under normal feeding conditions. Results indicate the oysters were capable of assimilating crude fiber extracted from 14 C-Spartina alterniflora with an efficiency of approximately 3% and that enteric bacteria did not enhance this process. Less than 1% of an oyster's energetic demands could be met by direct utilization of this substrate, in the Choptank River subestuary of the Chesapeake Bay. The potential contribution of refractory organics to oysters in large salt marshes having crude fiber concentration greater than in the Choptank system, are discussed. The ability of the oyster to utilize 14 C and 15 N from cellulolytic marine bacteria, isolated from a S. alterniflora dominated salt marsh, was also studied

  18. Behavior of pathogenic bacteria in the oyster, Crassostrea commercialis, during depuration, re-laying, and storage.

    Son, N T; Fleet, G H

    1980-01-01

    Oysters (Crassostrea commercials) harvested from major cultivation areas within the state of New South Wales, Australia, were commonly contaminated with low levels of the food-poisoning organisms Bacillus cereus, Clostridium perfringens, and Vibrio parahaemolyticus. Salmonella was found in oysters on only one occasion. These bacteria were cleansed from oysters during oyster purification by re-laying in a non-polluted waterway. Oysters were laboratory contaminated to levels in excess 1,000 cel...

  19. Interactions between the introduced Pacific oyster Crassostrea gigas and the indigenous blue mussel Mytilus edulis. Local-scale food competition

    Hans, I.W.

    2004-01-01

    The aim of this study was to determine if food competition between mussels and oysters occurs, and how mussel and oyster growth is affected by this interaction. This was done by relating mussel growth to oyster density relating oyster growth to oyster biomass and perform a field control, by

  20. Prevalence and characterization of Salmonella serovars isolated from oysters served raw in restaurants.

    Brillhart, Crystal D; Joens, Lynn A

    2011-06-01

    To determine if Salmonella-contaminated oysters are reaching consumer tables, a survey of raw oysters served in eight Tucson restaurants was performed from October 2007 to September 2008. Salmonella spp. were isolated during 7 of the 8 months surveyed and were present in 1.2% of 2,281 oysters tested. This observed prevalence is lower than that seen in a previous study in which U.S. market oysters were purchased from producers at bays where oysters are harvested. To test whether the process of refrigerating oysters in restaurants for several days reduces Salmonella levels, oysters were artificially infected with Salmonella and kept at 4°C for up to 13 days. Direct plate counts of oyster homogenate showed that Salmonella levels within oysters did not decrease during refrigeration. Six different serovars of Salmonella enterica were found in the restaurant oysters, indicating multiple incidences of Salmonella contamination of U.S. oyster stocks. Of the 28 contaminated oysters, 12 (43%) contained a strain of S. enterica serovar Newport that matched by pulsed-field gel electrophoresis a serovar Newport strain seen predominantly in the study of bay oysters performed in 2002. The repeated occurrence of this strain in oyster surveys is concerning, since the strain was resistant to seven antimicrobials tested and thus presents a possible health risk to consumers of raw oysters.

  1. Oyster spat recruitment in Espírito Santo State, Brazil, using recycled materials

    Rosebel C. Nalesso

    2008-12-01

    Full Text Available This paper evaluated the effectiveness of four types of oyster spat collectors, made with recycled materials, in the recruitment of the mangrove oyster Crassostrea spp. at five sites in the Benevente river estuary, Anchieta District and on two islands in Piúma District, both in Espírito Santo State. The collectors were made of: 1- oyster shells, 2- PET bottles, 3- car tires and 4- tiles, all of them suspended by ropes and tied to roots of Rhizophora mangle or mussel long-lines. The number of spat recruited on each collector and their shell lengths were registered bimonthly, as well as the physico-chemical-trophic parameters of the water: salinity, temperature, dissolved oxygen, particulate organic matter and chlorophyll a, which were correlated (by Spearman's correlation with the number of spat recruited. Spat settlement was significantly higher on oyster shell, tile and tire collectors, mainly at points with higher salinities, such as Praia do Coqueiro in Anchieta and on Meio and Cabrito Islands in Piúma (Kruskal-Wallis: H= 10.01; 3 d.f.; p 0.05. The number of oyster spat was positively correlated with the salinity (ρs= 0.331; p Este trabalho avaliou a eficiência de quatro tipos de coletores de sementes no recrutamento de ostras Crassostrea sp., em cinco pontos do estuário do Rio Benevente, município de Anchieta, e em duas ilhas no município de Piúma, estado do Espírito Santo. Foram utilizados quatro tipos de coletores: 1-conchas de ostras, 2- garrafas PET, 3-tiras de pneu e 4- telhas, todos suspensos por cordas e amarrados em rizóforos de Rhizophora mangle ou em "long-lines" de mexilhões. Bimensalmente, as sementes recrutadas foram contadas e medidas quanto à altura, determinando-se os parâmetros físico-químicos-tróficos da água: salinidade, temperatura, oxigênio dissolvido, matéria orgânica particulada e clorofila-a, que foram correlacionados com o número de sementes nos coletores (através de correlações de Spearman

  2. A mathematical model of the accumulation of radionuclides by oysters (C. virginica) aquacultured in the effluent of a nuclear power reactor to include major biological parameters

    Hess, C.T.; Smith, C.W.; Price, A.H.

    1977-01-01

    The uptake, accumulation and loss of radionuclides by the American oyster (C. virginica) aquacultured in the effluent of a nuclear power reactor has been measured monthly for 3 yr at four field stations in the Montsweag Estuary of the Sheepscot River and at a control station in the nearby Damariscotta River Estuary, southern central coastal Maine, U.S.A. A mathematical model for the time variation of the specific activity of the oysters has been developed to include the physical half-lives of the various radionuclides, the biological half-lives of the various radionuclides (biological depuration), the water temperature (oyster hibernation) and shell growth. The resulting first order linear differential equation incorporating these phenomena is driven by the liquid radionuclide effluent release of the Maine Yankee Nuclear Reactor. Comparison of the monthly measurements of the specific activity for 58 Co, 60 Co, 54 Mn, 134 Cs and 137 Cs in oysters with model calculations show close agreement over all ranges of variation observed. A special feature of this mathematical model is its ability to describe the non-chemostatic field situation. (author)

  3. The culture of pearl oysters, Pinctada fucata (Gould, 1850 in Phuket with temperature shock method and survival rates on various feeds

    Rativat, V.

    2005-02-01

    Full Text Available Marine pearl farming at Phuket Island has exploited natural pearl oysters. In order to obtain sufficient pearl oysters, Pinctada fucata (Gould, 1850, the oyster cultivation was carried out to determine appropriate kinds of food and types of spat collectors. The male and female oysters were stimulated to spawn with this temperature shock method (treated with 32ºC and then with 26ºC. The fertilized eggs developed into the stages of polar body, cleavage, blastula, gastrula, trochophore and then D-shape larvae. At the ageof 19-26 hrs. the larvae were fed with three kinds of food: Isochrysis galbana, Chaetoceros calcitrans and the mixture of 1:1 I. galbana and C. calcitrans. Upon the first 30 days, shell lengths of the spats fed with I. Galbana, C. calcitrans and the mixture were 422.00±59.32, 221.33±12.46 and 347.33±67.98 μg, respectively. The 26-29th day spat stage settled to the collectors: saran net, plastic plates and wavy tile. Number of spats settling to saran net was the highest. But after being moved into the sea for 30 days, the survival rate was89.06% which was lower than for those settling to plastic plates (93.29% and wavy tile (93.99%.

  4. Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96 h) exposure to cadmium

    Moncaleano-Niño, Angela M.; Barrios-Latorre, Sergio A.; Poloche-Hernández, Javier F.; Becquet, Vanessa; Huet, Valérie; Villamil, Luisa; Thomas-Guyon, Hélène; Ahrens, Michael J.; Luna-Acosta, Andrea

    2017-01-01

    Highlights: • The cup oyster Saccostrea sp. is present in Santa Marta, Colombian Caribbean. • 96 h exposure of oysters to Cd increased metallothionein concentrations in digestive glands up to 2-fold. • 96 h exposure of oysters to Cd decreased vitellogenin concentrations in gonads up to 6-fold. • Metallothionein and vitellogenin tissue concentrations correlated with whole tissue Cd concentrations. • Significant changes in metallothionein and vitellogenin levels were only evident at Cd concentrations above 100 μg/L. - Abstract: Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96 h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5–5.0 cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5 days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000 μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations ≥ 100 μg/L showed a significant increase, from 8.0 to 14.8 μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297 μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96 h of exposure to 1000 μg/L Cd, were significantly lower (0

  5. Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96 h) exposure to cadmium

    Moncaleano-Niño, Angela M.; Barrios-Latorre, Sergio A.; Poloche-Hernández, Javier F. [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Becquet, Vanessa; Huet, Valérie [Littoral Environnement et Sociétés (LIENSs) – UMR 7266, CNRS-Université de La Rochelle, Bâtiment ILE 2, rue Olympe de Gouges, 17 000 La Rochelle (France); Villamil, Luisa [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Thomas-Guyon, Hélène [Littoral Environnement et Sociétés (LIENSs) – UMR 7266, CNRS-Université de La Rochelle, Bâtiment ILE 2, rue Olympe de Gouges, 17 000 La Rochelle (France); Ahrens, Michael J., E-mail: michael.ahrens@utadeo.edu.co [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Luna-Acosta, Andrea [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia)

    2017-04-15

    Highlights: • The cup oyster Saccostrea sp. is present in Santa Marta, Colombian Caribbean. • 96 h exposure of oysters to Cd increased metallothionein concentrations in digestive glands up to 2-fold. • 96 h exposure of oysters to Cd decreased vitellogenin concentrations in gonads up to 6-fold. • Metallothionein and vitellogenin tissue concentrations correlated with whole tissue Cd concentrations. • Significant changes in metallothionein and vitellogenin levels were only evident at Cd concentrations above 100 μg/L. - Abstract: Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96 h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5–5.0 cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5 days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000 μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations ≥ 100 μg/L showed a significant increase, from 8.0 to 14.8 μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297 μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96 h of exposure to 1000 μg/L Cd, were significantly lower (0

  6. Developing a national spat collection program for pearl oysters in the Fiji Islands supporting pearl industry development and livelihoods

    Pranesh Kishore

    2018-02-01

    Full Text Available Cultured pearl farming in Fiji relies on wild spat collection to supply the oysters used for pearl production. This supply can be inconsistent and a research program was implemented to determine recruitment of pearl oysters to spat collectors at sites throughout Fiji as a basis for developing a national spat collection program to improve reliability of oyster supply to the industry. Twenty-nine sites across Fiji were used in this study. Spat collectors consisted of a 100 m longline from which 310 individual spat collectors were suspended. Spat collectors were deployed for a period of 10–15 months when the number of pearl oyster (Pinctada margaritifera and Pteria penguin spat attached to each collector was counted and shell size recorded. A total of 5478 P. margaritifera juveniles were collected from all sites with the highest number of recruits (693 and the highest number of recruits per collector (2.10 ± 0.17 occurring at Nacobau (Vanua Levu. The largest mean dorso-ventral measurement (DVM of P. margaritifera at any site was 8.61 ± 0.30 cm while the smallest was 4.26 ± 0.13 cm. Some sites did not record any P. margaritifera recruitment during the study and these were generally sites with relatively turbid water. A total of 4224 Pt. penguin were collected from all sites, with the highest number of recruits (495 recorded from Namarai (Viti Levu. The mean DVM of Pt. penguin ranged from 7.53 cm to 13.62 cm across sites. Results indicate that Pt. penguin have greater tolerance of more turbid inshore sites than P. margaritifera based on greater levels of recruitment at these sites. Results identified sites supporting high levels of pearl oyster recruitment as a basis for an ongoing national spat collection program, and support better targeting of spat collection activities that maximise oyster supply to the Fijian pearl industry. The national spat collection program will generate significant livelihood benefits across

  7. Effects of microplastics on European flat oysters, Ostrea edulis and their associated benthic communities.

    Green, Dannielle Senga

    2016-09-01

    Plastic pollution is recognised as an emerging threat to aquatic ecosystems, with microplastics now the most abundant type of marine debris. Health effects caused by microplastics have been demonstrated at the species level, but impacts on ecological communities remain unknown. In this study, impacts of microplastics on the health and biological functioning of European flat oysters (Ostrea edulis) and on the structure of associated macrofaunal assemblages were assessed in an outdoor mesocosm experiment using intact sediment cores. Biodegradable and conventional microplastics were added at low (0.8 μg L(-1)) and high (80 μg L(-1)) doses in the water column repeatedly for 60 days. Effects on the oysters were minimal, but benthic assemblage structures differed and species richness and the total number of organisms were ∼1.2 and 1.5 times greater in control mesocosms than in those exposed to high doses of microplastics. Notably, abundances of juvenile Littorina sp. (periwinkles) and Idotea balthica (an isopod) were ∼2 and 8 times greater in controls than in mesocosms with the high dose of either type of microplastic. In addition, the biomass of Scrobicularia plana (peppery furrow shell clam) was ∼1.5 times greater in controls than in mesocosms with the high dose of microplastics. This work indicates that repeated exposure to high concentrations of microplastics could alter assemblages in an important marine habitat by reducing the abundance of benthic fauna. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. The cost and feasibility of marine coastal restoration.

    Bayraktarov, Elisa; Saunders, Megan I; Abdullah, Sabah; Mills, Morena; Beher, Jutta; Possingham, Hugh P; Mumby, Peter J; Lovelock, Catherine E

    2016-06-01

    Land-use change in the coastal zone has led to worldwide degradation of marine coastal ecosystems and a loss of the goods and services they provide. Restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed and is critical for habitats where natural recovery is hindered. Uncertainties about restoration cost and feasibility can impede decisions on whether, what, how, where, and how much to restore. Here, we perform a synthesis of 235 studies with 954 observations from restoration or rehabilitation projects of coral reefs, seagrass, mangroves, salt-marshes, and oyster reefs worldwide, and evaluate cost, survival of restored organisms, project duration, area, and techniques applied. Findings showed that while the median and average reported costs for restoration of one hectare of marine coastal habitat were around US$80000 (2010) and US$1600000 (2010), respectively, the real total costs (median) are likely to be two to four times higher. Coral reefs and seagrass were among the most expensive ecosystems to restore. Mangrove restoration projects were typically the largest and the least expensive per hectare. Most marine coastal restoration projects were conducted in Australia, Europe, and USA, while total restoration costs were significantly (up to 30 times) cheaper in countries with developing economies. Community- or volunteer-based marine restoration projects usually have lower costs. Median survival of restored marine and coastal organisms, often assessed only within the first one to two years after restoration, was highest for saltmarshes (64.8%) and coral reefs (64.5%) and lowest for seagrass (38.0%). However, success rates reported in the scientific literature could be biased towards publishing successes rather than failures. The majority of restoration projects were short-lived and seldom reported monitoring costs. Restoration success depended primarily on the ecosystem, site selection, and techniques

  9. The effect of structural complexity, prey density, and "predator-free space" on prey survivorship at created oyster reef mesocosms

    Humphries, Austin T.; La Peyre, Megan K.; Decossas, Gary A.

    2011-01-01

    Interactions between predators and their prey are influenced by the habitat they occupy. Using created oyster (Crassostrea virginica) reef mesocosms, we conducted a series of laboratory experiments that created structure and manipulated complexity as well as prey density and “predator-free space” to examine the relationship between structural complexity and prey survivorship. Specifically, volume and spatial arrangement of oysters as well as prey density were manipulated, and the survivorship of prey (grass shrimp, Palaemonetes pugio) in the presence of a predator (wild red drum, Sciaenops ocellatus) was quantified. We found that the presence of structure increased prey survivorship, and that increasing complexity of this structure further increased survivorship, but only to a point. This agrees with the theory that structural complexity may influence predator-prey dynamics, but that a threshold exists with diminishing returns. These results held true even when prey density was scaled to structural complexity, or the amount of “predator-free space” was manipulated within our created reef mesocosms. The presence of structure and its complexity (oyster shell volume) were more important in facilitating prey survivorship than perceived refugia or density-dependent prey effects. A more accurate indicator of refugia might require “predator-free space” measures that also account for the available area within the structure itself (i.e., volume) and not just on the surface of a structure. Creating experiments that better mimic natural conditions and test a wider range of “predator-free space” are suggested to better understand the role of structural complexity in oyster reefs and other complex habitats.

  10. Perkinsus beihaiensis (Perkinsozoa in oysters of Bahia State, Brazil

    M. S. A. Luz

    2017-08-01

    Full Text Available Abstract This study reports the pathogen Perkinsus beihaiensis in oysters of the genus Crassostrea on the coast of the State of Bahia (Brazil, its prevalence, infection intensity and correlation with salinity. Oysters (n = 240 were collected between October and December 2014 at eight sampling stations between latitudes 13°55'S and 15°42'S. The laboratory procedures included macroscopic analysis, histology, culture in Ray's fluid thioglycollate medium (RFTM, Polymerase Chain Reaction (PCR and DNA sequencing. PCR and sequencing have been used for the genetic identification of oysters as well. Two species of oysters have been identified: Crassostrea rhizophorae and C. brasiliana. In both oyster species P. beihaiensis was the only Perkinsus species detected. In C. rhizophorae, the average prevalence was 82.8% by histology and 65.2% by RFTM. In C. brasiliana, the prevalences were 70.5% and 35.7%, respectively. The higher prevalence of P. beihaiensis in C. rhizophorae was probably influenced by salinity, with which was positively correlated (r> 0.8. In both oysters, P. beihaiensis was located mainly in the gastric epithelium. The infection was generally mild or moderate, without apparent harm to the hosts, but in cases of severe infection, there was hemocytical reaction and tissue disorganization. The generally high prevalence in the region suggests that oysters should be monitored with respect to this pathogen, especially in growing areas.

  11. Anthropogenic impacts on an oyster metapopulation: Pathogen introduction, climate change and responses to natural selection

    David Bushek

    2016-08-01

    Full Text Available Abstract Humans rely on marine ecosystems for a variety of services but often impact these ecosystems directly or indirectly limiting their capacity to provide such services. One growing impact is the emergence of marine disease. We present results from a unique case study examining how oysters, a dominant organism in many coastal bays and estuaries that is often harvested for food, have responded to pathogens influenced by human activities, namely the introduction of novel pathogens. Climate change has enabled a northward spread and establishment of Dermo disease in oysters along the eastern seaboard of North America and human activities inadvertently introduced MSX disease along this same coast. Oysters in Delaware Bay have responded differently to each pathogen, and uniquely to MSX disease by developing a highly resistant baywide population not documented in any other bay. Offspring were produced using parents collected from low or high disease (MSX and Dermo regions of Delaware Bay and exposed in a common garden experiment along with a naïve population from Maine. Results indicated widespread resistance to MSX disease, but not to Dermo disease, across Delaware Bay. One striking result was the demonstration of resilience in the population through its capacity to spread, presumably through larval transport, resistance to MSX disease into portions of the population that have experienced little to no MSX disease pressure themselves. Related studies indicated that larval transport mechanisms allowed widespread dispersal such that the entire metapopulation could acquire a high level of resistance over time if disease resistance is sufficiently heritable. The findings have implications for restoration, management and recovery of diseased populations. Namely, that if left to their own devices, natural selection may find a solution that enables populations to recover from introduced pathogens.

  12. Drought Increases Consumer Pressure on Oyster Reefs in Florida, USA.

    Hanna G Garland

    Full Text Available Coastal economies and ecosystems have historically depended on oyster reefs, but this habitat has declined globally by 85% because of anthropogenic activities. In a Florida estuary, we investigated the cause of newly reported losses of oysters. We found that the oyster reefs have deteriorated from north to south and that this deterioration was positively correlated with the abundance of carnivorous conchs and water salinity. In experiments across these gradients, oysters survived regardless of salinity if conchs were excluded. After determining that conchs were the proximal cause of oyster loss, we tested whether elevated water salinity was linked to conch abundance either by increasing conch growth and survivorship or by decreasing the abundance of a predator of conchs. In field experiments across a salinity gradient, we failed to detect spatial variation in predation on conchs or in conch growth and survivorship. A laboratory experiment, however, demonstrated the role of salinity by showing that conch larvae failed to survive at low salinities. Because this estuary's salinity increased in 2006 in response to reduced inputs of freshwater, we concluded that the ultimate cause of oyster decline was an increase in salinity. According to records from 2002 to 2012, oyster harvests have remained steady in the northernmost estuaries of this ecoregion (characterized by high reef biomass, low salinity, and low conch abundance but have declined in the southernmost estuaries (characterized by lower reef biomass, increases in salinity, and increases in conch abundance. Oyster conservation in this ecoregion, which is probably one of the few that still support viable oyster populations, may be undermined by drought-induced increases in salinity causing an increased abundance of carnivorous conchs.

  13. Human enteroviruses in oysters and their overlying waters.

    Goyal, S M; Gerba, C P; Melnick, J L

    1979-03-01

    The presence of enteroviruses in oysters and oyster-harvesting waters of the Texas Gulf coast was monitored over a period of 10 months. Viruses were detected in water and oyster samples obtained from areas both open and closed to shellfish harvesting. Viruses were detected periodically in waters that met current bacteriological standards for shellfish harvesting. No significant statistical relationship was demonstrated between virus concentration in oysters and the bacteriological and physiochemical quality of water and shellfish. Viruses in water were, however, moderately correlated with total coliforms in water and oysters and with fecal coliforms in oysters. Total coliforms in water were realted to total coliforms in sediment were related only to total coliforms in sediment. Among the physiochemical characteristics of water, turbidity was related statistically to the organic matter content of water and to fecal coliforms in water. There was a marked effect of rainfall on the bacteriological quality of water. Of a total of 44 water samples, 26 yielded virus in concentrations from 4 to 167 plaque-forming units per 100-gallon (ca. 378.5-liter) sample. Of a total of 40 pools of 10 to 12 oysters each, virus was found in 14 pools at a concentration of 6 to 224 plaque-forming units per 100 g of oyster meat. On five occasions, virus was found in water samples when no virus could be detected in oysters harvested from the same sites. This study indicates that current bacteriological standards for determining the safety of shellfish and shellfish-growing waters do no reflect the occurrence of enteroviruses.

  14. Drought Increases Consumer Pressure on Oyster Reefs in Florida, USA.

    Garland, Hanna G; Kimbro, David L

    2015-01-01

    Coastal economies and ecosystems have historically depended on oyster reefs, but this habitat has declined globally by 85% because of anthropogenic activities. In a Florida estuary, we investigated the cause of newly reported losses of oysters. We found that the oyster reefs have deteriorated from north to south and that this deterioration was positively correlated with the abundance of carnivorous conchs and water salinity. In experiments across these gradients, oysters survived regardless of salinity if conchs were excluded. After determining that conchs were the proximal cause of oyster loss, we tested whether elevated water salinity was linked to conch abundance either by increasing conch growth and survivorship or by decreasing the abundance of a predator of conchs. In field experiments across a salinity gradient, we failed to detect spatial variation in predation on conchs or in conch growth and survivorship. A laboratory experiment, however, demonstrated the role of salinity by showing that conch larvae failed to survive at low salinities. Because this estuary's salinity increased in 2006 in response to reduced inputs of freshwater, we concluded that the ultimate cause of oyster decline was an increase in salinity. According to records from 2002 to 2012, oyster harvests have remained steady in the northernmost estuaries of this ecoregion (characterized by high reef biomass, low salinity, and low conch abundance) but have declined in the southernmost estuaries (characterized by lower reef biomass, increases in salinity, and increases in conch abundance). Oyster conservation in this ecoregion, which is probably one of the few that still support viable oyster populations, may be undermined by drought-induced increases in salinity causing an increased abundance of carnivorous conchs.

  15. Development of Genetic Markers for Triploid Verification of the Pacific Oyster,

    Jung-Ha Kang

    2013-07-01

    Full Text Available The triploid Pacific oyster, which is produced by mating tetraploid and diploid oysters, is favored by the aquaculture industry because of its better flavor and firmer texture, particularly during the summer. However, tetraploid oyster production is not feasible in all oysters; the development of tetraploid oysters is ongoing in some oyster species. Thus, a method for ploidy verification is necessary for this endeavor, in addition to ploidy verification in aquaculture farms and in the natural environment. In this study, a method for ploidy verification of triploid and diploid oysters was developed using multiplex polymerase chain reaction (PCR panels containing primers for molecular microsatellite markers. Two microsatellite multiplex PCR panels consisting of three markers each were developed using previously developed microsatellite markers that were optimized for performance. Both panels were able to verify the ploidy levels of 30 triploid oysters with 100% accuracy, illustrating the utility of microsatellite markers as a tool for verifying the ploidy of individual oysters.

  16. The Molecular Differentiation of Anatomically Paired Left and Right Mantles of the Pacific Oyster Crassostrea gigas.

    Wei, Lei; Xu, Fei; Wang, Yuzhi; Cai, Zhongqiang; Yu, Wenchao; He, Cheng; Jiang, Qiuyun; Xu, Xiqiang; Guo, Wen; Wang, Xiaotong

    2018-03-28

    Left-right (L-R) asymmetry is controlled by gene regulation pathways for the L-R axis, and in vertebrates, the gene Pitx2 in TGF-β signaling pathway plays important roles in the asymmetrical formation of organs. However, less is known about the asymmetries of anatomically identical paired organs, as well as the transcriptional regulation mechanism of the gene Pitx in invertebrates. Here, we report the molecular biological differences between the left and right mantles of an invertebrate, the Pacific oyster Crassostrea gigas, and propose one possible mechanism underlying those differences. RNA sequencing (RNA-seq) analysis indicated that the paired organs showed different gene expression patterns, suggesting possible functional differences in shell formation, pheromone signaling, nerve conduction, the stress response, and other physiological processes. RNA-seq and real-time qPCR analysis indicated high right-side expression of the Pitx homolog (cgPitx) in oyster mantle, supporting a conserved role for Pitx in controlling asymmetry. Methylation-dependent restriction-site associated DNA sequencing (MethylRAD) identified a methylation site in the promoter region of cgPitx and showed significantly different methylation levels between the left and right mantles. This is the first report, to our knowledge, of such a difference in methylation in spiralians, and it was further confirmed in 18 other individuals by using a pyrosequencing assay. The miRNome analysis and the TGF-β receptor/Smad inhibition experiment further supported that several genes in TGF-β signaling pathway may be related with the L/R asymmetry of oyster mantles. These results suggested that the molecular differentiation of the oyster's paired left and right mantles is significant, TGF-β signaling pathway could be involved in establishing or maintaining the asymmetry, and the cgPitx gene as one of genes in this pathway; the different methylation levels in its promoter regions between L/R mantles was

  17. Application of Reflectance Transformation Imaging Technique to Improve Automated Edge Detection in a Fossilized Oyster Reef

    Djuricic, Ana; Puttonen, Eetu; Harzhauser, Mathias; Dorninger, Peter; Székely, Balázs; Mandic, Oleg; Nothegger, Clemens; Molnár, Gábor; Pfeifer, Norbert

    2016-04-01

    The world's largest fossilized oyster reef is located in Stetten, Lower Austria excavated during field campaigns of the Natural History Museum Vienna between 2005 and 2008. It is studied in paleontology to learn about change in climate from past events. In order to support this study, a laser scanning and photogrammetric campaign was organized in 2014 for 3D documentation of the large and complex site. The 3D point clouds and high resolution images from this field campaign are visualized by photogrammetric methods in form of digital surface models (DSM, 1 mm resolution) and orthophoto (0.5 mm resolution) to help paleontological interpretation of data. Due to size of the reef, automated analysis techniques are needed to interpret all digital data obtained from the field. One of the key components in successful automation is detection of oyster shell edges. We have tested Reflectance Transformation Imaging (RTI) to visualize the reef data sets for end-users through a cultural heritage viewing interface (RTIViewer). The implementation includes a Lambert shading method to visualize DSMs derived from terrestrial laser scanning using scientific software OPALS. In contrast to shaded RTI no devices consisting of a hardware system with LED lights, or a body to rotate the light source around the object are needed. The gray value for a given shaded pixel is related to the angle between light source and the normal at that position. Brighter values correspond to the slope surfaces facing the light source. Increasing of zenith angle results in internal shading all over the reef surface. In total, oyster reef surface contains 81 DSMs with 3 m x 2 m each. Their surface was illuminated by moving the virtual sun every 30 degrees (12 azimuth angles from 20-350) and every 20 degrees (4 zenith angles from 20-80). This technique provides paleontologists an interactive approach to virtually inspect the oyster reef, and to interpret the shell surface by changing the light source direction

  18. Comparison of methods for detection of norovirus in oysters

    Schultz, Anna Charlotte; Saadbye, Peter; Hoorfar, Jeffrey

    2007-01-01

    a successful detection it is of great importance to remove the tissue inhibitors during the viral RNA extraction. To select the most efficient extraction procedure of oysters we have compared four protocols. A pool of digestive gland material from oyster samples was divided into 1.5 g portions and spiked...... with I 0-fold dilutions of human faecal samples containing norovirus genogroup II. The samples were tested on three different occasions using four different sample treatment protocols. The protocols were assessed with regard to their ability to recover viral RNA and detect norovirus in spiked oysters...

  19. A Preliminary Study on the Pattern, the Physiological Bases and the Molecular Mechanism of the Adductor Muscle Scar Pigmentation in Pacific Oyster Crassostrea gigas

    Wenchao Yu

    2017-09-01

    Full Text Available The melanin pigmentation of the adductor muscle scar and the outer surface of the shell are among attractive features and their pigmentation patterns and mechanism still remains unknown in the Pacific oyster Crassostrea gigas. To study these pigmentation patterns, the colors of the adductor muscle scar vs. the outer surface of the shell on the same side were compared. No relevance was found between the colors of the adductor muscle scars and the corresponding outer surface of the shells, suggesting that their pigmentation processes were independent. Interestingly, a relationship between the color of the adductor muscle scars and the dried soft-body weight of Pacific oysters was found, which could be explained by the high hydroxyl free radical scavenging capacity of the muscle attached to the black adductor muscle scar. After the transcriptomes of pigmented and unpigmented adductor muscles and mantles were studied by RNAseq and compared, it was found that the retinol metabolism pathway were likely to be involved in melanin deposition on the adductor muscle scar and the outer surface of the shell, and that the different members of the tyrosinase or Cytochrome P450 gene families could play a role in the independent pigmentation of different organs.

  20. A Global Synthesis Reveals Gaps in Coastal Habitat Restoration Research

    Y. Stacy Zhang

    2018-04-01

    Full Text Available Coastal ecosystems have drastically declined in coverage and condition across the globe. To combat these losses, marine conservation has recently employed habitat restoration as a strategy to enhance depleted coastal ecosystems. For restoration to be a successful enterprise, however, it is necessary to identify and address potential knowledge gaps and review whether the field has tracked scientific advances regarding best practices. This enables managers, researchers, and practitioners alike to more readily establish restoration priorities and goals. We synthesized the peer-reviewed, published literature on habitat restoration research in salt marshes, oyster reefs, and seagrasses to address three questions related to restoration efforts: (i How frequent is cross-sector authorship in coastal restoration research? (ii What is the geographic distribution of coastal restoration research? and (iii Are abiotic and biotic factors equally emphasized in the literature, and how does this vary with time? Our vote-count survey indicated that one-third of the journal-published studies listed authors from at least two sectors, and 6% listed authors from all three sectors. Across all habitat types, there was a dearth of studies from Africa, Asia, and South America. Finally, despite many experimental studies demonstrating that species interactions can greatly affect the recovery and persistence of coastal foundation species, only one-fourth of the studies we examined discussed their effects on restoration. Combined, our results reveal gaps and discrepancies in restoration research that should be addressed in order to further propel coastal restoration science.

  1. Water Awareness Through Environmental Restoration

    Davis-Caldwell, K.

    2012-04-01

    and negative effects of human presence on the local and global water supply. Student research scientifically tested ways to slow down the effects of run-off contaminants. Students also revisit water analysis and plant trees as buffers as part of their stream preservation efforts in a culminating activity. Oyster Reef Restoration Project: As a result of changes in climate, pollution and human consumption, the oyster population in the Chesapeake Bay had previously been on a rapid decline. The Oyster Reef Restoration Project allows students to understand the creatures of the bay and the cause of this decline. They explore the domino effect this has had on the quality of the water in the bay and future implications on the environment when the oyster population fluctuates significantly. Students construct concrete reefs and study the components of its contents and the reef's impact on the bay. Students are responsible for mixing, pouring and preparing the reef for its eventual drop in the bay. Wetlands Recovery: Following the elimination of a substantial amount of the natural wetlands behind the elementary and middle schools, a wetlands area was erected on the school grounds. This pond has been used to learn about habitats and the role humans, plants and organisms play in the preservation of the earth soil and water supply. This wetland is used by both the elementary and middle schools as a place for hands-on inquiry based learning. Students maintain the upkeep of the pond and teach other students at lower grades.

  2. Episodic recruitment of the rock oyster Saccostrea cucullata (Born ...

    Episodic recruitment of the rock oyster Saccostrea cucullata (Born, 1778) on the Transkei coast. ... This single recruitment, which is 6 to 31 times the annual mean recorded over the last 6 to 7 years, represents 5 ... AJOL African Journals Online.

  3. The Edibility and Cultivation of the Oyster Mushroom.

    Brenneman, James; Guttman, Mark C.

    1994-01-01

    Describes an enjoyable and fascinating experience that involves the cultivation of oyster mushrooms. By allowing students to participate in this process, the students are able to better understand the biology and utility of fungi. (ZWH)

  4. Phylogeny and Species Diversity of Gulf of California Oysters

    U.S. Environmental Protection Agency — Dataset of DNA sequence data from two mitochondrial loci (COI and 16S) used to infer the phylogeny of oysters in the genus Ostrea along the Pacific coast of North...

  5. Oyster radiation sensitivity; Sensibilidade de ostras a radiacao

    Marchese, Sandra R.M. [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil); Mastro, Nelida L. del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1996-07-01

    Various food products like oysters, crabs and shrimps have been described as possible Vibrio spp. transmitting agents. Seafood irradiation is been presented as an alternative among the different public health intervention measures to control food borne diseases. The objective of this work was to establish, firstly, the radioresistance of Crassostrea brasiliana oysters. The oysters were irradiated with Co-60 radiation with doses of 0, 1.5,3 and 6 kGy. Survival curves a function of time showed that 100% of samples irradiated with 3 kGy survived at least 6 days; among those irradiated with 6 kGy, 100% survived 3 days. These results are encouraging since a dose of 2 kGy is already effective in diminishing oyster bioburden. (author)

  6. Cadmium uptake in oyster isognomon alatus under laboratory condition

    Katayon Saed; Ahmad Ismail; Missri Kusnan; Hishamuddin Omar

    1999-01-01

    The uptake of cadmium in Flat tree oyster Isognomon alatus was investigated under controlled laboratory conditions for two weeks. Oysters were exposed to 100 μg 1'-1 cadmium and the accumulation of cadmium in the tissues was measured for every two days. Soft tissues of oyster were digested in concentrated acid and cadmium concentrations were determined by using Atomic Absorption Spectrophotometer. The accumulation of cadmium in the soft tissues of oysters was increased during the first six days from 0.73 μg g- 1 to 10.77 μg g'-1, and remaining constant for four days at average level of 10.96 μg g'-1. The Cl concentrations was increased to 32.70 μg g'-1 until the end of experiment. There was no sign of cadmium accumulation approaching saturation for the period of exposure. (author)

  7. Carbon And Nitrogen Requirements For The Cultivation Of Oyster ...

    Carbon And Nitrogen Requirements For The Cultivation Of Oyster Mushroom ... It was found that under these experimental conditions, the carbon compounds supported growth except ribose, starch and dextrin. ... HOW TO USE AJOL.

  8. IS COPPER REQUIRED FOR EASTERN OYSTER SETTING AND METAMORPHOSIS?

    Recent field research with eastern oysters demonstrated higher defense activities, including hemocyte numbers, locomotion and bactericidal ability, associated with locations exhibiting relatively high contamination. Copper and zinc, found in high concentrations in tissues of oyst...

  9. Molecular and Antibacterial Profile of Edible Oyster Mushrooms ...

    2012r

    2014-09-24

    Sep 24, 2014 ... Phenol/Chloroform DNA extraction protocol and the DNA was ... DNA from oyster mushroom fermentation broth, mycelia or fruiting bodies. .... Sample preparation: The different strains of Pleurotus were obtained in test- tubes.

  10. Virus, protozoa and organic compounds decay in depurated oysters.

    Souza, Doris Sobral Marques; Piazza, Rômi Sharon; Pilotto, Mariana Rangel; do Nascimento, Mariana de Almeida; Moresco, Vanessa; Taniguchi, Satie; Leal, Diego Averaldo Guiguet; Schmidt, Éder der Carlos; Cargin-Ferreira, Eduardo; Bícego, Márcia Caruso; Sasaki, Silvio Tarou; Montone, Rosalinda Carmela; de Araujo, Rafael Alves; Franco, Regina Maura Bueno; Bouzon, Zenilda Laurita; Bainy, Afonso Celso Dias; Barardi, Célia Regina Monte

    2013-11-01

    (1) Evaluate the dynamic of the depuration process of Crassostrea gigas oysters using different ultraviolet doses with different amounts of contaminants (virus, protozoa and organic contaminants) and (2) investigate the morphological changes in the oysters' tissues produced by the depuration procedures. The oysters were allocated in sites with different degrees of contamination and analyzed after 14 days. Some animals were used as positive controls by artificial bioaccumulation with HAdV2 and MNV1 and subjected to depuration assays using UV lamps (18 or 36 W) for 168 h. The following pollutants were researched in the naturally contaminated oysters, oysters after 14 days in sites and oysters during the depuration processes: virus (HAdV, HAV, HuNoV GI/GII and JCPyV), by (RT) qPCR; protozoa (Cryptosporidium and Giardia species), by immunomagnetic separation and immunofluorescence; and organic compounds (AHs, PAHs, LABs, PCBs and organochlorine pesticides-OCs), by chromatography. Changes in the oysters' tissues produced by the depuration processes were also evaluated using histochemical analysis by light microscopy. In the artificially bioaccumulated oysters, only HAdV2 and MNV1 were investigated by (RT) qPCR before the depuration procedures and after 96 and 168 h of these procedures. At 14 days post-allocation, HAdV was found in all the sites (6.2 × 105 to 4.4 × 107 GC g(-1)), and Giardia species in only one site. Levels of PCBs and OCs in the oyster's tissues were below the detection limit for all samples. AHs (3.5 to 4.4 μg g(-1)), PAHs (11 to 191 ng g(-1)) and LABs (57 to 751 ng g(-1)) were detected in the samples from 3 sites. During the depuration assays, we found HAdV, Giardia and Cryptosporidium species until 168 h, independent of UV treatment. AHs, PAHs and LABs were found also after 168 h of depuration (36 W and without UV lamp). The depuration procedures did not produce changes in the oysters' tissues. In the artificially contaminated and depurated

  11. Effect of gamma radiation on shellstock oysters. Extension of shelf-life and reduction in bacterial numbers, with particular reference to Vibrio vulnificus

    Dixon, D.W.; Rodrick, G.E.

    1998-01-01

    Shellstock oysters from Apalachicola Bay, Florida, United States of America, were irradiated at the nation's first commercial food irradiator, Vindicator, Inc. in Mulberry, Florida, with four doses, and analysed for their shelf-life and bacterial levels. A 2-3 log cycle reduction in bacterial numbers was observed at all the doses immediately after irradiation. The shelf-life was limited in that the D 50 values were found to be 30, 25, 7 and 6 days at 0.5, 1, 2 and 3 kGy, respectively. The D 20 values were calculated as 17, 9, 4 and 4 days at 0.5, 1, 2 and 3 kGy, respectively. Even though the bacterial numbers were significantly lower in the irradiated oysters, the shelf-life was reduced markedly at doses higher than 1 kGy. The irradiated shellstock did not demonstrate any extension in shelf-life, above that of the non-irradiated controls; in fact, they experienced a reduction in shelf-life and there was a growing back of the surviving organisms, which reached levels that were higher than those observed in the controls. Vibrio vulnificus demonstrated high radiosensitivity, with D 10 values of 0.062 and 0.037 kGy for the virulent and avirulent forms, respectively. Preliminary data indicate that the viable but non-culturable form of V. vulnificus is more radioresistant than the corresponding viable and culturable forms, but this needs further elucidation. Also, current research is directed at analysing the effects of the shell to meat ratio of the oysters, and how this affects their radioresistance. Furthermore, oysters from different locations have different shell to meat weight ratios, and this can influence the efficiency of radiation treatment. (author)

  12. Interim restorations.

    Gratton, David G; Aquilino, Steven A

    2004-04-01

    Interim restorations are a critical component of fixed prosthodontic treatment, biologically and biomechanically. Interim restoration serves an important diagnostic role as a functional and esthetic try-in and as a blueprint for the design of the definitive prosthesis. When selecting materials for any interim restoration, clinicians must consider physical properties, handling properties, patient acceptance, and material cost. Although no single material meets all the requirements and material classification alone of a given product is not a predictor of clinical performance, bis-acryl materials are typically best suited to single-unit restorations, and poly(methylmethacrylate) interim materials are generally ideal for multi-unit, complex, long-term, interim fixed prostheses. As with most dental procedures, the technique used for fabrication has a greater effect on the final result than the specific material chosen.

  13. Restoring forests

    Jacobs, Douglass F.; Oliet, Juan A.; Aronson, James

    2015-01-01

    of land requiring restoration implies the need for spatial prioritization of restoration efforts according to cost-benefit analyses that include ecological risks. To design resistant and resilient ecosystems that can adapt to emerging circumstances, an adaptive management approach is needed. Global change......, in particular, imparts a high degree of uncertainty about the future ecological and societal conditions of forest ecosystems to be restored, as well as their desired goods and services. We must also reconsider the suite of species incorporated into restoration with the aim of moving toward more stress resistant...... and competitive combinations in the longer term. Non-native species may serve an important role under some circumstances, e.g., to facilitate reintroduction of native species. Propagation and field establishment techniques must promote survival through seedling stress resistance and site preparation. An improved...

  14. High-pressure treatment for shelf-life extension and quality improvement of oysters cooked in a traditional Taiwanese oyster omelet.

    Lai, Kung-Ming; Chi, Hsin-Yi; Hsu, Kuo-Chiang

    2010-01-01

    Whole oysters were processed using high-pressure (HP) treatment at 250 and 300 MPa for 0 to 10 min and stored at 4 degrees Celsius for up to 28 days. HP-treated oysters and untreated oysters were evaluated for lipid oxidation, growth of microorganisms, and sensory characteristics after cooking at 160 degrees Celsius for 90 s. Microbial counts after HP treatment revealed that the bacterial load was initially reduced at all pressures. HP-treated oysters had significantly higher pH and moisture (P oysters during storage. HP treatment increased lipid oxidation with unpleasant odor during storage compared with the control. HP treatment decreased redness but did not significantly affect the brightness and yellowness of cooked oysters. From tests of mechanical properties, 300 MPa-treated oysters after cooking had significantly increased toughness as measured by cutting force. HP-treated oysters after cooking received higher quality scores than did the control during the storage trial. Results indicated that 300 MPa for 2 min is the optimum HP treatment that results in oysters most acceptable for oyster omelets during storage at 4 degrees Celsius, and this treatment may extend the shelf life of these oysters to 21 days.

  15. National survey of foodborne viruses in Australian oysters at production.

    Torok, Valeria; Hodgson, Kate; McLeod, Catherine; Tan, Jessica; Malhi, Navreet; Turnbull, Alison

    2018-02-01

    Internationally human enteric viruses, such as norovirus (NoV) and hepatitis A virus (HAV), are frequently associated with shellfish related foodborne disease outbreaks, and it has been suggested that acceptable NoV limits based on end-point testing be established for this high risk food group. Currently, shellfish safety is generally managed through the use of indicators of faecal contamination. Between July 2014 and August 2015, a national prevalence survey for NoV and HAV was done in Australian oysters suitable for harvest. Two sampling rounds were undertaken to determine baseline levels of these viruses. Commercial Australian growing areas, represented by 33 oyster production regions in New South Wales, South Australia, Tasmania and Queensland, were included in the survey. A total of 149 and 148 samples were collected during round one and two of sampling, respectively, and tested for NoV and HAV by quantitative RT-PCR. NoV and HAV were not detected in oysters collected in either sampling round, indicating an estimated prevalence for these viruses in Australian oysters of oysters was consistent with epidemiological evidence, with no oyster-related foodborne viral illness reported during the survey period. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Copper and zinc contamination in oysters: subcellular distribution and detoxification.

    Wang, Wen-Xiong; Yang, Yubo; Guo, Xiaoyu; He, Mei; Guo, Feng; Ke, Caihuan

    2011-08-01

    Metal pollution levels in estuarine and coastal environments have been widely reported, but few documented reports exist of severe contamination in specific environments. Here, we report on a metal-contaminated estuary in Fujian Province, China, in which blue oysters (Crassostrea hongkongensis) and green oysters (Crassostrea angulata) were discovered to be contaminated with Cu and other metals. Extraordinarily high metal concentrations were found in the oysters collected from the estuary. Comparison with historical data suggests that the estuary has recently been contaminated with Cr, Cu, Ni, and Zn. Metal concentrations in blue oysters were as high as 1.4 and 2.4% of whole-body tissue dry wt for Cu and Zn, respectively. Cellular debris was the main subcellular fraction binding the metals, but metal-rich granules were important for Cr, Ni, and Pb. With increasing Cu accumulation, its partitioning into the cytosolic proteins decreased. In contrast, metallothionein-like proteins increased their importance in binding with Zn as tissue concentrations of Zn increased. In the most severely contaminated oysters, only a negligible fraction of their Cu and Zn was bound with the metal-sensitive fraction, which may explain the survival of oysters in such contaminated environments. Copyright © 2011 SETAC.

  17. Raw oysters can be a risk for infections

    Regine Helena Silva dos Fernandes Vieira

    Full Text Available The aims of this study were to count and identify sucrose positive and negative vibrios isolated from cultivated Crassostrea rhizophorae oysters during their growing cycle. Every month for 12 months, 10 to 18 oysters were collected for study. Collections occurred at the Center for Studies of Coastal Aquaculture (CSCA, which is associated with the Institute of Marine Science, Labomar, located in Euzebio, Ceará, Brazil. Approximately 150 oysters and their intervalvular liquor were studied. Vibrio Standard Plates Counts (SPC from oyster meat and their intervalvular liquor varied from 25 to 59,000,000 CFU/g. For most of the 12 months of the oysters' life, it was possible to identify Vibrio parahaemolyticus. Vibrio carchariae was identified in four collections. Among other isolated species, the most important, considering public health risks, was V. vulnificus, although only one strain was confirmed. We concluded that retail purchased oysters should never be eaten raw or undercooked because many species of the genus Vibrio are known to be pathogenic to humans and live naturally on and in shellfish throughout their life cycle.

  18. DIFFERENTIAL EFFECTS OF OYSTER (CRASSOSTREA VIRGINICA) DEFENSES ON CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHEMOLYTICUS

    Three clinical (2030, 2062, and 2107) and three environmental (1094, 1163, and ATCC 17802) isolates of Vibrio parahaemolyticus were exposed to hemocytes and plasma collected from oysters (Crassostrea virginica) to determine their susceptibility to putative oyster defenses. Clinic...

  19. Brote de norovirus en Mallorca asociado al consumo de ostras Norovirus outbreak in Majorca (Spain associated with oyster consumption

    Antònia Galmés Truyols

    2011-04-01

    Full Text Available Se describe la investigación de un brote de gastroenteritis por norovirus asociado al consumo de ostras. Se encuestaron 346 expuestos (266 afectados. Solamente se enviaron 14 muestras de heces de pacientes al Centro Nacional de Microbiología. Se mandaron ostras recogidas en el lugar de producción al Centro Nacional de Alimentación. Las ostras cumplían los parámetros microbiológicos de calidad aplicables antes de la comercialización, que no incluyen investigación de virus. El análisis epidemiológico asoció la aparición de la enfermedad al consumo de ostras (odds ratio [OR]=60,4; intervalo de confianza del 95% [IC95%]: 26,2-139,3 y de navajas (OR=3,13; IC95%: 1,4-6,9. Los análisis microbiológicos identificaron norovirus en los afectados, pero no en las ostras que habían estado sometidas a un tiempo mayor de depuración que las consumidas. Es necesario un control riguroso de los alimentos de especial riesgo para la transmisión de norovirus y disponer de recursos de laboratorio para investigar brotes alimentarios por norovirus.We describe investigation into an outbreak of norovirus gastroenteritis associated with oyster consumption. A survey was conducted in 346 exposed persons, 266 of whom were cases. Only 14 feces samples from patients were sent to the National Microbiology Laboratory. Oysters collected at the production site were sent to the National Food Center. The oysters met the microbiological quality standard required before sale, which did not include virus investigation. Epidemiological analysis showed an association between gastroenteritis and consumption of oysters (OR=60.4; 95% CI: 26.2-139.3 and razor shells (OR=3.13; 95% CI: 1.4-6.9. Microbiological analysis confirmed norovirus in affected individuals but not in the oysters that had been tested after a longer purification period than those consumed. Food with a special risk of norovirus transmission should be strictly monitored. Investigators should dispose of the

  20. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Northwest), Pacific Oyster

    1988-09-01

    are provided by Galtsoff (1964). Pho- The germinal vesicle is eccentricall, tographs of C. ia larval develop- located within the nucleolus . ment at vari... composition to cultures, and together with high tem- which oysters are exposed (Grave 1916; peratures may cause oyster mortality Morse 1944). (Lipovsky...setting in oyster. Bull. Jap. Soc. Sci. Fish. European and American oysters: 43(9): 1069-1076. response to surface chemistry versus waterborne

  1. Effect of storage on the quality of purified live Pacific and Sydney rock oysters

    Bird, P; Arnold, G; Holliday, J; Boronovshy, A

    1992-01-01

    In December, 1990, the N.S.W. Minister for Agriculture and Rural Affairs removed the Pacific oyster (Crassostrea gigas) from the noxious fish list for the Port Stephens area, permitting it's cultivation. As Port Stephens Pacific oysters are grown intertidally, similar to Sydney rock oysters (Saccostrea commercialis) there was a belief that they may have different storage requirements to overseas Pacific oysters which are cultivated in deep water exclusively. Consequently, the keeping quality ...

  2. First isolation of Nocardia crassostreae from Pacific oysters (Crassostrea gigas) in Europe

    Engelsma, M.Y.; Roozenburg, I.; Joly, J.P.

    2008-01-01

    In summer 2006 an extensive mortality of Pacific oysters Crassostrea gigas occurred in Lake Grevelingen, the Netherlands. A sample of Pacific oysters was investigated for the presence of shellfish pathogens as potential causes of the mortality. Yellow-green lesions were observed in several oysters

  3. 21 CFR 161.30 - Declaration of quantity of contents on labels for canned oysters.

    2010-04-01

    ... canned oysters. 161.30 Section 161.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH....30 Declaration of quantity of contents on labels for canned oysters. (a) For many years packers of canned oysters in the Gulf area of the United States have labeled their output with a declaration of the...

  4. Isolation of Vibrio cholerae serotype O1 from the eastern oyster, Crassostrea virginica.

    Hood, M A; Ness, G E; Rodrick, G E

    1981-01-01

    Two strains of Vibrio cholerae serotype O1 Inaba were isolated from eastern oysters, Crassostrea virginica, collected from estuarine waters in Florida during April 1980. The oyster meats and waters from which the oysters were collected had low fecal coliform counts, and the area had no prior evidence of sewage contamination. PMID:7235700

  5. Detection of hepatitis A virus and bacterial contamination in raw oysters in Thailand.

    Kittigul, Leera; Pombubpa, Kannika; Sukonthalux, Suntharee; Rattanatham, Tippawan; Utrarachkij, Fuangfa; Diraphat, Pornphan

    2010-01-01

    This study was conducted to determine the presence of hepatitis A virus (HAV) in raw oysters (Crassostrea belcheri) using a virus concentration method and reverse transcription-nested polymerase chain reaction (RT-nested PCR). A total of 220 oyster samples were collected from oyster farms and local markets in Thailand. HAV was found in three oyster samples. Nested PCR products of HAV detected in oysters were characterized further by DNA sequencing of the VP1/2A region and subjected to phylogenetic analysis. All HAV sequences (168 basepairs) were associated with human HAV subgenotype IB (GIB). Fecal coliforms and Escherichia coli were determined using the multiple tube fermentation method, to assess the microbiological quality of collected oysters. Among oyster samples tested, 65% had fecal coliforms higher than the standard level for raw shellfish [oyster samples (85%) were contaminated with E. coli in the range of 3.0-4.6 x 10(4) MPN/g. One oyster sample with an acceptable level of fecal coliforms contained HAV GIB. E. coli was found in all HAV-positive oyster samples. The results suggest a significant presence of HAV and bacterial indicators of fecal contamination in raw oysters, which are a health risk for consumers and a source of gastrointestinal illness. Enteric viruses should also be tested to assess the microbiological quality of oysters.

  6. PARASITIC AND SYMBIOTIC FAUNA INHABITING OYSTERS (CRASSOSTREA VIRGINICA) SAMPLED FROM THE CALOOSAHATCHEE ESTUARY, FL

    Oysters, Crassostrea virginica, inhabiting 5 sites in the Caloosahatchee River estuary were studied over a 13 month period to determine the suitability of oyster habitat in relation to their health and condition. Histological examination of 650 oysters (10 animals per station per...

  7. Bacteriological quality of fresh and smoke-dried oysters sold in ...

    Bacterial isolates found in fresh oyster were Klebsiella sp. Escherichia sp., Proteus mirabilis, Citrobacter sp., Micrococcus sp., Bacillus sp., Staphylococccus sp. and Serratia sp. while E. coli, Streptococcus sp., Staphylococcus sp. and B. cereus predominated in dried oysters. The oyster meats did not meet the standards of ...

  8. Ocean Acidification Causes Increased Calcium Carbonate Turnover during Larval Shell Formation

    Frieder, C.; Pan, F.; Applebaum, S.; Manahan, D. T.

    2016-02-01

    Mollusca is a major taxon for studies of the evolution and mechanisms of calcification. Under current and future ocean change scenarios, decreases in shell size have been observed in many molluscan species during early development. The mechanistic basis for these decreases are of significant interest. In this study, Pacific oyster larvae (Crassostrea gigas) reared at aragonite undersaturation (Ω > 1). Coupling radioisotope tracer assays with mineral mass measurements allowed calculation of calcification budgets for first shell formation in veliger stage larvae. Three primary mechanisms (in order of increasing effect) contributed to the change in shell mass at undersaturation: delayed onset of calcification, increased dissolution rates, and decreased net calcification rates. The observation of dissolution indicates turnover of the newly formed shell, and physicochemical constraints of undersaturation provide a mechanistic basis for decreased calcification.

  9. Oyster reproduction is affected by exposure to polystyrene microplastics

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-01-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (−38%), diameter (−5%), and sperm velocity (−23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  10. Oyster reproduction is affected by exposure to polystyrene microplastics.

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-03-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L(-1)) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (-38%), diameter (-5%), and sperm velocity (-23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring.

  11. ramic restorations

    Ashish R Jain

    2013-01-01

    Full Text Available Rehabilitation of a patient with severely worn dentition after restoring the vertical dimension is a complex procedure and assessment of the vertical dimension is an important aspect in these cases. This clinical report describes the full mouth rehabilitation of a patient who was clinically monitored to evaluate the adaptation to a removable occlusal splint to restore vertical dimension for a period 1 month and provisional restorations to determine esthetic and functional outcome for a period of 3 months. It is necessary to recognizing that form follows function and that anterior teeth play a vital role in the maintenance of oral health. Confirmation of tolerance to changes in the vertical dimension of occlusion (VDO is of paramount importance. Articulated study casts and a diagnostic wax-up can provide important information for the evaluation of treatment options. Alteration of the VDO should be conservative and should not be changed without careful consideration.

  12. Hair restoration.

    Rawnsley, Jeffrey D

    2008-08-01

    The impact of male hair loss as a personal and social marker of aging is tremendous and its persistence as a human concern throughout recorded history places it in the forefront of male concern about the physical signs of aging. Restoration of the frontal hairline has the visual effect of re-establishing facial symmetry and turning back time. Follicular unit transplantation has revolutionized hair restoration, with its focus on redistributing large numbers of genetically stable hair to balding scalp in a natural distribution. Follicular unit hair restoration surgery is a powerful tool for the facial plastic surgeon in male aesthetic facial rejuvenation because it offers high-impact, natural-appearing results with minimal downtime and risk for adverse outcome.

  13. Challenges to the Application of δ15N measurements of the organic fraction of archaeological and fossil mollusk shells to assess paleoenvironmental change.

    Andrus, C. F. T.

    2015-12-01

    Nitrogen isotope analysis of the organic fraction of mollusk shells is beginning to be applied to questions of past anthropogenic and natural environmental variation using samples from archaeological and fossil deposits. Fairly extensive proxy validation research has been conducted in the past decade, documenting the relationship between the δ15N of ambient particulate organic matter, mollusk soft tissues, and shell organic matrix. However, comparatively little research has addressed the potential effects of taphonomy and diagenesis on these proxy records. Assessing archaeological samples are especially complex in that humans may have transported and/or cooked shell prior to deposition. Shell δ15N data will be presented from modern and archaeological oyster (Crassostrea virginica) and clam shell (Mercenaria spp.) of various late Holocene ages and late Cretaceous Crassatellites vadosus shells. Archaeological shells show some loss of organic matter over time, yet some Cretaceous shells retain enough matrix to permit δ15N analysis. The Cretaceous samples required concentration of the remaining organic matrix by removing carbonate via acid pretreatment prior to EA-IRMS analysis, but modern and archaeological shells had sufficient organic matrix to permit analysis without acid pretreatment. The δ15N data from the archaeological shells do not display obvious alteration from the loss of organic matrix. The results of cooking experiments performed on modern oyster shells also indicate little alteration of δ15N values, unless the shell was heated to the point of disintegration. While these experiments indicate promise for the application of δ15N analysis of shell organic matter, the results are incomplete and lack ideal control over initial δ15N values in ancient samples used for comparisons. Future research, perhaps focused on compound-specific δ15N analysis and additional controlled experiments on moderns shells, may improve this assessment.

  14. Preliminary assessment of the potential for mangrove oyster cultivation in Piraquê-açu river estuary (Aracruz, ES

    Luciana Alvarenga

    2006-01-01

    Full Text Available At Piraquê-açu river estuary, Aracruz, ES, the technical viability of Crassostrea rhizophorae cultivation was determined through monthly measures in shell length and weight. Seeds of C. rhizophorae were put in cages and suspended in rafts. Increase in height and weight (flesh and dry of the oysters was measured. During ten months (July/98 to May/99, oyster shell reached an average of 37.6 mm in shell height and 3.0 g in flesh weight (the whole animal. High mortality rates were registered and could be related to the high salinity water and to high predation observed, especially by flatworms Stylochophana divae and snails Cymatium parthenopeum, as well as fouling organisms such as barnacles, Serpulidae polychaetes and seed of the same species.No estuário do Rio Piraquê-açu, município de Aracruz, ES, foi avaliada a viabilidade técnica da implantação do cultivo de ostras Crassostrea rhizophorae em lanternas suspensas numa balsa de cultivo, através da estimativa de crescimento e ganho de peso fresco e seco das ostras. Verificou-se que, durante os dez meses de cultivo (junho/98 a maio/99, as ostras atingiram, em média, 37,6 mm de altura e 3,0 g no peso total. Foi registrada uma alta taxa de mortalidade, que poderia ser atribuída aos altos valores de salinidade na água e também aos predadores observados como planárias Stylochoplana divae e gastrópodos Cymatium parthenopeum, além de incrustantes como cracas, poliquetos Serpulidae e principalmente sementes da própria ostra.

  15. Transparent Restoration

    Barou, L.; Bristogianni, T.; Oikonomopoulou, F.

    2017-01-01

    This paper investigates the application of structural glass in restoration and conservation practices in order to highlight and safeguard our built heritage. Cast glass masonry is introduced in order to consolidate a half-ruined historic tower in Greece, by replacing the original parts of the façade

  16. Site Restoration

    Noynaert, L.; Bruggeman, A.; Cornelissen, R.; Massaut, V.; Rahier, A

    2001-04-01

    The objectives, the programme, and the achievements of the Site Restoration Department of SCK-CEN in 2000 are summarised. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and activities related to the management of decommissioning projects. The department provides consultancy and services to external organisations.

  17. Site Restoration

    Noynaert, L.; Bruggeman, A.; Cornelissen, R.; Massaut, V.; Rahier, A.

    2001-01-01

    The objectives, the programme, and the achievements of the Site Restoration Department of SCK-CEN in 2000 are summarised. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and activities related to the management of decommissioning projects. The department provides consultancy and services to external organisations

  18. Restorative neuroscience

    Andres, Robert H; Meyer, Morten; Ducray, Angélique D

    2008-01-01

    There is increasing interest in the search for therapeutic options for diseases and injuries of the central nervous system (CNS), for which currently no effective treatment strategies are available. Replacement of damaged cells and restoration of function can be accomplished by transplantation of...

  19. Environmental Restoration

    Zeevaert, T.; Vanmarcke, H

    1998-07-01

    The objectives of SCK-CEN's programme on environmental restoration are (1) to optimize and validate models for the impact assessment from environmental, radioactive contaminations, including waste disposal or discharge; (2) to support the policy of national authorities for public health and radioactive waste management. Progress and achievements in 1997 are reported.

  20. Obtainment of calcium carbonate from mussels shell; Obtencao de carbonato de calcio a partir de conchas de mariscos

    Hamester, M.R.R.; Becker, D., E-mail: michele.rosa@sociesc.org.b [Sociedade Educacional de Santa Catarina (SOCIESC), Joinville, SC (Brazil). Mestrado Profissional em Engenharia Mecanica

    2010-07-01

    The mussels and oyster shell are discarded at environment, and this accumulation is causing negative consequences to ecosystem. Calcium carbonate is main constituent of the shell chemical composition. Aiming to reduce environmental aggression and generate income to shellfish producer, there was the possibility of using these shells as an alternative to commercial calcium carbonate. For this physics, chemicals and thermal properties were evaluated, using X-ray fluorescence, thermogravimetric analysis, size distribution, abrasiveness and scanning electronic microscopy. The results indicate that mussels shells have an initial degradation temperature higher than commercial calcium carbonate e same lost weight behavior and 95% of shell chemical composition is calcium carbonate. The sample size distribution was influenced by grinding condition and time as well as its abrasiveness. (author)

  1. Histopathological effect and stress response of mantle proteome following TBT exposure in the Hooded oyster Saccostrea cucullata.

    Khondee, Phattirapa; Srisomsap, Chantragan; Chokchaichamnankit, Daranee; Svasti, Jisnuson; Simpson, Richard J; Kingtong, Sutin

    2016-11-01

    Tributyltin (TBT), an environmental pollutant in marine ecosystems, is toxic to organisms. Although contamination by and bioaccumulation and toxicity of this compound have been widely reported, its underlying molecular mechanisms remain unclear. In the present study, we exposed the Hooded oyster Saccostrea cucullata to TBT to investigate histopathological effects and proteome stress response. Animals were exposed to three TBT sub-lethal concentrations, 10, 50 and 150 μg/l for 48 h. TBT produced stress leading to histopathological changes in oyster tissues including mantle, gill, stomach and digestive diverticula. TBT induced mucocyte production in epithelia and hemocyte aggregation in connective tissue. Cell necrosis occurred when exposure dosages were high. Comparative proteome analyses of mantle protein of oysters exposed to 10 μg/l and control animals were analyzed by a 2-DE based proteomic approach. In total, 32 protein spots were found to differ (p TBT induced the expression of proteins involved in defensive mechanisms (HSP-78, HSP-70, aldehyde dehydrogenase and catalase), calcium homeostasis (VDAC-3), cytoskeleton and cytoskeleton-associated proteins, energy metabolism and amino acid metabolism. Our study revealed that TBT disturbs calcium homeostasis via VDAC-3 protein in mantle and this probably is the key molecular mechanism of TBT acting to distort shell calcification. Moreover, proteins involved in cell structure (tubulin-alpha and tubulin-beta) and protein synthesis were reduced after TBT exposure. Additionally, differential proteins obtained from this work will be useful as potential TBT biomarkers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Suspension of oysters reduces the populations of Vibrio parahaemolyticus and Vibrio vulnificus.

    Cole, K M; Supan, J; Ramirez, A; Johnson, C N

    2015-09-01

    Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) are associated with the consumption of raw oysters and cause illnesses ranging from simple gastroenteritis to life-threatening septicaemia. These halophilic bacteria are frequently found in marine and estuarine systems, accumulating within the tissues of a number of aquatic organisms and passing on to humans after consumption, through contaminated water, or via open wounds. As benthic organisms capable of filtering 40 gallons of water per hour, sediment is an important source of potentially pathogenic vibrios in oysters destined for raw consumption. This research used off-bottom oyster culture to reduce vibrio concentrations in oysters. Colony hybridization was used to enumerate Vp and Vv in bottom and suspended oysters. Vv and Vp concentrations were generally lower in oysters suspended off-bottom, and suspension decreased vibrio loads in oysters by an average of 13%. Suspension of oysters reduced vibrio concentrations. This study found that oyster suspension significantly reduced some populations of potentially pathogenic vibrios. These results indicate that oyster suspension could be a viable approach for preharvest treatment to reduce illness in consumers of raw oysters. © 2015 The Society for Applied Microbiology.

  3. Vibrio bacteria in raw oysters: managing risks to human health.

    Froelich, Brett A; Noble, Rachel T

    2016-03-05

    The human-pathogenic marine bacteria Vibrio vulnificus and V. parahaemolyticus are strongly correlated with water temperature, with concentrations increasing as waters warm seasonally. Both of these bacteria can be concentrated in filter-feeding shellfish, especially oysters. Because oysters are often consumed raw, this exposes people to large doses of potentially harmful bacteria. Various models are used to predict the abundance of these bacteria in oysters, which guide shellfish harvest policy meant to reduce human health risk. Vibrio abundance and behaviour varies from site to site, suggesting that location-specific studies are needed to establish targeted risk reduction strategies. Moreover, virulence potential, rather than simple abundance, should be also be included in future modeling efforts. © 2016 The Author(s).

  4. Cholera after the consumption of raw oysters. A case report.

    Klontz, K C; Tauxe, R V; Cook, W L; Riley, W H; Wachsmuth, I K

    1987-12-01

    In August 1986, a 76-year-old woman in Miami, Florida, developed profuse watery diarrhea and abdominal cramps. Two and four days before the onset of her illness, she had eaten six raw oysters at each of two restaurants in Miami. A stool specimen yielded toxigenic Vibrio cholerae O1 biotype El Tor, serotype Inaba. The results of toxin gene probing of the organism recovered from the patient differed significantly from those of other V. cholerae O1 isolates from the Gulf Coast and elsewhere in the world. A program of active surveillance identified no other cases of cholera in Miami. The source of the raw oysters eaten by the patient was traced to Louisiana. Her case represents the first reported case of cholera associated with eating raw oysters.

  5. Defining optimal freshwater flow for oyster production: effects of freshet rate and magnitude of change and duration on eastern oysters and Perkinsus marinus infection

    LaPeyre, Megan K.; Gossman, B.; La Peyre, Jerome F.

    2009-01-01

    In coastal Louisiana, the development of large-scale freshwater diversion projects has led to controversy over their effects on oyster resources. Using controlled laboratory experiments in combination with a field study, we examined the effects of pulsed freshwater events (freshet) of different magnitude, duration, and rate of change on oyster resources. Laboratory and field evidence indicate that low salinity events (oyster growth was positively correlated with salinity. To maximize oyster production, data indicate that both low and high salinity events will be necessary.

  6. Gulf-Wide Information System, Environmental Sensitivity Index Oyster Leases, Geographic NAD83, LDWF (2001) [esi_oyster_lease_LDWF_2001

    Louisiana Geographic Information Center — This data set contains Environmental Sensitivity Index (ESI) oyster leases data of coastal Louisiana. The ESI is a classification and ranking system, which...

  7. Genotoxicity of diuron and glyphosate in oyster spermatozoa and embryos.

    Akcha, F; Spagnol, C; Rouxel, J

    2012-01-15

    We investigated the effects of genotoxicant exposure in gametes and embryos to find a possible link between genotoxicity and reproduction/developmental impairment, and explore the impact of chemical genotoxicity on population dynamics. Our study focused on the genotoxic effects of two herbicides on oyster gametes and embryos: glyphosate (both as an active substance and in the Roundup formulation) and diuron. France is Europe's leading consumer of agrochemical substances and as such, contamination of France's coastal waters by pesticides is a major concern. Glyphosate and diuron are among the most frequently detected herbicides in oyster production areas; as oyster is a specie with external reproduction, its gametes and embryos are in direct contact with the surrounding waters and are hence particularly exposed to these potentially dangerous substances. In the course of this study, differences in genotoxic and embryotoxic responses were observed in the various experiments, possibly due to differences in pollutant sensitivity between the tested genitor lots. Glyphosate and Roundup had no effect on oyster development at the concentrations tested, whereas diuron significantly affected embryo-larval development from the lowest tested concentration of 0.05 μg L⁻¹, i.e. an environmentally realistic concentration. Diuron may therefore have a significant impact on oyster recruitment rates in the natural environment. Our spermiotoxicity study revealed none of the tested herbicides to be cytotoxic for oyster spermatozoa. However, the alkaline comet assay showed diuron to have a significant genotoxic effect on oyster spermatozoa at concentrations of 0.05 μg L⁻¹ upwards. Conversely, no effects due to diuron exposure were observed on sperm mitochondrial function or acrosomal membrane integrity. Although our initial results showed no negative effect on sperm function, the possible impact on fertilization rate and the consequences of the transmission of damaged DNA for

  8. Evidence of exceptional oyster-reef resilience to fluctuations in sea level.

    Ridge, Justin T; Rodriguez, Antonio B; Fodrie, F Joel

    2017-12-01

    Ecosystems at the land-sea interface are vulnerable to rising sea level. Intertidal habitats must maintain their surface elevations with respect to sea level to persist via vertical growth or landward retreat, but projected rates of sea-level rise may exceed the accretion rates of many biogenic habitats. While considerable attention is focused on climate change over centennial timescales, relative sea level also fluctuates dramatically (10-30 cm) over month-to-year timescales due to interacting oceanic and atmospheric processes. To assess the response of oyster-reef ( Crassostrea virginica ) growth to interannual variations in mean sea level (MSL) and improve long-term forecasts of reef response to rising seas, we monitored the morphology of constructed and natural intertidal reefs over 5 years using terrestrial lidar. Timing of reef scans created distinct periods of high and low relative water level for decade-old reefs ( n  = 3) constructed in 1997 and 2000, young reefs ( n  = 11) constructed in 2011 and one natural reef (approximately 100 years old). Changes in surface elevation were related to MSL trends. Decade-old reefs achieved 2 cm/year growth, which occurred along higher elevations when MSL increased. Young reefs experienced peak growth (6.7 cm/year) at a lower elevation that coincided with a drop in MSL. The natural reef exhibited considerable loss during the low MSL of the first time step but grew substantially during higher MSL through the second time step, with growth peaking (4.3 cm/year) at MSL, reoccupying the elevations previously lost. Oyster reefs appear to be in dynamic equilibrium with short-term (month-to-year) fluctuations in sea level, evidencing notable resilience to future changes to sea level that surpasses other coastal biogenic habitat types. These growth patterns support the presence of a previously defined optimal growth zone that shifts correspondingly with changes in MSL, which can help guide oyster-reef conservation and

  9. In vivo effects of metaldehyde on Pacific oyster, Crassostrea gigas: comparing hemocyte parameters in two oyster families.

    Moreau, Pierrick; Burgeot, Thierry; Renault, Tristan

    2015-06-01

    Pollutants via run-off into the ocean represent a potential threat to marine organisms, especially bivalves such as oysters living in coastal environments. These organisms filter large volumes of seawater and may accumulate contaminants within their tissues. Pesticide contamination in water could have a direct or indirect toxic action on tissues or cells and could induce alteration of immune system. Bivalve immunity is mainly supported by hemocytes and participates directly by phagocytosis to eliminate pathogens. Some studies have shown that pesticides can reduce immune defences and/or modify genomes in vertebrates and invertebrates. Metaldehyde is used to kill slugs, snails and other terrestrial gastropods. Although metaldehyde has been detected in surface waters, its effects on marine bivalves including the Pacific oyster, Crassostrea gigas, have never been studied. Given the mode of action of this molecule and its targets (molluscs), it could be potentially more toxic to oysters than other pesticides (herbicides, fungicides, insecticides, etc.). Effects of metaldehyde on oyster hemocyte parameters were thus monitored through in vivo experiments based on a short-term exposure. In this work, metaldehyde at 0.1 μg/L, which corresponds to an average concentration detected in the environment, modulated hemocyte activities of Pacific oysters after an in vivo short-term contact. Individuals belonging to two families showed different behaviours for some hemocyte activities after contamination by metaldehyde. These results suggested that effects of pollutants on oysters may differ from an individual to another in relation to genetic diversity. Finally, it appears essential to take an interest in the effects of metaldehyde on a wide variety of aquatic invertebrates including those that have a significant economic impact.

  10. Effects of High Hydrostatic Pressure on the Physical, Microbial, and Chemical Attributes of Oysters (Crassostrea virginica).

    Lingham, Talaysha; Ye, Mu; Chen, Haiqiang; Chintapenta, Lathadevi Karuna; Handy, Eunice; Zhao, Jing; Wu, Changqing; Ozbay, Gulnihal

    2016-05-01

    The change in the quality attributes (physical, microbial, and chemical) of oysters (Crassostrea virginica) after high hydrostatic pressure (HHP) treatment at 300 MPa at room temperature (RT, 25 °C) 300, 450, and 500 MPa at 0 °C for 2 min and control oysters without treatment were evaluated over 3 wk. The texture and tissue yield percentages of oysters HHP treated at 300 MPa, RT increased significantly (P oysters reached the spoilage point of 7 log CFU/g after 15 d. Coliform counts (log MPN/g) were low during storage with total and fecal coliforms less than 3.5 and 1.0. High pressure treated oysters at 500 MPa at 0 °C were significantly higher (P oysters HHP treated at 300 MPa at 0 °C in lipid oxidation values. The highest pressure (500 MPa) treatment in this study, significantly (P oysters at 3 wk was significantly higher (P oysters [300 MPa, (RT); 450 MPa (0 °C); and 500 MPa (0 °C)]. HHP treatments of oysters were not significantly different in pH, percent salt extractable protein (SEP), and total lipid values compared to control. Based on our results, HHP prolongs the physical, microbial, and chemical quality of oysters. © 2016 Institute of Food Technologists®

  11. Performance of selected eastern oyster lines across northeastern US estuaries

    Eastern oyster production derived from aquaculture has expanded, but growth potential is constrained by losses to disease. Breeding programs supporting industry in the Northeast have targeted resistance to three diseases: MSX, Dermo, and ROD. Selected lines should possess some level of resistance a...

  12. High pressure processing inactivates human norovirus within oysters

    Consumption of raw bivalve mollusks can result in norovirus infection. One potential intervention for virus-contaminated shellfish is high pressure processing (HPP). Currently HPP is known to inactivate Vibrio bacteria, hepatitis A virus, and murine norovirus within oysters. To evaluate the potentia...

  13. Genetic variation in anti-parasite behavior in oysters

    Behavioral avoidance of disease-causing parasites provides a first line of defense against the threat of infection, particularly when hosts are exposed to free-living parasite stages in the external environment. We report that suspension-feeding oysters (Crassostrea virginica) respond to the presenc...

  14. Length-Weight relationships of mangrove oyster, Crassostrea gasar ...

    The length-weight relationships (LWRs) of mangrove oyster, Crassostrea gasar, cultured under continuous and periodic submergence in tidal ponds, for a period of seven months, February to August 2010 were determined. A total of 375 individuals each of pond A (continuous submergence) and B (periodic submergence) ...

  15. Effect of Depuration on Microbial Content of Mangrove Oyster ...

    Mangrove oysters and water samples collected from Benya lagoon, located at Elmina in the Central Region of Ghana were investigated for microbial contamination. A total of nine fungal isolates were identified. These were Aspergilus niger, A. sulphurus, species of Penicillium, Rhizopus, Trichoderma, Fusarium, ...

  16. THE USE OF THE MANGROVE OYSTER ( CROSSOSTREA GASAR ...

    DR NWAGBOJE

    mangrove oyster (Crossostrea gasar) and water from Golubo creek in the Niger ... did not exceed the Federal Environmental Protection Agency (FEPA) maximum ... the area include farming, local gin production, lumbering and palm wine production. ..... Risk Assessment of Heavy Metals in Ogba River, Benin City, Nigeria.

  17. High protein complementation with high fiber substrates for oyster ...

    Agricultural residues have been world widely accepted for oyster mushroom culture. In this study, we used wheat straw, barley straw, maize stem residue, and lawn residue as substrates coupled with wheat bran, rice bran and soybean powder as complements for the growth of Pleurotus florida and Pleurotus ostreatus as ...

  18. Accumulation of diarrhetic shellfish poisoning toxins in the oyster ...

    Diarrhetic shellfish poisoning (DSP) poses a significant threat to the safe consumption of shellfish in the southern Benguela ecosystem. The accumulation of DSP toxins was investigated in two cultivated bivalve species, the Pacific oyster Crassostrea gigas and the mussel Choromytilus meridionalis, suspended from a ...

  19. Integrating the effects of salinity on the physiology of the eastern oyster, Crassostrea virginica, in the northern Gulf of Mexico through a Dynamic Energy Budget model

    Lavaud, Romain; LaPeyre, Megan K.; Casas, Sandra M.; Bacher, C.; La Peyre, Jerome F.

    2017-01-01

    We present a Dynamic Energy Budget (DEB) model for the eastern oyster, Crassostrea virginica, which enables the inclusion of salinity as a third environmental variable, on top of the standard foodr and temperature variables. Salinity changes have various effects on the physiology of oysters, potentially altering filtration and respiration rates, and ultimately impacting growth, reproduction and mortality. We tested different hypotheses as to how to include these effects in a DEB model for C. virginica. Specifically, we tested two potential mechanisms to explain changes in oyster shell growth (cm), tissue dry weight (g) and gonad dry weight (g) when salinity moves away from the ideal range: 1) a negative effect on filtration rate and 2) an additional somatic maintenance cost. Comparative simulations of shell growth, dry tissue biomass and dry gonad weight in two monitored sites in coastal Louisiana experiencing salinity from 0 to 28 were statistically analyzed to determine the best hypothesis. Model parameters were estimated through the covariation method, using literature data and a set of specifically designed ecophysiological experiments. The model was validated through independent field studies in estuaries along the northern Gulf of Mexico. Our results suggest that salinity impacts C. virginica’s energy budget predominantly through effects on filtration rate. With an overwhelming number of environmental factors impacting organisms, and increasing exposure to novel and extreme conditions, the mechanistic nature of the DEB model with its ability to incorporate more than the standard food and temperature variables provides a powerful tool to verify hypotheses and predict individual organism performance across a range of conditions.

  20. Cholinesterase activity in the cup oyster Saccostrea sp. exposed to chlorpyrifos, imidacloprid, cadmium and copper.

    Moncaleano-Niño, Angela M; Luna-Acosta, Andrea; Gómez-Cubillos, Maria Camila; Villamil, Luisa; Ahrens, Michael J

    2018-04-30

    In the present study, the sensitivity and concentration dependence of three functionally-defined components of cholinesterase activity (total: T-ChE; eserine-sensitive: Es-ChE; and eserine-resistant: Er-ChE) were quantified in the gill, digestive gland and adductor muscle of the tropical cup oyster Saccostrea sp., following acute (96h) aqueous exposure to commercial formulations of the organophosphate (OP) insecticide chlorpyrifos and the neonicotinoid (NN) imidacloprid (concentration range: 0.1-100mg/L), as well as to dissolved cadmium and copper (concentration range: 1-1000μg/L). Oysters (1.5-5.0cm shell length), field-collected from a boating marina in Santa Marta, Colombia (Caribbean Sea) were exposed in the laboratory to each substance at five concentrations. T-ChE, Es-ChE, and Er-ChE activity were quantified in the three tissues in pools of 5 individuals (3 replicates per concentration), before and after inhibition with the total cholinesterase inhibitor eserine (physostigmine, 100µM). Oysters exposed to chlorpyrifos, imidacloprid and Cd showed reduced T-ChE and Es-ChE activity in gills at highest exposure concentrations, with Es-ChE activity being inhibited proportionally more so than T-ChE, whereas Er-ChE activity showed no significant concentration-response. Digestive gland also showed diminished T-ChE, Es-ChE and Er-ChE activity for highest chlorpyrifos and Cd concentrations relative to controls, but an increase of T-ChE and Er-ChE activity at the highest imidacloprid concentration (100mg/L). For Cu, T-ChE, Es-ChE and Er-ChE activities in gills and digestive gland were elevated relative to controls in oysters exposed to Cu concentrations > 100µg/L. In adductor muscle, T-ChE, Es-ChE and Er-ChE activity showed no apparent pattern for any of the four xenobiotics and concentration levels tested. Although this study confirms acute (96h) concentration-dependent reduction of tissue T-ChE and Es-ChE activity in gills and digestive glands of Saccostrea sp

  1. Biochemical and volatile organic compound profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea gigas) cultivated in the Eastern Scheldt and Lake Grevelingen, the Netherlands

    Houcke, van Jasper; Medina, Isabel; Linssen, Jozef; Luten, Joop

    2016-01-01

    The aim of this study was to evaluate the effect of two important different geographical cultivation areas in the Netherlands (Eastern Scheldt and Lake Grevelingen) on the volatile organic compound (VOC) profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea

  2. Biosorption of divalent Pb, Cd and Zn on aragonite and calcite mollusk shells

    Du Yang; Lian Fei [Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Zhu Lingyan, E-mail: zhuly@nankai.edu.cn [Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

    2011-07-15

    The potential of using mollusk shell powder in aragonite (razor clam shells, RCS) and calcite phase (oyster shells, OS) to remove Pb{sup 2+}, Cd{sup 2+} and Zn{sup 2+} from contaminated water was investigated. Both biogenic sorbents displayed very high sorption capacities for the three metals except for Cd on OS. XRD, SEM and XPS results demonstrated that surface precipitation leading to crystal growth took place during sorption. Calcite OS displayed a remarkably higher sorption capacity to Pb than aragonite RCS, while the opposite was observed for Cd. However, both sorbents displayed similar sorption capacities to Zn. These could be due to the different extent of matching in crystal lattice between the metal bearing precipitate and the substrates. The initial pH of the solution, sorbent's dosage and grain size affected the removal efficiency of the heavy meals significantly, while the organic matter in mollusk shells affected the removal efficiency to a lesser extent. - Highlights: > Mollusk shells display high removal efficiency to heavy metals in contaminated water. > Surface precipitation leading to crystal growth takes place during the sorption. > Crystal structure similarity between precipitates and substrates affects the sorption. > pH, sorbent dosage and grain size of adsorbent affects the removal efficiency. > Organic matter in mollusk shells affects the removal efficiency to a less extent. - Mollusk shells display high sorption ability to heavy metals and crystal structure similarity between precipitates and substrates affects the sorption.

  3. Oysters as biomonitors of the apex barge oil spill

    Wade, T.L.; Jackson, T.J.; McDonald, T.J.; Wilkinson, D.L.; Brooks, J.M.

    1993-01-01

    The collision of the Greek tanker ship Shinoussa resulted in a spill of an estimated 692,000 gallons of catalytic feed stock oil into Galveston Bay on July 28, 1990. Oysters were collected from Galveston Bay Todds Dump (GBTD) 235 days previous to the spill and 6, 37, 132, and 495 days after the spill. Oysters were also collected from Galveston Bay Redfish Island (GBRI), a site known to be impacted by the spill, 37 and 110 days after the spill. The concentration of the 24 polynuclear aromatic hydrocarbons (PAH) measured for the National Oceanic and Atmospheric Administration's national status and trends program (NS ampersand T) site showed a sharp increase from about 100 ng/g to over 600 ng/g one week after the spill compared to concentrations 235 days previous to the spill. The concentration of the 24 NS ampersand T PAH in oysters from GBRI ranges from 400 to over 1000 ng/g. Soon after the spill the concentration of the 24 NS ampersand T PAH at Todds Dump decreased to levels not statistically different from prespill samples. However, analyses of alkylated and sulfur containing aromatic compounds indicate the oysters were still contaminated with Apex barge oil at least 37 and 110 days after the spill at GBTD and GBRI, respectively. Data from NS ampersand T sampling at GBTD more than a year after the spill (495 days) indicates the presence of alkylated aromatic hydrocarbons that may be from Apex barge oil still in the area. It appears that a sink of Apex barge oil (i.e., in sediments) may periodically be released by storms or other events into the ecosystem near GBTD. Therefore, bioavailable Apex barge oil is still present and may adversely affect oysters 495 days after the spill

  4. Biochemical profile of oyster Crassostrea madrasensis and its nutritional attributes

    K.K. Asha

    2014-01-01

    Full Text Available Oysters are highly esteemed sea food and considered a delicacy throughout the world. Yet this resource is not optimally utilised in several parts of the world. The aim of this study is to highlight its nutritional importance. Biochemical composition and nutritional attributes of oyster meat are discussed. Proximate composition, fatty acid and amino acid profiles and mineral content were determined in oysters (Crassostrea madrasensis. Moisture, protein, fat, carbohydrate and ash contents in the oyster were 82.64%, 9.41%, 3.25% 3.2% and 1.01%, respectively and it was rich in macro-minerals and trace elements especially selenium. Polyunsaturated fatty acids (PUFA were highest of the total lipids among which eicosapentaenoic acid, docosahexaenoic acid and linoleic acid were the prominent fatty acids. The n-3/n-6 index was high indicating a predominance of n-3 fatty acids in the species. Total amino acid content was 99.33 g/100 g crude protein, of which, essential amino acid lysine was the most abundant. Valine had the lowest essential amino acid score (EAAS (0.17 while threonine had the highest EAAS of 3.62. Chemical score was 17% and the lowest limiting amino acid was valine. Protein efficiency ratio, essential amino acid index and biological value of oyster were 3.92, 120.2 and 174.0, respectively which indicates that the protein is of superior quality. Data on biochemical composition, nutritional attributes and quality indices of C. madrasensis protein may prove important for future policies regarding exploitation of this species and for inducing favourable changes in consumer preferences.

  5. Latitudinal gradients in ecosystem engineering by oysters vary across habitats.

    McAfee, Dominic; Cole, Victoria J; Bishop, Melanie J

    2016-04-01

    Ecological theory predicts that positive interactions among organisms will increase across gradients of increasing abiotic stress or consumer pressure. This theory has been supported by empirical studies examining the magnitude of ecosystem engineering across environmental gradients and between habitat settings at local scale. Predictions that habitat setting, by modifying both biotic and abiotic factors, will determine large-scale gradients in ecosystem engineering have not been tested, however. A combination of manipulative experiments and field surveys assessed whether along the east Australian coastline: (1) facilitation of invertebrates by the oyster Saccostrea glomerata increased across a latitudinal gradient in temperature; and (2) the magnitude of this effect varied between intertidal rocky shores and mangrove forests. It was expected that on rocky shores, where oysters are the primary ecosystem engineer, they would play a greater role in ameliorating latitudinal gradients in temperature than in mangroves, where they are a secondary ecosystem engineer living under the mangrove canopy. On rocky shores, the enhancement of invertebrate abundance in oysters as compared to bare microhabitat decreased with latitude, as the maximum temperatures experienced by intertidal organisms diminished. By contrast, in mangrove forests, where the mangrove canopy resulted in maximum temperatures that were cooler and of greater humidity than on rocky shores, we found no evidence of latitudinal gradients of oyster effects on invertebrate abundance. Contrary to predictions, the magnitude by which oysters enhanced biodiversity was in many instances similar between mangroves and rocky shores. Whether habitat-context modifies patterns of spatial variation in the effects of ecosystem engineers on community structure will depend, in part, on the extent to which the environmental amelioration provided by an ecosystem engineer replicates that of other co-occurring ecosystem engineers.

  6. Experimental infection of Pacific oyster Crassostrea gigas spat by ostreid herpesvirus 1: demonstration of oyster spat susceptibility

    Schikorski David

    2011-02-01

    Full Text Available Abstract In 2008 and 2009, acute mortalities occurred in France among Pacific cupped oyster, Crassostrea gigas, spat. Different hypothesis including the implication of environmental factors, toxic algae and/or pathogens have been explored. Diagnostic tests indicated that OsHV-1 including a particular genotype, termed OsHV-1 μVar, was detected in most of samples and especially in moribund oysters with the highlighting of virus particles looking like herpes viruses by TEM examination. In this study, an experimental protocol to reproduce OsHV-1 infection in laboratory conditions was developed. This protocol was based on the intramuscular injection of filtered (0.22 μm tissue homogenates prepared from naturally OsHV-1 infected spat collected on French coasts during mortality outbreaks in 2008. Results of the experimental trials showed that mortalities were induced after injection. Moreover, filtered tissue homogenates induced mortalities whereas the same tissue homogenates exposed to an ultraviolet (UV treatment did not induce any mortality suggesting that oyster spat mortalities require the presence of a UV sensitive agent. Furthermore, analysis of injected oyster spat revealed the detection of high amounts of OsHV-1 DNA by real-time quantitative PCR. Finally, TEM analysis demonstrated the presence of herpes virus particles. The developed protocol allowed to maintain sources of infective virus which can be useful for the development of further studies concerning the transmission and the development of OsHV-1 infection.

  7. Site Restoration

    Noynaert, L.; Bruggeman, A.; Cornelissen, R.; Massaut, V.; Rahier, A

    2002-04-01

    The objectives, the programme, and the achievements of SCK-CEN's Site Restoration Department for 2001 are described. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and the management of spent fuel and the flow of dismantled materials and the recycling of materials from decommissioning activities based on the smelting of metallic materials in specialised foundries. The department provides consultancy and services to external organisations and performs R and D on new techniques including processes for the treatment of various waste components including the reprocessing of spent fuel, the treatment of tritium, the treatment of liquid alkali metals into cabonates through oxidation, the treatment of radioactive organic waste and the reconditioning of bituminised waste products.

  8. Influence of eutrophication on metal bioaccumulation and oral bioavailability in oysters, Crassostrea angulata.

    Li, Shun-Xing; Chen, Li-Hui; Zheng, Feng-Ying; Huang, Xu-Guang

    2014-07-23

    Oysters (Crassostrea angulata) are often exposed to eutrophication. However, how these exposures influence metal bioaccumulation and oral bioavailability (OBA) in oysters is unknown. After a four month field experimental cultivation, bioaccumulation factors (BAF) of metals (Fe, Cu, As, Cd, and Pb) from seawater to oysters and metal oral bioavailability in oysters by bionic gastrointestinal tract were determined. A positive effect of macronutrient (nitrate N and total P) concentration in seawater on BAF of Cd in oysters was observed, but such an effect was not significant for Fe, Cu, Pb, and As. Only OBA of As was significantly positively correlated to N and P contents. For Fe, OBA was negatively correlated with N. The regular variation of the OBA of Fe and As may be due to the effect of eutrophication on the synthesis of metal granules and heat-stable protein in oysters, respectively.

  9. A comparative proteomic study on the effects of metal pollution in oysters Crassostrea hongkongensis.

    Xu, Lanlan; Ji, Chenglong; Wu, Huifeng; Tan, Qiaoguo; Wang, Wen-Xiong

    2016-11-15

    The metal pollution has posed great risk on the coastal organisms along the Jiulongjiang Estuary in South China. In this work, two-dimensional electrophoresis-based proteomics was applied to the oysters Crassostrea hongkongensis from metal pollution sites to characterize the proteomic responses to metal pollution. Metal accumulation and proteomic responses indicated that the oysters from BJ site were more severely contaminated than those from FG site. Compared with those oyster samples from the clean site (JZ), metal pollution induced cellular injuries, oxidative and immune stresses in oyster heapatopancreas from both BJ and FG sites via differential metabolic pathways. In addition, metal pollution in BJ site induced disturbance in energy and lipid metabolisms in oysters. Results indicated that cathepsin L and ferritin GF1 might be the biomarkers of As and Fe in oyster C. hongkongensis, respectively. This study demonstrates that proteomics is a useful tool for investigating biological effects induced by metal pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Spatial analysis of biomineralization associated gene expression from the mantle organ of the pearl oyster Pinctada maxima

    2011-01-01

    Background Biomineralization is a process encompassing all mineral containing tissues produced within an organism. One of the most dynamic examples of this process is the formation of the mollusk shell, comprising a variety of crystal phases and microstructures. The organic component incorporated within the shell is said to dictate this architecture. However general understanding of how this process is achieved remains ambiguous. The mantle is a conserved organ involved in shell formation throughout molluscs. Specifically the mantle is thought to be responsible for secreting the protein component of the shell. This study employs molecular approaches to determine the spatial expression of genes within the mantle tissue to further the elucidation of the shell biomineralization. Results A microarray platform was custom generated (PmaxArray 1.0) from the pearl oyster Pinctada maxima. PmaxArray 1.0 consists of 4992 expressed sequence tags (ESTs) originating from mantle tissue. This microarray was used to analyze the spatial expression of ESTs throughout the mantle organ. The mantle was dissected into five discrete regions and analyzed for differential gene expression with PmaxArray 1.0. Over 2000 ESTs were determined to be differentially expressed among the tissue sections, identifying five major expression regions. In situ hybridization validated and further localized the expression for a subset of these ESTs. Comparative sequence similarity analysis of these ESTs revealed a number of the transcripts were novel while others showed significant sequence similarities to previously characterized shell related genes. Conclusions This investigation has mapped the spatial distribution for over 2000 ESTs present on PmaxArray 1.0 with reference to specific locations of the mantle. Expression profile clusters have indicated at least five unique functioning zones in the mantle. Three of these zones are likely involved in shell related activities including formation of nacre

  11. Metabolic Energy Demand Is Not Increased during Initial Shell Formation of Bivalves Exposed to Aragonite Undersaturation

    Pan, F.; Frieder, C.; Applebaum, S.; Manahan, D. T.

    2016-02-01

    The Pacific oyster, Crassostrea gigas, is a major commercial species in global aquaculture. Ocean acidification is having a negative effect on larval production of this species, so the mechanisms of this impact are of considerable interest. Formation of new shell in C. gigas during the first 2-days post-fertilization results in a rapid six-fold increase in total mass. This period of early development has high sensitivity to changes in carbonate chemistry, in particular aragonite saturation state (Ω). An elevated energy cost for calcification at low Ω is often invoked as a mechanism. In this study, we characterized the developmental progression of first shell formation, total metabolic expenditure, and underlying biochemical processes of energy allocation during early development of C. gigas, under control (Ω >> 1) and undersaturated conditions (Ω pump activity (Na+, K+-ATPase) between the two treatments. We conclude that early development to the shelled-veliger larval stage does not require more energy at undersaturation. This finding helps constrain potential mechanisms of larval sensitivity to ocean acidification and narrows the focus for possible mitigation strategies for oyster aquaculture production.

  12. Oyster Shell Dredging in Atchafalaya Bay and Adjacent Waters, Louisiana. Draft Environmental Impact Statement and Appendixes,

    1987-04-01

    importance with the development of the Atchafalaya Delta region (Thompson and Deegan , 1980). Although several works have been prepared which dealt with the...47:189-228. Craig , N.J., R.E. Turner, and J.W. Day, Jr. 1979. Land loss in coastal Louisiana (USA). J. Environ. Management 3(1): 133-144. Cratsley, D.W...University, Baton Rouge. 285 pp. EI-114 Thompson, B.A and L.A. Deegan . 1983. The Atchafalaya River delta: a "new" fishery nursery with recommendations for

  13. Detection, quantification and genotyping of noroviruses in oysters implicated in disease outbreaks

    Haefeli, Deborah; Gantenbein-Demarchi, Corinne; Böttiger, Blenda

    2012-01-01

    . While GI and GII have often been verified as causative agents of oyster-transmitted illness, GIV is rarely detected and has so far not been confirmed in outbreaks related to oysters. The aim of this study was to determine whether NoVs from oysters implicated in a disease outbreak were linked to the GI......Noroviruses (NoVs) are a major cause of foodborne outbreaks of acute gastroenteritis in humans. Transmission of NoV is commonly linked to the consumption of oysters as they accumulate viruses through filter feeding in faecal-contaminated water. The NoV genogroups (G)I, GII and GIV infect humans...

  14. Exploring spatial and temporal variations of cadmium concentrations in pacific oysters from british columbia.

    Feng, Cindy Xin; Cao, Jiguo; Bendell, Leah

    2011-09-01

    Oysters from the Pacific Northwest coast of British Columbia, Canada, contain high levels of cadmium, in some cases exceeding some international food safety guidelines. A primary goal of this article is the investigation of the spatial and temporal variation in cadmium concentrations for oysters sampled from coastal British Columbia. Such information is important so that recommendations can be made as to where and when oysters can be cultured such that accumulation of cadmium within these oysters is minimized. Some modern statistical methods are applied to achieve this goal, including monotone spline smoothing, functional principal component analysis, and semi-parametric additive modeling. Oyster growth rates are estimated as the first derivatives of the monotone smoothing growth curves. Some important patterns in cadmium accumulation by oysters are observed. For example, most inland regions tend to have a higher level of cadmium concentration than most coastal regions, so more caution needs to be taken for shellfish aquaculture practices occurring in the inland regions. The semi-parametric additive modeling shows that oyster cadmium concentration decreases with oyster length, and oysters sampled at 7 m have higher average cadmium concentration than those sampled at 1 m. © 2010, The International Biometric Society.

  15. Investigations of Salmonella enterica serovar newport infections of oysters by using immunohistochemistry and knockout mutagenesis.

    Morrison, Christopher M; Dial, Sharon M; Day, William A; Joens, Lynn A

    2012-04-01

    The consumption of raw oysters is an important risk factor in the acquisition of food-borne disease, with Salmonella being one of a number of pathogens that have been found in market oysters. Previous work by our lab found that Salmonella was capable of surviving in oysters for over 2 months under laboratory conditions, and this study sought to further investigate Salmonella's tissue affinity and mechanism of persistence within the oysters. Immunohistochemistry was used to show that Salmonella was capable of breaching the epithelial barriers, infecting the deeper connective tissues of the oysters, and evading destruction by the oysters' phagocytic hemocytes. To further investigate the mechanism of these infections, genes vital to the function of Salmonella's two main type III secretion systems were disrupted and the survivability of these knockout mutants within oysters was assayed. When the Salmonella pathogenicity island 1 and 2 mutant strains were exposed to oysters, there were no detectable deficiencies in their abilities to survive, suggesting that Salmonella's long-term infection of oysters does not rely upon these two important pathogenicity islands and must be due to some other, currently unknown, mechanism.

  16. Sediment quality guidelines for copper and zinc for filter-feeding estuarine oysters?

    Birch, G.F., E-mail: gavin.birch@sydney.edu.a [Environmental Geology Group, School of Geosciences, Sydney University, NSW (Australia); Hogg, T.D. [Environmental Geology Group, School of Geosciences, Sydney University, NSW (Australia)

    2011-01-15

    Sediment quality guidelines (SQGs) assess the ability of bottom sediment to sustain healthy infauna and water quality guidelines (WQGs) provide protection for a designated percentage of aquatic species. Filter-feeding marine species, e.g. oysters and mussels, acquire food from particles in the water column and protection of these animals is not provided by SQGs or WQGs. The current work investigated the relationship between metal (Cu, Zn) concentrations in total and fine-fraction (<62.5 {mu}m) surficial sediment digested in a range of acids and chelating agents and oyster tissue metal concentrations. A strong correlation between oyster tissue Cu and Zn concentrations and fine-fraction surficial sediment digested in 1 M HCl provided a sedimentary guideline which predicted tissue metal concentrations in oysters and established a level (<45 {mu}g g{sup -1} and <1000 {mu}g g{sup -1}, respectively) for protecting oysters from exceeding human consumption levels (70 {mu}g g{sup -1} and 1000 {mu}g g{sup -1}, respectively). - A strong correlation between oyster tissue Cu and Zn concentrations and fine-fraction surficial sediment digested in 1 M HCl provided a sedimentary guideline which predicted tissue metal concentrations in oysters and established a level for protecting oysters from exceeding human consumption levels for these metals. The guidelines for fine surficial sediment developed in the present work accurately predicted oyster tissue concentrations in the field.

  17. Late Jurassic–Early Cretaceous oysters from Siberia: A systematic review

    Igor N. Kosenko

    2017-11-01

    Full Text Available The present study reviews the taxonomy of Late Jurassic–Early Cretaceous oysters from the Northern and the Subpolar Urals (Western Siberia and northern East Siberia. Previous studies have documented 10 species from the genus Liostrea (L. delta, L. cucurbita, L. praeanabarensis, L. anabarensis, L. plastica, L. gibberosa, L. planoconvexa, L. siberica, L. uralensis, L. lyapinensis, and 3 species from the genus Gryphaea (G. borealis and 2 species in open nomenclature. Liostrea gibberosa, L. planoconvexa, L. uralensis, and L. cucurbita are transferred in this study to the genus Pernostrea. Furthermore, two new species of Pernostrea are described: P. mesezhnikovi sp. nov. and P.? robusta sp. nov. Liostrea siberica is transferred to the genus Praeexogyra. Liostrea praeanabarensis and L. anabarensis are attributed to the subgenus Boreiodeltoideum (genus Deltoideum as well as L. delta sensu Zakharov (1966 which is described here as new species Deltoideum (Boreiodeltoideum borealis sp. nov. The similar shell morphology of the genera Deltoideum and Pernostrea provides a basis to establish the new tribe Pernostreini trib. nov. in the subfamily Gryphaeinae. Three species are recorded for the first time from Siberia: Nanogyra? cf. thurmanni, “Ostrea” cf. moreana and Gryphaea (Gryphaea curva.

  18. Optimization of exposure factors for X-ray radiography non-destructive testing of pearl oyster

    Susilo; Yulianti, I.; Addawiyah, A.; Setiawan, R.

    2018-03-01

    One of the processes in pearl oyster cultivation is detecting the pearl nucleus to gain information whether the pearl nucleus is still attached in the shell or vomited. The common tool used to detect pearl nucleus is an X-ray machine. However, an X-ray machine has a drawback that is the energy used is higher than that used by digital radiography. The high energy make the resulted image is difficult to be analysed. One of the advantages of digital radiography is the energy used can be adjusted so that the resulted image can be analysed easily. To obtain a high quality of pearl image using digital radiography, the exposure factors should be optimized. In this work, optimization was done by varying the voltage, current, and exposure time. Then, the radiography images were analysed using Contrast to Noise Ratio (CNR). From the analysis, it can be determined that the optimum exposure factors are 60 kV of voltage, 16 mA of current, and 0.125 s of exposure time which result in CNR of 5.71.

  19. Coal option. [Shell Co

    1978-01-01

    This paper notes the necessity of developing an international coal trade on a very large scale. The role of Shell in the coal industry is examined; the regions in which Shell companies are most active are Australia, Southern Africa, Indonesia; Europe and North America. Research is being carried out on marketing and transportation, especially via slurry pipelines; coal-oil emulsions; briquets; fluidized-bed combustion; recovery of coal from potential waste material; upgrading of low-rank coals; unconventional forms of mining; coal conversion (the Shell/Koppers high-pressure coal gasification process). Techniques for cleaning flue gas (the Shell Flue Gas Desulfurization process) are being examined.

  20. Shell-like structures

    Altenbach, Holm

    2011-01-01

    In this volume, scientists and researchers from industry discuss the new trends in simulation and computing shell-like structures. The focus is put on the following problems: new theories (based on two-dimensional field equations but describing non-classical effects), new constitutive equations (for materials like sandwiches, foams, etc. and which can be combined with the two-dimensional shell equations), complex structures (folded, branching and/or self intersecting shell structures, etc.) and shell-like structures on different scales (for example: nano-tubes) or very thin structures (similar

  1. COMPARISON OF CARBON AND NITROGEN FLUXES IN TIDEFLAT FOOD WEBS DOMINATED BY BURROWING SHRIMP OR BY CULTURED OYSTERS

    Two species of indigenous, thalassinid burrowing shrimps are pests to the benthic culture of Pacific oysters (Crassostrea gigas) because deposition of sediment excavated by the shrimps buries or smothers the oysters. Carbaryl pesticide is used to reduce burrowing shrimp densitie...

  2. Multibiomarker assessment of three Brazilian estuaries using oysters as bioindicators

    Valdez Domingos, F.X.; Azevedo, M.; Silva, M.D.; Randi, M.A.F.; Freire, C.A.; Silva de Assis, H.C.; Oliveira Ribeiro, C.A.

    2007-01-01

    Oysters have been largely employed as bioindicators of environmental quality in biomonitoring studies. Crassostrea rhizophorae was selected to evaluate the health status of three estuarine areas impacted by anthropogenic activities along the Brazilian coast, in three estuarine complexes, ranging in latitude from 7 to 25 deg. S. In each estuary three sites were sampled in Winter and in Summer: a site considered as reference, and two sites next to contamination sources. Condition index was similar at all sites and estuaries, with the highest values found for Itamaraca oysters in Summer. Necrosis, hyperplasia, mucocyte hypertrophy and fusion of ordinary filaments were the main histopathological lesions observed. Muscle cholinesterase activity was overall similar, but with a strong seasonal effect. Inhibition or activation of branchial total ATPase and Na,K-ATPase activities at the contaminated sites was observed. The health status of these estuarine areas is quite similar, and the combined use of biomarkers is recommended

  3. Plesiomonas shigelloides Periprosthetic Knee Infection After Consumption of Raw Oysters.

    Hustedt, Joshua W; Ahmed, Sarim

    Periprosthetic infections are a leading cause of morbidity after total joint arthroplasty. Common pathogens include Staphylococcus aureus, streptococcus, enterococcus, Escherichia coli, and Pseudomonas aeruginosa. However, there are many cases in which rare bacteria are isolated. This case report describes a periprosthetic knee infection caused by Plesiomonas shigelloides. In the United States, P shigelloides and 2 other Vibrionaceae family members, Vibrio vulnificus and Vibrio parahaemolyticus, are most often contracted from eating raw oysters and shellfish. P shigelloides usually causes a self-limiting watery diarrhea, but in immunosuppressed people it can cause septicemia. In this case report, a chemically and biologically immunosuppressed man consumed raw oysters and developed P shigelloides septicemia and acute periprosthetic knee infection that required surgical intervention.

  4. Retran simulation of Oyster Creek generator trip startup test

    Alammar, M.A.

    1987-01-01

    RETRAN simulation of Oyster Creek generator trip startup test was carried out as part of Oyster Creek RETRAN model qualification program for reload licensing applications. The objective of the simulation was to qualify the turbine model and its interface with the control valve and bypass systems under severe transients. The test was carried out by opening the main breakers at rated power. The turbine speed governor closed the control valves and the pressure regulator opened the bypass valves within 0.5 sec. The stop valves closed by a no-load turbine trip, before the 10 percent overspeed trip was reached and the reactor scrammed on high APRM neutron flux. The simulation resulted in qualifying a normalized hydraulic torque for the turbine model and a 0.3 sec, delay block for the bypass model to account for the different delays in the hydraulic linkages present in the system. One-dimensional kinetics was used in this simulation

  5. Multiple enzymatic profiles of Vibrio parahaemolyticus strains isolated from oysters

    Renata Albuquerque Costa

    Full Text Available The enzymatic characterization of vibrios has been used as a virulence indicator of sanitary interest. The objective of this study was to determine the enzymatic profile of Vibrio parahaemolyticus strains (n = 70 isolated from Crassostrea rhizophorae oysters. The strains were examined for the presence of gelatinase (GEL, caseinase (CAS, elastase (ELAS, phospholipase (PHOS, lipase (LIP, amilase (AML and DNase. All enzymes, except elastase, were detected in more than 60% of the strains. The most recurrent enzymatic profiles were AML + DNase + PHOS + GEL + LIP (n = 16; 22.9% and AML + CAS + DNase + PHOS + GEL + LIP (n = 21; 30%. Considering the fact that exoenzyme production by vibrios is closely related to virulence, one must be aware of the bacteriological risk posed to human health by the consumption of raw or undercooked oysters.

  6. Factors affecting the uptake and retention of Vibrio vulnificus in oysters.

    Froelich, Brett A; Noble, Rachel T

    2014-12-01

    Vibrio vulnificus, a bacterium ubiquitous in oysters and coastal water, is capable of causing ailments ranging from gastroenteritis to grievous wound infections or septicemia. The uptake of these bacteria into oysters is often examined in vitro by placing oysters in seawater amended with V. vulnificus. Multiple teams have obtained similar results in studies where laboratory-grown bacteria were observed to be rapidly taken up by oysters but quickly eliminated. This technique, along with suggested modifications, is reviewed here. In contrast, the natural microflora within oysters is notoriously difficult to eliminate via depuration. The reason for the transiency of exogenous bacteria is that those bacteria are competitively excluded by the oyster's preexisting microflora. Evidence of this phenomenon is shown using in vitro oyster studies and a multiyear in situ case study. Depuration of the endogenous oyster bacteria occurs naturally and can also be artificially induced, but both of these events require extreme conditions, natural or otherwise, as explained here. Finally, the "viable but nonculturable" (VBNC) state of Vibrio is discussed. This bacterial torpor can easily be confused with a reduction in bacterial abundance, as bacteria in this state fail to grow on culture media. Thus, oysters collected from colder months may appear to be relatively free of Vibrio but in reality harbor VBNC cells that respond to exogenous bacteria and prevent colonization of oyster matrices. Bacterial-uptake experiments combined with studies involving cell-free spent media are detailed that demonstrate this occurrence, which could explain why the microbial community in oysters does not always mirror that of the surrounding water. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. The biofilteration ability of oysters (Crassostrea gigas) to reduce Aeromonas salmonicida in salmon culture.

    Ma, Xiaona; Li, Xian; Sun, Guoxiang; Sharawy, Zaki Zaki; Qiu, Tianlong; Du, Yishuai; Liu, Ying

    2017-07-01

    Pathogen contamination in the environment is inevitable with the rapid development of intensive aquaculture. Therefore, alternative ecofriendly biological strategies to control pathogenic bacteria are required. However, our aim was to investigate the ability of oysters (Crassostrea gigas) to filter the important opportunistic pathogen, Aeromonas salmonicida (strain C4), using a green fluorescent protein tag (GFP) in the Atlantic salmon (Salmo salar) farming wastewater. Hence, A. salmonicida removal efficiency and ingestion rate were detected in two different oyster stages (larvae and adults). To evaluate the practical performance of oysters as A. salmonicida biofilter, adult oysters were applied to an integrated constructed wetlands system (ICWS) and their long-term C4-GFP removal efficiency was recorded for 60 days. Overall, our results clearly indicated that oysters had substantial A. salmonicida removal ability via their ingestion process when observed under a fluorescent microscope. Approximately 88-95% of C4-GFP was removed by oyster larvae at an ingestion rate of 6.4 × 10 3 -6.2 × 10 5  CFU/h·ind, while 79-92% of C4-GFP was removed by adult oysters at an ingestion rate of 2.1 × 10 4 -3.1 × 10 6  CFU/h·ind. Furthermore, 57.9 ± 17.2% of C4-GFP removal efficiency was achieved when oysters were applied to ICWS. We, therefore, concluded that using oysters as a biofilter represents an effective alternative for removing A. salmonicida from aquaculture wastewater. However, the fate of oysters after ingesting the pathogenic bacteria, acting as a potential reservoir or vector for pathogens, is still debatable. This research provides the basis for the application of oysters as a biofilter to remove pathogens from aquaculture wastewater in industrialized production.

  8. 46 CFR 2.01-50 - Persons other than crew on towing, oyster, or fishing steam vessels.

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Persons other than crew on towing, oyster, or fishing steam vessels. 2.01-50 Section 2.01-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES... than crew on towing, oyster, or fishing steam vessels. (a) A steam vessel engaged in towing, oyster...

  9. Shell coal gasification process

    Hennekes, B. [Shell Global Solutions (US) Inc. (United States). Technology Marketing

    2002-07-01

    The presentation, on which 17 slides/overheads are included in the papers, explained the principles of the Shell coal gasification process and the methods incorporated for control of sulfur dioxide, nitrogen oxides, particulates and mercury. The economics of the process were discussed. The differences between gasification and burning, and the differences between the Shell process and other processes were discussed.

  10. The theory of spherically symmetric thin shells in conformal gravity

    Berezin, Victor; Dokuchaev, Vyacheslav; Eroshenko, Yury

    The spherically symmetric thin shells are the nearest generalizations of the point-like particles. Moreover, they serve as the simple sources of the gravitational fields both in General Relativity and much more complex quadratic gravity theories. We are interested in the special and physically important case when all the quadratic in curvature tensor (Riemann tensor) and its contractions (Ricci tensor and scalar curvature) terms are present in the form of the square of Weyl tensor. By definition, the energy-momentum tensor of the thin shell is proportional to Diracs delta-function. We constructed the theory of the spherically symmetric thin shells for three types of gravitational theories with the shell: (1) General Relativity; (2) Pure conformal (Weyl) gravity where the gravitational part of the total Lagrangian is just the square of the Weyl tensor; (3) Weyl-Einstein gravity. The results are compared with these in General Relativity (Israel equations). We considered in detail the shells immersed in the vacuum. Some peculiar properties of such shells are found. In particular, for the traceless ( = massless) shell, it is shown that their dynamics cannot be derived from the matching conditions and, thus, is completely arbitrary. On the contrary, in the case of the Weyl-Einstein gravity, the trajectory of the same type of shell is completely restored even without knowledge of the outside solution.

  11. The reproductive cycle of the oyster Crassostrea gasar

    CHAM Gomes

    Full Text Available The purpose of this study was to analyze the reproductive cycle of the oyster Crassostrea gasar (= C. brasiliana in the field and the laboratory. The reproductive cycle of the animals was evaluated in the field at Sambaqui Beach, Florianópolis, SC (27° 29′18″ S and 48° 32′12″ W from May 2008 through November 2009. In July, the animals were in the resting stage. The early growth stage began in August and was followed by the late growth stage in October. In November and December, the oysters began to enter the mature stage. Females in spawning condition were predominant during these months. The stages of the reproductive cycle were positively associated with temperature (r=0.77, P<0.01 and negatively associated with salinity (r=−0.56, P=0.042. These findings demonstrated that increased temperature and reduced salinity influence the reproductive development of Crassostrea gasar. The condition index (CI of the animals was also associated with the seawater temperature. The highest values of the condition index were observed during the months when the temperature of the seawater was gradually increasing. A laboratory experiment was performed to test the effect of salinity on the reproductive cycle of the oysters. The experiment was conducted in standardized tanks. The animals were conditioned using two salinities (24‰ and 34‰. The salinity regime influenced the development of the gonadal tissue of the oysters. A salinity of 24‰ produced greater reproductive development.

  12. Wrinkling of Pressurized Elastic Shells

    Vella, Dominic; Ajdari, Amin; Vaziri, Ashkan; Boudaoud, Arezki

    2011-01-01

    We study the formation of localized structures formed by the point loading of an internally pressurized elastic shell. While unpressurized shells (such as a ping-pong ball) buckle into polygonal structures, we show that pressurized shells

  13. Hanford Site waste management and environmental restoration integration plan

    Merrick, D.L.

    1990-01-01

    The ''Hanford Site Waste Management and Environmental Restoration Integration Plan'' describes major actions leading to waste disposal and site remediation. The primary purpose of this document is to provide a management tool for use by executives who need to quickly comprehend the waste management and environmental restoration programs. The Waste Management and Environmental Restoration Programs have been divided into missions. Waste Management consists of five missions: double-shell tank (DST) wastes; single-shell tank (SST) wastes (surveillance and interim storage, stabilization, and isolation); encapsulated cesium and strontium; solid wastes; and liquid effluents. Environmental Restoration consists of two missions: past practice units (PPU) (including characterization and assessment of SST wastes) and surplus facilities. For convenience, both aspects of SST wastes are discussed in one place. A general category of supporting activities is also included. 20 refs., 14 figs., 7 tabs

  14. Electrical stimulation in white oyster mushroom (Pleurotus florida) production

    Roshita, I.; Nurfazira, K. M. P.; Fern, C. Shi; Ain, M. S. Nur

    2017-09-01

    White oyster mushroom (Pleurotus florida) is an edible mushroom that gained popularity due to its nutritional values, low production cost and ease of cultivation. There are several research reported on the mushroom fruiting bodies which were actively developed when applying electrical shock treatment. This study was aimed to investigate the effects of different electrical voltages on the growth and yield of white oyster mushroom (Pleurotus florida). Five different electrical voltages had been applied during spawning period which were 6V, 9V, 12V, 15V and mushroom bags without any treatment served as control. Treatment at 6V showed the highest rate for mycelium growth while 15V took the shortest time for fruiting body formation. However, no significant different (P>0.05) among all the treatments was observed for the time taken for the mycelium to fill-up the bag and pinhead emergence. The total fresh weight and percentage of biological efficiency for treatment at 9V showed higher values compared to control. Treatment at 9V also showed the largest pileus diameter and the most firm in the pileus texture. Meanwhile, treatment at 6V showed the highest a* value (redness). In addition, different electrical voltage treatments applied did not show any significant effect on substrate utilization efficiency, colour L* and b* values. In conclusion, among all the electrical treatments applied, 9V could be considered as the best treatment to enhance the yield of white oyster mushroom.

  15. Detection of Toxoplasma gondii DNA in Brazilian oysters (Crassostrea rhizophorae).

    Ribeiro, L A; Santos, L K N S S; Brito, P A; Maciel, B M; Da Silva, A V; Albuquerque, G R

    2015-05-04

    The aim of this study was to detect evidence of Toxoplasma gondii using polymerase chain reaction (PCR)-based techniques in oysters (Crassostrea rhizophorae) obtained from the southern coastal region of Bahia, Brazil. A total of 624 oysters were collected, and the gills and digestive glands were dissected. Each tissue sample was separated into pools containing tissues (of the same type) from three animals, leading to a total of 416 experimental samples for analysis (208 samples each from the gills and digestive glands). Molecular analysis using PCR-based detection of the T. gondii AF 146527 repetitive fragment yielded negative results for all samples. However, when nested-PCR was used for detection of the T. gondii SAG-1 gene, 17 samples were positive, with the gills being the tissue with maximal detection of the parasite. These positive results were confirmed by sample sequencing. It is therefore suggested that C. rhizophorae oysters are capable of filtering and retaining T. gondii oocysts in their tissue. This represents a risk to public health because they are traditionally ingested in natura.

  16. A conserved tad pilus promotes Vibrio vulnificus oyster colonization.

    Pu, Meng; Duriez, Patrick; Arazi, Mattan; Rowe-Magnus, Dean A

    2018-02-01

    Vibrio vulnificus has the highest death rate (>35%) and per-case economic burden ($3.3 million) of any foodborne pathogen in the United States. Infections occur via open wounds or following ingestion of contaminated seafood, most infamously oysters. We isolated a 1000th generation descendant, designated NT that exhibited increased biofilm and aggregate formation relative to its parent. We identified two significant causal changes underlying these phenotypes. First, the entire 24-kb capsular polysaccharide biosynthesis locus, which is essential for virulence but inhibits biofilm formation, had been purged from the genome. However, NT formed more extensive biofilms and aggregates than a defined cps mutant, suggesting that additional factor(s) contributed to its phenotypes. Second, the expression of a tight adherence (tad) pilus locus was elevated in NT. Deletion of the associated pilin (flp) decreased NT biofilm and aggregate formation. Furthermore, NTΔflp strains were deficient relative to NT in an oyster colonization model, demonstrating a positive correlation between the biofilm and aggregation phenotypes associated with Tad pilus production and efficient bacterial retention by feeding oysters. Despite being widely distributed in the Vibrionaceae, this is the first demonstration of a bona fide physiological role for a Tad pilus in this bacterial family. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. The effect of algae diets (Skeletonema costatum and Rhodomonas baltica) on the biochemical composition and sensory characteristics of Pacific cupped oysters (Crassostrea gigas) during land-based refinement

    Houcke, van Jasper; Medina, Isabel; Maehre, Hanne K.; Cornet, Josiane; Cardinal, Mireille; Linssen, Jozef; Luten, Joop

    2017-01-01

    Oyster refinement, a common practice in France, is aimed at increasing the weight of oyster tissue and influencing the taste properties of the refined oysters. Refinement usually takes place in land-based systems where the oysters are fed with relatively high concentrations of microalgae. In this

  18. Equatorial seawater temperatures and latitudinal temperature gradients during the Middle to Late Jurassic: the stable isotope record of brachiopods and oysters from Gebel Maghara, Egypt

    Alberti, Matthias; Fürsich, Franz T.; Abdelhady, Ahmed A.; Andersen, Nils

    2017-04-01

    The Jurassic climate has traditionally been described as equable, warmer than today, with weak latitudinal temperature gradients, and no polar glaciations. This view changed over the last decades with studies pointing to distinct climate fluctuations and the occasional presence of polar ice caps. Most of these temperature reconstructions are based on stable isotope analyses of fossil shells from Europe. Additional data from other parts of the world is slowly completing the picture. Gebel Maghara in the northern Sinai Peninsula of Egypt exposes a thick Jurassic succession. After a phase of terrestrial sedimentation in the Early Jurassic, marine conditions dominated since the end of the Aalenian. The stable isotope (δ18O, δ13C) composition of brachiopod and oyster shells was used to reconstruct seawater temperatures from the Bajocian to the Kimmeridgian at a palaeolatitude of ca. 3°N. Throughout this time interval, temperatures were comparatively constant aorund an average of 25.7°C. Slightly warmer conditions existed in the Early Bathonian ( 27.0°C), while the Kimmeridgian shows the lowest temperatures ( 24.3°C). The seasonality has been reconstructed with the help of high-resolution sampling of two oyster shells and was found to be very low (temperature gradients. During the Middle Jurassic, this gradient was much steeper than previously expected and comparable to today. During the Kimmeridgian, temperatures in Europe were generally warmer leading to weaker latitudinal gradients. Based on currently used estimates for the δ18O value of seawater during the Jurassic, reconstructed water temperatures for localities above the thermocline in Egypt and Europe were mostly lower than Recent sea-surface temperatures. These results improve our understanding of the Jurassic climate and its influence on marine faunal diversity patterns.

  19. Oyster Reef Restoration and Aquaculture Impacts on Denitrification and the Benthic Community

    Human impacts have greatly altered coastal ecosystems through a variety of processes including nutrient enrichment and overfishing. The negative consequences of these actions are well known and include increased macroalgae blooms, low oxygen conditions, and losses of biodiversity...

  20. Oysters as vectors of marine aliens, with notes on four introduced ...

    Surveys of oyster farms in South Africa revealed four newly-recorded alien species: the black sea urchin, Tetrapygus niger, from Chile; the European flat oyster, Ostrea edulis (thought to be extinct since its intentional introduction in 1946); Montagu's crab, Xantho incisus, from the North Eastern Atlantic seas of Europe, and ...

  1. The eastern oyster genome: A resource for comparative genomics in shellfish aquaculture species

    Oyster aquaculture is an important sector of world food production. As such, it is imperative to develop a high quality reference genome for the eastern oyster, Crassostrea virginica, to assist in the elucidation of the genomic basis of commercially important traits. All genetic, gene expression and...

  2. Growth and yield performance of Pleurotus ostreatus (Jacq. Fr.) Kumm (oyster mushroom) on different substrates.

    Girmay, Zenebe; Gorems, Weldesemayat; Birhanu, Getachew; Zewdie, Solomon

    2016-12-01

    Mushroom cultivation is reported as an economically viable bio-technology process for conversion of various lignocellulosic wastes. Given the lack of technology know-how on the cultivation of mushroom, this study was conducted in Wondo Genet College of Forestry and Natural Resource, with the aim to assess the suitability of selected substrates (agricultural and/or forest wastes) for oyster mushroom cultivation. Accordingly, four substrates (cotton seed, paper waste, wheat straw, and sawdust) were tested for their efficacy in oyster mushroom production. Pure culture of oyster mushroom was obtained from Mycology laboratory, Department of Plant Biology and Biodiversity Management, Addis Ababa University. The pure culture was inoculated on potato dextrose agar for spawn preparation. Then, the spawn containing sorghum was inoculated with the fungal culture for the formation of fruiting bodies on the agricultural wastes. The oyster mushroom cultivation was undertaken under aseptic conditions, and the growth and development of mushroom were monitored daily. Results of the study revealed that oyster mushroom can grow on cotton seed, paper waste, sawdust and wheat straw, with varying growth performances. The highest biological and economic yield, as well as the highest percentage of biological efficiency of oyster mushroom was obtained from cotton seed, while the least was from sawdust. The study recommends cotton seed, followed by paper waste as suitable substrates for the cultivation of oyster mushroom. It also suggests that there is a need for further investigation on various aspects of oyster mushroom cultivation in Ethiopia to promote the industry.

  3. A habitat suitability model for Pacific oysters (Crassostrea gigas) in the Oosterschelde

    Schellekens, T.; Wijsman, J.W.M.; Brink, van den A.M.

    2012-01-01

    The modelled habitat suitability maps show a reasonable estimation of the suitability for oysters throughout the Delta and can be used to broadly indicate the consequences of the effect of climate change and infrastructural changes on the habitat suitability for oysters. The largest effect on the

  4. Thermal inactivation of enteric viruses and bioaccumulation of enteric foodborne viruses in live oysters (Crassostrea virginica)

    Human enteric viruses are one of the main causative agents of shellfish associated outbreaks. In this study, the kinetics of viral bioaccumulation in live oysters and the heat stability of the most predominant enteric viruses were determined in both tissue culture and in oyster tissues. A human nor...

  5. Growth, morphometrics and nutrient content of farmed eastern oysters, Crassostrea virginica (Gmelin), in New Hampshire, USA

    When harvested, oysters represent a removal from the ecosystem of nutrients such as nitrogen (N)and carbon (C). A number of factors potentially affect nutrient content, but a quantitative understanding across the geographical range of the eastern oysters is lacking. This study wa...

  6. Temperature-dependent persistence of human norovirus within oysters (Crassotrea virginica)

    This study characterizes the persistence of human norovirus in Eastern oysters (Crassostrea virginica) held at different seawater temperatures. Oysters were contaminated with human norovirus GI.1 (Norwalk strain 8fIIa) by exposing them to virus contaminated water at 15 degrees C, and subsequently ho...

  7. Behavior of pathogenic bacteria in the oyster, Crassostrea commercialis, during depuration, re-laying, and storage.

    Son, N T; Fleet, G H

    1980-12-01

    Oysters (Crassostrea commercials) harvested from major cultivation areas within the state of New South Wales, Australia, were commonly contaminated with low levels of the food-poisoning organisms Bacillus cereus, Clostridium perfringens, and Vibrio parahaemolyticus. Salmonella was found in oysters on only one occasion. These bacteria were cleansed from oysters during oyster purification by re-laying in a non-polluted waterway. Oysters were laboratory contaminated to levels in excess 1,000 cells per g with either B. cereus, C. perfringens, V. parahaemolyticus, Salmonella typhimurium, or S. senftenberg. These species were cleansed from such oysters during purification in a laboratory depuration unit that used ultraviolet light for sterilizing the depuration water. Escherichia coli was also cleansed from oysters under the same re-laying or depuration conditions so that its measurement alone could be used to indicate the cleansing of the above pathogenic species. The levels of these bacteria were also measured during the storage of oysters under conditions that occur during marketing. While B. cereus counts remained relatively stable during storage, the Salmonella spp. gradually decreased in numbers and C. perfringens rapidly died off. V. parahaemolyticus counts increased slightly during the first 4 days of storage, after which decreases occurred.

  8. Impact of an icy winter on the Pacific oyster (Crassostrea gigas Thunberg, 1793) populations in Scandinavia

    Strand, Åsa; Blanda, Elisa; Bodvin, Torjan

    2012-01-01

    The Pacific oyster (Crassostrea gigas) is an invasive species that has dispersed into Scandinavia during the last few decades. The objective of this study was to evaluate the effects of extreme winter conditions on the mortality of the Pacific oyster in Scandinavia. The study was done by compilin...

  9. ANTIMICROBIAL ACTIVITY OF COPPER AND ZINC ACCUMULATED BY EASTERN OYSTER AMEBOCYTES

    Fisher, William S. Submitted. Antimicrobial Activity of Copper and Zinc Accumulated by Eastern Oyster Amebocytes. J. Shellfish Res. 54 p. (ERL,GB 1196). The distribution of eastern oysters Crassostrea virginica near terrestrial watersheds has led to a general impression t...

  10. ANTIOXIDANT ENZYMES, POTENTIAL VIRULENT FACTORS, IN DIFFERENT STRAINS OF THE OYSTER PROTOZOAN PARASITE, PERKINSUS MARINUS

    The oyster protozoan parasite, Perkinsus marinus, is one of the two important parasites causing severe mortality in the eastern oysters (Crassostrea virginica) on the US east coast. Our recent study suggests that P. marinus cells and its extracellular products (ECP) could scaveng...

  11. High pressure processing with hot sauce flavoring enhances sensory quality for raw oysters (Crassostrea virginica)

    This study evaluated the feasibility of flavoring raw oysters by placing them under pressure in the presence of selected flavorings. Hand-shucked raw oysters were processed at high pressure (600 MPa), in the presence or absence of (Sriracha®) flavoring, and evaluated by a trained sensory panel 3 an...

  12. Desirability of oysters treated by high pressure processing at different temperatures and elevated pressures

    Organoleptic changes in sterile triploid oysters (Crassostrea virginica) induced by high pressure processing (HPP) were investigated using a volunteer panel. Using a 1-7 hedonic scale, where seven is “like very much”, and one is “dislike very much”, oysters were evaluated organoleptically for flavo...

  13. Molluscan shell colour.

    Williams, Suzanne T

    2017-05-01

    The phylum Mollusca is highly speciose, and is the largest phylum in the marine realm. The great majority of molluscs are shelled, including nearly all bivalves, most gastropods and some cephalopods. The fabulous and diverse colours and patterns of molluscan shells are widely recognised and have been appreciated for hundreds of years by collectors and scientists alike. They serve taxonomists as characters that can be used to recognise and distinguish species, however their function for the animal is sometimes less clear and has been the focus of many ecological and evolutionary studies. Despite these studies, almost nothing is known about the evolution of colour in molluscan shells. This review summarises for the first time major findings of disparate studies relevant to the evolution of shell colour in Mollusca and discusses the importance of colour, including the effects of visual and non-visual selection, diet and abiotic factors. I also summarise the evidence for the heritability of shell colour in some taxa and recent efforts to understand the molecular mechanisms underpinning synthesis of shell colours. I describe some of the main shell pigments found in Mollusca (carotenoids, melanin and tetrapyrroles, including porphyrins and bile pigments), and their durability in the fossil record. Finally I suggest that pigments appear to be distributed in a phylogenetically relevant manner and that the synthesis of colour is likely to be energetically costly. © 2016 Cambridge Philosophical Society.

  14. [Comparison of two nucleic acid extraction methods for norovirus in oysters].

    Yuan, Qiao; Li, Hui; Deng, Xiaoling; Mo, Yanling; Fang, Ling; Ke, Changwen

    2013-04-01

    To explore a convenient and effective method for norovirus nucleic acid extraction from oysters suitable for long-term viral surveillance. Two methods, namely method A (glycine washing and polyethylene glycol precipitation of the virus followed by silica gel centrifugal column) and method B (protease K digestion followed by application of paramagnetic silicon) were compared for their performance in norovirus nucleic acid extraction from oysters. Real-time RT-PCR was used to detect norovirus in naturally infected oysters and in oysters with induced infection. The two methods yielded comparable positive detection rates for the samples, but the recovery rate of the virus was higher with method B than with method A. Method B is a more convenient and rapid method for norovirus nucleic acid extraction from oysters and suitable for long-term surveillance of norovirus.

  15. Eastern oyster (Crassostrea virginica) δ15N as a bioindicator of nitrogen sources: Observations and modeling

    Fertig, B.; Carruthers, T.J.B.; Dennison, W.C.; Fertig, E.J.; Altabet, M.A.

    2010-01-01

    Stable nitrogen isotopes (δ 15 N) in bioindicators are increasingly employed to identify nitrogen sources in many ecosystems and biological characteristics of the eastern oyster (Crassostrea virginica) make it an appropriate species for this purpose. To assess nitrogen isotopic fractionation associated with assimilation and baseline variations in oyster mantle, gill, and muscle tissue δ 15 N, manipulative fieldwork in Chesapeake Bay and corresponding modeling exercises were conducted. This study (1) determined that five individuals represented an optimal sample size; (2) verified that δ 15 N in oysters from two locations converged after shared deployment to a new location reflecting a change in nitrogen sources; (3) identified required exposure time and temporal integration (four months for muscle, two to three months for gill and mantle); and (4) demonstrated seasonal δ 15 N increases in seston (summer) and oysters (winter). As bioindicators, oysters can be deployed for spatial interpolation of nitrogen sources, even in areas lacking extant populations.

  16. Population dynamics of freshwater oyster Etheria elliptica (Bivalvia: Etheriidae in the Pendjari River (Benin-Western Africa

    Akélé G.D.

    2015-01-01

    Full Text Available Etheria elliptica (Bivalvia: Etheriidae is the only freshwater oyster occurring in Africa. The current study provides the first data on the population structure, growth, age, mortality and exploitation status of this species in the Pendjari River. E. elliptica length-frequency data were collected monthly from January to December 2009 and analyzed with FiSAT software. Population parameters including the asymptotic length (L∞ and growth coefficient (K were assessed to evaluate the stock status. The recruitment pattern was modeled with a FiSAT routine. The asymptotic length (L∞ was 14.75 cm, while the growth coefficient (K was 0.38 year-1. The growth performance index (ø′ reached 1.92. Specimens of Etheria elliptica reached a mean size of 4.66 cm and 6.41 cm at the end of one year and 1.5 years, respectively. We estimated total mortality (Z, natural mortality (M and fishing mortality (F to be 2.90 year-1, 1.16 year-1 and 1.74 year-1, respectively. The recruitment pattern was continuous over the year with one major peak event during the rainy season (July. The exploitation rate (E = 0.60 revealed that the freshwater oyster was probably facing overexploitation due to lack of a minimum limit size and also due to an increase in the harvesting effort. Therefore, efficient management methods were urgently required to conserve the species. The return of empty shells into the water to increase the recruitment surface, rotation planning among harvesting sites and the imposition of a minimum limit size were recommendations made in order to ensure the sustainable exploitation of wild stocks.

  17. Nuclear shell theory

    de-Shalit, Amos; Massey, H S W

    1963-01-01

    Nuclear Shell Theory is a comprehensive textbook dealing with modern methods of the nuclear shell model. This book deals with the mathematical theory of a system of Fermions in a central field. It is divided into three parts. Part I discusses the single particle shell model. The second part focuses on the tensor algebra, two-particle systems. The last part covers three or more particle systems. Chapters on wave functions in a central field, tensor fields, and the m-Scheme are also presented. Physicists, graduate students, and teachers of nuclear physics will find the book invaluable.

  18. Intertidal oysters reach their physiological limit in a future high-CO2 world.

    Scanes, Elliot; Parker, Laura M; O'Connor, Wayne A; Stapp, Laura S; Ross, Pauline M

    2017-03-01

    Sessile marine molluscs living in the intertidal zone experience periods of internal acidosis when exposed to air (emersion) during low tide. Relative to other marine organisms, molluscs have been identified as vulnerable to future ocean acidification; however, paradoxically it has also been shown that molluscs exposed to high CO 2 environments are more resilient compared with those molluscs naive to CO 2 exposure. Two competing hypotheses were tested using a novel experimental design incorporating tidal simulations to predict the future intertidal limit of oysters in a high-CO 2 world; either high-shore oysters will be more tolerant of elevated P CO 2 because of their regular acidosis, or elevated P CO 2  will cause high-shore oysters to reach their limit. Sydney rock oysters, Saccostrea glomerata , were collected from the high-intertidal and subtidal areas of the shore and exposed in an orthogonal design to either an intertidal or a subtidal treatment at ambient or elevated P CO 2 , and physiological variables were measured. The combined treatment of tidal emersion and elevated P CO 2  interacted synergistically to reduce the haemolymph pH (pH e ) of oysters, and increase the P CO 2  in the haemolymph ( P e,CO 2 ) and standard metabolic rate. Oysters in the intertidal treatment also had lower condition and growth. Oysters showed a high degree of plasticity, and little evidence was found that intertidal oysters were more resilient than subtidal oysters. It is concluded that in a high-CO 2 world the upper vertical limit of oyster distribution on the shore may be reduced. These results suggest that previous studies on intertidal organisms that lacked tidal simulations may have underestimated the effects of elevated P CO 2 . © 2017. Published by The Company of Biologists Ltd.

  19. Evaluation of Ice Slurries as a Control for Postharvest Growth of Vibrio spp. in Oysters and Potential for Filth Contamination.

    Lydon, Keri Ann; Farrell-Evans, Melissa; Jones, Jessica L

    2015-07-01

    Raw oyster consumption is the most common route of exposure for Vibrio spp. infections in humans. Vibriosis has been increasing steadily in the United States despite efforts to reduce the incidence of the disease. Research has demonstrated that ice is effective in reducing postharvest Vibrio spp. growth in oysters but has raised concerns of possible contamination of oyster meat by filth (as indicated by the presence of fecal coliform bacteria or Clostridium perfringens). This study examined the use of ice slurries (oysters, from 23.9°C (75°F) to 10°C (50°F) within 12 min. The initial bacterial loads in the ice slurry waters were near the limits of detection. Following repeated dipping of oysters into ice slurries, water samples exhibited significant (P oyster meat, however, was unchanged after 15 min of submergence, with no significant differences (P oysters to minimize Vibrio growth.

  20. Treatment of shrimp effluent by sedimentation and oyster filtration using Crassostrea gigas and C. rhizophorae

    Roberto Ramos

    2009-06-01

    Full Text Available Efficiency in removing particulate matter from Litopenaeus vannamei shrimp culture effluent was assessed in laboratory scale employing sedimentation and oysters Crassostrea gigas and C. rhizophorae filtration processes. Cylindroconical tanks (100 L were used in duplicate for sedimentation and 50-L in triplicate for oyster filtration. Fifteen oysters of each species weighing 76-80 g were stocked in each of the filtration treatment experimental units (biomass of 1065 - 1174 g oyster per unit. The control treatment was a tank similar to those used in the filtration treatment but with empty oyster shells. Hydraulic retention time of the effluent was of 6 hours in each treatment. First, effluent went through sedimentation, and then the supernatant went through the filtration tanks. Temperature, pH, dissolved oxygen, salinity, turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5 were evaluated. During sedimentation and filtration, temperature, pH, salinity and dissolved oxygen concentration remained stable. Sedimentation removed 18, 5.6, 27.5, 45.40 and 23.2% of turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5, respectively. Chlorophyll a and BOD5 after sedimentation presented significant difference (PEm escala laboratorial, foi comparada a eficiência de remoção de material particulado presente no efluente do cultivo de camarão branco Litopenaeus vannamei, mediante o processo de sedimentação e filtração com ostra nativa Crassostrea rhizophorae e com ostra do pacifico Crassostrea gigas. No processo de sedimentação foram empregados tanques cilindro cônico, em duplicata, de cor preta com 100 L de capacidade total. Para o processo de filtração foram empregados tanques cilindro cônicos, em triplicata, de cor preta de 50 L de volume total. No tratamento de filtração cada unidade experimental foi estocada com 15 indivíduos de ostras de ambas as espécies, com peso médio entre 76

  1. Shell Buckling Knockdown Factors

    National Aeronautics and Space Administration — The Shell Buckling Knockdown Factor (SBKF) Project, NASA Engineering and Safety Center (NESC) Assessment #: 07-010-E, was established in March of 2007 by the NESC in...

  2. Shells and Patterns

    Sutley, Jane

    2009-01-01

    "Shells and Patterns" was a project the author felt would easily put smiles on the faces of her fifth-graders, and teach them about unity and the use of watercolor pencils as well. It was thrilling to see the excitement in her students as they made their line drawings of shells come to life. For the most part, they quickly got the hang of…

  3. Transcriptome of American oysters, Crassostrea virginica, in response to bacterial challenge: insights into potential mechanisms of disease resistance.

    McDowell, Ian C; Nikapitiya, Chamilani; Aguiar, Derek; Lane, Christopher E; Istrail, Sorin; Gomez-Chiarri, Marta

    2014-01-01

    The American oyster Crassostrea virginica, an ecologically and economically important estuarine organism, can suffer high mortalities in areas in the Northeast United States due to Roseovarius Oyster Disease (ROD), caused by the gram-negative bacterial pathogen Roseovarius crassostreae. The goals of this research were to provide insights into: 1) the responses of American oysters to R. crassostreae, and 2) potential mechanisms of resistance or susceptibility to ROD. The responses of oysters to bacterial challenge were characterized by exposing oysters from ROD-resistant and susceptible families to R. crassostreae, followed by high-throughput sequencing of cDNA samples from various timepoints after disease challenge. Sequence data was assembled into a reference transcriptome and analyzed through differential gene expression and functional enrichment to uncover genes and processes potentially involved in responses to ROD in the American oyster. While susceptible oysters experienced constant levels of mortality when challenged with R. crassostreae, resistant oysters showed levels of mortality similar to non-challenged oysters. Oysters exposed to R. crassostreae showed differential expression of transcripts involved in immune recognition, signaling, protease inhibition, detoxification, and apoptosis. Transcripts involved in metabolism were enriched in susceptible oysters, suggesting that bacterial infection places a large metabolic demand on these oysters. Transcripts differentially expressed in resistant oysters in response to infection included the immune modulators IL-17 and arginase, as well as several genes involved in extracellular matrix remodeling. The identification of potential genes and processes responsible for defense against R. crassostreae in the American oyster provides insights into potential mechanisms of disease resistance.

  4. Off-shell CHY amplitudes

    Lam, C.S., E-mail: Lam@physics.mcgill.ca [Department of Physics, McGill University, Montreal, Q.C., H3A 2T8 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Yao, York-Peng, E-mail: yyao@umich.edu [Department of Physics, The University of Michigan Ann Arbor, MI 48109 (United States)

    2016-06-15

    The Cachazo–He–Yuan (CHY) formula for on-shell scattering amplitudes is extended off-shell. The off-shell amplitudes (amputated Green's functions) are Möbius invariant, and have the same momentum poles as the on-shell amplitudes. The working principles which drive the modifications to the scattering equations are mainly Möbius covariance and energy momentum conservation in off-shell kinematics. The same technique is also used to obtain off-shell massive scalars. A simple off-shell extension of the CHY gauge formula which is Möbius invariant is proposed, but its true nature awaits further study.

  5. Metal leaching from experimental coal fly-ash oyster cultch

    Homziak, J.; Bennett, L.; Simon, P.; Herring, R. (Mississippi State University, MS (USA). Coastal Research and Extension Center)

    1993-08-01

    Because oysters accumulate metals far in excess of ambient concentrations potential leaching and bioaccumulation of metals may be important public health concerns where ash-cement aggregates are being considered for oyster cultivation. This study examined the potential for metal release from an ash-cement aggregate proposed for use in oyster reef construction in Mississippi coastal waters. Seven acid-washed aquaria were each filled with 77L of artificial seawater. Five randomly selected aquaria each received 8.6 L of aggregate pellets. Samples were taken from each aquarium one hour after the start of the experiment and at 10 day intervals on six subsequent sampling dates. The samples were analysed for arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, nickel, selenium and zinc. Cadmium, iron and mercury were essentially not detected in the treatment aquaria. Except for chromium, the mean concentrations of metals in the treatment samples were generally less than 10 ppb. An overall comparison of the concentrations of 8 metals among all aquaria and sampling dates detected significant differences in the concentration of chromium (p[lt]0.001), manganese (p[lt]0.05) and selenium (p[lt]0.001). Treatment aquaria had significantly greater concentrations of chromium and selenium than did either control (nonparametric multiple comparison, p[lt]0.05). Most of the chromium found in the treatment aquaria was the hexavalent form (means range from 0.052 to 1.328 ppm). Treatment hexavalent chromium concentrations increased over time. 14 refs., 1 fig., 2 tabs.

  6. Increases in the amounts of Vibrio spp. in oysters upon addition of exogenous bacteria.

    Froelich, Brett; Oliver, James

    2013-09-01

    The bacterial pathogen Vibrio vulnificus is found naturally in brackish coastal waters but can be greatly concentrated by filter-feeding organisms such as shellfish. Numerous experiments in which exogenous V. vulnificus cells are added to oysters in an attempt to measure uptake and depuration have been performed. In nearly all cases, results have shown that laboratory-grown bacteria are rapidly taken up by the oysters but ultimately eliminated, while naturally present Vibrio populations in oysters are resistant to depuration. In this study, oysters harvested during winter months, with low culturable Vibrio concentrations, were incubated in aquaria supplemented with strains of V. vulnificus that were either genotypically or phenotypically distinct from the background bacteria. These exogenous cells were eliminated from the oysters, as previously seen, but other vibrios already inhabiting the oysters responded to the V. vulnificus inoculum by rapidly increasing in number and maintaining a large stable population. The presence of such an oyster-adapted Vibrio population would be expected to prevent colonization by exogenous V. vulnificus cells, thus explaining the rapid depuration of these added bacteria.

  7. Proteomic analysis of Sydney Rock oysters (Saccostrea glomerata) exposed to metal contamination in the field

    Thompson, Emma L.; Taylor, Daisy A.; Nair, Sham V.; Birch, Gavin; Hose, Grant C.; Raftos, David A.

    2012-01-01

    This study used proteomics to assess the impacts of metal contamination in the field on Sydney Rock oysters. Oysters were transplanted into Lake Macquarie, NSW, for two weeks in both 2009 and 2010. Two-dimensional electrophoresis identified changes in protein expression profiles of oyster haemolymph between control and metal contaminated sites. There were unique protein expression profiles for each field trial. Principal components analysis attributed these differences in oyster proteomes to the different combinations and concentrations of metals and other environmental variables present during the three field trials. Identification of differentially expressed proteins showed that proteins associated with cytoskeletal activity and stress responses were the most commonly affected biological functions in the Sydney Rock oyster. Overall, the data show that proteomics combined with multivariate analysis has the potential to link the effects of contaminants with biological consequences. - Highlights: ► Sydney Rock oyster haemolymph was analysed by proteomics after metal exposure in 3 field trials. ► 2-DE analysis was used to compare protein profiles between control and contaminated sites. ► Different protein expression profiles were revealed per field trial. ► Principal components analysis attributed profiles to different suites of metals and environmental variables per trial. ► The study highlights the need to do multiple field trials and to combine proteomic and enviro. data. - This study used proteomics to analyse impacts of metal contamination on Sydney Rock oyster (Saccostrea glomerata) haemolymph in multiple field trials.

  8. Annual dose of Taiwanese from the ingestion of 210Po in oysters.

    Lee, Hsiu-wei; Wang, Jeng-Jong

    2013-03-01

    Oysters around the coast of Taiwan were collected, dried, spiked with a (209)Po tracer for yield, digested with concentrated HNO(3) and H(2)O(2), and finally dissolved in 0.5 N HCl. The polonium was then spontaneously deposited onto a silver disc, and the activity of (210)Po was measured using an alpha spectrum analyzer equipped with a silicon barrier detector. Meanwhile, the internal effective dose of (210)Po coming from the intake of oysters by Taiwanese was evaluated. The results of the present study indicate that (210)Po average activity concentrations ranged from 23.4 ± 0.4 to 126 ± 94 Bq kg(-1) of fresh oysters. The oysters coming from Penghu island and Kinmen island regions contain higher concentrations of (210)Po in comparison with oysters from other regions of Taiwan. The value of (210)Po weighted average activity concentrations for all oyster samples studied is 25.9 Bq kg(-1). The annual effective dose of Taiwanese due to the ingestion of (210)Po in oysters was estimated to be 4.1 × 10(-2) mSv y(-1). Copyright © 2013. Published by Elsevier Ltd.

  9. The role of tissue-specific microbiota in initial establishment success of Pacific oysters.

    Lokmer, Ana; Kuenzel, Sven; Baines, John F; Wegner, Karl Mathias

    2016-03-01

    Microbiota can have positive and negative effects on hosts depending on the environmental conditions. Therefore, it is important to decipher host-microbiota-environment interactions, especially under natural conditions exerting (a)biotic stress. Here, we assess the relative importance of microbiota in different tissues of Pacific oyster for its successful establishment in a new environment. We transplanted oysters from the Southern to the Northern Wadden Sea and controlled for the effects of resident microbiota by administering antibiotics to half of the oysters. We then followed survival and composition of haemolymph, mantle, gill and gut microbiota in local and translocated oysters over 5 days. High mortality was recorded only in non-antibiotic-treated translocated oysters, where high titres of active Vibrio sp. in solid tissues indicated systemic infections. Network analyses revealed the highest connectivity and a link to seawater communities in the haemolymph microbiota. Since antibiotics decreased modularity and increased connectivity of the haemolymph-based networks, we propose that community destabilization in non-treated translocated oysters could be attributed to interactions between resident and external microbiota, which in turn facilitated passage of vibrios into solid tissues and invoked disease. These interactions of haemolymph microbiota with the external and internal environment may thus represent an important component of oyster fitness. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Epizootiology of Perkinsus sp. inCrassostrea gasar oysters in polyculture with shrimps in northeastern Brazil

    Patricia Mirella da Silva

    2016-03-01

    Full Text Available Abstract Bivalve culture is of considerable economic and social interest in northeastern (NE Brazil. The polyculture is an alternative approach to traditional monoculture for reducing the environmental impact of shrimp farming and improving oyster culture. Perkinsus marinus andPerkinsus olseni were found infecting oysters in NE Brazil and can threaten oyster production. This study evaluatedPerkinsus spp. occurrence in Crassostrea gasar during all production stages. Oyster spats were produced in a hatchery and grown in shrimp ponds in Rio Grande do Norte state.Perkinsus spp. were surveyed by Ray’s fluid thioglycollate medium and confirmed by polymerase chain reaction. Prevalence and intensity of infection were determined in oysters until they reached 7 cm. Results showed that the broodstock was already infected by Perkinsus (60%, but the derived spats were Perkinsus-free. Oyster spats acquired Perkinsus infection when transferred to ponds. The prevalence gradually increased in the seven months following placement in ponds (73%, and then decreased to 17% by the tenth month. The infections were initially mild, but intensity increased at the final growth stage. In conclusion, it is possible to produce Perkinsus-free C. gasar oyster spats from infected broodstock, and their culture in shrimp ponds is feasible.

  11. Effects of a thermal effluent on the reproduction of the American oyster

    Tinsman, J.C.; Tinsman, S.G.; Maurer, D.

    1976-01-01

    Oysters were sampled from September 1970 to September 1972 from two stations in Indian River Bay, Delaware, for histological examination. Station 1 (control) was located near the intake of the Delmarva Power and Light Company's fossil-fuel plant in Millsboro, Del. Station 2 (effluent) was 2.5 km east of the plant at the mouth of Island Creek. A combination of classical and quantitative methods was used to document changes in the developmental cycle of oysters resulting from the influence of a thermal effluent. Oysters in the effluent showed precocious gonadal development during the spring, but the time of maximum ripeness and spawning activity was the same at both stations. An extension of the spawning season for several weeks in September was noted for oysters in the effluent. During 1972, oysters in the thermal effluent showed a significantly lower level of gonadal development than did controls. Since this season of decreased reproductive amplitude corresponds with a period of high mortalities among effluent oysters, it seems likely that these oysters were thermally stressed, requiring more energy for maintenance and leaving less available for reproduction

  12. Incorporation of metabolites into glycogen and lipids of the oyster, crassostrea virginica

    Swift, M.L.; Humphrey, C.L.

    1987-01-01

    Groups of oysters, either fed or unfed, were exposed to U- 14 C labelled D-glucose, L-asp, L-leu, L-ala or acetate for 6 hrs. Except for the glucose trials, the disappearance of radioactivity from the saline of the unfed oysters was greater (83%) than for the fed animals (65%). With glucose, 88% of the radioactivity disappeared in each trial. The specific radioactivity of glycogen isolated from oysters exposed to labelled glucose, asp and ala was 1283, 468 and 8.22 dpm/mg glycogen respectively. Radioactivity was found primarily in the triacylglycerols and phospholipids (PL) in fed oysters and in PL only in unfed oysters. Phosphatidyl choline, phosphatidyl ethanolamine, and a fraction containing phosphatidyl serine and phosphatidyl inositol, had 32%, 25% and 35-40% of the radioactivity respectively. Incorporation of total radioactivity into PL was 70% lower in unfed vs. fed trials, but the distribution of counts among the phospholipids classes was unchanged. Glycogenesis does not appear to be a significant pathway in the oyster. Apparently well-fed oysters are able to store excess dietary calories as lipid. During periods of starvation exogenous small metabolites along with glucose from glycogen are catabolized

  13. Role of bacteria in bioaccumulation of mercury in the oyster Crassostrea virginica

    Sayler, G.S.; Nelson, J.D. Jr.; Colwell, R.R.

    1975-01-01

    An investigation of mercury-resistant bacteria was undertaken to determine their role in the accumulation of mercury in a simplified food chain. Oysters (Crassostrea virginica) were maintained in a closed system, sealed aquarium with stirred, aerated water containing 10 μg of 203 HgCl 2 per liter. Uptake of 203 Hg by oysters held under control conditions was compared with that of 203 Hg uptake by oysters under similar conditions except that mercury-accumulating and mercury-metabolizing species of Pseudomonsa, isolated from Chesapeake Bay, were added to the experimental oysters. After incubation for 4 days, the major portion of the 203 Hg in the water column was found to be associated with the microparticulate fraction, corresponding to a rise in total viable count. Mercury accumulation in the oysters was significantly higher in the gill and fisceral tissue than other tissues. Mercury concentrations were 200 times greater in tissue fractions of oysters dosed with mercury-metabolizing bacteria compared with the oysters held under control conditions without mercury-metabolizing bacteria. (U.S.)

  14. Parasites infecting the cultured oyster Crassostrea gasar (Adanson, 1757) in Northeast Brazil.

    Queiroga, Fernando Ramos; Vianna, Rogério Tubino; Vieira, Cairé Barreto; Farias, Natanael Dantas; Da Silva, Patricia Mirella

    2015-05-01

    The oyster Crassostrea gasar is a species widely used as food and a source of income for the local population of the estuaries of Northeast Brazil. Perkinsus marinus and Perkinsus olseni are deleterious parasites for oyster farming and were recently detected in Brazil. In this study, a histopathologic survey of the oyster C. gasar cultured in the estuary of the River Mamanguape (Paraíba State) was performed. Adult oysters were collected in December 2011 and March, May, August and October 2012 and processed for histology and Perkinsus sp. identification by molecular analyses. Histopathological analysis revealed the presence of parasitic organisms including viral gametocytic hypertrophy, prokaryote-like colonies, protozoans (Perkinsus sp. and Nematopsis sp.) and metazoans (Tylocephalum sp. and cestodes). Other commensal organisms were also detected (the protozoan Ancistrocoma sp. and the turbellarian Urastoma sp.). The protozoan parasite Perkinsus sp. had the highest overall prevalence among the symbiotic organisms studied (48.9%), followed by Nematopsis sp. (36.3%). The other organisms were only sporadically observed. Only the protozoan Perkinsus sp. caused alterations in the oysters' infected organs. Molecular analyses confirmed the presence of P. marinus, P. olseni and Perkinsus beihaiensis infecting the oyster C. gasar. This is the first report of P. beihaiensis in this oyster species.

  15. Biofiltration, growth and body composition of oyster Crassostrea rhizophorae in effluents from shrimp Litopenaeus vannamei1

    Rafael Vieira de Azevedo

    Full Text Available The objective of this study was to use oyster as biofilter to improve the quality of effluent from shrimp farming and to assess its growth performance and body composition. It was distributed 1,080 oysters into lanterns in fiberglass tanks (170 L in a completely randomized design with three treatments (0, 60 and 120 oysters and six replicates. It was used the effluent from the sedimentation tank. It was measured weekly: temperature, salinity, dissolved oxygen and pH, and it was analyzed ammonia-N, nitrite-N, nitrate-N, orthophosphate-P, suspended solids and chlorophyll-α of the input effluent. The control tanks (without oysters were more efficient at removing ammonia-N, nitrite-N, nitrate-N and orthophosphate-P. The tanks containing oysters were more efficient at removing suspended solids and chlorophyll-α. Stocking density influenced the height growth of oysters, but not width. Wet and daily weight, condition and yield index were not affected by stocking density, and a significant increase in comparison to the initials values was observed. Body composition was not affected by stocking density, and a significant difference (p0.05. Under the conditions evaluated, the oyster Crassostrea rhizophorae improves water quality and presents growth rates and body composition similar to those obtained in traditional crops.

  16. Angiotensin I-Converting Enzyme Inhibitor Derived from Cross-Linked Oyster Protein

    Cheng-Liang Xie

    2014-01-01

    Full Text Available Following cross-linking by microbial transglutaminase, modified oyster proteins were hydrolyzed to improve inhibitory activity against angiotensin-converting enzyme (ACE inhibitory activity with the use of a single protease, or a combination of six proteases. The oyster hydrolysate with the lowest 50% ACE inhibitory concentration (IC50 of 0.40 mg/mL was obtained by two-step hydrolysis of the cross-linked oyster protein using Protamex and Neutrase. Five ACE inhibitory peptides were purified from the oyster hydrolysate using a multistep chromatographic procedure comprised of ion-exchange, size exclusion, and reversed-phase liquid chromatography. Their sequences were identified as TAY, VK, KY, FYN, and YA, using automated Edman degradation and mass spectrometry. These peptides were synthesized, and their IC50 values were measured to be 16.7, 29.0, 51.5, 68.2, and 93.9 μM, respectively. Toxicity of the peptides on the HepG2 cell line was not detected. The oyster hydrolysate also significantly decreased the systolic blood pressure of spontaneously hypertensive rats (SHR. The antihypertensive effect of the oyster hydrolysate on SHR was rapid and long-lasting, compared to commercially obtained sardine hydrolysate. These results suggest that the oyster hydrolysate could be a source of effective nutraceuticals against hypertension.

  17. The invasive Pacific oyster, Crassostrea gigas, in Scandinavia coastal waters

    Dolmer, Per; Holm, Mark Wejlemann; Strand, Åsa

    visualized the need for a continued collaboration between scientists in the Scandinavian countries, as the bio-invasion is a cross-border issue and management actions then have to be synchronized, and based on a “state of the art” knowledge of the Scandinavian bio-invasion of the species. The risk assessment......A massive invasion of the Pacific oyster, Crassostrea gigas , has occurred in Scandinavia during the last decade. The introduction and dispersal was described through collaboration between scientists from Sweden, Denmark and Norway. This work has been followed up by national activities that clearly...

  18. Bioaccumulation factor of tritium in oyster and tilapia

    Garcia, T.Y.; Juan, N.B.

    1984-01-01

    This paper reports on the bioaccumulation factor as well as the residence time of tritium in marine organisms such as tilapia fish (Tilapia mossambica) and oyster (Crassostrea iredalei) reared under laboratory conditions. The organisms were submerged in aquarium water containing tritium with specific activity of 1.0 nCi/ml. The samples were analyzed for tissue-free water tritium (TFWT) by freeze drying and for tissue-bound tritium (TBT) by combustion methods. Tritiated water collected was assayed using the liquid scintillation counting technique. (author)

  19. Contrasting impacts of ocean acidification and warming on the molecular responses of CO2-resilient oysters.

    Goncalves, Priscila; Thompson, Emma L; Raftos, David A

    2017-06-02

    This study characterises the molecular processes altered by both elevated CO 2 and increasing temperature in oysters. Differences in resilience of marine organisms against the environmental stressors associated with climate change will have significant implications for the sustainability of coastal ecosystems worldwide. Some evidence suggests that climate change resilience can differ between populations within a species. B2 oysters represent a unique genetic resource because of their capacity to better withstand the impacts of elevated CO 2 at the physiological level, compared to non-selected oysters from the same species (Saccostrea glomerata). Here, we used proteomic and transcriptomic analysis of gill tissue to evaluate whether the differential response of B2 oysters to elevated CO 2 also extends to increased temperature. Substantial and distinctive effects on protein concentrations and gene expression were evident among B2 oysters responding to elevated CO 2 or elevated temperature. The combination of both stressors also altered oyster gill proteomes and gene expression. However, the impacts of elevated CO 2 and temperature were not additive or synergistic, and may be antagonistic. The data suggest that the simultaneous exposure of CO 2 -resilient oysters to near-future projected ocean pH and temperature results in complex changes in molecular processes in order to prevent stress-induced cellular damage. The differential response of B2 oysters to the combined stressors also indicates that the addition of thermal stress may impair the resilience of these oysters to decreased pH. Overall, this study reveals the intracellular mechanisms that might enable marine calcifiers to endure the emergent, adverse seawater conditions resulting from climate change.

  20. Controlling Vibrio vulnificus and spoilage bacteria in fresh shucked oysters using natural antimicrobials.

    Mahmoud, B S M

    2014-01-01

    This study evaluated the efficacy of grape seed extract (GE), citric acid (CA) and lactic acid (LA) on the inactivation of Vibrio vulnificus and inherent microflora in fresh shucked oysters. The minimum inhibitory concentration (MIC) of GE, CA or LA against V. vulnificus was determined. Furthermore, the shucked oysters were artificially inoculated with V. vulnificus. The inoculated shucked oysters (25 g) were then dipped in 250 ml GE, CA or LA solutions for 10 min. The population of V. vulnificus in shucked oysters was determined. The effects of the treatments with GE, CA or LA solutions on the inherent microbiota in fresh shucked oysters during storage at 5°C for 20 days were also studied. The MICs of GE, CA or LA against V. vulnificus were 10.0, 5.0 or 1.0 mg ml(-1), respectively. The concentrations of 500, 300 or 150 mg ml(-1) GE, CA or LA solutions were needed to reduce the population of V. vulnificus to below the detection level (1.0 log g(-1)). Treatment with 500, 300, 150 mg ml(-1) GE, CA or LA significantly reduced the initial inherent microbiota in fresh shucked oysters, and inherent levels were significantly (P Oysters filter large volume of seawater during their feeding activities that concentrate bacteria such as Vibrio vulnificus in their body. The presence of V. vulnificus in oysters has a serious impact on public health and international trade. There is increasing concern over the use of chemical preservatives. Furthermore, the food industry is looking for new natural preservation methods. This study indicated that lactic acid and citric acid wash solutions could offer an inexpensive, natural and strong approach to control V. vulnificus and spoilage bacteria in fresh shucked for the oyster industry. © 2013 The Society for Applied Microbiology.

  1. Mortalities of Eastern and Pacific oyster Larvae caused by the pathogens Vibrio coralliilyticus and Vibrio tubiashii.

    Richards, Gary P; Watson, Michael A; Needleman, David S; Church, Karlee M; Häse, Claudia C

    2015-01-01

    Vibrio tubiashii is reported to be a bacterial pathogen of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) and has been associated with major hatchery crashes, causing shortages in seed oysters for commercial shellfish producers. Another bacterium, Vibrio coralliilyticus, a well-known coral pathogen, has recently been shown to elicit mortality in fish and shellfish. Several strains of V. coralliilyticus, such as ATCC 19105 and Pacific isolates RE22 and RE98, were misidentified as V. tubiashii until recently. We compared the mortalities caused by two V. tubiashii and four V. coralliilyticus strains in Eastern and Pacific oyster larvae. The 50% lethal dose (LD50) of V. coralliilyticus in Eastern oysters (defined here as the dose required to kill 50% of the population in 6 days) ranged from 1.1 × 10(4) to 3.0 × 10(4) CFU/ml seawater; strains RE98 and RE22 were the most virulent. This study shows that V. coralliilyticus causes mortality in Eastern oyster larvae. Results for Pacific oysters were similar, with LD50s between 1.2 × 10(4) and 4.0 × 10(4) CFU/ml. Vibrio tubiashii ATCC 19106 and ATCC 19109 were highly infectious toward Eastern oyster larvae but were essentially nonpathogenic toward healthy Pacific oyster larvae at dosages of ≥1.1 × 10(4) CFU/ml. These data, coupled with the fact that several isolates originally thought to be V. tubiashii are actually V. coralliilyticus, suggest that V. coralliilyticus has been a more significant pathogen for larval bivalve shellfish than V. tubiashii, particularly on the U.S. West Coast, contributing to substantial hatchery-associated morbidity and mortality in recent years. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Effect of carbonate chemistry alteration on the early embryonic development of the Pacific oyster (Crassostrea gigas).

    Gazeau, Frédéric; Gattuso, Jean-Pierre; Greaves, Mervyn; Elderfield, Henry; Peene, Jan; Heip, Carlo H R; Middelburg, Jack J

    2011-01-01

    Ocean acidification, due to anthropogenic CO₂ absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportions of abnormal development under low pH conditions, they did not allow attribution to pH induced changes in physiology or changes due to a decrease in aragonite saturation state. This study aims to assess the impact of several carbonate-system perturbations on the growth of Pacific oyster (Crassostrea gigas) larvae during the first 3 days of development (until shelled D-veliger larvae). Seawater with five different chemistries was obtained by separately manipulating pH, total alkalinity and aragonite saturation state (calcium addition). Results showed that the developmental success and growth rates were not directly affected by changes in pH or aragonite saturation state but were highly correlated with the availability of carbonate ions. In contrast to previous studies, both developmental success into viable D-shaped larvae and growth rates were not significantly altered as long as carbonate ion concentrations were above aragonite saturation levels, but they strongly decreased below saturation levels. These results suggest that the mechanisms used by these organisms to regulate calcification rates are not efficient enough to compensate for the low availability of carbonate ions under corrosive conditions.

  3. Effect of carbonate chemistry alteration on the early embryonic development of the Pacific oyster (Crassostrea gigas.

    Frédéric Gazeau

    Full Text Available Ocean acidification, due to anthropogenic CO₂ absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportions of abnormal development under low pH conditions, they did not allow attribution to pH induced changes in physiology or changes due to a decrease in aragonite saturation state. This study aims to assess the impact of several carbonate-system perturbations on the growth of Pacific oyster (Crassostrea gigas larvae during the first 3 days of development (until shelled D-veliger larvae. Seawater with five different chemistries was obtained by separately manipulating pH, total alkalinity and aragonite saturation state (calcium addition. Results showed that the developmental success and growth rates were not directly affected by changes in pH or aragonite saturation state but were highly correlated with the availability of carbonate ions. In contrast to previous studies, both developmental success into viable D-shaped larvae and growth rates were not significantly altered as long as carbonate ion concentrations were above aragonite saturation levels, but they strongly decreased below saturation levels. These results suggest that the mechanisms used by these organisms to regulate calcification rates are not efficient enough to compensate for the low availability of carbonate ions under corrosive conditions.

  4. Restoration of Gooseberry Creek

    Jonathan W. Long

    2000-01-01

    Grazing exclusion and channel modifications were used to restore wet meadows along a stream on the Fort Apache Indian Reservation. The efforts are reestablishing functional processes to promote long-term restoration of wetland health and species conservation.

  5. Hemolymph chemistry and histopathological changes in Pacific oysters (Crassostrea gigas) in response to low salinity stress.

    Knowles, Graeme; Handlinger, Judith; Jones, Brian; Moltschaniwskyj, Natalie

    2014-09-01

    This study described seasonal differences in the histopathological and hemolymph chemistry changes in different family lines of Pacific oysters, Crassostrea gigas, in response to the stress of an abrupt change to low salinity, and mechanical grading. The most significant changes in pallial cavity salinity, hemolymph chemistry and histopathological findings occurred in summer at low salinity. In summer (water temperature 18°C) at low salinity, 9 (25.7% of full salinity), the mean pallial cavity salinity in oysters at day 3 was 19.8±1.6 (SE) and day 10 was 22.8±1.6 (SE) lower than oysters at salinity 35. Associated with this fall in pallial cavity salinity, mean hemolymph sodium for oysters at salinity 9 on day 3 and 10 were 297.2mmol/L±20(SE) and 350.4mmol/L±21.3(SE) lower than oysters at salinity 35. Similarly mean hemolymph potassium in oysters held at salinity 9 at day 3 and 10 were 5.6mmol/L±0.6(SE) and 7.9mmol/L±0.6 (SE) lower than oysters at salinity 35. These oysters at low salinity had expanded intercellular spaces and significant intracytoplasmic vacuolation distending the cytoplasm of epithelial cells in the alimentary tract and kidney and hemocyte infiltrate (diapedesis) within the alimentary tract wall. In contrast, in winter (water temperature 8°C) oyster mean pallial cavity salinity only fell at day 10 and this was by 6.0±0.6 (SE) compared to that of oysters at salinity 35. There were limited histopathological changes (expanded intercellular spaces and moderate intracytoplasmic vacuolation of renal epithelial cells) in these oysters at day 10 in low salinity. Mechanical grading and family line did not influence the oyster response to sudden low salinity. These findings provide additional information for interpretation of non-lethal, histopathological changes associated with temperature and salinity variation. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. [History of oyster as drug from the origin to the 21st century].

    Bonnemain, Bruno

    2015-06-01

    Since Antiquity, oyster is a subject of interest and medical use, as indicated by Oribiase and Galien. From the 17th century, this unique drug was proposed by physicians for various diseases, and more often for (la rage). One could think that that drug disappeared at the 20th and 21st centuries. But we can observe that it was still recommended by several authors as drug. Still today, companies offer oyster under various forms for allopathic and homeopathic treatments, as well as for food supplement. Research are ongoing to discover active substances within oyster and their potential medical interests.

  7. Effect of linear alkylbenzene mixtures and sanitary sewage in biochemical and molecular responses in pacific oyster Crassostrea gigas.

    Flores-Nunes, Fabrício; Mattos, Jacó J; Zacchi, Flávia L; Serrano, Miguel A S; Piazza, Clei E; Sasaki, Silvio T; Taniguchi, Satie; Bicego, Márcia C; Melo, Cláudio M R; Bainy, Afonso C D

    2015-11-01

    Urban effluents are rich in nutrients, organic matter, pharmaceuticals and personal care products (PPCPs), pesticides, hydrocarbons, surfactants, and others. Previous studies have shown that oysters Crassostrea gigas accumulate significant levels of linear alkylbenzenes (LABs) in sanitary sewage contaminated sites, but there is little information about its toxicological effects in marine bivalves. The aim of this study was to analyze the transcription of genes in two tissues of C. gigas exposed for 12, 24, and 36 h to LABs or sanitary sewage. Likewise, the activity of antioxidant and biotransformation enzymes was measured in oysters exposed for 36 h in all groups. Oysters exposed to LABs and oysters exposed to sanitary sewage showed different patterns of transcriptional responses. LAB-exposed oysters showed lower level of biological responses than the oysters exposed to sanitary sewage. Despite the ability of the oyster C. gigas to accumulate LABs (28-fold), the data indicate that these contaminants are not the cause for the transcriptional responses observed in oysters exposed to sanitary sewage. Possibly, the biological changes observed in the sanitary sewage-exposed oysters are associated with the presence of other contaminants, which might have caused synergistic, additive, or antagonistic effects. The results show that FABP-like and GST-ω-like messenger RNAs (mRNAs) have a rapid response in tissues of oyster C. gigas exposed to sanitary sewage, suggesting a possible protective response and a role in maintaining homeostasis of these organisms.

  8. Dyson shells: a retrospective

    Bradbury, Robert J.

    2001-08-01

    More than 40 years have passed since Freeman Dyson suggested that advanced technological civilizations are likely to dismantle planets in their solar systems to harvest all of the energy their stars wastefully radiate into space. Clearly this was an idea that was ahead of its time. Since that time, dozens of SETI searches have been conducted and almost all of them have focused their attention on stars which by definition cannot be the advanced civilizations that Dyson envisioned. I will review the data that created the confusion between Dyson spheres and Dyson shells. The sources that disprove Dyson spheres while still allowing Dyson shells will be discussed. The use of outmoded ideas that have biased the few searches for Dyson Shells that have occurred will be pointed out. An update of the concept of Dyson shells to include our current knowledge of biotechnology, nanotechnology and computer science will be explored. Finally, an approach to setting limits on the abundance of Dyson shells in our galaxy using existing optical astronomical data and future optical satellites will be proposed.

  9. Neuropeptides encoded by the genomes of the Akoya pearl oyster Pinctata fucata and Pacific oyster Crassostrea gigas: a bioinformatic and peptidomic survey.

    Stewart, Michael J; Favrel, Pascal; Rotgans, Bronwyn A; Wang, Tianfang; Zhao, Min; Sohail, Manzar; O'Connor, Wayne A; Elizur, Abigail; Henry, Joel; Cummins, Scott F

    2014-10-02

    Oysters impart significant socio-ecological benefits from primary production of food supply, to estuarine ecosystems via reduction of water column nutrients, plankton and seston biomass. Little though is known at the molecular level of what genes are responsible for how oysters reproduce, filter nutrients, survive stressful physiological events and form reef communities. Neuropeptides represent a diverse class of chemical messengers, instrumental in orchestrating these complex physiological events in other species. By a combination of in silico data mining and peptide analysis of ganglia, 74 putative neuropeptide genes were identified from genome and transcriptome databases of the Akoya pearl oyster, Pinctata fucata and the Pacific oyster, Crassostrea gigas, encoding precursors for over 300 predicted bioactive peptide products, including three newly identified neuropeptide precursors PFGx8amide, RxIamide and Wx3Yamide. Our findings also include a gene for the gonadotropin-releasing hormone (GnRH) and two egg-laying hormones (ELH) which were identified from both oysters. Multiple sequence alignments and phylogenetic analysis supports similar global organization of these mature peptides. Computer-based peptide modeling of the molecular tertiary structures of ELH highlights the structural homologies within ELH family, which may facilitate ELH activity leading to the release of gametes. Our analysis demonstrates that oysters possess conserved molluscan neuropeptide domains and overall precursor organization whilst highlighting many previously unrecognized bivalve idiosyncrasies. This genomic analysis provides a solid foundation from which further studies aimed at the functional characterization of these molluscan neuropeptides can be conducted to further stimulate advances in understanding the ecology and cultivation of oysters.

  10. Global Ecosystem Restoration Index

    Fernandez, Miguel; Garcia, Monica; Fernandez, Nestor

    2015-01-01

    The Global ecosystem restoration index (GERI) is a composite index that integrates structural and functional aspects of the ecosystem restoration process. These elements are evaluated through a window that looks into a baseline for degraded ecosystems with the objective to assess restoration...

  11. Linking restoration ecology with coastal dune restoration

    Lithgow, D.; Martínez, M. L.; Gallego-Fernández, J. B.; Hesp, P. A.; Flores, P.; Gachuz, S.; Rodríguez-Revelo, N.; Jiménez-Orocio, O.; Mendoza-González, G.; Álvarez-Molina, L. L.

    2013-10-01

    Restoration and preservation of coastal dunes is urgently needed because of the increasingly rapid loss and degradation of these ecosystems because of many human activities. These activities alter natural processes and coastal dynamics, eliminate topographic variability, fragment, degrade or eliminate habitats, reduce diversity and threaten endemic species. The actions of coastal dune restoration that are already taking place span contrasting activities that range from revegetating and stabilizing the mobile substrate, to removing plant cover and increasing substrate mobility. Our goal was to review how the relative progress of the actions of coastal dune restoration has been assessed, according to the ecosystem attributes outlined by the Society of Ecological Restoration: namely, integrity, health and sustainability and that are derived from the ecological theory of succession. We reviewed the peer reviewed literature published since 1988 that is listed in the ISI Web of Science journals as well as additional references, such as key books. We exclusively focused on large coastal dune systems (such as transgressive and parabolic dunefields) located on natural or seminatural coasts. We found 150 articles that included "coastal dune", "restoration" and "revegetation" in areas such as title, keywords and abstract. From these, 67 dealt specifically with coastal dune restoration. Most of the studies were performed in the USA, The Netherlands and South Africa, during the last two decades. Restoration success has been assessed directly and indirectly by measuring one or a few ecosystem variables. Some ecosystem attributes have been monitored more frequently (ecosystem integrity) than others (ecosystem health and sustainability). Finally, it is important to consider that ecological succession is a desirable approach in restoration actions. Natural dynamics and disturbances should be considered as part of the restored system, to improve ecosystem integrity, health and

  12. Modeling the carbon isotope composition of bivalve shells (Invited)

    Romanek, C.

    2010-12-01

    The stable carbon isotope composition of bivalve shells is a valuable archive of paleobiological and paleoenvironmental information. Previous work has shown that the carbon isotope composition of the shell is related to the carbon isotope composition of dissolved inorganic carbon (DIC) in the ambient water in which a bivalve lives, as well as metabolic carbon derived from bivalve respiration. The contribution of metabolic carbon varies among organisms, but it is generally thought to be relatively low (e.g., 90%) in the shells from terrestrial organisms. Because metabolic carbon contains significantly more C-12 than DIC, negative excursions from the expected environmental (DIC) signal are interpreted to reflect an increased contribution of metabolic carbon in the shell. This observation contrasts sharply with modeled carbon isotope compositions for shell layers deposited from the inner extrapallial fluid (EPF). Previous studies have shown that growth lines within the inner shell layer of bivalves are produced during periods of anaerobiosis when acidic metabolic byproducts (e.g., succinic acid) are neutralized (or buffered) by shell dissolution. This requires the pH of EPF to decrease below ambient levels (~7.5) until a state of undersaturation is achieved that promotes shell dissolution. This condition may occur when aquatic bivalves are subjected to external stressors originating from ecological (predation) or environmental (exposure to atm; low dissolved oxygen; contaminant release) pressures; normal physiological processes will restore the pH of EPF when the pressure is removed. As a consequence of this process, a temporal window should also exist in EPF at relatively low pH where shell carbonate is deposited at a reduced saturation state and precipitation rate. For example, EPF chemistry should remain slightly supersaturated with respect to aragonite given a drop of one pH unit (6.5), but under closed conditions, equilibrium carbon isotope fractionation

  13. Utilization following of bioremediation attributes using oyster mushrooms - Pleurotus ostreatus

    Galanda, D.; Matel, L.

    2007-01-01

    The mushrooms are not only rich food products, but also a specific component of forest biogeocenoses playing an important role in their functioning, including radionuclide migration. The reason why fungi work as such good indicators for radioactivity and pollution in general is connected to their structure. Using absorption to obtain their nutrition, fungi lack water-conducting organs like stems and roots. They absorb moisture and nutrients from the soil background through surface cells. Dissolved or airborne materials, which include pollutants, move freely through the compartments of hyphae. What is more, radiation released during nuclear testing or accidents is absorbed, especially in areas where it rained heavily shortly after the incident. The present work is devoted to an estimation of the transfer coefficient between reared oyster mushrooms and their support die, which was injected with known activity of 241 Am and 242 Pu. After 2 months when we get the reared mushrooms of cane oyster mushrooms were dried and prepared by liquid extraction with Aliquat 336. The samples were measured by alpha-spectrometry. The results of activity 241 Am and 242 Pu in the mushrooms body and residual activity in the support was detected and calculated (authors)

  14. NIF Double Shell outer/inner shell collision experiments

    Merritt, E. C.; Loomis, E. N.; Wilson, D. C.; Cardenas, T.; Montgomery, D. S.; Daughton, W. S.; Dodd, E. S.; Desjardins, T.; Renner, D. B.; Palaniyappan, S.; Batha, S. H.; Khan, S. F.; Smalyuk, V.; Ping, Y.; Amendt, P.; Schoff, M.; Hoppe, M.

    2017-10-01

    Double shell capsules are a potential low convergence path to substantial alpha-heating and ignition on NIF, since they are predicted to ignite and burn at relatively low temperatures via volume ignition. Current LANL NIF double shell designs consist of a low-Z ablator, low-density foam cushion, and high-Z inner shell with liquid DT fill. Central to the Double Shell concept is kinetic energy transfer from the outer to inner shell via collision. The collision determines maximum energy available for compression and implosion shape of the fuel. We present results of a NIF shape-transfer study: two experiments comparing shape and trajectory of the outer and inner shells at post-collision times. An outer-shell-only target shot measured the no-impact shell conditions, while an `imaging' double shell shot measured shell conditions with impact. The `imaging' target uses a low-Z inner shell and is designed to perform in similar collision physics space to a high-Z double shell but can be radiographed at 16keV, near the viable 2DConA BL energy limit. Work conducted under the auspices of the U.S. DOE by LANL under contract DE-AC52-06NA25396.

  15. Year-round screening of noncommercial and commercial oysters for the presence of human pathogenic viruses

    Lodder-Verschoor, F.; Husman, A.M.R.; Berg, van den H.H.J.L.; Stein, A.; Pelt-Heerschap, van H.M.L.; Poel, van der W.H.M.

    2005-01-01

    Consumption of virus-contaminated shellfish has caused numerous outbreaks of gastroenteritis and hepatitis worldwide. In The Netherlands, oysters are cultured and imported both for consumption and export; therefore, the presence of noroviruses, rotaviruses, astroviruses, hepatitis A viruses, and

  16. Evaluation of waste concrete road materials for use in oyster aquaculture.

    2013-02-01

    The primary objective of this study was to determine the suitability of recycled concrete : aggregate (RCA) from road projects as bottom conditioning material for on-bottom oyster : aquaculture in the Chesapeake Bay. The testing was designed to (1) e...

  17. Phase II evaluation of waste concrete road materials for use in oyster aquaculture - field test.

    2015-02-01

    The overall objective of this study was to determine the suitability of recycled concrete aggregate : (RCA) from road projects as bottom conditioning material for on-bottom oyster aquaculture in the : Chesapeake Bay. During this Phase of the study, t...

  18. Network analysis of oyster transcriptome revealed a cascade of cellular responses during recovery after heat shock.

    Lingling Zhang

    Full Text Available Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes.

  19. IN VITRO KILLING OF PERKINSUS MARINUS BY HEMOCYTES OF OYSTERS CRASSOSTREA VIRGINICA

    A colorimetric microbicidal assay was adapted, optimized and applied in experiments to characterize the in vitro capacity of eastern oyster (Crassostrea virginica) hemocytes to kill cultured isolates of Perkinsus marinus, a protozoan parasite causing a highly destructive disease...

  20. EFFECTS OF FRESHWATER RELEASES AND SEASON ON OYSTERS (CRASSOSTREA VIRGINICA) IN CALOOSAHATCHEE ESTUARY, FLORIDA

    The influence of freshwater releases and season on disease prevalence and intensity of Perkinsus marinus, condition index, gonadal condition, recruitment potential, and growth of oysters was examined monthly at five locations along the Caloosahatchee estuary, Florida. Temperature...

  1. ESTABLISHING MINIMUM FLOWS AND LEVELS OF FRESHWATER IN THE CALOOSAHATCHEE RIVER, FLORIDA, USING RESPONSES OF OYSTERS.

    Alterations in freshwater inflow resulting from watershed development and water management practices have impacted salinity and water quality and led to declines in oyster populations within southwest Florida estuaries. In the Caloosahatchee Estuary, Florida watershed management ...

  2. PARASITIC AND SYMBIONIC FAUNA IN OYSTERS (CRASSOSTREA VIRGINICA) COLLECTED FROM THE CALOOSAHATCHEE RIVER AND ESTUARY, FLORIDA

    Studies of oysters, Crassostrea virginica, collected from ten sites in the Caloosahatchee River and Estuary, Florida, revealed a varied parasite and symbiotic fauna that have never been reported from this area. Organisms observed included ovacystis virus infecting gametes...

  3. CREEK Project's Oyster Biomass Database for Eight Creeks in the North Inlet Estuary, South Carolina

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — A group of eight tidal creeks dominated by oysters, Crassostrea virginica, in North Inlet Estuary, South Carolina, USA were studied using a replicated BACI (Before -...

  4. Phase II evaluation of waste concrete road materials for use in oyster aquaculture - field test.

    2014-11-01

    The overall objective of this study was to determine the suitability of recycled concrete : aggregate (RCA) from road projects as bottom conditioning material for on-bottom oyster : aquaculture in the Chesapeake Bay. During this Phase of the study, t...

  5. SEASONAL VARIATION IN LYSOSOMAL DESTABILIZATION IN OYSTERS, CRASSOSTREA VIRGINICA. (R826201)

    Lysosomal destabilization assays have been used as valuable biomarkers of pollutant exposures in a variety of bivalve and fish species. The responses of oysters, Crassostrea virginica, deployed at and native to various reference and degraded sites were evaluated for lys...

  6. Physicochemical and sensorial characteristics of noodle enriched with oyster mushroom (Pleorotus ostreatus) powder

    Wahyono, A.; Novianti; Bakri, A.; Kasutjianingati

    2018-01-01

    Oyster Mushroom is a mushroom that can be used for food and medicine. It contains highly nutritious and functional substances such as statins and beta-glucan. A comprehensive evaluation of noodle-enriched with Oyster Mushroom powder has not been performed so far. In this study, we performed a comprehensive evaluation of noodle-enriched with Oyster Mushroom powder. The aim of this study was to assess the effects of enrichment of Oyster Mushroom Powder (OMP) on the quality of noodle. The quality of noodle was evaluated based on physical, chemical and sensorial characteristics. This study was done by substituting wheat flour with OMP at the level of 0 (control); 5; 7.5; 10; 12.5; and 15%. The results showed that OMP significantly affected (Pvalues of noodle.

  7. INFLUENCE OF SEASONAL FACTORS ON OYSTER HEMOCYTE KILLING OF VIBRIO PARAHEMOLYTICUS

    Seasonal variation of cellular defenses of oyster Crassostrea virginica against Vibrio parahaemolyticus were examined from June 1997 to December 1998 using a recently developed bactericidal assay that utilizes a tetrazolium dye. Mean hemocyte numbers, plasma lysozyme, and P. mari...

  8. THE EFFECT OF PCBS ON GLYCOGEN RESERVES IN THE EASTERN OYSTER CRASSOSTREA VIRGINICA. (R825349)

    Recent declines in Chesapeake Bay oyster populations have been attributed to disease, and reduced water quality from pollution. The stress associated with pollutant exposure may reduce energy available for growth and reproduction. Polychlorinated biphenyls (PCBs) are lipophilic c...

  9. Pathogenic bacteria associated with oysters (Crassostrea brasiliana) and estuarine water along the south coast of Brazil.

    Ristori, Christiane A; Iaria, Sebastião T; Gelli, Dilma S; Rivera, Irma N G

    2007-08-01

    Oysters and estuarine water samples were collected monthly, from June 1998 to March 1999, in the Cananéia estuary, on the south coast of São Paulo, Brazil, and analyzed for bacterial hazards with and without depuration in filtered estuarine water. Aeromonas spp., Plesiomonas shigelloides, Vibrio cholerae O1, Vibrio parahaemolyticus, and Vibrio vulnificus were counted in oyster samples using the most probable number (MPN) and their presence verified in the surrounding estuarine water samples. The presence of Salmonella, Shigella, Escherichia coli O157:H7, and fecal coliforms counts were determined in oysters and in water samples too. Sixty percent of water samples contained fecal coliforms ranging from 200 CFU/100 ml and 100%, 30%, 20% and 10% were positive for V. parahaemolyticus, Salmonella, Aeromonas, and V. vulnificus in 5 l of water samples, respectively. In oyster samples, the fecal coliforms concentration ranged from or =2.4 x 10(3) MPN/g in 40% of untreated and from oyster samples and their concentration varied from 3.6 to > or =2.4 x 10(3) MPN/g. For the untreated oyster samples 80%, 70%, and 10% were positive for V. vulnificus (oyster samples 60%, 30%, and 0% of them contained the same bacteria, respectively. Escherichia coli O157:H7, Shigella spp., P. shigelloides, and V. cholerae O1 were not detected in any of the samples. Fecal indicators did not correlate with Vibrio presence (p>0.05), although the isolation of Aeromonas species had a positive correlation (p = 0.017). The results showed no correlation between temperature, salinity, and bacteria (p > 0.05). The comparison between bacterial concentration in treated and untreated oyster samples, showed that only Aeromonas was higher in untreated oyster samples (p = 0.039). This study contributes toward creating a more global understanding of food-borne bacterial pathogens. The presence and concentration of viable bacterial hazards in oysters and water surrounding areas was determined for the first time

  10. Sidewall coring shell

    Edelman, Ya A; Konstantinov, L P; Martyshin, A N

    1966-12-12

    A sidewall coring shell consists of a housing and a detachable core catcher. The core lifter is provided with projections, the ends of which are situated in another plane, along the longitudinal axis of the lifter. The chamber has corresponding projections.

  11. Using oysters as anthropogenic indicators to evaluate the occurrence of the wastewater contamination of the estuaries

    Ding, Wang-Hsien

    2015-04-01

    The oyster (Crossostrea gigas) is an important aquacultural species in Taiwan. With an area of over 85% of the total inshore aquacultural field, its production, measured by quantity or economic value, ranks above all other aquacultural products in Taiwan. Since oyster's habitat is on shelves near the coast, the samples from a particular "oyster cultural site" can be applied to evaluate the pollution of a segment of the coastal water. Deficient wastewater treatment has caused untreated wastewaters to have flown in rivers into oyster cultural areas in estuaries as well as shallow coastal water. Therefore, the concentration of pollutants in the oysters can be used as anthropogenic indicators to evaluate the occurrence of the for wastewater contamination of the coastal water. In this study, two groups of anthropogenic organic compounds, chlorinated flame retardant (i.e., Dechlorane Plus) and benzophenone-type UV absorbing substances (i.e., 2-hydroxy-4-methoxybenzophenone), were determined in oyster samples as wastewater contamination pollutants. The method involves the use of matrix solid-phase dispersion prior to their determination by gas chromatography mass spectrometry. The results show that these two groups of compounds are ubiquitous in oysters with the concentrations of chlorinated flame retardant and benzophenone-type UV absorbing substances ranging from 0.3 to 3.6 ng/g and from 120 to 910 ng/g (lipid weight), respectively. Oysters are useful anthropogenic indicators of organic pollutants in Taiwan's marine environment. The ubiquity of these pollutants in Taiwan's coastal environment supports the need for greater awareness of bioaccumulation processes.

  12. A hemocyte gene expression signature correlated with predictive capacity of oysters to survive Vibrio infections

    Rosa Rafael

    2012-06-01

    Full Text Available Abstract Background The complex balance between environmental and host factors is an important determinant of susceptibility to infection. Disturbances of this equilibrium may result in multifactorial diseases as illustrated by the summer mortality syndrome, a worldwide and complex phenomenon that affects the oysters, Crassostrea gigas. The summer mortality syndrome reveals a physiological intolerance making this oyster species susceptible to diseases. Exploration of genetic basis governing the oyster resistance or susceptibility to infections is thus a major goal for understanding field mortality events. In this context, we used high-throughput genomic approaches to identify genetic traits that may characterize inherent survival capacities in C. gigas. Results Using digital gene expression (DGE, we analyzed the transcriptomes of hemocytes (immunocompetent cells of oysters able or not able to survive infections by Vibrio species shown to be involved in summer mortalities. Hemocytes were nonlethally collected from oysters before Vibrio experimental infection, and two DGE libraries were generated from individuals that survived or did not survive. Exploration of DGE data and microfluidic qPCR analyses at individual level showed an extraordinary polymorphism in gene expressions, but also a set of hemocyte-expressed genes whose basal mRNA levels discriminate oyster capacity to survive infections by the pathogenic V. splendidus LGP32. Finally, we identified a signature of 14 genes that predicted oyster survival capacity. Their expressions are likely driven by distinct transcriptional regulation processes associated or not associated to gene copy number variation (CNV. Conclusions We provide here for the first time in oyster a gene expression survival signature that represents a useful tool for understanding mortality events and for assessing genetic traits of interest for disease resistance selection programs.

  13. Integrated application of transcriptomics and metabolomics provides insights into glycogen content regulation in the Pacific oyster Crassostrea gigas.

    Li, Busu; Song, Kai; Meng, Jie; Li, Li; Zhang, Guofan

    2017-09-11

    The Pacific oyster Crassostrea gigas is an important marine fishery resource, which contains high levels of glycogen that contributes to the flavor and the quality of the oyster. However, little is known about the molecular and chemical mechanisms underlying glycogen content differences in Pacific oysters. Using a homogeneous cultured Pacific oyster family, we explored these regulatory networks at the level of the metabolome and the transcriptome. Oysters with the highest and lowest natural glycogen content were selected for differential transcriptome and metabolome analysis. We identified 1888 differentially-expressed genes, seventy-five differentially-abundant metabolites, which are part of twenty-seven signaling pathways that were enriched using an integrated analysis of the interaction between the differentially-expressed genes and the differentially-abundant metabolites. Based on these results, we found that a high expression of carnitine O-palmitoyltransferase 2 (CPT2), indicative of increased fatty acid degradation, is associated with a lower glycogen content. Together, a high level of expression of phosphoenolpyruvate carboxykinase (PEPCK), and high levels of glucogenic amino acids likely underlie the increased glycogen production in high-glycogen oysters. In addition, the higher levels of the glycolytic enzymes hexokinase (HK) and pyruvate kinase (PK), as well as of the TCA cycle enzymes malate dehydrogenase (MDH) and pyruvate carboxylase (PYC), imply that there is a concomitant up-regulation of energy metabolism in high-glycogen oysters. High-glycogen oysters also appeared to have an increased ability to cope with stress, since the levels of the antioxidant glutathione peroxidase enzyme 5 (GPX5) gene were also increased. Our results suggest that amino acids and free fatty acids are closely related to glycogen content in oysters. In addition, oysters with a high glycogen content have a greater energy production capacity and a greater ability to cope with

  14. Stability of charged thin shells

    Eiroa, Ernesto F.; Simeone, Claudio

    2011-01-01

    In this article we study the mechanical stability of spherically symmetric thin shells with charge, in Einstein-Maxwell and Einstein-Born-Infeld theories. We analyze linearized perturbations preserving the symmetry, for shells around vacuum and shells surrounding noncharged black holes.

  15. Temporal structures in shell models

    Okkels, F.

    2001-01-01

    The intermittent dynamics of the turbulent Gledzer, Ohkitani, and Yamada shell-model is completely characterized by a single type of burstlike structure, which moves through the shells like a front. This temporal structure is described by the dynamics of the instantaneous configuration of the shell...

  16. Rice straw addition as sawdust substitution in oyster mushroom (Pleurotus ostreatus) planted media

    Utami, Christine Pamardining; Susilawati, Puspita Ratna

    2017-08-01

    Oyster mushroom is favorite by the people because of the high nutrients. The oyster mushroom cultivation usually using sawdust. The availability of sawdust become difficult to find. It makes difficulties of mushroom cultivation. Rice straw as an agricultural waste can be used as planted media of oyster mushroom because they contain much nutrition needed to the mushroom growth. The aims of this research were to analysis the influence of rice straw addition in a baglog as planted media and to analysis the concentration of rice straw addition which can substitute sawdust in planted media of oyster mushroom. This research used 4 treatment of sawdust and rice straw ratio K = 75 % : 0 %, P1 = 60 % : 15 %, P2 = 40 % : 35 %, P3 = 15 % : 60 %. The same material composition of all baglog was bran 20%, chalk 5%, and water 70%. The parameters used in this research were wet weight, dry weight, moisture content and number of the mushroom fruit body. Data analysis was used ANOVA test with 1 factorial. The results of this research based on statistical analysis showed that there was no influence of rice straw addition in a planted media on the oyster mushroomgrowth. 15% : 60% was the concentrationof rice straw additionwhich can substitute the sawdust in planted media of oyster mushroom.

  17. Widespread survey finds no evidence of Haplosporidium nelsoni (MSX) in Gulf of Mexico oysters.

    Ford, Susan E; Paterno, Jenny; Scarpa, Emily; Stokes, Nancy A; Kim, Yungkul; Powell, Eric N; Bushek, David

    2011-02-22

    The advent of molecular detection assays has provided a set of very sensitive tools for the detection of pathogens in marine organisms, but it has also raised problems of how to interpret positive signals that are not accompanied by visual confirmation. PCR-positive results have recently been reported for Haplosporidium nelsoni (MSX), a pathogen of the oyster Crassostrea virginica in 31 of 40 oysters from 6 sites in the Gulf of Mexico and the Caribbean Sea. Histological confirmation of the PCR results was not undertaken, and no haplosporidian has been reported from the numerous histological studies and surveys of oysters in the region. To further investigate the possibility that H. nelsoni is present in this region, we sampled 210 oysters from 40 sites around the Gulf of Mexico and Puerto Rico using PCR and 180 of these using tissue-section histology also. None of the oysters showed evidence of H. nelsoni by PCR or of any haplosporidian by histology. We cannot, therefore, confirm that H. nelsoni is present and widespread in the Gulf of Mexico and the Caribbean Sea. Our results do not prove that H. nelsoni is absent from the region, but taken together with results from previous histological surveys, they suggest that for the purposes of controlling oyster importation, the region should continue to be considered free of the parasite.

  18. Comparative and quantitative proteomics reveal the adaptive strategies of oyster larvae to ocean acidification

    Dineshram, R.; Q., Quan; Sharma, Rakesh; Chandramouli, Kondethimmanahalli; Yalamanchili, Hari Krishna; Chu, Ivan; Thiyagarajan, Vengatesen

    2015-01-01

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Decreasing pH due to anthropogenic CO2 inputs, called ocean acidification (OA), can make coastal environments unfavorable for oysters. This is a serious socioeconomical issue for China which supplies >70% of the world's edible oysters. Here, we present an iTRAQ-based protein profiling approach for the detection and quantification of proteome changes under OA in the early life stage of a commercially important oyster, Crassostrea hongkongensis. Availability of complete genome sequence for the pacific oyster (Crassostrea gigas) enabled us to confidently quantify over 1500 proteins in larval oysters. Over 7% of the proteome was altered in response to OA at pHNBS 7.6. Analysis of differentially expressed proteins and their associated functional pathways showed an upregulation of proteins involved in calcification, metabolic processes, and oxidative stress, each of which may be important in physiological adaptation of this species to OA. The downregulation of cytoskeletal and signal transduction proteins, on the other hand, might have impaired cellular dynamics and organelle development under OA. However, there were no significant detrimental effects in developmental processes such as metamorphic success. Implications of the differentially expressed proteins and metabolic pathways in the development of OA resistance in oyster larvae are discussed. The MS proteomics data have been deposited to the ProteomeXchange with identifiers PXD002138 (http://proteomecentral.proteomexchange.org/dataset/PXD002138).

  19. The depuration dynamics of oysters (Crassostrea gigas artificially contaminated with hepatitis A virus and human adenovirus

    Adriana de Abreu Corrêa

    2012-02-01

    Full Text Available Within the country of Brazil, Santa Catarina is a major shellfish producer. Detection of viral contamination is an important step to ensure production quality and consumer safety during this process. In this study, we used a depuration system and ultraviolet (UV disinfection to eliminate viral pathogens from artificially infected oysters and analysed the results. Specifically, the oysters were contaminated with hepatitis A virus (HAV or human adenovirus type 5 (HAdV5. After viral infection, the oysters were placed into a depuration tank and harvested after 48, 72 and 96 h. After sampling, various oyster tissues were dissected and homogenised and the viruses were eluted with alkaline conditions and precipitated with polyethylene glycol. The oyster samples were evaluated by cell culture methods, as well as polymerase chain reaction (PCR and quantitative-PCR. Moreover, at the end of the depuration period, the disinfected seawater was collected and analysed by PCR. The molecular assays showed that the HAdV5 genome was present in all of the depuration time samples, while the HAV genome was undetectable after 72 h of depuration. However, viral viability tests (integrated cell culture-PCR and immunofluorescence assay indicated that both viruses were inactivated with 96 h of seawater recirculation. In conclusion, after 96 h of UV treatment, the depuration system studied in this work purified oysters that were artificially contaminated with HAdV5 and HAV.

  20. Populations, not clones, are the unit of vibrio pathogenesis in naturally infected oysters.

    Lemire, Astrid; Goudenège, David; Versigny, Typhaine; Petton, Bruno; Calteau, Alexandra; Labreuche, Yannick; Le Roux, Frédérique

    2015-07-01

    Disease in oysters has been steadily rising over the past decade, threatening the long-term survival of commercial and natural stocks. Our understanding and management of such diseases are of critical importance as aquaculture is an important aspect of dealing with the approaching worldwide food shortage. Although some bacteria of the Vibrio genus isolated from diseased oysters have been demonstrated to be pathogenic by experimental infection, direct causality has not been established. Little is known about the dynamics of how the bacterial population hosted by oysters changes during disease progression. Combining experimental ecology, a high-throughput infection assay and genome sequencing, we show that the onset of disease in oysters is associated with progressive replacement of diverse benign colonizers by members of a phylogenetically coherent virulent population. Although the virulent population is genetically diverse, all members of that population can cause disease. Comparative genomics across virulent and nonvirulent populations identified candidate virulence factors that were clustered in population-specific genomic regions. Genetic analyses revealed that one gene for a candidate virulent factor, a putative outer membrane protein, is necessary for infection of oysters. Finally, analyses of oyster mortality following experimental infection suggest that disease onset can be facilitated by the presence of nonvirulent strains. This is a new form of polymicrobial disease, in which nonpathogenic strains contribute to increase mortality.

  1. A survey of Australian oysters for the presence of human noroviruses.

    Brake, Felicity; Ross, Tom; Holds, Geoffrey; Kiermeier, Andreas; McLeod, Catherine

    2014-12-01

    Impending international policies for norovirus in oysters and the lack of Australian data suggested there was a need to undertake a national survey of norovirus in oysters. Two geographically distinct oyster-growing areas from each of three Australian states were sampled on 4 occasions during 2010 and 2011. The sites selected were considered by state shellfish authorities to be the most compromised with respect to the potential for human faecal contamination as identified by shoreline surveys. The oysters were tested for norovirus GI, GII and Escherichia coli. Norovirus GII was detected in two of 120 (1.7%) samples and norovirus GI was not detected. One of the norovirus positive samples was cloned and sequenced as GII.3. Five of 120 (4.2%) samples were found to have more than the guidance concentration of 230 E. coli per 100 g of shellfish but these samples did not contain detectable concentrations of norovirus. The apparently low prevalence of norovirus in oysters from Australian growing areas supports epidemiological data that suggests norovirus contamination of Australian oysters is rare. The results from this study emphasise the need for future norovirus control measures for shellfish to be commensurate with the risk associated with the growing area. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Optimization and application of spray-drying process on oyster cooking soup byproduct

    Huibin CHEN

    Full Text Available Abstract Oyster drying processes have produced a large amount of cooking soup byproducts. In this study, oyster cooking soup byproduct was concentrated and spray-dried after enzymatic hydrolysis to produce seasoning powder. Response surface methodology (RSM was performed on the basis of single-factor studies to optimize the feeding temperature, hot air temperature, atomization pressure, and total solid content of oyster drying. Results revealed the following optimized parameters of this process: feeding temperature of 60 °C, total solid content of 30%, hot air temperature of 197 °C, and atomization pressure of 92 MPa. Under these conditions, the oyster powder yield was 63.7% ± 0.7% and the moisture content was 4.1% ± 0.1%. Our pilot trial also obtained 63.1% yield and 4.0% moisture content. The enzyme hydrolysis of cooking soup byproduct further enhanced the antioxidant activity of the produced oyster seasoning powder to some extent. Spray drying process optimized by RSM can provide a reference for high-valued applications of oyster cooking soup byproducts.

  3. Comparative and quantitative proteomics reveal the adaptive strategies of oyster larvae to ocean acidification

    Dineshram, R.

    2015-10-28

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Decreasing pH due to anthropogenic CO2 inputs, called ocean acidification (OA), can make coastal environments unfavorable for oysters. This is a serious socioeconomical issue for China which supplies >70% of the world\\'s edible oysters. Here, we present an iTRAQ-based protein profiling approach for the detection and quantification of proteome changes under OA in the early life stage of a commercially important oyster, Crassostrea hongkongensis. Availability of complete genome sequence for the pacific oyster (Crassostrea gigas) enabled us to confidently quantify over 1500 proteins in larval oysters. Over 7% of the proteome was altered in response to OA at pHNBS 7.6. Analysis of differentially expressed proteins and their associated functional pathways showed an upregulation of proteins involved in calcification, metabolic processes, and oxidative stress, each of which may be important in physiological adaptation of this species to OA. The downregulation of cytoskeletal and signal transduction proteins, on the other hand, might have impaired cellular dynamics and organelle development under OA. However, there were no significant detrimental effects in developmental processes such as metamorphic success. Implications of the differentially expressed proteins and metabolic pathways in the development of OA resistance in oyster larvae are discussed. The MS proteomics data have been deposited to the ProteomeXchange with identifiers PXD002138 (http://proteomecentral.proteomexchange.org/dataset/PXD002138).

  4. Quantitative assessment of viable Cryptosporidium parvum load in commercial oysters (Crassostrea virginica) in the Chesapeake Bay.

    Graczyk, Thaddeus K; Lewis, Earl J; Glass, Gregory; Dasilva, Alexandre J; Tamang, Leena; Girouard, Autumn S; Curriero, Frank C

    2007-01-01

    The epidemiological importance of increasing reports worldwide on Cryptosporidium contamination of oysters remains unknown in relation to foodborne cryptosporidiosis. Thirty market-size oysters (Crassostrea virginica), collected from each of 53 commercial harvesting sites in Chesapeake Bay, MD, were quantitatively tested in groups of six for Cryptosporidium sp. oocysts by immunofluorescent antibody (IFA). After IFA analysis, the samples were retrospectively retested for viable Cryptosporidium parvum oocysts by combined fluorescent in situ hybridization (FISH) and IFA. The mean cumulative numbers of Cryptosporidium sp. oocysts in six oysters (overall, 42.1+/-4.1) were significantly higher than in the numbers of viable C. parvum oocysts (overall, 28.0+/-2.9). Of 265 oyster groups, 221 (83.4%) contained viable C. parvum oocysts, and overall, from 10-32% (mean, 23%) of the total viable oocysts were identified in the hemolymph as distinct from gill washings. The amount of viable C. parvum oocysts was not related to oyster size or to the level of fecal coliforms at the sampling site. This study demonstrated that, although oysters are frequently contaminated with oocysts, the levels of viable oocysts may be too low to cause infection in healthy individuals. FISH assay for identification can be retrospectively applied to properly stored samples.

  5. Pesticides and Ostreid Herpesvirus 1 Infection in the Pacific Oyster, Crassostrea gigas.

    Moreau, Pierrick; Faury, Nicole; Burgeot, Thierry; Renault, Tristan

    2015-01-01

    Since 2008, mass mortality outbreaks have been reported in all French regions producing Pacific oysters, and in several Member States of the European Union. These mass mortality events of Pacific oysters are related to OsHV-1 infection. They occur during spring and summer periods leaving suspect the quality of the marine environment and the role of seasonal use of pesticides associated with the arrival of freshwater in oyster rearing areas. Pesticides have been also detected in French coastal waters, especially in areas of oyster production. Using PMA real-time PCR we showed that a mixture of 14 pesticides has no effect on the integrity of virus capsids from viral suspension in the conditions tested. A contact of oysters with this pesticide mixture was related to higher mortality rates among experimentally infected animals in comparison with control ones (no previous pesticide exposure before experimental infection). We therefore suggest that pesticides at realistic concentration can exert adverse effects on Pacific oysters and causes an increased susceptibility to the viral infection in experimental conditions.

  6. Detection and distribution of ostreid herpesvirus 1 in experimentally infected Pacific oyster spat.

    Segarra, Amélie; Baillon, Laury; Faury, Nicole; Tourbiez, Delphine; Renault, Tristan

    2016-01-01

    High mortality rates are reported in spat and larvae of Pacific oyster Crassostrea gigas and associated with ostreid herpesvirus 1 (OsHV-1) detection in France. Although the viral infection has been experimentally reproduced in oyster larvae and spat, little knowledge is currently available concerning the viral entry and its distribution in organs and tissues. This study compares OsHV-1 DNA and RNA detection and localization in experimentally infected oysters using two virus doses: a low dose that did not induce any mortality and a high dose inducing high mortality. Real time PCR demonstrated significant differences in terms of viral DNA amounts between the two virus doses. RNA transcripts were detected in oysters receiving the highest dose of viral suspension whereas no transcript was observed in oysters injected with the low dose. This study also allowed observing kinetics of viral DNA and RNA detection in different tissues of oyster spat. Finally, viral detection was significantly different in function of tissues (p<0.005), time (p<0.005) with an interaction between tissues and time (p<0.005) for each probe. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Ostreid herpesvirus type 1 replication and host response in adult Pacific oysters, Crassostrea gigas.

    Segarra, Amélie; Baillon, Laury; Tourbiez, Delphine; Benabdelmouna, Abdellah; Faury, Nicole; Bourgougnon, Nathalie; Renault, Tristan

    2014-10-08

    Since 2008, massive mortality outbreaks associated with OsHV-1 detection have been reported in Crassostrea gigas spat and juveniles in several countries. Nevertheless, adult oysters do not demonstrate mortality in the field related to OsHV-1 detection and were thus assumed to be more resistant to viral infection. Determining how virus and adult oyster interact is a major goal in understanding why mortality events are not reported among adult Pacific oysters. Dual transcriptomics of virus-host interactions were explored by real-time PCR in adult oysters after a virus injection. Thirty-nine viral genes and five host genes including MyD88, IFI44, IkB2, IAP and Gly were measured at 0.5, 10, 26, 72 and 144 hours post infection (hpi). No viral RNA among the 39 genes was detected at 144 hpi suggesting the adult oysters are able to inhibit viral replication. Moreover, the IAP gene (oyster gene) shows significant up-regulation in infected adults compared to control adults. This result suggests that over-expression of IAP could be a reaction to OsHV-1 infection, which may induce the apoptotic process. Apoptosis could be a main mechanism involved in disease resistance in adults. Antiviral activity of haemolymph against herpes simplex virus (HSV-1) was not significantly different between infected adults versus control.

  8. Sediment quality guidelines for copper and zinc for filter-feeding estuarine oysters?

    Birch, G.F.; Hogg, T.D.

    2011-01-01

    Sediment quality guidelines (SQGs) assess the ability of bottom sediment to sustain healthy infauna and water quality guidelines (WQGs) provide protection for a designated percentage of aquatic species. Filter-feeding marine species, e.g. oysters and mussels, acquire food from particles in the water column and protection of these animals is not provided by SQGs or WQGs. The current work investigated the relationship between metal (Cu, Zn) concentrations in total and fine-fraction ( -1 and -1 , respectively) for protecting oysters from exceeding human consumption levels (70 μg g -1 and 1000 μg g -1 , respectively). - A strong correlation between oyster tissue Cu and Zn concentrations and fine-fraction surficial sediment digested in 1 M HCl provided a sedimentary guideline which predicted tissue metal concentrations in oysters and established a level for protecting oysters from exceeding human consumption levels for these metals. The guidelines for fine surficial sediment developed in the present work accurately predicted oyster tissue concentrations in the field.

  9. Fluxomics of the Eastern Oyster for Environmental Stress Studies

    Andrey P. Tikunov

    2014-01-01

    Full Text Available The metabolism of 2-13C/15N-glycine and U-13C-glucose was determined in four tissue blocks (adductor muscle, stomach and digestive gland, mantle, and gills of the Eastern oyster (Crassostrea virginica using proton (1H and carbon-13 (13C nuclear magnetic resonance (NMR spectroscopy. The oysters were treated in aerated seawater with three treatments (5.5 mM U-13C-glucose, 2.7 mM 2-13C/15N-glycine, and 5.5 mM U-13C-glucose plus 2.7 mM 2-13C/15N-glycine and the relative mass balance and 13C fractional enrichments were determined in the four tissue blocks. In all tissues, glycine was metabolized by the glycine cycle forming serine exclusively in the mitochondria by the glycine cleavage system forming 2,3-13C-serine. In muscle, a minor amount of serine-derived pyruvate entered the Krebs cycle as substantiated by detection of a trace of 2,3-13C-aspartate. In all tissues, U-13C-glucose formed glycogen by glycogen synthesis, alanine by glycolysis, and glutamate and aspartate through the Krebs cycle. Alanine was formed exclusively from glucose via alanine transaminase and not glycine via alanine-glyoxylate transaminase. Based on isotopomer analysis, pyruvate carboxylase and pyruvate dehydrogenase appeared to be equal points for pyruvate entry into the Krebs cycle. In the 5.5 mM U-13C-glucose plus 2.7 mM 2-13C/15N-glycine emergence treatment used to simulate 12 h of “low tide”, oysters accumulated more 13C-labeled metabolites, including both anaerobic glycolytic and aerobic Krebs cycle intermediates. The aerobic metabolites could be the biochemical result of the gaping behavior of mollusks during emergence. The change in tissue distribution and mass balance of 13C-labeled nutrients (U-13C-glucose and 2-13C/15N-glycine provides the basis for a new quantitative fluxomic method for elucidating sub-lethal environmental effects in marine organisms called whole body mass balance phenotyping (WoMBaP.

  10. Nitrogenous compounds changes in emersed oysters: Crassostrea gigas

    Rafrafi, Sarra; Uglow, Roger F.

    2009-01-01

    The effects of emersing oysters ( Crassostrea gigas) for up to 66 h at 4 °C under humid air and nitrogen atmospheres were studied. A significant, gradual body mass loss occurred under nitrogen (8.36 ± 0.85% final weight loss) but no significant loss occurred under humid air (4.92 ± 2.67% final weight loss). Emersion duration and the mantle cavity fluid (MCF) total ammonia (TA) concentration showed a positive, linear relationship ( r2 = 0.73 and 0.74 under humid air and N 2, respectively). The MCF TA and trimethylamine (TMA) contents were also positively related ( r2 = 0.64 and 0.69 under humid air and N 2, respectively). Proline was the most abundant soft tissue free amino acid (71.07 ± 11.8%) in the control group and its concentration did not change significantly under either treatment. The concentration of alanine and valine increased significantly only under humid air. Under N 2, the concentrations of valine and lysine increased significantly and aspartate decreased significantly. Succinate showed a large increase during the first 6 h of emersion under both treatments but significantly more was accumulated in the N 2-exposed group (4.2-fold increase and 8.1-fold increase for the humid air- and N 2-exposed groups, respectively). The succinate concentration difference remained higher in the N 2-treated groups but, in the final 24 h, levels decreased again (quadratic regressions of r2 = 0.97 and 0.95 under humid air and N 2, respectively). Although the trend of succinate accumulation was similar under both treatments, the groups held under nitrogen did not gape (whereas those under humid air did). It is concluded that the implications of gaping behaviour on succinate accumulation in the initial hours of emersion have considerable ecological significance for oysters which occupy habitats in which they may become emersed for some hours naturally. Gaping behaviour also has considerable commercial implications because emersion occurs frequently during the marketing

  11. Transmission of the haplosporidian parasite MSX Haplosporidium nelsoni to the eastern oyster Crassostrea virginica in an upweller system.

    Sunila, I; Karolus, J; Lang, E P; Mroczka, M E; Volk, J

    2000-08-31

    The haplosporidian oyster parasite MSX (Multinucleated Sphere X) Haplosporidium nelsoni was transmitted to eastern oysters Crassostrea virginica. Hatchery-raised, MSX-free juvenile oysters were placed in upweller tanks. Water to the tanks was filtered through a screen with 1 mm2 openings and originated from the water column overlaying naturally infected oysters beds (MSX prevalence 17 to 57%). MSX was diagnosed by histopathological analysis. MSX-disease (57% prevalence) with increased mortality (19%) was observed 11 wk after the beginning of the exposure and mortality of 80% after 16 wk. The study demonstrates transmission of MSX via water-borne infectious agents capable of passing through a 1 mm filter.

  12. Modeling the impact of oyster culture on a mudflat food web in Marennes-Oleron Bay (France)

    Leguerrier, D; Niquil, Nathalie; Petiau, A; Bodoy, Alain

    2004-01-01

    We used a carbon-based food web model to investigate the effects of oyster cultivation on the ecosystem of an intertidal mudflat. A previously published food web model of a mudflat in Marennes-Oleron Bay, France, was updated with revised parameters, and a realistic surface area and density of existing oyster cultures on the mudflat. We developed 2 hypothetical scenarios to estimate the impact of oyster cultivation on the food web structure of the ecosystem: one with no oysters, the other with...

  13. Microbiological quality and bacterial diversity of the tropical oyster Crassostrea rhizophorae in a monitored farming system and from natural stocks.

    Silva Neta, M T; Maciel, B M; Lopes, A T S; Marques, E L S; Rezende, R P; Boehs, G

    2015-12-02

    Microbiological evaluation is one of the most important parameters for analyzing the viability of an oyster farming system, which addresses public health and ecological concerns. Here, the microbiological quality of the oyster Crassostrea rhizophorae cultivated in a monitored environment and from natural beds in Bahia, northeastern Brazil, was determined. Bacterial diversity in oysters was measured by polymerase chain reaction-denaturing gradient gel electrophoresis. Sequence analysis revealed that most bacterial species showed similarity with uncultured or unidentified bacteria from environmental samples, and were clustered into the phylum Proteobacteria. Diverse bacteria from cultivated (monitored) oyster samples were grouped in the same cluster with a high similarity index (above 79%). Microbiological analyses revealed that these oysters did not contain pathogens. These results reflect the natural balance of the microbial communities essential to the maintenance of health and in inhibiting pathogen colonization in the oyster. On the other hand, bacterial diversity of samples from native stocks in extractive areas displayed a similarity index varying between 55 and 77%, and all samples were clustered separately from each other and from the cluster of samples derived from the cultivation area. Microbiological analyses showed that oysters from the extractive area were not fit for human consumption. This reflected a different composition of the microbial community in this area, probably resulting from anthropic impact. Our study also demonstrated that low temperatures and high rainfall limits the bacterial concentration in tropical oysters. This is the first study analyzing the total bacterial community profiles of the oyster C. rhizophorae.

  14. Quantitative analysis of oyster larval proteome provides new insights into the effects of multiple climate change stressors

    Dineshram, Ramadoss

    2016-03-19

    The metamorphosis of planktonic larvae of the Pacific oyster (Crassostrea gigas) underpins their complex life-history strategy by switching on the molecular machinery required for sessile life and building calcite shells. Metamorphosis becomes a survival bottleneck, which will be pressured by different anthropogenically induced climate change-related variables. Therefore, it is important to understand how metamorphosing larvae interact with emerging climate change stressors. To predict how larvae might be affected in a future ocean, we examined changes in the proteome of metamorphosing larvae under multiple stressors: decreased pH (pH 7.4), increased temperature (30 °C), and reduced salinity (15 psu). Quantitative protein expression profiling using iTRAQ-LC-MS/MS identified more than 1300 proteins. Decreased pH had a negative effect on metamorphosis by down-regulating several proteins involved in energy production, metabolism, and protein synthesis. However, warming switched on these down-regulated pathways at pH 7.4. Under multiple stressors, cell signaling, energy production, growth, and developmental pathways were up-regulated, although metamorphosis was still reduced. Despite the lack of lethal effects, significant physiological responses to both individual and interacting climate change related stressors were observed at proteome level. The metamorphosing larvae of the C. gigas population in the Yellow Sea appear to have adequate phenotypic plasticity at the proteome level to survive in future coastal oceans, but with developmental and physiological costs. © 2016 John Wiley & Sons Ltd.

  15. Nacre formation by epithelial cell cultures from mantle of the black-lip pearl oyster, Pinctada margaritifera.

    Jayasankar, Vidya; Vasudevan, Srinivasa Raghavan; Poulose, Suja C; Divipala, Indira

    2018-06-12

    Mantle tissue from the black-lip pearl oyster, Pinctada margaritifera, was cultured in vitro using sterilized seawater supplemented with 0.1% yeast extract as the culture medium. Granular and agranular epithelial cells, hyalinocytes, and fibroblast-like cells were observed in the initial stages of culture. Epithelial cells later formed pseudopodial cell networks containing clusters of granulated cells, which upon maturation released their colored granules. These granules induced formation of nacre crystal deposits on the bottom of the culture plate. Cultures comprised of only granulated epithelial cells were established through periodic sub-culturing of mantle cells and maintained for over 18 mo in a viable condition. Reverse transcriptase PCR of cultured cells demonstrated gene expression of the shell matrix protein, nacrein. To further evaluate the functional ability of cultured granulated epithelial cells, nuclear shell beads were incubated in culture medium containing these cells to induce nacre formation on the beads. Observation of the bead surface under a stereomicroscope at periodic intervals showed the gradual formation of blackish yellow colored nacre deposits. Examination of the bead surface by scanning electron microscopy and energy dispersive X-ray analysis at periodic intervals revealed a distinct brick and mortar formation characteristic of nacre, comprised of aragonite platelets and matrix proteins. Calcium, carbon, and oxygen were the major elements in all stages examined. Our study shows that mantle epithelial cells in culture retain the ability to secrete nacre and can therefore form the basis for future studies on the biomineralization process and its application in development of sustainable pearl culture.

  16. Restorative dentistry for children.

    Donly, Kevin J

    2013-01-01

    This article discusses contemporary pediatric restorative dentistry. Indications and contraindications for the choice of different restorative materials in different clinical situations, including the risk assessment of the patient, are presented. The specific use of glass ionomer cement or resin-modified glass ionomer cement, resin-based composite, and stainless steel crowns is discussed so that preparation design and restoration placement is understood. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Digital feedwater and recirculation flow control for GPUN Oyster Creek

    Burjorjee, D.; Gan, B.

    1992-01-01

    This paper describes the digital system for feedwater and recirculation control that GPU Nuclear will be installing at Oyster Creek during its next outage - expected circa December 1992. The replacement was motivated by considerations of reliability and obsolescence - the analog equipment was aging and reaching the end of its useful life. The new system uses Atomic Energy of Canada Ltd.'s software platform running on dual, redundant, industrial-grade 386 computers with opto-isolated field input/output (I/O) accessed through a parallel bus. The feedwater controller controls three main feed regulating valves, two low flow regulating valves, and two block valves. The recirculation controller drives the five scoop positioners of the hydraulic couplers. The system also drives contacts that lock up the actuators on detecting an open circuit in their current loops

  18. Infectious diseases in oyster aquaculture require a new integrated approach.

    Pernet, Fabrice; Lupo, Coralie; Bacher, Cédric; Whittington, Richard J

    2016-03-05

    Emerging diseases pose a recurrent threat to bivalve aquaculture. Recently, massive mortality events in the Pacific oyster Crassostrea gigas associated with the detection of a microvariant of the ostreid herpesvirus 1 (OsHV-1µVar) have been reported in Europe, Australia and New Zealand. Although the spread of disease is often viewed as a governance failure, we suggest that the development of protective measures for bivalve farming is presently held back by the lack of key scientific knowledge. In this paper, we explore the case for an integrated approach to study the management of bivalve disease, using OsHV-1 as a case study. Reconsidering the key issues by incorporating multidisciplinary science could provide a holistic understanding of OsHV-1 and increase the benefit of research to policymakers. © 2016 The Author(s).

  19. Image analysis method to quantify the effect of different treatments on the visual meat/shell ratio of half-shelled green lipped mussels (Perna canaliculus).

    Kim, Min Geun; Alçiçek, Zayde; Balaban, Murat O; Atar, Hasan Huseyin

    2014-04-01

    Aquacultured green lipped mussel (Perna canaliculus) is the New Zealand export leader of seafood in terms of weight. Different treatments shrink mussel meat differently and affect the consumer perception of half-shelled mussels. In order to quantify this, digital images of half-shelled green lipped mussels subjected to two postharvest treatments (ultrahigh pressure (UHP) and heat treatment (HT)) and raw controls were taken. The ratio of the view area of the meat to that of the shell (labelled as 'visual condition index' (VCI)) was measured using image analysis. A polygonal region of interest was defined on the image to depict the boundary of the meat and to calculate the view area. Raw mussels had a VCI of 85%. HT mussels had a much reduced VCI of 41%, indicating shrinkage of the meat due to heat. UHP treatment used as a shucking method resulted in a VCI of 83%. Since VCI is one measure of quality for the consumer, this quantitative method can be used in the optimization of shucking treatment (HT or UHP). VCI can be used to optimize postharvest treatments to minimize meat shrinkage. This method can also be applied to other shellfish such as oysters and clams. © 2013 Society of Chemical Industry.

  20. Oysters and eelgrass: potential partners in a high pCO2 ocean.

    Groner, Maya L; Burge, Colleen A; Cox, Ruth; Rivlin, Natalie; Turner, Mo; Van Alstyne, Kathryn L; Wyllie-Echeverria, Sandy; Bucci, John; Staudigel, Philip; Friedman, Carolyn S

    2018-05-25

    Climate change is affecting the health and physiology of marine organisms and altering species interactions. Ocean acidification (OA) threatens calcifying organisms such as the Pacific oyster, Crassostrea gigas. In contrast, seagrasses, such as the eelgrass Zostera marina, can benefit from the increase in available carbon for photosynthesis found at a lower seawater pH. Seagrasses can remove dissolved inorganic carbon from OA environments, creating local daytime pH refugia. Pacific oysters may improve the health of eelgrass by filtering out pathogens such as Labyrinthula zosterae (LZ), which causes eelgrass wasting disease (EWD). We examined how co-culture of eelgrass ramets and juvenile oysters affected the health and growth of eelgrass and the mass of oysters under different pCO 2 exposures. In Phase I, each species was cultured alone or in co-culture at 12°C across ambient, medium, and high pCO 2 conditions, (656, 1158 and1606 μatm pCO 2 , respectively). Under high pCO 2 , eelgrass grew faster and had less severe EWD (contracted in the field prior to the experiment). Co-culture with oysters also reduced the severity of EWD. While the presence of eelgrass decreased daytime pCO 2 , this reduction was not substantial enough to ameliorate the negative impact of high pCO 2 on oyster mass. In Phase II, eelgrass alone or oysters and eelgrass in co-culture were held at 15°C under ambient and high pCO 2 conditions, (488 and 2013 μatm pCO 2 , respectively). Half of the replicates were challenged with cultured LZ. Concentrations of defensive compounds in eelgrass (total phenolics and tannins), were altered by LZ exposure and pCO 2 treatments. Greater pathogen loads and increased EWD severity were detected in LZ exposed eelgrass ramets; EWD severity was reduced at high relative to low pCO 2 . Oyster presence did not influence pathogen load or EWD severity; high LZ concentrations in experimental treatments may have masked the effect of this treatment. Collectively, these

  1. Shells on elastic foundations

    Das, Y.C.; Kedia, K.K.

    1977-01-01

    No realistic analytical work in the area of Shells on Elastic Foundations has been reported in the literature. Various foundation models have been proposed by several authors. These models involve one or more than one parameters to characterise the foundation medium. Some of these models cannot be used to derive the basic equations governing the behaviour of shells on elastic foundations. In the present work, starting from an elastic continuum hypothesis, a mathematical model for foundation has been derived in curvilinear orthogonal coordinates by the help of principle of virtual displacements, treating one of the virtual displacements as known to satisfy certain given conditions at its edge surfaces. In this model, several foundation parameters can be considered and it can also be used for layered medium of both finite and infinite thickness. (Auth.)

  2. The risk of Vibrio parahaemolyticus infections associated with consumption of raw oysters as affected by processing and distribution conditions in Taiwan

    The steadily increased consumption of raw oysters in Taiwan warrants an assessment of the risk (probability of illness) of raw oyster consumption attributed by Vibrio parahaemolyticus. The aim of this study was to estimate the risk of V. parahaemolyticus infection associated with raw oyster consumpt...

  3. MHD computation of feedback of resistive-shell instabilities in the reversed field pinch

    Zita, E.J.; Prager, S.C.

    1992-05-01

    MHD computation demonstrates that feedback can sustain reversal and reduce loop voltage in resistive-shell reversed field pinch (RFP) plasmas. Edge feedback on ∼2R/a tearing modes resonant near axis is found to restore plasma parameters to nearly their levels with a close-fitting conducting shell. When original dynamo modes are stabilized, neighboring tearing modes grow to maintain the RFP dynamo more efficiently. This suggests that experimentally observed limits on RFP pulselengths to the order of the shell time can be overcome by applying feedback to a few helical modes

  4. Use of Green Mussel Shell as a Desulfurizer in the Blending of Low Rank Coal-Biomass Briquette Combustion

    Mahidin Mahidin

    2016-08-01

    Full Text Available Calcium oxide-based material is available abundantly and naturally. A potential resource of that material comes from marine mollusk shell such as clams, scallops, mussels, oysters, winkles and nerites. The CaO-based material has exhibited a good performance as the desulfurizer oradsorbent in coal combustion in order to reduce SO2 emission. In this study, pulverized green mussel shell, without calcination, was utilized as the desulfurizer in the briquette produced from a mixture of low rank coal and palm kernel shell (PKS, also known as bio-briquette. The ratio ofcoal to PKS in the briquette was 90:10 (wt/wt. The influence of green mussel shell contents and combustion temperature were examined to prove the possible use of that materialas a desulfurizer. The ratio of Ca to S (Ca = calcium content in desulfurizer; S = sulfur content in briquette werefixed at 1:1, 1.25:1, 1.5:1, 1.75:1, and 2:1 (mole/mole. The burning (or desulfurization temperature range was 300-500 °C; the reaction time was 720 seconds and the air flow rate was 1.2 L/min. The results showed that green mussel shell can be introduced as a desulfurizer in coal briquette or bio-briquette combustions. The desulfurization process using that desulfurizer exhibited the first order reaction and the highest average efficiency of 84.5%.

  5. Ecological restoration [book review

    Eric J. Gustafson

    2010-01-01

    Ecological restoration has increased in prominence in recent years as environmental policies have slowed the rate of environmental degradation in many parts of the world and practitioners have looked for active ways to reverse the damage. Because of the vast number of types and contexts of degraded ecological systems, the field of ecological restoration is still very...

  6. Construction and evaluation of a high-density SNP array for the Pacific oyster (Crassostrea gigas.

    Haigang Qi

    Full Text Available Single nucleotide polymorphisms (SNPs are widely used in genetics and genomics research. The Pacific oyster (Crassostrea gigas is an economically and ecologically important marine bivalve, and it possesses one of the highest levels of genomic DNA variation among animal species. Pacific oyster SNPs have been extensively investigated; however, the mechanisms by which these SNPs may be used in a high-throughput, transferable, and economical manner remain to be elucidated. Here, we constructed an oyster 190K SNP array using Affymetrix Axiom genotyping technology. We designed 190,420 SNPs on the chip; these SNPs were selected from 54 million SNPs identified through re-sequencing of 472 Pacific oysters collected in China, Japan, Korea, and Canada. Our genotyping results indicated that 133,984 (70.4% SNPs were polymorphic and successfully converted on the chip. The SNPs were distributed evenly throughout the oyster genome, located in 3,595 scaffolds with a length of ~509.4 million; the average interval spacing was 4,210 bp. In addition, 111,158 SNPs were distributed in 21,050 coding genes, with an average of 5.3 SNPs per gene. In comparison with genotypes obtained through re-sequencing, ~69% of the converted SNPs had a concordance rate of >0.971; the mean concordance rate was 0.966. Evaluation based on genotypes of full-sib family individuals revealed that the average genotyping accuracy rate was 0.975. Carrying 133 K polymorphic SNPs, our oyster 190K SNP array is the first commercially available high-density SNP chip for mollusks, with the highest throughput. It represents a valuable tool for oyster genome-wide association studies, fine linkage mapping, and population genetics.

  7. Transcriptome Analysis of the Sydney Rock Oyster, Saccostrea glomerata: Insights into Molluscan Immunity.

    Nicole G Ertl

    Full Text Available Oysters have important ecological functions in their natural environment, acting as global carbon sinks and improving water quality by removing excess nutrients from the water column. During their life-time oysters are exposed to a variety of pathogens that can cause severe mortality in a range of oyster species. Environmental stressors encountered in their habitat can increase the susceptibility of oysters to these pathogens and in general have been shown to impact on oyster immunity, making immune parameters expressed in these marine animals an important research topic.Paired-end Illumina high throughput sequencing of six S. glomerata tissues exposed to different environmental stressors resulted in a total of 484,121,702 paired-end reads. When reads and assembled transcripts were compared to the C. gigas genome, an overall low level of similarity at the nucleotide level, but a relatively high similarity at the protein level was observed. Examination of the tissue expression pattern showed that some transcripts coding for cathepsins, heat shock proteins and antioxidant proteins were exclusively expressed in the haemolymph of S. glomerata, suggesting a role in innate immunity. Furthermore, analysis of the S. glomerata ORFs showed a wide range of genes potentially involved in innate immunity, from pattern recognition receptors, components of the Toll-like signalling and apoptosis pathways to a complex antioxidant defence mechanism.This is the first large scale RNA-Seq study carried out in S. glomerata, showing the complex network of innate immune components that exist in this species. The results confirmed that many of the innate immune system components observed in mammals are also conserved in oysters; however, some, such as the TLR adaptors MAL, TRIF and TRAM are either missing or have been modified significantly. The components identified in this study could help explain the oysters' natural resilience against pathogenic microorganisms

  8. Warm temperature acclimation impacts metabolism of paralytic shellfish toxins from Alexandrium minutum in commercial oysters.

    Farrell, Hazel; Seebacher, Frank; O'Connor, Wayne; Zammit, Anthony; Harwood, D Tim; Murray, Shauna

    2015-09-01

    Species of Alexandrium produce potent neurotoxins termed paralytic shellfish toxins and are expanding their ranges worldwide, concurrent with increases in sea surface temperature. The metabolism of molluscs is temperature dependent, and increases in ocean temperature may influence both the abundance and distribution of Alexandrium and the dynamics of toxin uptake and depuration in shellfish. Here, we conducted a large-scale study of the effect of temperature on the uptake and depuration of paralytic shellfish toxins in three commercial oysters (Saccostrea glomerata and diploid and triploid Crassostrea gigas, n = 252 per species/ploidy level). Oysters were acclimated to two constant temperatures, reflecting current and predicted climate scenarios (22 and 27 °C), and fed a diet including the paralytic shellfish toxin-producing species Alexandrium minutum. While the oysters fed on A. minutum in similar quantities, concentrations of the toxin analogue GTX1,4 were significantly lower in warm-acclimated S. glomerata and diploid C. gigas after 12 days. Following exposure to A. minutum, toxicity of triploid C. gigas was not affected by temperature. Generally, detoxification rates were reduced in warm-acclimated oysters. The routine metabolism of the oysters was not affected by the toxins, but a significant effect was found at a cellular level in diploid C. gigas. The increasing incidences of Alexandrium blooms worldwide are a challenge for shellfish food safety regulation. Our findings indicate that rising ocean temperatures may reduce paralytic shellfish toxin accumulation in two of the three oyster types; however, they may persist for longer periods in oyster tissue. © 2015 John Wiley & Sons Ltd.

  9. Oyster larvae settle in response to habitat-associated underwater sounds.

    Lillis, Ashlee; Eggleston, David B; Bohnenstiehl, DelWayne R

    2013-01-01

    Following a planktonic dispersal period of days to months, the larvae of benthic marine organisms must locate suitable seafloor habitat in which to settle and metamorphose. For animals that are sessile or sedentary as adults, settlement onto substrates that are adequate for survival and reproduction is particularly critical, yet represents a challenge since patchily distributed settlement sites may be difficult to find along a coast or within an estuary. Recent studies have demonstrated that the underwater soundscape, the distinct sounds that emanate from habitats and contain information about their biological and physical characteristics, may serve as broad-scale environmental cue for marine larvae to find satisfactory settlement sites. Here, we contrast the acoustic characteristics of oyster reef and off-reef soft bottoms, and investigate the effect of habitat-associated estuarine sound on the settlement patterns of an economically and ecologically important reef-building bivalve, the Eastern oyster (Crassostrea virginica). Subtidal oyster reefs in coastal North Carolina, USA show distinct acoustic signatures compared to adjacent off-reef soft bottom habitats, characterized by consistently higher levels of sound in the 1.5-20 kHz range. Manipulative laboratory playback experiments found increased settlement in larval oyster cultures exposed to oyster reef sound compared to unstructured soft bottom sound or no sound treatments. In field experiments, ambient reef sound produced higher levels of oyster settlement in larval cultures than did off-reef sound treatments. The results suggest that oyster larvae have the ability to respond to sounds indicative of optimal settlement sites, and this is the first evidence that habitat-related differences in estuarine sounds influence the settlement of a mollusk. Habitat-specific sound characteristics may represent an important settlement and habitat selection cue for estuarine invertebrates and could play a role in driving

  10. Oyster larvae settle in response to habitat-associated underwater sounds.

    Ashlee Lillis

    Full Text Available Following a planktonic dispersal period of days to months, the larvae of benthic marine organisms must locate suitable seafloor habitat in which to settle and metamorphose. For animals that are sessile or sedentary as adults, settlement onto substrates that are adequate for survival and reproduction is particularly critical, yet represents a challenge since patchily distributed settlement sites may be difficult to find along a coast or within an estuary. Recent studies have demonstrated that the underwater soundscape, the distinct sounds that emanate from habitats and contain information about their biological and physical characteristics, may serve as broad-scale environmental cue for marine larvae to find satisfactory settlement sites. Here, we contrast the acoustic characteristics of oyster reef and off-reef soft bottoms, and investigate the effect of habitat-associated estuarine sound on the settlement patterns of an economically and ecologically important reef-building bivalve, the Eastern oyster (Crassostrea virginica. Subtidal oyster reefs in coastal North Carolina, USA show distinct acoustic signatures compared to adjacent off-reef soft bottom habitats, characterized by consistently higher levels of sound in the 1.5-20 kHz range. Manipulative laboratory playback experiments found increased settlement in larval oyster cultures exposed to oyster reef sound compared to unstructured soft bottom sound or no sound treatments. In field experiments, ambient reef sound produced higher levels of oyster settlement in larval cultures than did off-reef sound treatments. The results suggest that oyster larvae have the ability to respond to sounds indicative of optimal settlement sites, and this is the first evidence that habitat-related differences in estuarine sounds influence the settlement of a mollusk. Habitat-specific sound characteristics may represent an important settlement and habitat selection cue for estuarine invertebrates and could play a

  11. Detection and forecasting of oyster norovirus outbreaks: recent advances and future perspectives.

    Wang, Jiao; Deng, Zhiqiang

    2012-09-01

    Norovirus is a highly infectious pathogen that is commonly found in oysters growing in fecally contaminated waters. Norovirus outbreaks can cause the closure of oyster harvesting waters and acute gastroenteritis in humans associated with consumption of contaminated raw oysters. Extensive efforts and progresses have been made in detection and forecasting of oyster norovirus outbreaks over the past decades. The main objective of this paper is to provide a literature review of methods and techniques for detecting and forecasting oyster norovirus outbreaks and thereby to identify the future directions for improving the detection and forecasting of norovirus outbreaks. It is found that (1) norovirus outbreaks display strong seasonality with the outbreak peak occurring commonly in December-March in the U.S. and April-May in the Europe; (2) norovirus outbreaks are affected by multiple environmental factors, including but not limited to precipitation, temperature, solar radiation, wind, and salinity; (3) various modeling approaches may be employed to forecast norovirus outbreaks, including Bayesian models, regression models, Artificial Neural Networks, and process-based models; and (4) diverse techniques are available for near real-time detection of norovirus outbreaks, including multiplex PCR, seminested PCR, real-time PCR, quantitative PCR, and satellite remote sensing. The findings are important to the management of oyster growing waters and to future investigations into norovirus outbreaks. It is recommended that a combined approach of sensor-assisted real time monitoring and modeling-based forecasting should be utilized for an efficient and effective detection and forecasting of norovirus outbreaks caused by consumption of contaminated oysters. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Rapid transcriptional acclimation following transgenerational exposure of oysters to ocean acidification.

    Goncalves, Priscila; Anderson, Kelli; Thompson, Emma L; Melwani, Aroon; Parker, Laura M; Ross, Pauline M; Raftos, David A

    2016-10-01

    Marine organisms need to adapt in order to cope with the adverse effects of ocean acidification and warming. Transgenerational exposure to CO2 stress has been shown to enhance resilience to ocean acidification in offspring from a number of species. However, the molecular basis underlying such adaptive responses is currently unknown. Here, we compared the transcriptional profiles of two genetically distinct oyster breeding lines following transgenerational exposure to elevated CO2 in order to explore the molecular basis of acclimation or adaptation to ocean acidification in these organisms. The expression of key target genes associated with antioxidant defence, metabolism and the cytoskeleton was assessed in oysters exposed to elevated CO2 over three consecutive generations. This set of target genes was chosen specifically to test whether altered responsiveness of intracellular stress mechanisms contributes to the differential acclimation of oyster populations to climate stressors. Transgenerational exposure to elevated CO2 resulted in changes to both basal and inducible expression of those key target genes (e.g. ecSOD, catalase and peroxiredoxin 6), particularly in oysters derived from the disease-resistant, fast-growing B2 line. Exposure to CO2 stress over consecutive generations produced opposite and less evident effects on transcription in a second population that was derived from wild-type (nonselected) oysters. The analysis of key target genes revealed that the acute responses of oysters to CO2 stress appear to be affected by population-specific genetic and/or phenotypic traits and by the CO2 conditions to which their parents had been exposed. This supports the contention that the capacity for heritable change in response to ocean acidification varies between oyster breeding lines and is mediated by parental conditioning. © 2016 John Wiley & Sons Ltd.

  13. Effects of heavy metals on the oyster (Crassostrea virginica at Mandinga Lagoon, Veracruz, Mexico

    X Guzmán-García

    2009-12-01

    Full Text Available The Mandinga Lagoon in the Mexican State of Veracruz is an important ecological zone that produces 32% of the oyster output in the state of Veracruz, the main oyster producer in Mexico. Samples of water, sediment, and oysters were collected in 2003 and 2004 to study heavy metal pollution. Metal concentrations were determined in water, soil, and oyster tissues from fresh and detoxified Crassostrea virginica, and histology samples were analyzed. Metal (Cr, Cd, and Pb concentrations in water were within the Mexican legal limits. The recorded values in sediments corresponded to those not producing biological effects (ERL. In the tissues, the highest concentrations corresponded to Pb, above 5.84 μgg-1 dry weight (d.w.; Cd was of 2.23 μgg-1 d.w., and Cr above 6 μgg-1 d.w. The metal levels detected in oysters exceeded the maximum permissible limits (MPL for Cd and Pb, and oysters were unable to eliminate the concentrations of the bioaccumulated metals during the detoxification stage. The histopathological analysis revealed lesions in the digestive gland, edema, atrophy of epithelia in the digestive tubules, the presence of brown vesicles, hemocytic reaction, and necrosis. During detoxification, a higher number of epithelia were observed in the tubules, as well as an increase in brown vesicles and hemocytic reaction. Forty seven percent of oysters presented histopathological lesions related to metal concentrations. It is important to monitor metal concentrations, to detect the source of pollution, andto evaluate the effects on organisms to establish culture areas and adequate criteria for the exploitation of such an important fishery resource. Rev. Biol. Trop. 57 (4: 955-962. Epub 2009 December 01.

  14. Challenges of ecological restoration

    Halme, Panu; Allen, Katherine A.; Aunins, Ainars

    2013-01-01

    we introduce northern forests as an ecosystem, discuss the historical and recent human impact and provide a brief status report on the ecological restoration projects and research already conducted there. Based on this discussion, we argue that before any restoration actions commence, the ecology......The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many...... on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here...

  15. Retributive and restorative justice.

    Wenzel, Michael; Okimoto, Tyler G; Feather, Norman T; Platow, Michael J

    2008-10-01

    The emergence of restorative justice as an alternative model to Western, court-based criminal justice may have important implications for the psychology of justice. It is proposed that two different notions of justice affect responses to rule-breaking: restorative and retributive justice. Retributive justice essentially refers to the repair of justice through unilateral imposition of punishment, whereas restorative justice means the repair of justice through reaffirming a shared value-consensus in a bilateral process. Among the symbolic implications of transgressions, concerns about status and power are primarily related to retributive justice and concerns about shared values are primarily related to restorative justice. At the core of these processes, however, lies the parties' construal of their identity relation, specifically whether or not respondents perceive to share an identity with the offender. The specific case of intergroup transgressions is discussed, as are implications for future research on restoring a sense of justice after rule-breaking.

  16. Cloning retinoid and peroxisome proliferator-activated nuclear receptors of the Pacific oyster and in silico binding to environmental chemicals.

    Susanne Vogeler

    Full Text Available Disruption of nuclear receptors, a transcription factor superfamily regulating gene expression in animals, is one proposed mechanism through which pollution causes effects in aquatic invertebrates. Environmental pollutants have the ability to interfere with the receptor's functions through direct binding and inducing incorrect signals. Limited knowledge of invertebrate endocrinology and molecular regulatory mechanisms, however, impede the understanding of endocrine disruptive effects in many aquatic invertebrate species. Here, we isolated three nuclear receptors of the Pacific oyster, Crassostrea gigas: two isoforms of the retinoid X receptor, CgRXR-1 and CgRXR-2, a retinoic acid receptor ortholog CgRAR, and a peroxisome proliferator-activated receptor ortholog CgPPAR. Computer modelling of the receptors based on 3D crystal structures of human proteins was used to predict each receptor's ability to bind to different ligands in silico. CgRXR showed high potential to bind and be activated by 9-cis retinoic acid and the organotin tributyltin (TBT. Computer modelling of CgRAR revealed six residues in the ligand binding domain, which prevent the successful interaction with natural and synthetic retinoid ligands. This supports an existing theory of loss of retinoid binding in molluscan RARs. Modelling of CgPPAR was less reliable due to high discrepancies in sequence to its human ortholog. Yet, there are suggestions of binding to TBT, but not to rosiglitazone. The effect of potential receptor ligands on early oyster development was assessed after 24h of chemical exposure. TBT oxide (0.2μg/l, all-trans retinoic acid (ATRA (0.06 mg/L and perfluorooctanoic acid (20 mg/L showed high effects on development (>74% abnormal developed D-shelled larvae, while rosiglitazone (40 mg/L showed no effect. The results are discussed in relation to a putative direct (TBT disruption effect on nuclear receptors. The inability of direct binding of ATRA to CgRAR suggests

  17. Sensitivity of hepatitis A and murine norovirus to electron beam irradiation in oyster homogenates and whole oysters - quantifying the reduction in potential infection risks

    Despite worldwide regulations and advisories restricting shellfish harvest to approved locations, consumption of raw oysters continues to be an exposure route for human norovirus (NoV) and hepatitis A virus (HAV). Therefore, a technology that can reduce the public health risks is needed. The focus...

  18. 76 FR 59423 - Drakes Bay Oyster Company Special-Use Permit, Draft Environmental Impact Statement, Point Reyes...

    2011-09-26

    ... commercial production, harvesting, processing, and sale of shellfish at Point Reyes National Seashore. The... Bay Oyster Company Special-Use Permit, Draft Environmental Impact Statement, Point Reyes National... Drakes Bay Oyster Company Special-use permit in Drakes Estero, Point Reyes National Seashore, California...

  19. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster (Crassostrea belcheri) in Thailand

    Thupila, Nunticha; Ratana-arporn, Pattama; Wilaipun, Pongtep

    2011-01-01

    In Thailand, white scar oyster (Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses (D 10 ) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D 10 values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10 5 CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  20. Apparent loss of Vibrio vulnificus from North Carolina oysters coincides with a drought-induced increase in salinity.

    Froelich, Brett A; Williams, Tiffany C; Noble, Rachel T; Oliver, James D

    2012-06-01

    Despite years of successful isolation of Vibrio vulnificus from estuarine waters, beginning in 2007, it was extremely difficult to culture V. vulnificus from either North Carolina estuarine water or oyster samples. After employing culture-based methods as well as PCR and quantitative PCR for the detection of V. vulnificus, always with negative results, we concluded that this pathogen had become nearly undetectable in the North Carolina estuarine ecosystem. We ensured that the techniques were sound by seeding North Carolina oysters with V. vulnificus and performing the same tests as those previously conducted on unadulterated oysters. V. vulnificus was readily detected in the seeded oysters using both classes of methods. Furthermore, oysters were obtained from the Gulf of Mexico, and V. vulnificus was easily isolated, confirming that the methodology was sound but that the oysters and waters of North Carolina were lacking the V. vulnificus population studied for decades. Strikingly, the apparent loss of detectable V. vulnificus coincided with the most severe drought in the history of North Carolina. The drought continued until the end of 2009, with an elevated water column salinity being observed throughout this period and with V. vulnificus being nearly nonexistent. When salinities returned to normal after the drought abated in 2010, we were again able to routinely isolate V. vulnificus from the water column, although we were still unable to culture it from oysters. We suggest that the oysters were colonized with a more salt-tolerant bacterium during the drought, which displaced V. vulnificus and may be preventing recolonization.

  1. SURVEY OF OYSTERS CRASSOSTREA VIRGINICA FROM TAMPA BAY, FLORIDA: ASSOCIATIONS OF INTERNAL DEFENSE MEASUREMENTS WITH CONTAMINANT BURDENS

    Oysters from 16 sites in Tampa Bay, Florida, were collected during a 6-week period in winter 1993 and analyzed for both biological characteristics and tissue chemical concentrations. Using previous sediment contamination and toxicity data, oyster tissues from the selected sites w...

  2. Effects of High-Hydrostatic Pressure on Inactivation of Human Norovirus and Physical and Sensory Characteristics of Oysters.

    Ye, Mu; Lingham, Talaysha; Huang, Yaoxin; Ozbay, Gulnihal; Ji, Lin; Karwe, Mukund; Chen, Haiqiang

    2015-06-01

    The purpose of the study was to determine the effect of high-hydrostatic pressure (HHP) on inactivation of human norovirus (HuNoV) in oysters and to evaluate organoleptic characteristics of oysters treated at pressure levels required for HuNoV inactivation. Genogroup I.1 (GI.1) or Genogroup II.4 (GII.4) HuNoV was inoculated into oysters and treated at 300 to 600 MPa at 25 and 0 °C for 2 min. After HHP, viral particles were extracted by porcine gastric mucin-conjugated magnetic beads (PGM-MBs) and viral RNA was quantified by real-time RT-PCR. Lower initial temperature (0 °C) significantly enhanced HHP inactivation of HuNoV compared to ambient temperature (25 °C; P oysters, respectively. HHP treatments did not significantly change color or texture of oyster tissue. A 1- to 5-scale hedonic sensory evaluation on appearance, aroma, color, and overall acceptability showed that pressure-treated oysters received significantly higher quality scores than the untreated control (P oysters. Oysters treated at 0 °C had slightly lower acceptability than the group treated at room temperature on day 1 (P 0.05). © 2015 Institute of Food Technologists®

  3. PROGRESSION OF DISEASES CAUSED BY THE OYSTER PARASITES, PERKINSUS MARINUS AND HAPLOSPORIDIUM NELSONI, IN CRASSOSTREA VIRGINICA ON CONSTRUCTED INTERTIDAL REEFS

    The progression of diseases caused by the oyster parasites, Perkinsus marinus and Haplosporidium nelsoni, were evaluated by periodic sampling (May 1994-Dec. 1995) of oysters, Crassostrea virginica, that set on an artificial reef located in the Piankatank River, Virginia, in Augus...

  4. Ecological studies on the seasonal production of the edible oyster, Crassostrea madrasensis (Preston) in Cochin Backwater, Kerala

    Purushan, K.S.; Gopalan, U.K.; Rao, T.S.S.

    the intertidal ones, but as regards percentage meat weight the latter out-weighed the former. Among environmental variables, salinity seemed to be the foremost factor in influencing the production of oysters. A large majority (90-98%) of the intertidal oysters...

  5. Evaluation of the proximate quality of the combination of Tuna (Thunnus albacares) and white oyster mushroom (Pleurotus ostreatus) nuggets

    Yufidasari, H. S.; Prihanto, A. A.; Nurdiani, R.; Jaziri, A. A.

    2018-04-01

    Nugget is a processed meat product which has great market demand but need variations to increase its nutritional content. Tuna is rich in omega-3 protein, vitamins, and minerals. White oyster mushrooms have high nutritional content which are about 23-33% protein, 36-68 % carbohydrates and 12-22 % amino acids. The purpose of this research is to evaluate the chemical quality of Tuna nugget (Thunnus albacores) with combination of white oyster mushroom (Pleurotus ostreatus). Complete Randomized Design (RAL) with parameters of Tuna and white oyster mushroom formulation, TJ1 (70 % Tuna: 30 % white oyster mushroom), TJ2 (50 % Tuna: 50 % white oyster mushroom), TJ3 (30 % Tuna: 70 % white oyster mushroom), and Control or K Treatment (100 % Tuna) is used. Results of Tuna nuggets with white oyster mushroom combination showed the highest value of water content in TJ3 50.14 %, protein K 19.6 %, fat TJ3 22.98 %, ash K 3.99 % and 2.47 % crude fiber. From these results, there is a need for further research on fat, ash and coarse fiber content that is used in the manufacture of fish nuggets combined with oyster mushrooms because it failed to meet Indonesian National Standard (SNI).

  6. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster ( Crassostrea belcheri) in Thailand

    Thupila, Nunticha; Ratana-arporn, Pattama; Wilaipun, Pongtep

    2011-07-01

    In Thailand, white scar oyster ( Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses ( D10) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D10 values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10 5 CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  7. Wrinkling of Pressurized Elastic Shells

    Vella, Dominic

    2011-10-01

    We study the formation of localized structures formed by the point loading of an internally pressurized elastic shell. While unpressurized shells (such as a ping-pong ball) buckle into polygonal structures, we show that pressurized shells are subject to a wrinkling instability. We study wrinkling in depth, presenting scaling laws for the critical indentation at which wrinkling occurs and the number of wrinkles formed in terms of the internal pressurization and material properties of the shell. These results are validated by numerical simulations. We show that the evolution of the wrinkle length with increasing indentation can be understood for highly pressurized shells from membrane theory. These results suggest that the position and number of wrinkles may be used in combination to give simple methods for the estimation of the mechanical properties of highly pressurized shells. © 2011 American Physical Society.

  8. Annual effective dose of {sup 210}Po from sea food origin (Oysters and Mussels) in Korea

    Cho, Bo Eum; Hong, Gi Hoon; Kim, Suk Hyun; Lee, Hyun Mi [Korea Institute of Ocean Science and Technology, Ansan (Korea, Republic of)

    2016-09-15

    Ingestion of {sup 210}Po laden seafood accounts for a substantial amount of the effective dose of {sup 210}Po. Among seafood items, mollusks, especially domestically produced oysters and mussels, are highly enriched in {sup 210}Po and are consumed in large quantities in Korea. Oysters and mussels around the Korean coasts were collected from major farm areas in November 2013. Samples were spiked with an aliquot of {sup 210}Po as a yield tracer, and they were digested with 6 mol·L{sup -1} HNO{sub 3} and H{sub 2}O{sub 2}. The {sup 210}Po and {sup 209}Po were spontaneously deposited onto a silver disc in an acidic solution of 0.5 mol·L{sup -1} HCl and measured using an alpha spectrometer. The activity concentrations of {sup 210}Pb and {sup 210}Po were decay corrected to the sampling date, accounting for the possible in-growth and decay of {sup 210}Po. {sup 210}Po activity concentrations in oysters were in a range from 41.3 to 206 Bq·(kg-ww{sup -1} and mussels in a range from 42.9 to 46.7 Bq·(kg-ww){sup -1}. The {sup 210}Po activity concentration of oysters in the turbid Western coast was higher than the Southern coast. The {sup 210}Po activity concentration of the oysters was positively correlated (R2=0.89) with those of the suspended particulate matter in the surface water. The calculated annual effective dose of {sup 210}Po from oysters and mussels consumed by the Korean population was 21-104 and 5.01-5.46 μSv·y{sup -1}. The combined effective dose due to the consumption of oysters and mussels appears to account for about 35±19% of that arising from seafood consumption in the Korean population. The annual effective dose of {sup 210}Po for oysters in the Korean population was found to be higher than other countries. The total annual effective dose of 210Po{sup 210}Po due to consumption of oysters and mussels consumed in Korea was found to be 76±42 μSv·y{sup -1}, accounting for 28±16% of the total effective dose of {sup 210}Po from food in Korea.

  9. Occurrence of marine algal toxins in oyster and phytoplankton samples in Daya Bay, South China Sea.

    Jiang, Tao; Liu, Lei; Li, Yang; Zhang, Jing; Tan, Zhijun; Wu, Haiyan; Jiang, Tianjiu; Lu, Songhui

    2017-09-01

    The occurrence and seasonal variations of marine algal toxins in phytoplankton and oyster samples in Daya Bay (DYB), South China Sea were investigated. Two Dinophysis species, namely, D. caudata and D. acuminata complex, were identified as Okadaic acid (OA)/pectenotoxin (PTX) related species. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis demonstrated that 2.04-14.47 pg PTX2 per cell was the predominant toxin in single-cell isolates of D. caudata. D. acuminata was not subjected to toxin analysis. The occurrence of OAs in phytoplankton concentrates of net-haul sample coincided with the presence of D. accuminata complex, suggesting that this species is most likely an OA producer in this sea area. OA, dinophysistoxins-1 (DTX1), PTX2, PTX2sa, gymnodimine (GYM), homoyessotoxin (homoYTX), and domoic acid (DA) demonstrated positive results in net haul samples. To our best knowledge, this paper is the first to report the detection of GYM, DA, and homoYTX in phytoplankton samples in Chinese coastal waters. Among the algal toxins, GYM demonstrated the highest frequency of positive detections in phytoplankton concentrates (13/17). Five compounds of algal toxins, including OA, DTX1, PTX2, PTX2sa, and GYM, were detected in oyster samples. DA and homoYTX were not detected in oysters despite of positive detections for both in the phytoplankton concentrates. However, neither the presence nor absence of DA in oysters can be determined because extraction conditions with 100% methanol used to isolate toxins from oysters (recommended by the EU-Harmonised Standard Operating Procedure, 2015) would likely be unsuitable for this water-soluble toxin. In addition, transformation of DA during the digestion process of oysters may also be involved in the negative detections of this toxin. GYM exhibited the highest frequency of positive results in oysters (14/17). OAs were only detected in the hydrolyzed oyster samples. The detection rates of PTX and PTX2sa in

  10. Annual effective dose of 210Po from sea food origin (Oysters and Mussels) in Korea

    Cho, Bo Eum; Hong, Gi Hoon; Kim, Suk Hyun; Lee, Hyun Mi

    2016-01-01

    Ingestion of 210 Po laden seafood accounts for a substantial amount of the effective dose of 210 Po. Among seafood items, mollusks, especially domestically produced oysters and mussels, are highly enriched in 210 Po and are consumed in large quantities in Korea. Oysters and mussels around the Korean coasts were collected from major farm areas in November 2013. Samples were spiked with an aliquot of 210 Po as a yield tracer, and they were digested with 6 mol·L -1 HNO 3 and H 2 O 2 . The 210 Po and 209 Po were spontaneously deposited onto a silver disc in an acidic solution of 0.5 mol·L -1 HCl and measured using an alpha spectrometer. The activity concentrations of 210 Pb and 210 Po were decay corrected to the sampling date, accounting for the possible in-growth and decay of 210 Po. 210 Po activity concentrations in oysters were in a range from 41.3 to 206 Bq·(kg-ww -1 and mussels in a range from 42.9 to 46.7 Bq·(kg-ww) -1 . The 210 Po activity concentration of oysters in the turbid Western coast was higher than the Southern coast. The 210 Po activity concentration of the oysters was positively correlated (R2=0.89) with those of the suspended particulate matter in the surface water. The calculated annual effective dose of 210 Po from oysters and mussels consumed by the Korean population was 21-104 and 5.01-5.46 μSv·y -1 . The combined effective dose due to the consumption of oysters and mussels appears to account for about 35±19% of that arising from seafood consumption in the Korean population. The annual effective dose of 210 Po for oysters in the Korean population was found to be higher than other countries. The total annual effective dose of 210Po 210 Po due to consumption of oysters and mussels consumed in Korea was found to be 76±42 μSv·y -1 , accounting for 28±16% of the total effective dose of 210 Po from food in Korea

  11. Effects of ambient exposure, refrigeration, and icing on Vibrio vulnificus and Vibrio parahaemolyticus abundances in oysters.

    Jones, J L; Lydon, K A; Kinsey, T P; Friedman, B; Curtis, M; Schuster, R; Bowers, J C

    2017-07-17

    Vibrio vulnificus (Vv) and V. parahaemolyticus (Vp) illnesses are typically acquired through the consumption of raw molluscan shellfish, particularly oysters. As Vibrio spp. are naturally-occurring bacteria, one means of mitigation of illness is achieved by limiting post-harvest growth. In this study, effects of ambient air storage, refrigeration, and icing of oysters on Vibrio spp. abundances were examined at two sites in Alabama (AL) [Dog River (DR) and Cedar Point (CP)] and one site in Delaware Bay, New Jersey (NJ). As the United States shellfish program recommendations include testing for total these organisms and gene targets, Vv and total (tlh) and pathogenic (tdh+ and trh+) Vp were enumerated from samples using MPN-real-time-PCR approaches. Mean Vv and Vp abundances in oysters from AL-DR were lowest in immediately iced samples (2.3 and -0.1 log MPN/g, respectively) and highest in the 5h ambient then refrigerated samples (3.4 and 0.5 log MPN/g, respectively). Similarly, in AL-CP Vv and Vp mean levels in oysters were lowest in immediately iced samples (3.6 and 1.2 log MPN/g, respectively) and highest in 5h ambient then refrigerated samples (5.1 and 3.2 log MPN/g, respectively). Mean levels of pathogenic Vp from AL sites were frequently below the limit of detection (oysters were highest in samples which were held for 7h in the shade (5.3 and 4.8 log MPN/g, respectively). Mean pathogenic Vp levels in oysters at initial harvest were also highest in oysters 7h in the shade (2.1 and 2.2 log MPN/g for tdh+ and trh+ Vp). Regardless of sampling location, Vibrio spp. levels were generally significantly (poysters exposed to 5h of air storage compared to the initially harvested samples. In addition, the data demonstrated that the use of layered ice resulted in lower Vibrio spp. levels in oysters, compared to those that were refrigerated post-harvest. These results suggest vibriosis risk can be mitigated by shorter storage times and more rapid cooling of oysters

  12. Persistence of Positive Carryover Effects in the Oyster, Saccostrea glomerata, following Transgenerational Exposure to Ocean Acidification.

    Laura M Parker

    Full Text Available Ocean acidification (OA is predicted to have widespread implications for marine organisms, yet the capacity for species to acclimate or adapt over this century remains unknown. Recent transgenerational studies have shown that for some marine species, exposure of adults to OA can facilitate positive carryover effects to their larval and juvenile offspring that help them to survive in acidifying oceanic conditions. But whether these positive carryover effects can persist into adulthood or the next generation is unknown. Here we tested whether positive carryover effects found in larvae of the oyster, Saccostrea glomerata following transgenerational exposure to elevated CO2, could persist into adulthood and whether subsequent transgenerational exposure of adults to elevated CO2 would facilitate similar adaptive responses in the next generation of larvae and juveniles. Following our previous transgenerational exposure of parental adults and first generation (F1 larvae to ambient (385 μatm and elevated (856 μatm CO2, newly settled F1 juveniles were transferred to the field at ambient CO2 for 14 months, until they reached reproductive maturity. At this time, the F1 adults were returned to the laboratory and the previous transgenerational CO2 exposure was repeated to produce F2 offspring. We found that the capacity of adults to regulate extracellular pH at elevated CO2 was improved if they had a prior history of transgenerational exposure to elevated CO2. In addition, subsequent transgenerational exposure of these adults led to an increase in the resilience of their larval and juvenile offspring. Offspring with a history of transgenerational exposure to elevated CO2 had a lower percentage abnormality, faster development rate, faster shell growth and increased heart rate at elevated CO2 compared with F2 offspring with no prior history of exposure to elevated CO2. Our results suggest that positive carryover effects originating during parental and larval

  13. Seismic analysis of axisymmetric shells

    Jospin, R.J.; Toledo, E.M.; Feijoo, R.A.

    1984-01-01

    Axisymmetric shells subjected to multiple support excitation are studied. The shells are spatialy discretized by the finite element method and in order to obtain estimates for the maximum values of displacements and stresses the response spectrum tecnique is used. Finally, some numerical results are presented and discussed in the case of a shell of revolution with vertical symmetry axis, subjected to seismic ground motions in the horizontal, vertical and rocking directions. (Author) [pt

  14. Creep analysis of orthotropic shells

    Mehra, V.K.; Ghosh, A.

    1975-01-01

    A method of creep analysis of orthotropic cylindrical shells subjected to axisymmetric loads has been developed. A general study of creep behaviour of cylindrical shells subjected to a uniform internal pressure has been conducted for a wide range of values of anisotropy coefficients and creep law exponent. Analysis includes determination of stress re-distribution, strain rates, stationary state stresses. Application of reference stress technique has been extended to analysis of shells. (author)

  15. Microbiological, physicochemical, and sensory characteristics of gamma-irradiated fresh oysters during storage

    Park, Jae Sek; Pak, Jae Nam; Park, Jin Gyu; Han, In Jun; Jung, Pil Mun; Song, Beaom Seok; Choi, Jong Il; Kim, Jae Hun; Byun, Myung Woo; Lee, Ju Woon; Han, Sang Bae

    2008-01-01

    The microbiological, physicochemical and sensory characteristics of gamma irradiated fresh oysters were evaluated regarding its shelf-life during refrigeration. Non-irradiated fresh oysters began to be putrefied after 14 days, while fresh oysters irradiated with 2 kGy showed 5.54 log CFU∙g-1 even after 28 days. Volatile basic nitrogen (VBN) value increased more rapidly in the non-irradiated sample than the irradiated samples during storage. Especially the VBN value of the non-irradiated sample was eight fold higher then that of the the sample irradiated with 2 kGy. The pH of the non-irradiated fresh oysters significantly decreased during storage while the samples irradiated with doses higher than 2 kGy showed no significant change. Thiobarbituric acid (TBA) value increased in all samples during a storage period, and gamma irradiation accelerated the increase of lipid oxidation. Sensory characteristics of fresh oysters were deteriorated as irradiation doses increased, and sensory scores of the samples irradiated with doses higher than 2 kGy were significantly decreased

  16. The ecology of intertidal oyster reefs of the South Atlantic Coast: A community profile

    Bahr, Leonard M.; Lanier, William P.

    1981-01-01

    The functional role of the intertidal oyster reef community in the southeastern Atlantic coastal zone is described. This description is based on a compilation of published data, as well as some unpublished information presented as hypotheses. The profile is organized in a hierarchical manner, such that relevant details of reef oyster biology (autecology) are presented, followed by a description of the reef community level of organization. Then the reef community is described as a subsystem of the coastal marsh-ecosystem (synecoloqy). This information is also synthesized in a series of nested conceptual models of oyster reefs at the regional level, the drainage basin level, and the individual reef level. The final chapter includes a summary overview and a section on management implications and guidelines. Intertidal oyster reefs are relatively persistent features of the salt marsh estuarine ecosystem in the southeastern Atlantic coastal zone. The average areal extent of the oyster reef subsystem in this larger ecosystem is relatively small (about 0.05%). This proportion does not reflect, however, the functional importance of the reef subsystem in stablizing the marsh, providing food for estuarine consumers, mineralizing organic matter, and providing firm substrates in this otherwise soft environment.

  17. Variability of total and pathogenic Vibrio parahaemolyticus densities in northern Gulf of Mexico water and oysters.

    Zimmerman, A M; DePaola, A; Bowers, J C; Krantz, J A; Nordstrom, J L; Johnson, C N; Grimes, D J

    2007-12-01

    Vibrio parahaemolyticus is indigenous to coastal environments and a frequent cause of seafood-borne gastroenteritis in the United States, primarily due to raw-oyster consumption. Previous seasonal-cycle studies of V. parahaemolyticus have identified water temperature as the strongest environmental predictor. Salinity has also been identified, although it is evident that its effect on annual variation is not as pronounced. The effects of other environmental factors, both with respect to the seasonal cycle and intraseasonal variation, are uncertain. This study investigated intraseasonal variations of densities of total and pathogenic V. parahaemolyticus organisms in oysters and overlying waters during the summer of 2004 at two sites in the northern Gulf of Mexico. Regression analyses indicated significant associations (P turbidity in water and in oysters at the Mississippi site but not at the Alabama site. Pathogenic V. parahaemolyticus organisms in Mississippi oyster and water samples were detected in 56% (9 out of 16) and 78% (43 out of 55) of samples, respectively. In contrast, 44% (7 out of 16) of oyster samples and 30% (14 out of 47) of water samples from Alabama were positive. At both sites, there was greater sample-to-sample variability in pathogenic V. parahaemolyticus densities than in total V. parahaemolyticus densities. These data suggest that, although total V. parahaemolyticus densities may be very informative, there is greater uncertainty when total V. parahaemolyticus densities are used to predict the risk of infection by pathogenic V. parahaemolyticus than previously recognized.

  18. Testing the effect of habitat structure and complexity on nekton assemblages using experimental oyster reefs

    Humphries, Austin T.; LaPeyre, Megan K.; Kimball, Matthew E.; Rozas, Lawrence P.

    2011-01-01

    Structurally complex habitats are often associated with more diverse and abundant species assemblages in both aquatic and terrestrial ecosystems. Biogenic reefs formed by the eastern oyster (Crassostrea virginica) are complex in nature and are recognized for their potential habitat value in estuarine systems along the US Atlantic and Gulf of Mexico coasts. Few studies, however, have examined the response of nekton to structural complexity within oyster reefs. We used a quantitative sampling technique to examine how the presence and complexity of experimental oyster reefs influence the abundance, biomass, and distribution of nekton by sampling reefs 4 months and 16 months post-construction. Experimental oyster reefs were colonized immediately by resident fishes and decapod crustaceans, and reefs supported a distinct nekton assemblage compared to mud-bottom habitat. Neither increased reef complexity, nor age of the experimental reef resulted in further changes in nekton assemblages or increases in nekton abundance or diversity. The presence of oyster reefs per se was the most important factor determining nekton usage.

  19. Microplastics in oysters Saccostrea cucullata along the Pearl River Estuary, China.

    Li, Heng-Xiang; Ma, Li-Sha; Lin, Lang; Ni, Zhi-Xin; Xu, Xiang-Rong; Shi, Hua-Hong; Yan, Yan; Zheng, Guang-Ming; Rittschof, Daniel

    2018-05-01

    As a transitional zone between riverine and marine environments, an estuary plays an important role for the sources, accumulation and transport of microplastics. Although estuarine environments are hotspots of microplastic pollution, the correlation between microplastic pollution and aquatic organisms is less known. Here we investigated microplastic pollution in wild oysters Saccostrea cucullata from 11 sampling sites along the Pearl River Estuary in South China. The microplastic abundances in oysters ranged from 1.4 to 7.0 items per individual or from 1.5 to 7.2 items per gram tissue wet weight, which were positively related to those in surrounding waters. The oysters near urban areas contained significantly more microplastics than those near rural areas. Fibers accounted for 69.4% of the total microplastics in oysters. Microplastic sizes varied from 20 to 5000 μm and 83.9% of which were less than 100 μm. Light color microplastics were significantly more common than dark color ones. Based on the results, oysters are recommended as a biomonitor for the microplastic pollution in estuaries. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Changes in the microbiological quality of mangrove oysters (Crassostrea brasiliana) during different storage conditions.

    Montanhini, Maike Taís Maziero; Montanhini Neto, Roberto

    2015-01-01

    This study aimed to determine the effect of temperature and period of postharvest storage on the microbiological quality and shelf life of raw mangrove oysters, Crassostrea brasiliana. A total of 150 dozen oysters were collected directly from the points of extraction or cultivation in southern Brazil, and in the laboratory, they were stored raw at 5, 10, 15, 20, and 25°C for 1, 4, 8, 11, and 15 days. On each of these days, the oysters were subjected to microbiological analyses of aerobic mesophilic count, total coliforms, enterococci, Escherichia coli, Staphylococcus aureus, and Salmonella. None of the tested samples under any storage condition showed contamination levels above those allowed by Brazilian legislation for E. coli, S. aureus, and Salmonella, and there was no change (P > 0.05) in the counts of these microorganisms due to the temperature and/or period of oyster storage. Counts of enterococci and total coliforms showed a tendency to increase (P mangrove oysters remain in safe microbiological conditions for consumption up to 8 days after harvesting, regardless of temperature, and their shelf life may be extended to 15 days if they are stored at temperatures not exceeding 15°C.