Science.gov

Sample records for oysters

  1. Oysters and Oyster Reef Communities in Florida.

    ERIC Educational Resources Information Center

    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. 21 CFR 161.136 - Olympia oysters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 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....

  3. 21 CFR 161.136 - Olympia oysters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 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....

  4. 21 CFR 161.136 - Olympia oysters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 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....

  5. 21 CFR 161.136 - Olympia oysters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 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....

  6. 78 FR 62293 - Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-15

    ... several events associated with the Oyster Bay Oyster Festival. The Oyster Festival 30th Anniversary... CFR Part 165 RIN 1625-AA00 Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay... Festival 30th Anniversary fireworks display. This temporary safety zone is necessary to protect...

  7. Oyster Fisheries App

    NASA Technical Reports Server (NTRS)

    Perez Guerrero, Geraldo A.; Armstrong, Duane; Underwood, Lauren

    2015-01-01

    This project is creating a cloud-enabled, HTML 5 web application to help oyster fishermen and state agencies apply Earth science to improve the management of this important natural and economic resource. The Oyster Fisheries app gathers and analyzes environmental and water quality information, and alerts fishermen and resources managers about problems in oyster fishing waters. An intuitive interface based on Google Maps displays the geospatial information and provides familiar interactive controls to the users. Alerts can be tailored to notify users when conditions in specific leases or public fishing areas require attention. The app is hosted on the Amazon Web Services cloud. It is being developed and tested using some of the latest web development tools such as web components and Polymer.

  8. 21 CFR 161.136 - Olympia oysters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Olympia oysters. 161.136 Section 161.136 Food and... CONSUMPTION FISH AND SHELLFISH Requirements for Specific Standardized Fish and Shellfish § 161.136 Olympia oysters. Olympia oysters, raw Olympia oysters, shucked Olympia oysters, are of the species Ostrea...

  9. Putting oysters under pressure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. The American Oyster.

    ERIC Educational Resources Information Center

    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…

  11. 21 CFR 161.145 - Canned oysters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Canned oysters. 161.145 Section 161.145 Food and... oysters. (a) Identity. (1) Canned oysters is the food prepared from one or any mixture of two or all of the forms of oysters specified in paragraph (a)(2) of this section, and a packing medium of water,...

  12. 21 CFR 161.145 - Canned oysters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Canned oysters. 161.145 Section 161.145 Food and... oysters. (a) Identity. (1) Canned oysters is the food prepared from one or any mixture of two or all of the forms of oysters specified in paragraph (a)(2) of this section, and a packing medium of water,...

  13. 21 CFR 161.145 - Canned oysters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Canned oysters. 161.145 Section 161.145 Food and... oysters. (a) Identity. (1) Canned oysters is the food prepared from one or any mixture of two or all of the forms of oysters specified in paragraph (a)(2) of this section, and a packing medium of water,...

  14. 21 CFR 161.130 - Oysters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... prescribed in §§ 161.131 to 161.140, inclusive. (b) If water, or salt water containing less than 0.75 percent... water or salt water. Any liquid accumulated with the oysters is removed. The oysters are washed, by blowing or otherwise, in water or salt water, or both. The total time that the oysters are in contact...

  15. 21 CFR 161.130 - Oysters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... prescribed in §§ 161.131 to 161.140, inclusive. (b) If water, or salt water containing less than 0.75 percent... water or salt water. Any liquid accumulated with the oysters is removed. The oysters are washed, by blowing or otherwise, in water or salt water, or both. The total time that the oysters are in contact...

  16. 21 CFR 161.130 - Oysters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... prescribed in §§ 161.131 to 161.140, inclusive. (b) If water, or salt water containing less than 0.75 percent... water or salt water. Any liquid accumulated with the oysters is removed. The oysters are washed, by blowing or otherwise, in water or salt water, or both. The total time that the oysters are in contact...

  17. 21 CFR 161.130 - Oysters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... prescribed in §§ 161.131 to 161.140, inclusive. (b) If water, or salt water containing less than 0.75 percent... water or salt water. Any liquid accumulated with the oysters is removed. The oysters are washed, by blowing or otherwise, in water or salt water, or both. The total time that the oysters are in contact...

  18. 21 CFR 161.130 - Oysters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... prescribed in §§ 161.131 to 161.140, inclusive. (b) If water, or salt water containing less than 0.75 percent... water or salt water. Any liquid accumulated with the oysters is removed. The oysters are washed, by blowing or otherwise, in water or salt water, or both. The total time that the oysters are in contact...

  19. 21 CFR 161.145 - Canned oysters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Canned oysters. 161.145 Section 161.145 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... oysters. (a) Identity. (1) Canned oysters is the food prepared from one or any mixture of two or all...

  20. Sediment bioassays with oyster larvae

    SciTech Connect

    Chapman, P.M.; Morgan, J.D.

    1983-10-01

    Tests with naturally-occurring sediments are rare and sediment testing methodology is not standardized. The authors present a simple methodology for undertaking sediment bioassays with oyster larvae, and present data from a recent study to prove the utility of this method.

  1. Hyperspectral remote sensing of wild oyster reefs

    NASA Astrophysics Data System (ADS)

    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

  2. SETTLEMENT AND SURVIVAL OF THE OYSTER CRASSOSTREA VIRGINICA ON CREATED OYSTER REEF HABITATS IN CHESAPEAKE BAY

    EPA Science Inventory

    Efforts to restore the Eastern oyster (Crassostrea virginica) reef habitats in Chesapeake Bay typically begin with the placement of hard substrata to form three-dimensional mounds on the seabed to serve as a base for oyster recruitment and growth. A shortage of oyster shell for ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Mapping Oyster Reef Habitats in Mobile Bay

    NASA Technical Reports Server (NTRS)

    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

  5. 21 CFR 161.145 - Canned oysters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Canned oysters. 161.145 Section 161.145 Food and Drugs 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 § 161.145 Canned oysters. (a) Identity. (1) Canned...

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

    SciTech Connect

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

    2008-06-15

    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 {mu}g/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 {mu}g/L and in urine was 0.76 {mu}g/g creatinine. Thirty-six percent of participants had urinary Cd levels above 1 {mu}g/g creatinine and 5% were above 2 {mu}g/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{sup 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.

  7. Thermoluminescence analysis of irradiated oyster shells.

    PubMed

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

    2012-12-01

    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. PMID:22341648

  8. Norovirus contamination on French marketed oysters

    PubMed Central

    Schaeffer, Julien; Le Saux, Jean-Claude; Lora, Monica; Atmar, Robert L.; Le Guyader, Françoise S.

    2014-01-01

    Contaminated shellfish have been implicated in gastroenteritis outbreaks in different countries. As no regulation has been set up yet regarding viral contamination of food, very few data are available on the prevalence of contaminated products on the market. This study presents data obtained from oysters collected on the French market in one producing area over a 16 month period of time. Noroviruses were detected in 9% of samples with a seasonal impact and influence of climatic events. Contamination levels were low and, surprisingly, oysters sampled directly from the producer were found to have less contamination than oysters from supermarkets. PMID:23973835

  9. Norovirus contamination on French marketed oysters.

    PubMed

    Schaeffer, Julien; Le Saux, Jean-Claude; Lora, Monica; Atmar, Robert L; Le Guyader, Françoise S

    2013-09-01

    Contaminated shellfish have been implicated in gastroenteritis outbreaks in different countries. As no regulation has been set up yet regarding viral contamination of food, very few data are available on the prevalence of contaminated products on the market. This study presents data obtained from oysters collected on the French market in one producing area over a 16 month period of time. Noroviruses were detected in 9% of samples with a seasonal impact and influence of climatic events. Contamination levels were low and, surprisingly, oysters sampled directly from the producer were found to have less contamination than oysters from supermarkets. PMID:23973835

  10. ACTIVATION OF OYSTER DEFENSES BY ENVIRONMENTAL CONTAMINANTS

    EPA Science Inventory

    Four field studies performed on eastern oysters Crassostrea virginica support a hypothesis that Cu, Zn, and perhaps butyltins and polycyclic aromatic hydrocarbons (PAH) can stimulate hemopoiesis, hemocyte locomotion and hemocyte bactericidal capacity. The first study found circul...

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

    ERIC Educational Resources Information Center

    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…

  12. Antiviral active peptide from oyster

    NASA Astrophysics Data System (ADS)

    Zeng, Mingyong; Cui, Wenxuan; Zhao, Yuanhui; Liu, Zunying; Dong, Shiyuan; Guo, Yao

    2008-08-01

    An active peptide against herpes virus was isolated from the enzymic hydrolysate of oyster ( Crassostrea gigas) and purified with the definite direction hydrolysis technique in the order of alcalase and bromelin. The hydrolysate was fractioned into four ranges of molecular weight (>10 kDa, 10 5 kDa, 5 1 kDa and <1 kDa) using ultrafiltration membranes and dialysis. The fraction of 10 5 kDa was purified using consecutive chromatographic methods including DEAE Sephadex A-25 column, Sephadex G-25 column, and high performance liquid chromatogram (HPLC) by activity-guided isolation. The antiviral effect of the obtained peptide on herpetic virus was investigated in Vero cells by observing cytopathic effect (CPE). The result shows that the peptide has high inhibitory activity on herpetic virus.

  13. BOILER, LOCATED IN BACK ROOM OF OYSTER SHUCKING BUILDING. STEAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BOILER, LOCATED IN BACK ROOM OF OYSTER SHUCKING BUILDING. STEAM WAS USED IN OYSTER PROCESSING, FOR EXAMPLE IN STERILIZING EQUIPMENT. - F. & H. Benning Company, 1014 Benning Road, Galesville, Anne Arundel County, MD

  14. Oyster shell conveyor used to lift shells from the dock ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Oyster shell conveyor used to lift shells from the dock into the receiving room housed in the 1965 concrete block addition. - J.C. Lore Oyster House, 14430 Solomons Island Road, Solomons, Calvert County, MD

  15. INFLUENCE OF ALTERED FRESHWATER FLOWS ON EASTERN OYSTERS

    EPA Science Inventory

    Abstract for National Shellfisheries Association

    Eastern 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...

  16. Metagenomic Assessment of the Eastern Oyster-Associated Microbiota

    PubMed Central

    Wafula, Denis; Lewis, Dawn E.; Pathak, Ashish

    2014-01-01

    Bacteria associated with the Eastern oysters (Crassostrea virginica) native to Apalachicola Bay, FL, were investigated using 16S rRNA gene amplicon metagenomic sequencing which revealed that the oyster microbiome was predominated by Cyanobacteria and Proteobacteria. We also found that the oyster tissues were predominated by the pathogenic and symbiotic Photobacterium spp. (formerly known as Vibrio damselae). PMID:25342691

  17. Metagenomic assessment of the eastern oyster-associated microbiota.

    PubMed

    Chauhan, Ashvini; Wafula, Denis; Lewis, Dawn E; Pathak, Ashish

    2014-01-01

    Bacteria associated with the Eastern oysters (Crassostrea virginica) native to Apalachicola Bay, FL, were investigated using 16S rRNA gene amplicon metagenomic sequencing which revealed that the oyster microbiome was predominated by Cyanobacteria and Proteobacteria. We also found that the oyster tissues were predominated by the pathogenic and symbiotic Photobacterium spp. (formerly known as Vibrio damselae). PMID:25342691

  18. Intraspecific variation influences natural settlement of eastern oysters.

    PubMed

    Smee, Delbert L; Overath, R Deborah; Johnson, Keith D; Sanchez, James A

    2013-11-01

    As populations decline, their intraspecific diversity also diminishes. Population decline may be exacerbated if a decrease in intraspecific diversity also reduces important ecological functions that maintain population numbers. Oyster reefs are severely overharvested, declining by ~85 % worldwide. We tested how increasing within-species diversity of eastern oysters (Crassostrea virginica) using transplants would affect recruitment of oyster larvae, a key function necessary to maintain future populations. If harvesting reduces population numbers, within-species diversity, and connectivity, then oysters may lose the ability to adapt to changing environmental conditions as well as incur lower levels of recruitment that may hasten their decline. Results from laboratory and field studies indicated that oyster larvae use chemical cues from adult oysters and not from associated fouling communities to select settlement sites. To test how increasing within-species diversity of oysters affected recruitment, we collected oysters from three distinct bay systems in Texas, USA, and compared natural settlement in treatments where all oysters were from a single bay to a mixture of all three bays. Significantly greater recruitment occurred in mixed treatments in 2010, 2011, and 2012 even though oyster recruitment varied by order of magnitude during this time. The net biodiversity effect was positive in all 3 years, indicating that increased recruitment in mixed treatments can be greater than the additive effect of the single bay treatments. Losing intraspecific diversity may reduce recruitment and lead to further declines in oyster populations, illustrating the need for understanding how intraspecific diversity influences ecological functions. PMID:23543216

  19. Directly measured denitrification reveals oyster aquaculture and restored oyster reefs remove nitrogen at comparable high rates

    EPA Science Inventory

    Coastal systems are increasingly impacted by over-enrichment of nutrients, which has cascading effects for ecosystem functioning. Oyster restoration and aquaculture are both hypothesized to mitigate excessive nitrogen (N) loads via benthic denitrification (DNF). However, this has...

  20. HISTOPATHOLOGY AND BIOACCUMULATION IN OYSTERS CRASSOSTREA VIRGINICA LIVING ON WOOD PRESERVED WITH CHROMATED COPPER ARSENATE

    EPA Science Inventory

    Oysters (Crassostrea virginica) growing on wood treated with chromated cooper arsenate (CCA) have elevated levels of metals, especially copper. oysters living inside a residential canal lined with CCA wood bulkheads were often green and had high copper concentrations. hese oyster...

  1. Predation by native brown shrimp on invasive Pacific oyster spat

    NASA Astrophysics Data System (ADS)

    Weerman, E. J.; Eriksson, B. K.; Olff, H.; van der Heide, T.

    2014-01-01

    In the last decades, the invasive Pacific oyster (Crassostrea gigas) increased dramatically in the Wadden Sea. One of the driving mechanisms for the success of the Pacific oyster could be a relatively low predation pressure by epibenthic predators and shore birds on oyster spat. Nevertheless, observations and experiments on predation rates on early life-stages of the Pacific oyster are rare. Therefore, we examined predation rates of brown shrimps on Pacific oyster spat in a number of laboratory experiments. Our results demonstrate that spat of Pacific oysters are most susceptible to predation by brown shrimps (Crangon crangon) in the first days after settlement, when attachment to the substrate (unglazed tiles in our study) is still absent or weak. At this stage the shell length of oyster spat is around ~ 300 μm, and around 50% of the individuals in the experiment were consumed in the two hour trials. Predation rates decreased rapidly as the spat grew larger and reached zero within 10 days after settlement of the spat (shell length > 700 μm). Additional experiments revealed that the attachment of oysters is probably limiting predation by brown shrimps rather than the size of the spat. This indicates that Pacific oyster spat may limit predation loss faster compared to native bivalves, which commonly depend on size to reduce predation rates. Overall, our results suggest that the invasive success of Pacific oysters may in part be explained by relatively low predation rates throughout their life stages.

  2. Drywell corrosion stopped at Oyster Creek

    SciTech Connect

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

    1993-11-01

    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.

  3. Oyster School Stands the Test of Time.

    ERIC Educational Resources Information Center

    Fern, Veronica

    1995-01-01

    Describes Oyster Elementary School's award-winning two-way bilingual (Spanish-English) program. The school's success has been maintained by strong parent and community support, high academic standards, and ongoing professional development efforts. However, cultural, generational, and socioeconomic differences among staff, students, and parents…

  4. Oyster shell calcium induced parotid swelling

    PubMed Central

    Palaniappan, Muthiah; Selvarajan, Sandhiya; Srinivasamurthy, Sureshkumar; Chandrasekaran, Adithan

    2014-01-01

    A 59 year old female consumer was started on therapy with oyster shell calcium in combination with vitamin D3 and she presented with swelling below the ear, after two doses. She stopped the drug by herself and the swelling disappeared in one day. She started the drug one day after recovery and again she developed the swelling. She was advised to stop the drug with a suggestion to take lemon to enhance parotid secretion and the swelling subsided. Calcium plays major role in salivary secretion and studies have shown reduced parotid secretion in rats, deficient of vitamin D. But in humans involvement of calcium and vitamin D3 in parotid secretion is unknown. However, the patient had no history of reaction though she had previously taken vitamin D3 with calcium carbonate which was not from oyster shell. Hence, we ruled out vitamin D3 in this reaction and suspecting oyster shell calcium as a culprit. This adverse drug reaction (ADR) was assessed using World Health Organization (WHO) causality assessment, Naranjo's and Hartwig severity scales. As per WHO causality assessment scale, the ADR was classified as “certain”. This reaction was analyzed as per Naranjo's algorithm and was classified as probable. According to Hartwig's severity scale the reaction was rated as mild. Our case is an example of a mild but rare adverse effect of oyster shell calcium carbonate which is widely used. PMID:25422569

  5. 7 CFR 701.54 - Oysters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... be made available under this section for the eligible cost of refurbishing public or private oyster... ECP participant shall not receive more than 90 percent of the participant's actual cost or of the total allowable cost described in paragraph (a) of this section. (c) The provisions of §...

  6. INORGANIC ELEMENTS AND DISTRIBUTION OF EASTERN OYSTERS.

    EPA Science Inventory

    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...

  7. Use of oysters to mitigate eutrophication in coastal waters

    NASA Astrophysics Data System (ADS)

    Kellogg, M. Lisa; Smyth, Ashley R.; Luckenbach, Mark W.; Carmichael, Ruth H.; Brown, Bonnie L.; Cornwell, Jeffrey C.; Piehler, Michael F.; Owens, Michael S.; Dalrymple, D. Joseph; Higgins, Colleen B.

    2014-12-01

    Enhancing populations of suspension feeding bivalves, particularly the eastern oyster, Crassostrea virginica, has been proposed as a means of mitigating eutrophication in coastal waters. Review of studies evaluating the effects of C. virginica on nitrogen (N) cycling found that oysters can have effects on water quality that vary by orders of magnitude among sites, seasons, and growing condition (e.g., oyster reefs, aquaculture). Nitrogen contained in phytoplankton consumed by oysters may be returned to the water column, assimilated into oyster tissue and shell, buried in the sediments, or returned to the atmosphere as dinitrogen gas, primarily via denitrification. Accurately quantifying oyster-related N removal requires detailed knowledge of these primary fates of N in coastal waters. A review of existing data demonstrated that the current state of knowledge is incomplete in many respects. Nitrogen assimilated into oyster tissue and shell per gram of dry weight was generally similar across sites and in oysters growing on reefs compared to aquaculture. Data on long-term burial of N associated with oyster reefs or aquaculture are lacking. When compared to suitable reference sites, denitrification rates were not consistently enhanced. Depending on environmental and oyster growing conditions, changes in denitrification rates varied by orders of magnitude among studies and did not always occur. Oyster aquaculture rarely enhanced denitrification. Unharvested oyster reefs frequently enhanced denitrification rates. Incorporating oysters into nutrient reduction strategies will require filling gaps in existing data to determine the extent to which relationships between N removal and environmental and/or growing conditions can be generalized.

  8. 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

    EPA Science Inventory

    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...

  9. From artificial structures to self-sustaining oyster reefs

    NASA Astrophysics Data System (ADS)

    Walles, Brenda; Troost, Karin; van den Ende, Douwe; Nieuwhof, Sil; Smaal, Aad C.; Ysebaert, Tom

    2016-02-01

    Coastal ecosystems are increasingly recognized as essential elements within coastal defence schemes and coastal adaptation. The capacity of coastal ecosystems, like marshes and oyster reefs, to maintain their own habitat and grow with sea-level rise via biophysical feedbacks is seen as an important advantage of such systems compared to man-made hard engineering structures. Providing a suitable substrate for oysters to settle on offers a kick-start for establishment at places where they were lost or are desirable for coastal protection. Accumulation of shell material, through recruitment and growth, is essential to the maintenance of oyster reefs as it provides substrate for new generations (positive feedback loop), forming a self-sustainable structure. Insight in establishment, survival and growth thresholds and knowledge about the population dynamics are necessary to successfully implement oyster reefs in coastal defence schemes. The aim of this paper is to investigate whether artificial Pacific oyster reefs develop into self-sustaining oyster reefs that contribute to coastal protection. Reef development was investigated by studying recruitment, survival and growth rates of oysters on artificial oyster reefs in comparison with nearby natural Pacific oyster reefs. The artificial reef structure successfully offered substrate for settlement of oysters and therefore stimulated reef formation. Reef development, however, was hampered by local sedimentation and increasing tidal emersion. Tidal emersion is an important factor that can be used to predict where artificial oyster reefs have the potential to develop into self-sustaining reefs that could contribute to coastal protection, but it is also a limiting factor in using oyster reefs for coastal protection.

  10. Extraordinary intraspecific diversity in oyster sperm bindin

    PubMed Central

    Moy, G. W.; Springer, S. A.; Adams, S. L.; Swanson, W. J.; Vacquier, V. D.

    2008-01-01

    In free-spawning invertebrates sperm–egg incompatibility is a barrier to mating between species, and divergence of gamete recognition proteins (GRPs) can result in reproductive isolation. Of interest are processes that create reproductive protein diversity within species, because intraspecific variants are potentially involved in mate choice and early speciation. Sperm acrosomes of the Pacific oyster Crassostrea gigas contain the protein bindin that bonds sperm to egg during fertilization. Oyster bindin is a single-copy gene encoding a diversity of protein variants. Oyster bindins have a conserved N-terminal region followed by one to five tandem fucose-binding lectin (F-lectin) domains. These repeats have diversified by positive selection at eight sites clustered on the F-lectin's fucose binding face. Additional bindin variants result from recombination in an intron in each F-lectin repeat. Males also express alternatively spliced bindin cDNAs with one to five repeats, but typically translate only one or two isoforms into protein. Thus, positive selection, alternative splicing, and recombination can create thousands of bindin variants within C. gigas. Models of sexual conflict predict high male diversity when females are diverse and sexual conflict is strong. The amount of intraspecific polymorphism in male GRPs may be a consequence of the relative efficiency of local (molecular recognition) and global (electrical, cortical, and physical) polyspermy blocks that operate during fertilization. PMID:18268333

  11. PATHOLOGICAL AND GENOTOXICOLOGICAL OBSERVATIONS IN OYSTERS (CRASSOSTREA VIRGINICA) LIVING ON CHROMATED COPPER ARSENATE (CCA) TREATED WOOD

    EPA Science Inventory

    Oysters living on chromated copper arsenate (CCA) treated wood in a residential canal were compared with oysters from a reference site 1.2 km distant. anal oysters were frequently green in color and had 15X more copper (app. 3 ug/g) than reference oysters. istological examination...

  12. TRANSPORT OF NAPHTHALENE IN THE OYSTER 'OSTREA EDULIS'

    EPA Science Inventory

    In small oysters (Ostrea edulis), transport of naphthalene between tissues is primarily by diffusion and not via the circulatory system. In intact oysters, accumulation in the adductor muscle and body followed accumulation in the gills after a large lag-time. In isolated tissues ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. CAN OYSTERS PLAY A ROLE IN ENVIRONMENTAL MANAGEMENT?

    EPA Science Inventory

    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...

  15. Heritability of shell pigmentation in the Pacific oyster, Crassostrea gigas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pacific oyster (Crassostrea gigas) is a species of considerable economic importance, with among the highest global production of any cultured aquatic animal species. In the interest of increasing the value of Pacific oysters sold as “singles” for the half-shell market, we explored the feasibili...

  16. Bioavailability of lead in oysters fed to young Japanese quail

    SciTech Connect

    Stone, C.L.; Spivey Fox, M.R.; Hogye, K.S.

    1981-12-01

    The presence of lead in atmospheric particulates, soil, and seawater reflects the input of both domestic and industrial wastes. Because bivalves can concentrate large quantities of heavy metals, particularly lead, consumption of their meat may be a potential risk. The relative bioavailability of lead physiologicaly incorporated into oyster meat was investigated. Day-old Japanese quail were fed purified diets with three levels of lead added as either lead acetate, freeze-dried lead-dosed oyster, or lead acetate plus freeze-dried control oyster for 2 weeks. Feeding lead from any source had little or no effect on body weight, hemoglobin, hematocrit, or percentage ash in the tibia. The concentration of lead in tibia at each level of dietary lead for each type of diet was different from those for all other levels of dietary lead. Slope-ratio analysis of the data showed that lead intrinsically incorporated into oyster meat was 69-75% as bioavailable as lead in lead acetate at levels between 25 and 100 ppm dietary lead. The combinations of (1) control oyster meat with lead acetate and (2) lead acetate with copper and zinc levels equal to those in oyster meat gave responses similar to those of the lead-dosed oyster groups. Although these data showed lower bioavailability of lead in oyster meat as compared with lead acetate, the intercept of the lines at 25 ppm dietary lead suggests that the relative bioavailability may be reserved at lower levels of lead intake.

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

    ERIC Educational Resources Information Center

    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…

  18. Development of a Simple Method for Concentrating Enteroviruses from Oysters

    PubMed Central

    Sobsey, Mark D.; Wallis, Craig; Melnick, Joseph L.

    1975-01-01

    The development of a simple method for concentrating enteroviruses from oysters is described. In this method viruses in homogenized oyster tissues are efficiently adsorbed to oyster solids at pH 5.5 and low salt concentration. After low-speed centrifugation, the supernatant is discarded and viruses are eluted from the sedimented oyster solids by resuspending them in pH 3.5 glycine-buffered saline. The solids are then removed by low-speed centrifugation, and the virus-containing supernatant is filtered through a 0.2-μm porosity filter to remove bacteria and other small particulates without removing viruses. The virus-containing filtrate is then concentrated to a volume of a few milliliters by ultrafiltration, and the concentrate obtained is inoculated directly into cell cultures for virus assay. When tested with pools of oysters experimentally contaminated with small amounts of different enteroviruses, virus recovery efficiency averaged 63%. PMID:234154

  19. Adult Pacific Oyster (Crassostrea gigas) May Have Light Sensitivity

    PubMed Central

    Yang, Yanjian; Li, Zhuang; Guo, Ting; Li, Yongchuan; Wang, Xiaotong

    2015-01-01

    Light-sensitivity is an important aspect of mollusk survival as it plays a vital role in reproduction and predator avoidance. In the Pacific oyster Crassostrea gigas light sensitivity has been demonstrated in the larval stage but has not yet been conclusively demonstrated in adult oysters. In this paper we describe an experiment which was undertaken to determine if adult Pacific oysters were sensitive to light. One LED flashlight was used to shine light onto adult oysters while they were filtering seawater through their shell openings. We found that the degree of opening increased gradually during the light period but rapidly decreased when the flashlight was turned off in the treated group but not in the control group. These results suggest that adult Pacific oyster may be sensitive to light. PMID:26474058

  20. Volatile composition of oyster leaf (Mertensia maritima (L.) Gray).

    PubMed

    Delort, Estelle; Jaquier, Alain; Chapuis, Christian; Rubin, Mark; Starkenmann, Christian

    2012-11-28

    Oyster leaf (Mertensia maritima), also called vegetarian oyster, has a surprising oyster-like aroma. Its volatile composition was investigated here for the first time. In total, 109 compounds were identified by gas chromatography-mass spectrometry (GC-MS) and quantified by GC-FID. The use of GC-olfactometry on both polar and nonpolar columns allowed the detection of the molecules having an oyster-like, marine odor. Four compounds were identified and confirmed by synthesis: (Z)-3-nonenal, (Z)-1,5-octadien-3-ol, (Z,Z)-3,6-nonadienal, and (Z)-1,5-octadien-3-one. After evaluation of freshly prepared reference samples, these compounds were confirmed to be reminiscent of the oyster-like marine notes perceived in the tasting of cut leaves. PMID:23140514

  1. Norwalk Virus–specific Binding to Oyster Digestive Tissues

    PubMed Central

    Loisy, Fabienne; Atmar, Robert L.; Hutson, Anne M.; Estes, Mary K.; Ruvoën-Clouet, Nathalie; Pommepuy, Monique; Le Pendu, Jacques

    2006-01-01

    The primary pathogens related to shellfishborne gastroenteritis outbreaks are noroviruses. These viruses show persistence in oysters, which suggests an active mechanism of virus concentration. We investigated whether Norwalk virus or viruslike particles bind specifically to oyster tissues after bioaccumulation or addition to tissue sections. Since noroviruses attach to carbohydrates of the histo-blood group family, tests using immunohistochemical analysis were performed to evaluate specific binding of virus or viruslike particles to oyster tissues through these ligands. Viral particles bind specifically to digestive ducts (midgut, main and secondary ducts, and tubules) by carbohydrate structures with a terminal N-acetylgalactosamine residue in an α linkage (same binding site used for recognition of human histo-blood group antigens). These data show that the oyster can selectively concentrate a human pathogen and that conventional depuration will not eliminate noroviruses from oyster tissue. PMID:16707048

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

    SciTech Connect

    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 /sup 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 /sup 14/C and /sup 15/N from cellulolytic marine bacteria, isolated from a S. alterniflora dominated salt marsh, was also studied.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Modelling Oyster Population Response to Variation in Freshwater Input

    NASA Astrophysics Data System (ADS)

    Livingston, R. J.; Lewis, F. G.; Woodsum, G. C.; Niu, X.-F.; Galperin, B.; Huang, W.; Christensen, J. D.; Monaco, M. E.; Battista, T. A.; Klein, C. J.; Howell, R. L.; Ray, G. L.

    2000-05-01

    This paper describes the linkage of a three-dimensional hydrodynamic circulation model with descriptive and experimental biological data concerning oyster (Crassostrea virginica) population dynamics in the Apalachicola Estuary (Florida, U.S.A.). Our intent was to determine the direct and indirect role of Apalachicola River flow in the maintenance of oyster production. Results of a monthly field sampling programme conducted on the oyster reefs in the Apalachicola system during 1985-1986 were used to develop statistical models relating several life-history characteristics of oysters to physical-chemical aspects of water quality. The same life-history characteristics were related statistically to output from a circulation model of Apalachicola Bay. Highest oyster densities and overall bar growth were found in the vicinity of the confluence of high salinity water moving westwards from St George Sound and river-dominated (low salinity) water moving south and eastwards from East Bay. With the exception of models for oyster mortality, the predictive capability of results from the parallel modelling efforts was low. A time-averaged model was developed for oyster mortality during the summer of 1985 by running a regression analysis with averaged predictors derived from the hydrodynamic model and observed (experimental) mortality rates throughout the estuary. A geographic information system was then used to depict the results spatially and to compare the extent of expected mortality in 1985 and 1986. High salinity, relatively low-velocity current patterns, and the proximity of a given oyster bar to entry points of saline Gulf water into the bay were important factors that contribute to increased oyster mortality. Mortality was a major determinant of oyster production in the Apalachicola Estuary with predation as a significant aspect of such mortality. By influencing salinity levels and current patterns throughout the bay, the Apalachicola River was important in controlling

  5. Deployed bivalves (oysters and clams) as indicators of estuarine condition

    SciTech Connect

    Ringwood, A.H.; Holland, A.F.; Keppler, C.; Wert, M.; Hyland, J.

    1995-12-31

    Hatchery-reared bivalves, oysters (Crassostrea virginica) and clams (Mercenaria mercenaria), were deployed simultaneously at reference and degraded sites in SC estuaries for approximately 1 month. Juvenile bivalves with endogenously high growth rates were used because effects on growth can be detected in a short time frame. The effects on growth and bioaccumulation of metal contaminants, as well as two biochemical indices (expression of metallothioneins, MT, and multi-xenobiotic transporting proteins, {at}R) were evaluated. Metal concentrations of sediments were also measured. Adverse effects on growth of both species were observed at degraded sites. However, oysters tended to grow more rapidly than clams, and adverse effects on oysters were more pronounced than in clams. Many of the sediments were characterized by elevated concentrations of multiple metals (Cu, Pb, Cr, etc.). However, increases in metal concentrations of oyster tissues were observed primarily with Cu, suggesting that many of the other metals had low bioavailability. There was little evidence of bioconcentration of any metals in clams. There was a significant correlation between sediment Cu and Cu in oyster tissues, but not in clams. Alterations in MT and MXR expression were also observed in oysters deployed at degraded sites. These studies suggest that oysters may be better in-situ indicators of habitat condition because they have more rapid growth rates and greater bioaccumulation potentials.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:26275296

  8. Hemocytes Are Sites of Enteric Virus Persistence within Oysters

    PubMed Central

    Provost, Keleigh; Dancho, Brooke A.; Ozbay, Gulnihal; Anderson, Robert S.; Richards, Gary P.; Kingsley, David H.

    2011-01-01

    The goal of this study was to determine how enteric viruses persist within shellfish tissues. Several lines of novel evidence show that phagocytic blood cells (hemocytes) of Eastern oysters (Crassostrea virginica) play an important role in the retention of virus particles. Our results demonstrated an association of virus contamination with hemocytes but not with hemolymph. Live oysters contaminated overnight with hepatitis A virus (HAV) and murine norovirus (MNV) had 56% and 80% of extractable virus associated with hemocytes, respectively. Transfer of HAV-contaminated hemocytes to naïve (virus-free) oysters resulted in naïve oyster meat testing HAV positive for up to 3 weeks. Acid tolerance of HAV, MNV, poliovirus (PV), and feline calicivirus (FCV) correlated with the ability of each virus to persist within oysters. Using reverse transcription-PCR (RT-PCR) to evaluate persistence of these viruses in oysters, we showed that HAV persisted the longest (>21 days) and was most acid resistant, MNV and PV were less tolerant of acidic pH, persisting for up to 12 days and 1 day, respectively, and FCV did not persist (<1 day) within oysters and was not acid tolerant. This suggests that the ability of a virus to tolerate the acidic conditions typical of phagolysosomal vesicles within hemocytes plays a role in determining virus persistence in shellfish. Evaluating oyster and hemocyte homogenates and live contaminated oysters as a prelude to developing improved viral RNA extraction methods, we found that viruses were extracted more expediently from hemocytes than from whole shellfish tissues and gave similar RT-PCR detection sensitivities. PMID:21948840

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

    PubMed Central

    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. PMID:26275296

  10. Assessing shoreline exposure and oyster habitat suitability maximizes potential success for sustainable shoreline protection using restored oyster reefs.

    PubMed

    La Peyre, Megan K; Serra, Kayla; Joyner, T Andrew; Humphries, Austin

    2015-01-01

    Oyster reefs provide valuable ecosystem services that contribute to coastal resilience. Unfortunately, many reefs have been degraded or removed completely, and there are increased efforts to restore oysters in many coastal areas. In particular, much attention has recently been given to the restoration of shellfish reefs along eroding shorelines to reduce erosion. Such fringing reef approaches, however, often lack empirical data to identify locations where reefs are most effective in reducing marsh erosion, or fully take into account habitat suitability. Using monitoring data from 5 separate fringing reef projects across coastal Louisiana, we quantify shoreline exposure (fetch + wind direction + wind speed) and reef impacts on shoreline retreat. Our results indicate that fringing oyster reefs have a higher impact on shoreline retreat at higher exposure shorelines. At higher exposures, fringing reefs reduced marsh edge erosion an average of 1.0 m y(-1). Using these data, we identify ranges of shoreline exposure values where oyster reefs are most effective at reducing marsh edge erosion and apply this knowledge to a case study within one Louisiana estuary. In Breton Sound estuary, we calculate shoreline exposure at 500 random points and then overlay a habitat suitability index for oysters. This method and the resulting visualization show areas most likely to support sustainable oyster populations as well as significantly reduce shoreline erosion. Our results demonstrate how site selection criteria, which include shoreline exposure and habitat suitability, are critical to ensuring greater positive impacts and longevity of oyster reef restoration projects. PMID:26500825

  11. Assessing shoreline exposure and oyster habitat suitability maximizes potential success for sustainable shoreline protection using restored oyster reefs

    PubMed Central

    Serra, Kayla; Joyner, T. Andrew; Humphries, Austin

    2015-01-01

    Oyster reefs provide valuable ecosystem services that contribute to coastal resilience. Unfortunately, many reefs have been degraded or removed completely, and there are increased efforts to restore oysters in many coastal areas. In particular, much attention has recently been given to the restoration of shellfish reefs along eroding shorelines to reduce erosion. Such fringing reef approaches, however, often lack empirical data to identify locations where reefs are most effective in reducing marsh erosion, or fully take into account habitat suitability. Using monitoring data from 5 separate fringing reef projects across coastal Louisiana, we quantify shoreline exposure (fetch + wind direction + wind speed) and reef impacts on shoreline retreat. Our results indicate that fringing oyster reefs have a higher impact on shoreline retreat at higher exposure shorelines. At higher exposures, fringing reefs reduced marsh edge erosion an average of 1.0 m y−1. Using these data, we identify ranges of shoreline exposure values where oyster reefs are most effective at reducing marsh edge erosion and apply this knowledge to a case study within one Louisiana estuary. In Breton Sound estuary, we calculate shoreline exposure at 500 random points and then overlay a habitat suitability index for oysters. This method and the resulting visualization show areas most likely to support sustainable oyster populations as well as significantly reduce shoreline erosion. Our results demonstrate how site selection criteria, which include shoreline exposure and habitat suitability, are critical to ensuring greater positive impacts and longevity of oyster reef restoration projects. PMID:26500825

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

    EPA Science Inventory

    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...

  13. The Edibility and Cultivation of the Oyster Mushroom.

    ERIC Educational Resources Information Center

    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)

  14. OCCURRENCE OF AGGLUTININS IN THE PALLIAL CAVITY MUCUS OF OYSTERS

    EPA Science Inventory

    Lectins, carbohydrate-binding glycoproteins that cause agglutination of homologous particles, were found in the mucus and fluid from the mantel (pallial) cavity of eastern oysters Crassostrea virginica. ccurrence in mantle cavity fluid was probably due to dissociation from mucus ...

  15. CHEMICAL EFFECTS ON OYSTER (CRASSOSTREA VIRGINICA) HEMOCYTE MICROBICIDAL ACTIVITY

    EPA Science Inventory

    Oyster (Crassostrea virginica) hemocytes, or blood cells, perform important internal defense functions such as phagocytosis and intracellular destruction of pathogens and bacteria. Using techniques such as phagocytosis and chemiluminescence assays, potential impairment of hemocyt...

  16. 'PROCTOECES' SP. (TREMATODA: DIGENEA) IN THE AMERICAN OYSTER, 'CRASSOSTREA VIRGINICA'

    EPA Science Inventory

    Histological examination of over 6,000 oysters, Crassostrea virginica, inhabiting northern Gulf Coast estuaries revealed unencysted junvenile and possible adult stages of digenetic trematode, Proctoeces sp., inhabiting the gonadal ducts of the mollusc. The morphology of the worm ...

  17. Epizootiology and pathology of juvenile oyster disease in the Eastern oyster, Crassostrea virginica.

    PubMed

    Ford, S E; Borrero, F J

    2001-10-01

    Juvenile Oyster Disease (JOD) causes mortalities of small cultured oysters, Crassostrea virginica. The present study was an intensive epizootiological and pathological investigation of JOD in eight sequentially deployed cohorts at sites on Long Island, New York. JOD symptoms and mortalities began in all groups at about the same time. Lesions on the mantle were detected histologically about 1 week before the principal symptom, a conchiolin deposit on the inner shell, appeared. Mortality began about 1 week later and reached 60-90% in oysters <25 mm. Mantle lesions were highly correlated with subsequent conchiolin-deposit prevalence and with total mortality. Larger juveniles (25-40 mm) were affected by the disease and produced conchiolin deposits, but mortalities did not exceed 30%. Mortalities were consistently related to size, but not necessarily to age or length of "exposure" in the field. There was no indication that JOD was linked to a particular broodstock or hatchery. Wild spat deployed at experimental sites showed JOD symptoms before the hatchery-produced groups did and cohorts maintained inside a hatchery experienced essentially no JOD. Histological examination of cohorts experiencing high mortalities failed to reveal an obvious etiological agent, but showed a disease pattern similar to that described for other bivalve diseases with a bacterial etiology. Similarities and differences between this and other studies of JOD suggest that one or more bacterial species is responsible for JOD, but that a trigger, probably temperature, is also involved and may vary from site to site. PMID:11812117

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

    PubMed

    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

  19. Ancient oyster shells on the atlantic continental shelf

    USGS Publications Warehouse

    Merrill, A.S.; Emery, K.O.; Rubin, M.

    1965-01-01

    Shells of long-dead Crassostrea virginica are reported at 71 stations in depths of 14 to 82 meters. The depths exceed those of the estuaries where the species flourishes. Radiocarbon measurements indicate that the oysters were alive 8000 to 11,000 years ago. It is concluded that the oysters lived in lagoons or estuaries which became submerged when the sea level rose at the end of the latest glacial epoch.

  20. Oyster shell as substitute for aggregate in mortar.

    PubMed

    Yoon, Hyunsuk; Park, Sangkyu; Lee, Kiho; Park, Junboum

    2004-06-01

    Enormous amounts of oyster shell waste have been illegally disposed of at oyster farm sites along the southern coast of Korea. In this study to evaluate the possibility of recycling this waste for use as a construction material, the mechanical characteristics of pulverized oyster shell were investigated in terms of its potential utilization as a substitute for the aggregates used in mortar. The unconfined compressive strengths of various soil mortar specimens, with varying blending ratios of cement, water and oyster shell, were evaluated by performing unconfined compression tests, and the results were compared with the strengths of normal cement mortar made with sand. In addition, the effect of organic chemicals on the hardening of concrete was evaluated by preparing ethyl-benzene-mixed mortar specimens. The long-term strength improvement resulting from the addition of fly ash was also examined by performing unconfined compression tests on specimens with fly-ash content. There was no significant reduction in the compressive strength of the mortars containing small oyster shell particles instead of sand. From these test data, the possible application of oyster shells in construction materials could be verified, and the change in the strength parameters according to the presence of organic compounds was also evaluated. PMID:15253499

  1. Thiabendazole uptake in shimeji, king oyster, and oyster mushrooms and its persistence in sterile and nonsterile substrates.

    PubMed

    Zhang, Zhiyong; Jiang, Wayne; Jian, Qiu; Song, Wencheng; Zheng, Zuntao; Ke, Changjie; Liu, Xianjin

    2014-02-12

    Thiabendazole in the substrates incurred from spraying and premixing was translocated to the pileus, stipe, and volva of selected mushrooms. The spraying on the substrates resulted in higher residues of thiabendazole in all three mushrooms than the premixing treatment. For premixing, in the five substrates, half-lives of thiabendazole were found to be 13.6 days for shimeji, 10.0 days for king oyster, 13.7 days for oyster, 19.1 days for sterilized substrate, and 8.4 days for nonsterilized substrate, respectively. For spraying, the longest and shortest half-lives were found to be 19.5 and 8.1 days for the nonsterilized and sterilized substrates, respectively. The residues of thiabendazole in three edible fungi were increased with the incubation days from 3 to 5 to 7. The residues of thiabendazole in king oyster were the highest among the three fungi while those in shimeji and oyster showed similar patterns. PMID:24432721

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

    PubMed

    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 < 0.05) relative to control (untreated) 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. PMID:20051204

  3. Respirators, internal dose, and Oyster Creek

    SciTech Connect

    Michal, R.

    1996-06-01

    This article looks at the experience of Oyster Creek in relaxing the requirements for the use of respirators in all facets of plant maintenance, on the overall dose received by plant maintenance personnel. For Roger Shaw, director of radiological controls for three years at GPU Nuclear Corporation`s Oyster Creek nuclear plant the correct dose balance is determined on a job-by-job basis: Does the job require a respirator, which is an effective means of decreasing worker inhalation of airborne radioactive particles? Will wearing a respirator slow down a worker, consequently increasing whole body radiation exposure by prolonging the time spent in fields of high external radiation? How does respiratory protection affect worker safety and to what degree? While changes to the Nuclear Regulatory Commission`s 10CFR20 have updated the radiation protection requirements for the nuclear industry, certain of the revisions have been directed specifically at reducing worker dose, Shaw said. {open_quotes}It basically delineates that dose is dose,{close_quotes} Shaw said, {open_quotes}regardless of whether it is acquired externally or internally.{close_quotes} The revision of Part 20 changed the industry`s attitude toward internal dose, which had always been viewed negatively. {open_quotes}Internal dose was always seen as preventable by wearing respirators and by using engineering techniques such as ventilation control and decontamination,{close_quotes} Shaw said, {open_quotes}whereas external dose, although reduced where practical, was seen as a fact of the job.{close_quotes}

  4. [Poliovirus uptake into and excretion from oysters: a model experiment for elimination of Norwalk-like viruses from oysters].

    PubMed

    Fukuta, Miwa; Kawada, Kazunobu; Yano, Takuya; Sugiyama, Akira; Nakayama, Osamu; Nishio, Osamu; Sekine, Hiromasa; Sakurai, Nakao

    2003-02-01

    Outbreaks of gastroenteritis caused by Norwalk-like viruses are often induced by the consumption of raw shellfish such as oysters. Incidences reach a peak during the cold season in Japan, when seawater temperatures fall below 10 degrees C. We investigated oysters' uptake and excretion of viruses, over varying lengths of exposure, monitoring the effects of changes in temperature and flow rate of seawater, and the presence of plankton. The study was performed using a poliovirus and an experimental circulatory system, which was framed on the same principle as a model practically used for the depuration of oysters. Polioviruses present in the seawater were taken rapidly into the midgut gland of oysters. However, virus levels detected in oysters at both 10 degrees C and 20 degrees C were decreased to approximately 1/1,000 to 1/10,000 within 6 hrs after the circulatory seawater was replaced by UV irradiated seawater. These results demonstrate the effectiveness of the circulatory depuration system for the elimination of poliovirus from oysters, and indicate that controlling the temperature and flow rate of the circulatory system could decrease the risk of NLV infection. PMID:12661085

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

    USGS Publications Warehouse

    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.

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

    EPA Science Inventory

    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...

  7. PERKINSUS-"CIDAL" ACTIVITY OF OYSTER HEMOCYTES USING A TETRAZOLIUM DYE REDUCTION ASSAY: OPTIMIZATION AND APPLICATIONS

    EPA Science Inventory

    A bactericidal assay developed to assess the ability of oyster (Crassostrea virginica) hemocytes to kill the human pathogen Vibrio parahaemolyticus was optimized to estimate killing of the oyster parasite Perkinsus marinus. Assay variables, temperature, hemocyte:parasite ratio, i...

  8. RESPONSES OF OYSTER (CRASSOSTREA VIRGINICA) HEMOCYTES TO NONPATHOGENIC AND CLINICAL ISOLATES OF VIBRIO PARAHAEMOLYTICUS

    EPA Science Inventory

    Bacterial uptake by oysters (Crassostrea virginica) and bactericidal activity of oyster hemocytes were studied using four environmental isolates and three clinical isolates of Vibrio parahaemolyticus. Clinical isolates (2030, 2062, 2107) were obtained from gastroenteritis patien...

  9. 75 FR 33656 - Exelon Generation Company, LLC Oyster Creek Nuclear Generating Station Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-14

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Exelon Generation Company, LLC Oyster Creek Nuclear Generating Station Environmental Assessment....2, as requested by Exelon Generation Company, LLC (the licensee), for operation of the Oyster...

  10. 76 FR 79227 - Exemption Request Submitted by Oyster Creek Nuclear Generating Station; Exelon Generation Company...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-21

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Exemption Request Submitted by Oyster Creek Nuclear Generating Station; Exelon Generation Company... Generation Company, LLC (the licensee), for operation of the Oyster Creek Nuclear Generating Station...

  11. Oyster reproduction is affected by exposure to polystyrene microplastics

    PubMed Central

    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

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

    PubMed

    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. PMID:26831072

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

    EPA Science Inventory

    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...

  14. 21 CFR 161.30 - Declaration of quantity of contents on labels for canned oysters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  15. 21 CFR 161.30 - Declaration of quantity of contents on labels for canned oysters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  16. 40 CFR 408.270 - Applicability; description of the steamed and canned oyster processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... steamed and canned oyster processing subcategory. 408.270 Section 408.270 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Steamed and Canned Oyster Processing Subcategory § 408.270 Applicability; description of the steamed and canned oyster processing subcategory. The provisions of this subpart...

  17. 40 CFR 408.270 - Applicability; description of the steamed and canned oyster processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... steamed and canned oyster processing subcategory. 408.270 Section 408.270 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Steamed and Canned Oyster Processing Subcategory § 408.270 Applicability; description of the steamed and canned oyster processing subcategory. The provisions of this subpart...

  18. 21 CFR 161.30 - Declaration of quantity of contents on labels for canned oysters.

    Code of Federal Regulations, 2010 CFR

    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...

  19. 40 CFR 408.270 - Applicability; description of the steamed and canned oyster processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... steamed and canned oyster processing subcategory. 408.270 Section 408.270 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Steamed and Canned Oyster Processing Subcategory § 408.270 Applicability; description of the steamed and canned oyster processing subcategory. The provisions of this subpart...

  20. 21 CFR 161.30 - Declaration of quantity of contents on labels for canned oysters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

  1. 21 CFR 161.30 - Declaration of quantity of contents on labels for canned oysters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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...

  2. 40 CFR 408.270 - Applicability; description of the steamed and canned oyster processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... steamed and canned oyster processing subcategory. 408.270 Section 408.270 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Steamed and Canned Oyster Processing Subcategory § 408.270 Applicability; description of the steamed and canned oyster processing subcategory. The provisions of this subpart...

  3. 40 CFR 408.270 - Applicability; description of the steamed and canned oyster processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... steamed and canned oyster processing subcategory. 408.270 Section 408.270 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Steamed and Canned Oyster Processing Subcategory § 408.270 Applicability; description of the steamed and canned oyster processing subcategory. The provisions of this subpart...

  4. Fluorescence from Pearls under N2 Laser Excitation and Its Application to Distinction of Mother Oysters

    NASA Astrophysics Data System (ADS)

    Miyoshi, Tadaki; Matsuda, Yasunori; Komatsu, Hiroshi

    1986-10-01

    Fluorescence spectra of pearls of Pinctada fucata (Japan’s Akoya oyster) and Pinctada maxima (white lip oyster) have been measured in order to distinguish species of the mother oyster which produce that pearl. A distinction is possible for these pearls using the difference in the fluorescence spectra under N2 laser excitation.

  5. Reconstructing early 17th century estuarine drought conditions from Jamestown oysters

    PubMed Central

    Harding, Juliana M.; Spero, Howard J.; Mann, Roger; Herbert, Gregory S.; Sliko, Jennifer L.

    2010-01-01

    Oysters (Crassostrea virginica) were a central component of the Chesapeake Bay ecosystem in 1607 when European settlers established Jamestown, VA, the first permanent English settlement in North America. These estuarine bivalves were an important food resource during the early years of the James Fort (Jamestown) settlement while the colonists were struggling to survive in the face of inadequate supplies and a severe regional drought. Although oyster shells were discarded as trash after the oysters were eaten, the environmental and ecological data recorded in the bivalve geochemistry during shell deposition remain intact over centuries, thereby providing a unique window into conditions during the earliest Jamestown years. We compare oxygen isotope data from these 17th century oyster shells with modern shells to quantify and contrast estuarine salinity, season of oyster collection, and shell provenance during Jamestown colonization (1609–1616) and the 21st century. Data show that oysters were collected during an extended drought between fall 1611 and summer 1612. The drought shifted the 14 psu isohaline above Jamestown Island, facilitating individual oyster growth and extension of oyster habitat upriver toward the colony, thereby enhancing local oyster food resources. Data from distinct well layers suggest that the colonists also obtained oysters from reefs near Chesapeake Bay to augment oyster resources near Jamestown Island. The oyster shell season of harvest reconstructions suggest that these data come from either a 1611 well with a very short useful period or an undocumented older well abandoned by late 1611. PMID:20534581

  6. Mortalities of eastern and pacific oyster larvae caused by the pathogens Vibrio coralliilyticus and Vibrio tubiashii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 cora...

  7. Genetic improvement for disease resistance in oysters: A review.

    PubMed

    Dégremont, Lionel; Garcia, Céline; Allen, Standish K

    2015-10-01

    Oyster species suffer from numerous disease outbreaks, often causing high mortality. Because the environment cannot be controlled, genetic improvement for disease resistance to pathogens is an attractive option to reduce their impact on oyster production. We review the literature on selective breeding programs for disease resistance in oyster species, and the impact of triploidy on such resistance. Significant response to selection to improve disease resistance was observed in all studies after two to four generations of selection for Haplosporidium nelsoni and Roseovarius crassostrea in Crassostrea virginica, OsHV-1 in Crassostrea gigas, and Martelia sydneyi in Saccostrea glomerata. Clearly, resistance in these cases was heritable, but most of the studies failed to provide estimates for heritability or genetic correlations with other traits, e.g., between resistance to one disease and another. Generally, it seems breeding for higher resistance to one disease does not confer higher resistance or susceptibility to another disease. For disease resistance in triploid oysters, several studies showed that triploidy confers neither advantage nor disadvantage in survival, e.g., OsHV-1 resistance in C. gigas. Other studies showed higher disease resistance of triploids over diploid as observed in C. virginica and S. glomerata. One indirect mechanism for triploids to avoid disease was to grow faster, thus limiting the span of time when oysters might be exposed to disease. PMID:26037230

  8. An efficient method of noroviruses recovery from oysters and clams

    NASA Astrophysics Data System (ADS)

    Zhou, Deqing; Ma, Liping; Zhao, Feng; Yao, Lin; Su, Laijin; Li, Xinguang

    2013-03-01

    Noroviruses (NoVs) are widespread causes of nonbacterial gastroenteritis. Outbreaks of NoVs caused diseases are commonly ascribed to the consumption of contaminated shellfish. The concentration and RNA extraction of NoVs are crucial steps of detecting NoVs in shellfish. This study aimed to select a simple, rapid and highly efficient recovery method of NoVs detection with real-time RT-PCR. Four methods of recovering GI.3 and GII.4 NoVs from spiked digestive tissues of oysters and clams, respectively, were compared, of them, the method involving proteinase K and PEG 8000 was found the most efficient. With this method, 9.3% and 13.1% of GI.3 and GII.4 NoVs were recovered from oysters and 9.6% and 12.3% of GI.3 and GII.4 NoVs were recovered from clams, respectively. This method was further used to detect NoVs in 84 oysters ( Crassostrea gigas) and 86 clams ( Ruditapes philippinarum) collected from 10 coastal cities in China from Jan. 2011 to Feb. 2012. The NoVs isolation rates were 10.47% of clams (9/86) and 7.14% of oysters (6/84). All the detected NoVs belonged to genotype GII. The NoVs recovery method selected is efficient for NoVs detection in oysters and clams.

  9. Guidelines for evaluating performance of oyster habitat restoration

    USGS Publications Warehouse

    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.

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

    PubMed

    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. PMID:24938813

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

    PubMed

    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 < 0.05) compared to control. Aerobic and psychrotrophic bacteria in control 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 < 0.05) than oysters HHP treated at 300 MPa at 0 °C in lipid oxidation values. The highest pressure (500 MPa) treatment in this study, significantly (P < 0.05) decreased unsaturated fatty acid percentage compared to control. The glycogen content of control oysters at 3 wk was significantly higher (P < 0.05) when compared to HHP treated 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. PMID:27074447

  12. Passage of a coccidial parasite (Eimeria acervulina) through the Eastern oyster (Crassostrea virginica).

    PubMed

    Lee, Marilyn B; Lee, Eng-Hong

    2003-04-01

    Human illness resulting from the consumption of raw oysters is well documented for bacterial and viral pathogens but not for coccidial parasites. This study explores the passage of coccidial parasites through and the viability of these parasites in the Eastern oyster, Crassostrea virginica. Because both Cryptosporidium and Toxoplasma are human parasites and are not safe to handle, we chose to work with a close relative, Eimeria acervulina, as a surrogate. This parasite was analyzed in chickens. Oysters were found to concentrate coccidial oocysts within 6 h of exposure in a seawater tank. After 24 h, oysters still contained viable oocysts, but by 48 h, few oysters contained viable oocysts. No oysters were found to harbor oocysts 72 or 96 h after exposure to oocysts. After oysters had been exposed to oocysts for 24 h in one saltwater tank and then transferred to a clean saltwater tank for 48 h, their feces tested positive for viable oocysts. We conclude that coccidial parasites are not pathogenic to oysters, but move through oysters in just 1 day. Unless contaminated waters continuously carry oocysts, raw oysters are unlikely to pose a threat to human health through the carriage of coccidial parasites. PMID:12696696

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

    PubMed

    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

    2016-06-01

    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. PMID:27217572

  14. OYSTER HABITAT SUITABILITY AS A COMPONENT OF RESOURCE MANAGEMENT

    EPA Science Inventory

    Economic and ecological issues have led resource managers to examine depletion of eastern oyster reefs along the U.S. Gulf of Mexico and Atlantic coasts. Crassostrea virginica is a lucrative commercial species (over $60M in 2000) that also supports ecosystem integrity by providin...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Culture and Sustainability: Lessons from the Oyster and Other Metaphors

    ERIC Educational Resources Information Center

    Galloway, Vicki

    2015-01-01

    Consider the oyster. Like all good metaphors, it has done some morphing since the days of Shakespeare's "Merry Wives of Windsor." Newer bands of shell material have repainted the mollusk metaphor, transforming it from ostracism, opportunism, and exploitation to openness, opportunity and exploration, and thus an apt symbol for the…

  17. Cancer risk assessment for arsenic exposure through oyster consumption.

    PubMed Central

    Guo, How-Ran

    2002-01-01

    Risk is assessed on the basis of assumptions, but this practice might not be well received by the general public. To avoid miscommunication, the assumptions should be stated clearly in reporting the results. Recently, a report on an assessment of the cancer risk associated with consumption of oysters caused a panic among consumers in Taiwan and produced significant effects on related industries. A group of researchers measured the arsenic content in oysters in the Taiwan area and conducted a cancer risk assessment accordingly. The results, published in a research article in an international journal, included a lifetime cancer risk estimate of 5.10/10(-4) as calculated based on the assumption that a person consumes oysters with the highest arsenic level (19.3 mg/g dry weight) at the highest rate (139 g/day) for 30 years. A national newspaper in Taiwan translated part of the article and published results that focused on the finding that this estimate was more than 500 times higher than what would be considered acceptable by the U.S. Environmental Protection Agency. As a result, most consumers stopped purchasing oysters, and the related industries suffered substantial losses. The newspaper's omission of the key assumptions in the risk assessment and the extreme assumptions made in the risk assessment led to this tragedy. This event demonstrated the importance of careful communication of risk assessment results. PMID:11836137

  18. High pressure processing inactivates human norovirus within oysters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. Oyster reefs can outpace sea-level rise

    NASA Astrophysics Data System (ADS)

    Rodriguez, Antonio B.; Fodrie, F. Joel; Ridge, Justin T.; Lindquist, Niels L.; Theuerkauf, Ethan J.; Coleman, Sara E.; Grabowski, Jonathan H.; Brodeur, Michelle C.; Gittman, Rachel K.; Keller, Danielle A.; Kenworthy, Matthew D.

    2014-06-01

    In the high-salinity seaward portions of estuaries, oysters seek refuge from predation, competition and disease in intertidal areas, but this sanctuary will be lost if vertical reef accretion cannot keep pace with sea-level rise (SLR). Oyster-reef abundance has already declined ~85% globally over the past 100 years, mainly from over harvesting, making any additional losses due to SLR cause for concern. Before any assessment of reef response to accelerated SLR can be made, direct measures of reef growth are necessary. Here, we present direct measurements of intertidal oyster-reef growth from cores and terrestrial lidar-derived digital elevation models. On the basis of our measurements collected within a mid-Atlantic estuary over a 15-year period, we developed a globally testable empirical model of intertidal oyster-reef accretion. We show that previous estimates of vertical reef growth, based on radiocarbon dates and bathymetric maps, may be greater than one order of magnitude too slow. The intertidal reefs we studied should be able to keep up with any future accelerated rate of SLR (ref. ) and may even benefit from the additional subaqueous space allowing extended vertical accretion.

  20. Development of thermal-hydraulic analysis capabilities for Oyster creek

    SciTech Connect

    Lee, R.B.

    1987-01-01

    GPU Nuclear (GPUN) has been involved in developing analytical methodologies for Oyster Creek plant thermal-hydraulic response simulation for approx. 15 yr. Plant-system-related transient analysis is being accomplished via RETRAN02 MOD4 and loss-of-coolant accident (LOCA) analysis by SAFER-CORECOOL. This paper reviews the developmental process and lessons learned through this process.

  1. ACCUMULATION OF CADMIUM BY THE AMERICAN OYSTER, 'CRASSOSTREA VIRGINICA'

    EPA Science Inventory

    The report demonstrates that 5 mg/l of cadmium can be accumulated from seawater by adult oysters to levels exceeding 13 mg/l wet weight, a level found to cause illness in man. Bioaccumulation of cadmium concentrations greater than 13 mg/l wet weight occurs in about 40 weeks when ...

  2. Shell disease in eastern oysters, Crassostrea virginica, reared in France.

    PubMed

    Renault, T; Chollet, B; Cochennec, N; Gerard, A

    2002-01-01

    Progeny of eastern oyster, Crassostrea virginica, introduced into France in 1992, were reared in IFREMER facilities to test their growth performances. During the summer of 1993, sporadic mass mortalities (80-90%) occurred among C. virginica spat reared in the IFREMER laboratories in La Tremblade (Charente Maritime, France) and Bouin (Vendée, France). Affected oysters presented mantle retraction and deposition of an anomalous conchiolin layer on the inner surface of the shell. The incidence of oysters with gross signs exceeded 80%. No obvious pathogen was identified in soft tissues by histology and transmission electron microscopy (TEM). However, histological examination showed the presence of anomalous basophilic round structures, 0.5-1 microm in diameter, in gill and mantle connective tissues. These extracellular Feulgen-negative structures reacted positively with the von Kossa stain. TEM examination on mantle and gill samples in diseased spat showed that the basophilic bodies consisted of concentric deposits of an amorphous substance interpreted as containing calcium. These observations may indicate that the mineralization process in spat shells was disturbed without exact determination of the cause. Based on the similarities of the gross signs to those reported in juvenile eastern oysters in the United States, we believe that the cause of the mortalities observed in France was probably the Juvenile Oyster Disease. Moreover, we report for the first time the detection of anomalous amorphous structures in gill and mantle connective tissues associated with mortalities and deposition of an anomalous conchioloin layer on the inner shell surface in C. virginica spat. PMID:12054781

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

    PubMed

    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

  4. CADMIUM INTAKE VIA OYSTERS AND HEALTH EFFECTS IN NEW ZEALAND: CADMIUM INTAKE, METABOLISM AND EFFECTS IN PEOPLE WITH A HIGH INTAKE OF OYSTERS IN NEW ZEALAND

    EPA Science Inventory

    The aim of this study was to confirm the high dietary intakes of cadmium and other trace elements from oysters in a population associated with the oystering industry, and to determine (1) the impact of those high intakes on cadmium concentrations in accessible tissues of the stud...

  5. Hepatitis A in New South Wales, Australia from consumption of oysters: the first reported outbreak.

    PubMed Central

    Conaty, S.; Bird, P.; Bell, G.; Kraa, E.; Grohmann, G.; McAnulty, J. M.

    2000-01-01

    Between 22 January and 4 April 1997, 467 hepatitis A cases were reported to the New South Wales Health Department, Australia. To identify the cause of the outbreak, we conducted a matched case-control study, and an environmental investigation. Among 66 cases and 66 postcode-matched controls, there was a strong association between illness and consumption of oysters (adjusted odds ratio 42; 95 % confidence interval 5-379). More than two-thirds of cases reported eating oysters, including one third of cases and no controls who reported eating oysters in the Wallis Lake area. A public warning was issued on 14 February, and Wallis Lake oysters were withdrawn from sale. Hepatitis A virus was subsequently identified in oyster samples taken from the lake. Hepatitis A virus poses a special risk to consumers who eat raw oysters because it can survive for long periods in estuaries and cause severe disease. PMID:10722139

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

    PubMed

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

    2014-03-01

    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. PMID:24430847

  7. Fluorescence from Pearls to Distinguish Mother Oysters Used in Pearl Culture

    NASA Astrophysics Data System (ADS)

    Miyoshi, Tadaki; Matsuda, Yasunori; Komatsu, Hiroshi

    1987-04-01

    The fluorescence spectra of pearls and shells of Pteria penguin (mabe), Pinctada fucata (Japan’s Akoya oyster) and Pinctada maxima (yellow lip oyster) have been measured in order to distinguish species of the mother oyster which produce that pearl. A distinction is possible for these pearls using differences in the fluorescence spectra. The spectral difference has been attributable to colouring matter or screloprotain in pearls and shells.

  8. Effect of parasitism by the pyramidellid gastropod Boonea impressa on the net productivity of oysters ( Crassostrea virginica)

    NASA Astrophysics Data System (ADS)

    White, M. E.; Powell, E. N.; Ray, S. M.

    1988-04-01

    The effect of an ectoparasitic gastropod, Boonea (= Odostomia) impressa, on the energy bidget of its host, the American oyster, Crassostrea virginica, was examined. A model was developed from laboratory and field data, as well as from equations developed by Powell and Stanton (1985). The model predicted that net productivity by large (7 cm length) oysters parasitized by 10 and 30 large (6 mm length) snails would be reduced by 21% and 63%, respectively. In contrast, net productivity in small (3 cm length) oysters would be reduced 25% by only 3 snails. Small oysters would have a negative energy balance when parasitized by 10 snails. The predicted reduction in growth was compared with measured growth in small and large oysters parasitized at abundances typical of Texas oyster reefs. Control oysters (no parasites) gained more shell weight than parasitized oysters. In four-week experiments conducted during the spring and fall, small control oysters gained 86% and 75% more weight than highly parasitized oysters. Large control oysters had 29% and 88% more shell deposition. Snail parasitism produced 75% mortality in small, highly parasitized oysters in the summer. In typical field populations in Texas bays, a minimal estimate of 4-12% of the energy otherwise available to the oyster for growth and reproduction is consumed by Boonea impressa.

  9. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Pacific Northwest): Olympia oyster

    SciTech Connect

    Couch, D. . Coll. of Natural Resources); Hassler, T.J. . California Cooperative Fishery Research Unit)

    1989-12-01

    Species profiles are literature summaries of the taxonomy, morphology, range, life history, and environmental requirements of coastal aquatic species. They are designed to assist in environmental impact assessments. Olympia oysters initially spawn as males then alternate their functional genders. Spawning begins at 13-16 {degree}C and occurs from spring to fall. After a short planktonic stage, larvae attach to the substrate. Olympia oysters thrive at salinities of 25 ppt or above; they are killed by freezing temperatures. Olympia oysters once supported large sustenance and commercial fisheries. Olympia oysters have not returned to pre-exploitation population levels which declined because of pollution and loss of habitat. 32 refs., 2 figs.

  10. Reproductive responses and detoxification of estuarine oyster Crassostrea hongkongensis under metal stress: a seasonal study.

    PubMed

    Weng, Nanyan; Wang, Wen-Xiong

    2015-03-01

    Understanding the impacts of metal stress on the reproduction of dominant species, such as oysters, in seriously contaminated estuarine environments has great ecological implications. In the present study, the reproductive conditions were examined monthly for 1 year in oysters Crassostrea hongkongensis from a heavily metal-contaminated site (Baijiao, mainly by Cu and Zn) in the Jiulong River estuary and a relatively clean nearby estuary (Jiuzhen). Oysters sampled in the contaminated site showed a delayed gametogenesis, a relatively shorter spawning period, and a lower gonad condition index in comparison to the oysters sampled in the reference site. In particular, we found that the proportion of females increased significantly in the contaminated oysters, which provided the first evidence that the feminization in wild oyster populations could be related to trace metal pollution. Additionally, the potential detoxification mechanism of trace metals in oysters was also investigated. Compartmentalization of trace metals in membrane-limited vesicles in hemocytes could be an important detoxification mechanism for the contaminated oysters. Our findings indicated that the long-term metal exposure may greatly influence the reproduction of the oysters and finally affect the recruitment and population of this species. PMID:25660751

  11. Associations between freshwater inflows and oyster productivity in Apalachicola Bay, Florida

    NASA Astrophysics Data System (ADS)

    Wilber, Dara H.

    1992-08-01

    Increased and varied demands for consumptive water uses on the Apalachicola-Chattahoochee-Flint River system threaten to reduce freshwater inflows to the Apalachicola estuary and thus may affect estuarine productivity. To investigate how freshwater inflows are associated with productive estuarine conditions, Apalachicola Bay oyster data from 1960-84 and river flows were analysed with linear regression models. Lag periods were incorporated into the analyses to examine the potential effects of various flow magnitudes and durations on different oyster life history stage. Oysters reach a harvestable size in 2 years in this region. Low flows were positively correlated with oyster catch per unit effort (C.P.U.E.) 2 years later, i.e. years with lower minimum flows were followed 2 years later by poor oyster productivity. A possible mechanism behind this association is that lower minimum flows result in higher estuarine salinities, permitting predation by marine species on newly settled spat, and thus reducing harvestable oyster population sizes 2 years later. High flows of short duration (⩽ 30 days) were not significantly correlated with oyster C.P.U.E. for the same year or any time lag period. Oyster landings were low, however, in those years in which flows exceeded 30 000 cfs for 100 days or more, suggesting sustained high flows were detrimental to the same year's harvestable oyster population. Experiments that investigate possible mechanistic causes of these associations are needed to more fully understand the potential impacts of future water allocation decisions.

  12. CHEMICAL INDUCTION OF TUMORS IN OYSTERS BY A MIXTURE OF AROMATIC AND CHLORINATED HYDROCARBONS, AMINES, AND METALS

    EPA Science Inventory

    Tumors were induced in eastern oysters (Crassotrea virginica) by a mixture f aromatic hydrocarbons, an aromatic amine, polychlori-nated biphenyls, chlorinated hydrocarbons, a nitrosoamine and heavy metals. idney and nteric tumors developed in oysters following exposure to a mixtu...

  13. AN OVACYSTIS-LIKE CONDITION IN THE AMERICAN OYSTER CRASSOSTREA VIRGINICA GMELIN FROM THE NORTHEASTERN GULF OF MEXICO

    EPA Science Inventory

    Histological examination of the eastern oyster, Crassostrea virginica, from a study in Pensacola Bay, Florida, revealed two cases of abnormally large, basophilic ova that resemble ovacystis disease previously reported in oysters from Maine and Long Island. The hypertrophied gamet...

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

    EPA Science Inventory

    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...

  15. PROGRESSION OF DISEASES CAUSED BY THE OYSTER PARASITES, PERKINSUS MARINUS AND HAPLOSPORIDIUM NELSONI IN CRASSOSTREA VIRGINICA ON CONSTRUCTED INTERTIDAL REEFS

    EPA Science Inventory

    The progression of diseases caused by the oyster parasites, Perkinsus marinus and Haplosporidium nelsoni, were evaluated by periodic sampling (May 1994 - December 1995) of oysters, Crassostrea virginica, on an artificial reef located in the Piankatank River, Virginia. The infecti...

  16. Multibiomarker assessment of three Brazilian estuaries using oysters as bioindicators

    SciTech Connect

    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.

    2007-11-15

    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.

  17. An outbreak of norovirus linked to oysters in Tasmania.

    PubMed

    Lodo, Kerryn L; Veitch, Mark G K; Green, Michelle L

    2014-03-01

    Norovirus is the most commonly reported virus in shellfish related gastroenteritis outbreaks. In March 2013 an investigation was conducted following the receipt of reports of gastroenteritis after the consumption of oysters at private functions in Tasmania. Cases were ascertained through general practitioners, emergency departments, media releases and self-reporting. Of the 306 cases identified in Tasmania, ten faecal specimens were collected for laboratory testing and eight were positive for norovirus (GII.g). The most common symptoms were vomiting (87%), diarrhoea (85%), myalgia (82%) and fever (56%). The implicated oysters were traced to a single lease from which they were harvested and distributed locally and interstate. Nationally 525 cases were identified from Tasmania (306), Victoria (209), New South Wales (8) and Queensland (2). This report highlights the consequences of norovirus outbreaks in shellfish, even with rapid identification, trace back and removal of the implicated product from the market. PMID:25409349

  18. Interactions between Shewanella colwelliana, Oyster Larvae, and Hydrophobic Organophosphate Pesticides

    PubMed Central

    Labare, Michael P.; Weiner, Ronald M.

    1990-01-01

    Shewanella colwelliana (strain D) is a periphytic estuarine bacterium that forms biofilms beneficial to oyster set. Our study examined whether these and other films concentrated two hydrophobic, organophosphate pesticides, Abate and malathion, that are detected in Chesapeake Bay oyster waters. Both biofilms and purified exopolysaccharide of S. colwelliana did not adsorb more of the Abate or malathion than could be accounted for by adsorption to control surfaces. Similar results were obtained by using Deleya marina, Hyphomonas MHS3, and autochthonous biofilms. Conversely, decapsulated S. colwelliana D cells, prepared in the laboratory, bioconcentrated Abate. Significantly, the S. colwelliana D biofilms exposed to Abate did not inhibit the settlement and metamorphosis of Crassostrea gigas larvae. PMID:16348382

  19. A survey of the Oyster Creek reload licensing model

    SciTech Connect

    Alammar, M.A. )

    1991-01-01

    The Oyster Creek RETRAN licensing model was submitted for approval by the U.S. Nuclear Regulatory Commission in September 1987. This paper discusses the technical issues and concerns that were raised during the review process and how they were resolved. The technical issues are grouped into three major categories: the adequacy of the model benchmark against plant data; uncertainty analysis and model convergence with respect to various critical parameters (code correlations, nodalization, time step, etc.); and model application and usage.

  20. When r-selection may not predict introduced-species proliferation: predation of a nonnative oyster.

    PubMed

    Bishop, Melanie J; Peterson, Charles H

    2006-04-01

    Predicting outcomes of species introductions may be enhanced by integrating life-history theory with results of contained experiments that compare ecological responses of exotic and analogue native species to dominant features of the recipient environment. An Asian oyster under consideration for introduction to the Chesapeake Bay, USA, the rapidly growing Suminoe oyster (Crassostrea ariakensis), may not be as successful an invader as its r-selected life history suggests if the trade-off for rapid growth and maturation is lower investment in defenses against blue crab (Callinectes sapidus) predation than the native Eastern oyster (Crassostrea virginica). In laboratory trials, blue crabs simultaneously offered equal numbers of Suminoe and Eastern oysters consumed more nonnatives, irrespective of whether the crabs had previous experience with Suminoe oysters as prey. Satiated blue crabs consumed nearly three times as many Suminoe oysters as Eastern oysters of 25-mm shell height, and eight times as many of 35-mm shell height. Despite blue crabs consuming small (30 mm) Suminoe oysters at twice the rate of large (40 mm) Suminoe oysters, when 40-mm Suminoe were paired with 30-mm Eastern oysters, seven times as many of the larger (Suminoe) oysters were consumed. The greater susceptibility of C. ariakensis than C. virginica to blue crab predation appears to be based upon the biomechanics of shell strength rather than active selection of a more attractive food. Much less force was required to crush shells of Suminoe than Eastern oysters of similar shell height. Tissue transplant experiments demonstrated greater predation on oyster tissues in weaker C. ariakensis shells independent of tissue identity, and duration of handling time before rejection of C. virginica exceeded the time to crush C. ariakensis. These results, coupled with the present importance of blue crab predation in limiting recovery of native Eastern oysters, imply a role for blue crabs in inhibiting Suminoe

  1. Factors Affecting the Uptake and Retention of Vibrio vulnificus in Oysters

    PubMed Central

    Noble, Rachel T.

    2014-01-01

    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. PMID:25261513

  2. DISEASE INCIDENCE AND POTENTIAL MECHANISMS OF DEFENSE FOR MSX-RESISTANT AND -SUSCEPTIBLE EASTERN OYSTERS HELD IN CHESAPEAKE BAY

    EPA Science Inventory

    A disease of eastern oysters, Crassostreaco virginica(Gmelm, 1791), caused by a protistan, Haplosporidium nelsoni, has caused great losses in the oyster fisheries of the northern Atlantic coast of North America. Certain oyster stocks have been selectively bred to survive infectio...

  3. 40 CFR 408.250 - Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Pacific Coast hand-shucked oyster processing subcategory. 408.250 Section 408.250 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Pacific Coast Hand-Shucked Oyster Processing Subcategory § 408.250 Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory....

  4. 40 CFR 408.250 - Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Pacific Coast hand-shucked oyster processing subcategory. 408.250 Section 408.250 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Pacific Coast Hand-Shucked Oyster Processing Subcategory § 408.250 Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory....

  5. 40 CFR 408.250 - Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Pacific Coast hand-shucked oyster processing subcategory. 408.250 Section 408.250 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Pacific Coast Hand-Shucked Oyster Processing Subcategory § 408.250 Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory....

  6. 76 FR 59423 - Drakes Bay Oyster Company Special-Use Permit, Draft Environmental Impact Statement, Point Reyes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... whether a new SUP should be issued to Drakes Bay Oyster Company for 10 years. ] Project Objectives Manage... National Park Service Drakes Bay Oyster Company Special-Use Permit, Draft Environmental Impact Statement... statement to consider the Drakes Bay Oyster Company Special-use permit in Drakes Estero, Point...

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

    PubMed

    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. PMID:26575154

  8. 75 FR 65373 - Drakes Bay Oyster Company Special Use Permit/Environmental Impact Statement, Point Reyes National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ... National Park Service Drakes Bay Oyster Company Special Use Permit/Environmental Impact Statement, Point... Intent to prepare an Environmental Impact Statement for the Drakes Bay Oyster Company Special Use Permit... Statement (EIS) for the Drakes Bay Oyster Company Special Use Permit, Point Reyes National...

  9. Oyster Reef Communities in the Chesapeake Bay. Virginia Institute of Marine Science Educational Series. [CD-ROM].

    ERIC Educational Resources Information Center

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

    This CD-ROM, Oyster Reef Communities in the Chesapeake Bay, describes oyster reefs, reef communities, and their roles in the Chesapeake Bay ecosystem. Detailed descriptions of scientific research methods and techniques used to monitor and describe oyster reef communities as well as applications of the resulting data are provided. The CD-ROM was…

  10. 40 CFR 408.260 - Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster processing...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Atlantic and Gulf Coast hand-shucked oyster processing subcategory. 408.260 Section 408.260 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Atlantic and Gulf Coast Hand-Shucked Oyster Processing Subcategory § 408.260 Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster...

  11. 40 CFR 408.260 - Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster processing...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Atlantic and Gulf Coast hand-shucked oyster processing subcategory. 408.260 Section 408.260 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Atlantic and Gulf Coast Hand-Shucked Oyster Processing Subcategory § 408.260 Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster...

  12. 40 CFR 408.260 - Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster processing...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Atlantic and Gulf Coast hand-shucked oyster processing subcategory. 408.260 Section 408.260 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Atlantic and Gulf Coast Hand-Shucked Oyster Processing Subcategory § 408.260 Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster...

  13. 40 CFR 408.260 - Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster processing...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Atlantic and Gulf Coast hand-shucked oyster processing subcategory. 408.260 Section 408.260 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Atlantic and Gulf Coast Hand-Shucked Oyster Processing Subcategory § 408.260 Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster...

  14. 40 CFR 408.250 - Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Pacific Coast hand-shucked oyster processing subcategory. 408.250 Section 408.250 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Pacific Coast Hand-Shucked Oyster Processing Subcategory § 408.250 Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory....

  15. 40 CFR 408.250 - Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Pacific Coast hand-shucked oyster processing subcategory. 408.250 Section 408.250 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Pacific Coast Hand-Shucked Oyster Processing Subcategory § 408.250 Applicability; description of the Pacific Coast hand-shucked oyster processing subcategory....

  16. 40 CFR 408.260 - Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster processing...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Atlantic and Gulf Coast hand-shucked oyster processing subcategory. 408.260 Section 408.260 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Atlantic and Gulf Coast Hand-Shucked Oyster Processing Subcategory § 408.260 Applicability; description of the Atlantic and Gulf Coast hand-shucked oyster...

  17. Kl-impregnated Oyster Shells as a Solid Catalyst for Soybean Oil Transesterificaton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research on inexpensive and green catalysts is needed for economical production of biodiesel. The goal of the research was to test KI-impregnated oyster shell as a solid catalyst for transesterification of soybean oil. Specific objectives were to characterize KI-impregnated oyster shell, determine t...

  18. Comparison of different methods for isolation of bacterial DNA from retail oyster tissues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oysters are filter-feeders that bio-accumulate bacteria in water while feeding. To evaluate the bacterial genomic DNA extracted from retail oyster tissues, including the gills and digestive glands, four isolation methods were used. Genomic DNA extraction was performed using the Allmag™ Blood Genomic...

  19. Differential recruitment of introduced Pacific oysters and native mussels at the North Sea coast: coexistence possible?

    NASA Astrophysics Data System (ADS)

    Diederich, Susanne

    2005-04-01

    Pacific oysters ( Crassostrea gigas Thunberg 1793) have been introduced into the Wadden Sea (North Sea), where they settle on native mussel beds ( Mytilus edulis L.), which represent the only extensive insular hard substrata in this soft-sediment environment. As abundances of C. gigas rose, some mussel beds became increasingly overgrown with oysters, whereas others did not. Field experiments revealed that recruitment of C. gigas was higher in the lower intertidal than in the upper subtidal zone, that it was higher on conspecifics than on mussels, and that it was not affected by barnacle epigrowth except when settling on mussels. Mussel recruitment is known from inter- and subtidal zones. It occurred equally on oyster and mussel shells but showed a clear preference for barnacle epigrowth over clean shells. Assuming that settlement and recruitment are key processes for species abundances on the North Sea coast, it is predicted that the positive feedback in oyster settlement will lead to rapid reef formation of this invader at the expense of mussel beds. Mussels, however, may escape competitive exclusion by settling between or on the larger oysters especially when barnacles are abundant. Experimental patches with mussels were more often covered by fucoid algae ( Fucus vesiculosus forma mytili Nienburg) than patches with oysters, and oyster recruitment was poor underneath such algal canopies. Thus, fucoids may provide the native mussels with a refuge from the invading oysters and the two bivalves may coexist, provided food is not limiting.

  20. FACTORS INFLUENCING IN VITRO KILLING OF BACTERIA BY HEMOCYTES OF THE EASTERN OYSTER (CRASSOSTREA VIRGINICA)

    EPA Science Inventory

    A tetrazolium dye reduction assay was used to study factors governing killing of bacteria by oyster hemocytes. In vitro tests were performed on bacterial strains by using hemocytes from oysters collected from the same location in winter and summer. Vibrio parahaemolyticus strains...

  1. STUDIES ON THE DEPURATION OF CADMIUM AND COPPER BY THE AMERICAN OYSTER 'CRASSOSTREA VIRGINICA'

    EPA Science Inventory

    Few studies concerned with the accumulation of trace metals by the oyster have dealt with depuration. Depuration, or a loss of metal, has been observed during gametogenesis. Spawning has also been implicated in metal loss from the oyster. Some depuration studies have been perform...

  2. Desirability of oysters treated by high pressure processing at different temperatures and elevated pressures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. Are pesticide residues associated to rice production affecting oyster production in Delta del Ebro, NE Spain?

    PubMed

    Ochoa, Victoria; Riva, Carmen; Faria, Melissa; Köck-Schulmeyer, Marianne; de Alda, Miren López; Barceló, Damià; Fernandez Tejedor, Margarita; Roque, Ana; Ginebreda, Antoni; Barata, Carlos

    2012-10-15

    Pesticide usage in Delta del Ebro (NE Spain) during the rice growing season has been associated with oyster episodes of mortality that occur early in summer. However, there are no studies that have directly evaluated pesticide levels and effects in oysters (Crassotrea gigas) cultured in Ebro's Bays. In this study pesticide levels in water, metal body burdens and up to 12 different biochemical markers were monitored in gills and digestive glands of oysters transplanted from May to June in 2008 and 2009. Biochemical responses evidenced clear differences in oysters from 2008 and 2009. Oysters transplanted in 2009 showed their antioxidant defenses unaffected from May to June and consequently increased levels of tissue damage measured as lipid peroxidation and DNA strand breaks and of mortality rates. Conversely oysters transplanted in 2008 increase their antioxidant defenses from May to June, had low levels of lipid peroxidation and DNA damage and low mortality rates. Some pesticides in water such as bentazone and propanil together with high temperatures and salinity levels were related with tissue damage in oyster transplanted in 2008 but the observed large differences between years indicate that abiotic factors alone could not explain the high mortalities observed in 2009. An analysis of recent reported studies pointed out in the direction that in addition to abiotic factors the use of oysters sensitive to diseases may explain the observed responses. PMID:22940045

  4. The Potential Use of Electricity to Control Burrowing Shrimp in Oyster Aquaculture Beds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thalassinid shrimp cause significant problems for oyster aquaculture in the Pacific Northwest (USA) where oysters succumb to the physical disruption of the sediment by the burrowing activity of these animals. While electrofishing is a commonly used technique to capture fish and some invertebrates i...

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

    PubMed Central

    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 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. PMID:6257164

  6. ALPHA METHYLGLUCOSIDE TRANSPORT BY THE GILL OF THE OYSTER 'OSTREA EDULIS'

    EPA Science Inventory

    The present study defines the mechanism of glucose transport in the isolated gill of oysters, using the European flat oyster, Ostrea edulis, as a representative species. The specific objectives were: (1) identify a non-metabolized transport analog, (2) determine the effects of kn...

  7. High concentrations of trace metals in oysters from the Patuxent River, Maryland

    SciTech Connect

    Riedel, G.; Sanders, J.; Abbe, G.

    1995-12-31

    Oyster (Crassostrea virginica) populations from the Patuxent River have been analyzed for trace metals by a number of organizations over at least the past 19 years. During that period, high concentrations of Cu (200--500 {micro}g/g dry weight), Cd (3--7 {micro}g/g) and Ag (2--8 /{micro}g/g) have been found in oysters from the oyster bars furthest up river. In particular, Cd values in oysters from this region have had concentrations approaching or exceeding current FDA warning levels throughout the period. In previous studies it was suggested that a coal-burning power plant located in that region, Chalk Point Steam Electric Station, was responsible for the copper enrichment due to the corrosion of Cu/Ni alloy condenser tubes. However, a monthly survey of trace elements in the nearby oyster populations from 1986 to the present showed only a small decline in copper concentrations after the plant switched from Cu/Ni to Ti alloy condenser tubes in 1987. Other potential sources for trace metals in the region include municipal and industrial discharges, atmospheric deposition, and biocides (anti-fouling paint in particular). The very rapid rise in trace element concentrations in oysters with position up river, and the lack of such a response by another local bivalve, the hooked mussel (Ischadium recurvum), suggests that a physiological effect of low salinity stress on oysters may be in part responsible for the high concentrations of trace metals in oysters in this region.

  8. High pressure processing with hot sauce flavoring enhances sensory quality for raw oysters (Crassostrea virginica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. A norovirus outbreak associated with consumption of NSW oysters: implications for quality assurance systems.

    PubMed

    Huppatz, Clare; Munnoch, Sally A; Worgan, Tory; Merritt, Tony D; Dalton, Craig; Kelly, Paul M; Durrheim, David N

    2008-03-01

    Norovirus is a common cause of gastroenteritis outbreaks associated with raw shellfish consumption. In Australia there have been several reports of norovirus outbreaks associated with oysters despite the application of regulatory measures recommended by Food Standards Australia New Zealand. This study describes an outbreak of norovirus gastroenteritis following the consumption of New South Wales oysters. In September 2007, OzFoodNet conducted a cohort study of a gastroenteritis outbreak amongst people that had dined at a Port Macquarie restaurant. Illness was strongly associated with oyster consumption, with all cases having eaten oysters from the same lease (RR undefined, p < 0.0001). Norovirus was detected in a faecal specimen. Although no pathogen was identified during the environmental investigation, the source oyster lease had been closed just prior to harvesting due to sewage contamination. Australian quality assurance programs do not routinely test oysters for viral contamination that pose a risk to human health. It is recommended that the feasibility of testing oysters for norovirus, particularly after known faecal contamination of oyster leases, be assessed. PMID:18522310

  10. ANTIOXIDANT ENZYMES, POTENTIAL VIRULENT FACTORS, IN DIFFERENT STRAINS OF THE OYSTER PROTOZOAN PARASITE, PERKINSUS MARINUS

    EPA Science Inventory

    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. CONCURRENT NEOPLASTIC AND PROTISTAN DISORDERS IN THE AMERICAN OYSTER (CRASSOSTREA VIRGINICA)

    EPA Science Inventory

    One of 373 oysters examined as part of a histological survey of oysters from Apalachicola Bay, Florida, USA, had a concurrent blood cell proliferative disorder and a protistan infection. The neoplastic blood cells (leukocytes) were found throughout the vesicular connective tissue...

  12. Characterization studies on the cadmium-binding proteins from two species of New Zealand oysters.

    PubMed Central

    Nordberg, M; Nuottaniemi, I; Cherian, M G; Nordberg, G F; Kjellström, T; Garvey, J S

    1986-01-01

    Two different types of New Zealand oysters--Ostrea lutaria (OL) and Crassostrea glomerata (CG)--contained different concentrations of zinc, copper, and cadmium. OL oysters had 5.3 micrograms Cd/g, 3.4 micrograms Cu/g, 100 micrograms Zn/g; CG oysters had 1.4 micrograms Cd/g and 936 micrograms Zn/g. Both kinds of oysters were shown by gel filtration (G-75) to contain cadmium and zinc in fractions corresponding to a high molecular weight protein (corresponding to the size of albumin or larger) which was heat labile. OL oysters contained cadmium in fractions corresponding to a molecular weight of approximately 6500. The cadmium-binding protein in these fractions was heat-stable. This protein contained no detectable amounts of zinc and was not present in the CG oysters. Further purification by gel filtration (G-50) was performed to obtain a purer protein fraction. Isoelectric focusing of the protein obtained by G-50 filtration showed one main fraction of protein with a pI approximately 5.9 at approximately 13 degrees C. CG oysters contained cadmium and zinc in a polypeptide with low molecular weight (MW 1000). The cadmium-binding oyster proteins are minimally reactive in a competitive binding radioimmunoassay in comparison to the reactivity of a typical vertebrate metallothionein; the proteins may be metallothioneins, but, if so, they do not exhibit the principal determinants characteristic of vertebrate metallothioneins. PMID:3709467

  13. RESPONSES OF OYSTERS AND THEIR HEMOCYTES TO CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHAEMOLYTICUS

    EPA Science Inventory

    Interactions of Vibrio parahaemolyticus with oysters and oyster hemocytes were studied using three environmental isolates (1094, 1163 and ATCC 17802) and three clinical isolates (2030, 2062, 2107). Clinical isolates were from patients who became ill during the June 1998 food pois...

  14. ANTIMICROBIAL ACTIVITY OF COPPER AND ZINC ACCUMULATED BY EASTERN OYSTER AMEBOCYTES

    EPA Science Inventory

    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...

  15. Thermal inactivation of enteric viruses and bioaccumulation of enteric foodborne viruses in live oysters (Crassostrea virginica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Heavy metals in the eastern oyster, Crassostrea virginica, of the Mississippi Sound

    SciTech Connect

    Lytle, T.F.; Lytle, J.S. )

    1990-01-01

    Levels of metals in oysters in the Sound are of profound interest not only because they document those geographic areas where metal pollution levels may be problematic but because they may disclose possible problems to consumers of oysters. At the present time objective federal standards for heavy metals in oysters and other seafood are restricted to mercury. The closure of Mississippi oyster reefs has been predicated upon bacteriological standards with little if any attention paid to heavy metals. A study of fourteen metals in oysters of the Sound was began in 1988 with objectives differing from that of the Status and Trends Program (STP) in three ways. STP levels are reported on dry weight basis of composites from three sites. In the present study, oysters were analyzed and reported on wet weight basis. Additionally analyses were made of individual specimens to indicate expected specimen to specimen variations and were conducted on oysters from the three STP and two other important oyster reef sites. In the future three or more additional sites will be added to this continuing survey effort. Metals chosen for this study were lead (Pb), cadmium (Cd), iron (Fe), copper (Cu), cobalt (Co), manganese (Mn), zinc (Zn), silver (Ag), nickel (Ni), mercury (Hg), aluminum (Al), chromium (Cr), molybdenum (Mo), and vanadium (V).

  17. Surveying a fossil oyster reef using terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    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

  18. A new identification method for five species of oysters in genus Crassostrea from China based on high-resolution melting analysis

    NASA Astrophysics Data System (ADS)

    Wang, Jiafeng; Xu, Fei; Li, Li; Zhang, Guofan

    2014-03-01

    The high phenotypic plasticity in the shell of oysters presents a challenge during taxonomic and phylogenetic studies of these economically important bivalves. However, because DNA can exhibit marked differences among morphologically similar species, DNA barcoding offers a potential means for oyster identification. We analyzed the complete sequences of the cytochrome oxidase subunit I (COI) of five common Crassostrea species in China (including Hong Kong oyster C. hongkongensis, Jinjiang oyster C. ariakensis, Portuguese oyster C. angulata, Kumamoto oyster C. sikamea, and Pacific oyster C. gigas) and screened for distinct fragments. Using these distinct fragments on a high-resolution melting analysis platform, we developed an identification method that does not rely on species-specific PCR or fragment length polymorphism and is efficient, reliable, and easy to visualize. Using a single pair of primers (Oyster-COI-1), we were able to successfully distinguish among the five oyster species. This new method provides a simple and powerful tool for the identification of oyster species.

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

    PubMed

    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. PMID:25843147

  20. Eastern oyster (Crassostrea virginica) δ15N as a bioindicator of nitrogen sources: Observations and modeling

    PubMed Central

    Fertig, B.; Carruthers, T.J.B.; Dennison, W.C.; Fertig, E.J.; Altabet, M.A.

    2013-01-01

    Stable nitrogen isotopes (δ15N) 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 δ15N, 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 δ15N 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 δ15N 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. PMID:20381097

  1. Crassaostrea gigas oyster shell extract inhibits lipogenesis via suppression of serine palmitoyltransferase.

    PubMed

    Tran, Nguyen Khoi Song; Kwon, Jeong Eun; Kang, Se Chan; Shim, Soon-Mi; Park, Tae-Sik

    2015-02-01

    Oysters are widely consumed seafood, but their shells impose a serious environmental problem. To extend the utilization of oyster shell waste, we investigated the biological role of oyster shell extract. In this study, we verified that the ethanol extract of oyster shell (EOS) contains taurine and betaine, the major components of oyster body. EOS downregulated transcription of Sptlc1 and Sptlc2 mRNA, the subunits of serine palmitoyltransferase (SPT). Suppression of SPT subunits reduced sphinganine and sphingomyelin by inhibiting de novo sphingolipid biosynthesis. Inhibition of sphingomyelin biosynthesis resulted in downregulation of lipogenic gene expression such as ACC, FAS, SCD1, and DGAT2. Consistent with inhibition of lipogenesis, cellular triglyceride levels were diminished by EOS, but cholesterol levels were not altered. Taken together, these results suggest that EOS has a lipid-lowering effect and could be applied as either a therapeutic or preventive measure for metabolic dysfunction. PMID:25920281

  2. High mortality of Pacific oysters in a cold winter in the North-Frisian Wadden Sea

    NASA Astrophysics Data System (ADS)

    Büttger, Heike; Nehls, Georg; Witte, Sophia

    2011-12-01

    Mortality of introduced Pacific oysters ( Crassostrea gigas) was studied in the northern Wadden Sea in response to an ice winter. After a decade of mild winters, in January and February 2010, the first severe winter occurred since the Pacific oysters became dominant on former intertidal blue mussel ( Mytilus edulis) beds in the North-Frisian Wadden Sea. After the ice winter, mortality of Pacific oysters on densely populated beds in the List tidal basin reached about 90%, indicating much higher losses in comparison to former mild winters. At lower densities between the islands of Amrum and Föhr, oysters were less or even not affected. Although Pacific oysters are assumed to be very tolerant to frost, the duration of cold water- and air temperatures accompanied by mechanical stress of the ice burden might have caused the high mortality in the winter 2009/2010 in formerly dense beds.

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

    USGS Publications Warehouse

    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 (<5 psu) decreased Perkinsus marinus infection intensities. Furthermore, when salinity was low (<5 psu), parasite infection intensities continued to decrease even as temperatures exceeded 20°C. At the same time, oyster growth was positively correlated with salinity. To maximize oyster production, data indicate that both low and high salinity events will be necessary.

  4. Survey for protozoan parasites in Eastern oysters (Crassostrea virginica) from the Gulf of Maine using PCR-based assays.

    PubMed

    Marquis, Nicholas D; Record, Nicholas R; Robledo, José A Fernández

    2015-10-01

    Protozoan pathogens represent a serious threat to oyster aquaculture, since they can lead to significant production loses. Moreover, oysters can concentrate human pathogens through filter feeding, thus putting at risk raw oyster consumers' health. Using PCR-based assays in oysters (Crassostrea virginica) from Maine, we expand the Northeast range in the USA for the protozoans Perkinsus marinus, Perkinsus chesapeaki, and Haplosporidium nelsoni, and report for the first time the detection of the human pathogens Toxoplasma gondii and Cryptosporidium parvum. Oysters hosting both P. marinus and P. chesapeaki were more than three times as likely to be infected by a non-Perkinsus than those free of Perkinsus infections. PMID:25889457

  5. Multistate outbreak of viral gastroenteritis associated with consumption of oysters--Apalachicola Bay, Florida, December 1994-January 1995.

    PubMed

    1995-01-20

    On January 3, 1995, the Florida Department of Health and Rehabilitative Services (HRS) was notified of an outbreak of acute gastroenteritis associated with eating oysters. The subsequent investigation by HRS has identified 34 separate clusters of cases, many of which were associated with oysters harvested during December 29-31 from 13 Mile Area and Cat Point in Apalachicola Bay. Oysters were shipped to other states, but additional clusters of illness associated with these oysters have been reported only in Georgia. Most of these oysters were served steamed or roasted. This report summarizes the preliminary findings of the ongoing investigation of this outbreak.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7808387

  6. The Effect of Oyster Reef Morphology on Particulate Transfer in a North Carolina Tidal Creek

    NASA Astrophysics Data System (ADS)

    Lemon, M. G.; Posey, M.; Mallin, M.; Alphin, T.

    2014-12-01

    The eastern oyster (Crassostrea virginica) is a vital ecosystem engineer species, providing a number of ecosystem services that structure and maintain estuarine environments through the construction of large, hard-bottom reef complexes. Through suspension feeding, oysters clear the water column of particulates, leading to decreased suspended material and enhanced benthic pelagic coupling. Past field studies have indicated the potential importance of the physical reef structure in regulating the transfer of particulate material in the seston. In order to directly assess the existence of the physical reef effect, multiple field experiments were performed in a small tidal creek estuary along the south eastern coast of North Carolina. Comparison of clearance rates derived from two different in situ methods, one accounting for the physical structure of the oyster reef in addition to oyster filtration and one looking at oyster filtration alone, indicate that the reef structure may increase the amount of particulate removal performed by the reef by more than 4 times the removal performed by oyster filtration alone. A defaunation experiment was performed by eliminating the live component of the oyster reef and comparing particulate transfer of this defaunated transect to that of an adjacent faunated transect. The defaunated transect had reduced but not significantly lower material removal when compared to the faunated transect prior to defaunation. Results from short and long term sediment collection and flow velocity measurements indicate that the physical effect of oyster reefs is strong over short temporal scales (days) but is much smaller when evaluated over longer time periods (months). Generally, large silt and small sand sized material is permanently removed from the seston due to the interaction of oyster reef structure and tidal flows, however the transfer of small and medium sized silt grains is only slowed down by the presence of large reef complexes. This

  7. Cloning and characterization of neoplasia-related genes in flat oyster Ostrea edulis.

    PubMed

    Martín-Gómez, Laura; Villalba, Antonio; Carballal, María Jesús; Abollo, Elvira

    2014-04-01

    Bonamiosis and disseminated neoplasia (DN) are the most important diseases affecting cultured flat oysters Ostrea edulis in Galicia (NW Spain). Previous research using suppresive substraction hybridisation that had been performed addressing the molecular basis of DN as well as the induction and development of the disease in oysters, yielded the whole open reading frame of nine genes: XBP-1, RACK, NDPk, C1qTNF, RPA3, SAP18, p23, ubiquitin and ferritin. These nine genes were characterized in this study. The phylogenetic relationships for each gene were studied using minimum-evolution methods. Quantitative-PCR assays were also developed to analyse the modulation of the expression of these genes by bonamiosis and disseminated neoplasia. Gene expression profiles were studied in haemolymph cells and in various organs (gill, gonad, mantle and digestive gland) of oysters affected by bonamiosis, disseminated neoplasia, both diseases and in non-affected oysters (control). The expression of XBP-1, NDPk, RPA3, SAP18 and ferritin increased in haemolymph cells of oysters with heavy bonamiosis. The expression of C1qTNF; SAP18 and p23 increased in haemolymph cells of oysters with DN. The expression of XBP-1, RACK, NDPk, RPA3 and p23 significantly increased in haemolymph cells of oysters affected by both diseases. There were changes in the expression of a number of genes in different organs depeding on disease stage: RACK expression increased in gills of oysters with bonamiosis, XBP-1 increased in mantle and digestive organs of oysters with light DN and RPA3 expression increased in gonads of oysters with heavy bonamiosis and heavy neoplasia. PMID:24560728

  8. Influence of water allocation and freshwater inflow on oyster production: a hydrodynamic-oyster population model for Galveston Bay, Texas, USA.

    PubMed

    Powell, Eric N; Klinck, John M; Hofmann, Eileen E; McManus, Margaret A

    2003-01-01

    A hydrodynamic-oyster population model was developed to assess the effect of changes in freshwater inflow on oyster populations in Galveston Bay, Texas, USA. The population model includes the effects of environmental conditions, predators, and the oyster parasite, Perkinsus marinus, on oyster populations. The hydrodynamic model includes the effects of wind stress, river runoff, tides, and oceanic exchange on the circulation of the bay. Simulations were run for low, mean, and high freshwater inflow conditions under the present (1993) hydrology and predicted hydrologies for 2024 and 2049 that include both changes in total freshwater inflow and diversions of freshwater from one primary drainage basin to another. Freshwater diversion to supply the Houston metropolitan area is predicted to negatively impact oyster production in Galveston Bay. Fecundity and larval survivorship both decline. Mortality from Perkinsus marinus increases, but to a lesser extent. A larger negative impact in 2049 relative to 2024 originates from the larger drop in fecundity under that hydrology. Changes in recruitment and mortality, resulting in lowered oyster abundance, occur because the bay volume available for mixing freshwater input from the San Jacinto and Buffalo Bayou drainage basins that drain metropolitan Houston is small in comparison to the volume of Trinity Bay that presently receives the bulk of the bay's freshwater inflow. A smaller volume for mixing results in salinities that decline more rapidly and to a greater extent under conditions of high freshwater discharge.Thus, the decline in oyster abundance results from a disequilibrium between geography and salinity brought about by freshwater diversion. Although the bay hydrology shifts, available hard substrate does not. The simulations stress the fact that it is not just the well-appreciated reduction in freshwater inflow that can result in decreased oyster production. Changing the location of freshwater inflow can also

  9. Transcriptome of American Oysters, Crassostrea virginica, in Response to Bacterial Challenge: Insights into Potential Mechanisms of Disease Resistance

    PubMed Central

    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. PMID:25122115

  10. D Central Line Extraction of Fossil Oyster Shells

    NASA Astrophysics Data System (ADS)

    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

  11. Does Vessel Noise Affect Oyster Toadfish Calling Rates?

    PubMed

    Luczkovich, Joseph J; Krahforst, Cecilia S; Hoppe, Harry; Sprague, Mark W

    2016-01-01

    The question we addressed in this study is whether oyster toadfish respond to vessel disturbances by calling less when vessels with lower frequency spectra are present in a sound recording and afterward. Long-term data recorders were deployed at the Neuse (high vessel-noise site) and Pamlico (low vessel-noise site) Rivers. There were many fewer toadfish detections at the high vessel-noise site than the low-noise station. Calling rates were lower in the high-boat traffic area, suggesting that toadfish cannot call over loud vessel noise, reducing the overall calling rate, and may have to call more often when vessels are not present. PMID:26611015

  12. Improving early detection of exotic or emergent oyster diseases in France: identifying factors associated with shellfish farmer reporting behaviour of oyster mortality.

    PubMed

    Lupo, C; Osta Amigo, A; Mandard, Y V; Peroz, C; Renault, T

    2014-09-01

    Farmers' vigilance is essential for the detection of epidemics, including potential emerging diseases, in marine shellfish. A field study was conducted to investigate oyster farmers' reporting practices and behaviour, and to identify factors influencing the reporting process of oyster mortality, with the ultimate aim of improving early detection of unexplained oyster mortality outbreaks. A retrospective case-control study of oyster farmers from Charente-Maritime (France) was designed, based on interviews with 27 non-reporting and 89 reporting farmers, further split into 40 formerly-reporting and 49 currently-reporting farmers. Information about farmer and farm characteristics, farming practices, farm health history and related financial compensation on the farm, knowledge of the mortality reporting system and reporting behaviour was collected. Sampling design was considered in the calculations and farmers' reporting behaviour was modelled using an ordinal logistic regression (continuation-ratio model). Notification procedures were fairly well known among farmers and the reporting system was well accepted overall. Nevertheless, a lack of awareness of the aims of the reporting system was revealed, which contributed to late reporting. Factors identified as driving a farmer's decision to report oyster mortality concerned their lack of awareness of mortality reporting (production type, farm size, location of the production cycle, accessibility of the leasing grounds) and willingness to report (possibility and extent of financial compensation, a feeling of not being involved, whether it was first year of reporting). Overall classification performance of the model built in this study was 64%. In particular, financial compensation for oyster production losses appeared to be a clear incentive for reporting, but was countered by a habituation effect combined with a lack of awareness of the aims of the reporting system: oyster farmers looking for benefits for themselves in

  13. Parasites infecting the cultured oyster Crassostrea gasar (Adanson, 1757) in Northeast Brazil.

    PubMed

    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. PMID:25553815

  14. Epizootiology of Perkinsus sp. inCrassostrea gasar oysters in polyculture with shrimps in northeastern Brazil.

    PubMed

    da Silva, Patricia Mirella; Costa, Carolina Pereira; de Araújo, Jaíse Paiva Bragante; Queiroga, Fernando Ramos; Wainberg, Alexandre Alter

    2016-01-01

    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 and Perkinsus olseni were found infecting oysters in NE Brazil and can threaten oyster production. This study evaluated Perkinsus 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. PMID:27007244

  15. Immune response and mechanical stress susceptibility in diseased oysters, Crassostrea virginica.

    PubMed

    Roberts, Steven B; Sunila, Inke; Wikfors, Gary H

    2012-01-01

    Eastern oysters, Crassostrea virginica, naturally infected with the parasite Perkinsus marinus were subjected to a mechanical stress by centrifugation, and immune parameters, pathological conditions, and gene expression of selected transcripts were compared to uninfected controls. Immune parameters were assessed by flow cytometry, pathology and parasites by histotechnology and fluid thioglycollate assays, and gene expression by quantitative RT-PCR. Irrespective of mechanical stress, an increased number of hemocytes were observed in P. marinus-infected oysters that corresponded to increased expression of genes that have been shown to be involved in inflammation and apoptosis, two processes associated with regulating immune cell populations. Mechanically stressed, diseased oysters showed histological gill abnormalities and aggregations of hemocytes in tissues not seen in stressed, uninfected oysters. Expression of a high-mobility group protein and hemocyte phagocytosis were significantly upregulated upon mechanical stress only in uninfected oysters. The results of this study demonstrate the role of inflammation in the oyster immune response including possible underlying molecular mechanisms. Furthermore, this study highlights the importance of considering mechanical stressors when characterizing oyster immune function. PMID:21853237

  16. Analysis of Stomach and Gut Microbiomes of the Eastern Oyster (Crassostrea virginica) from Coastal Louisiana, USA

    PubMed Central

    King, Gary M.; Judd, Craig; Kuske, Cheryl R.; Smith, Conor

    2012-01-01

    We used high throughput pyrosequencing to characterize stomach and gut content microbiomes of Crassostrea virginica, the Easter oyster, obtained from two sites, one in Barataria Bay (Hackberry Bay) and the other in Terrebonne Bay (Lake Caillou), Louisiana, USA. Stomach microbiomes in oysters from Hackberry Bay were overwhelmingly dominated by Mollicutes most closely related to Mycoplasma; a more rich community dominated by Planctomyctes occurred in Lake Caillou oyster stomachs. Gut communities for oysters from both sites differed from stomach communities, and harbored a relatively diverse assemblage of phylotypes. Phylotypes most closely related to Shewanella and a Chloroflexi strain dominated the Lake Caillou and Hackberry Bay gut microbiota, respectively. While many members of the stomach and gut microbiomes appeared to be transients or opportunists, a putative core microbiome was identified based on phylotypes that occurred in all stomach or gut samples only. The putative core stomach microbiome comprised 5 OTUs in 3 phyla, while the putative core gut microbiome contained 44 OTUs in 12 phyla. These results collectively revealed novel microbial communities within the oyster digestive system, the functions of the oyster microbiome are largely unknown. A comparison of microbiomes from Louisiana oysters with bacterial communities reported for other marine invertebrates and fish indicated that molluscan microbiomes were more similar to each other than to microbiomes of polychaetes, decapods and fish. PMID:23251548

  17. Incorporation of metabolites into glycogen and lipids of the oyster, crassostrea virginica

    SciTech Connect

    Swift, M.L.; Humphrey, C.L. )

    1987-05-01

    Groups of oysters, either fed or unfed, were exposed to U-{sup 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.

  18. Angiotensin I-converting enzyme inhibitor derived from cross-linked oyster protein.

    PubMed

    Xie, Cheng-Liang; Kim, Jin-Soo; Ha, Jong-Myung; Choung, Se-Young; Choi, Yeung-Joon

    2014-01-01

    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. PMID:25140307

  19. Quantitative proteomics of heavy metal stress responses in Sydney rock oysters.

    PubMed

    Muralidharan, Sridevi; Thompson, Emma; Raftos, David; Birch, Gavin; Haynes, Paul A

    2012-03-01

    Currently, there are few predictive biomarkers in key biomonitoring species, such as oysters, that can detect heavy metal pollution in coastal waterways. Several attributes make oysters superior to other organisms for positive biomonitoring of heavy metal pollution. In particular, they are filter feeders with a high capacity for bioaccumulation. In this study, we used two proteomics approaches, namely label-free shotgun proteomics based on SDS-PAGE gel separation and gas phase fractionation, to investigate the heavy metal stress responses of Sydney rock oysters. Protein samples were prepared from haemolymph of oysters exposed to 100 μg/L of PbCl(2), CuCl(2), or ZnCl(2) for 4 days in closed aquaria. Peptides were identified using a Bivalvia protein sequence database, due to the unavailability of a complete oyster genome sequence. Statistical analysis revealed 56 potential biomarker proteins, as well as several protein biosynthetic pathways to be greatly impacted by metal stress. These have the potential to be incorporated into bioassays for prevention and monitoring of heavy metal pollution in Australian oyster beds. The study confirms that proteomic analysis of biomonitoring species is a promising approach for assessing the effects of environmental pollution, and our experiments have provided insights into the molecular mechanisms underlying oyster stress responses. PMID:22539440

  20. Increases in the Amounts of Vibrio spp. in Oysters upon Addition of Exogenous Bacteria

    PubMed Central

    Oliver, James

    2013-01-01

    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. PMID:23793640

  1. Persistence, seasonal dynamics and pathogenic potential of Vibrio communities from Pacific oyster hemolymph.

    PubMed

    Wendling, Carolin C; Batista, Frederico M; Wegner, K Mathias

    2014-01-01

    Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer periods. PMID:24728233

  2. Persistence, Seasonal Dynamics and Pathogenic Potential of Vibrio Communities from Pacific Oyster Hemolymph

    PubMed Central

    Wendling, Carolin C.; Batista, Frederico M.; Wegner, K. Mathias

    2014-01-01

    Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer periods. PMID:24728233

  3. Analysis of Stomach and Gut Microbiomes of the Eastern Oyster (Crassostrea virginica) from Coastal Louisiana, USA

    DOE PAGESBeta

    King, Gary M.; Judd, Craig; Kuske, Cheryl R.; Smith, Conor

    2012-12-12

    In this paper, we used high throughput pyrosequencing to characterize stomach and gut content microbiomes of Crassostrea virginica, the Easter oyster, obtained from two sites, one in Barataria Bay (Hackberry Bay) and the other in Terrebonne Bay (Lake Caillou), Louisiana, USA. Stomach microbiomes in oysters from Hackberry Bay were overwhelmingly dominated by Mollicutes most closely related to Mycoplasma; a more rich community dominated by Planctomyctes occurred in Lake Caillou oyster stomachs. Gut communities for oysters from both sites differed from stomach communities, and harbored a relatively diverse assemblage of phylotypes. Phylotypes most closely related to Shewanella and a Chloroflexi strainmore » dominated the Lake Caillou and Hackberry Bay gut microbiota, respectively. While many members of the stomach and gut microbiomes appeared to be transients or opportunists, a putative core microbiome was identified based on phylotypes that occurred in all stomach or gut samples only. The putative core stomach microbiome comprised 5 OTUs in 3 phyla, while the putative core gut microbiome contained 44 OTUs in 12 phyla. These results collectively revealed novel microbial communities within the oyster digestive system, the functions of the oyster microbiome are largely unknown. Finally, a comparison of microbiomes from Louisiana oysters with bacterial communities reported for other marine invertebrates and fish indicated that molluscan microbiomes were more similar to each other than to microbiomes of polychaetes, decapods and fish.« less

  4. Analysis of Stomach and Gut Microbiomes of the Eastern Oyster (Crassostrea virginica) from Coastal Louisiana, USA

    SciTech Connect

    King, Gary M.; Judd, Craig; Kuske, Cheryl R.; Smith, Conor

    2012-12-12

    In this paper, we used high throughput pyrosequencing to characterize stomach and gut content microbiomes of Crassostrea virginica, the Easter oyster, obtained from two sites, one in Barataria Bay (Hackberry Bay) and the other in Terrebonne Bay (Lake Caillou), Louisiana, USA. Stomach microbiomes in oysters from Hackberry Bay were overwhelmingly dominated by Mollicutes most closely related to Mycoplasma; a more rich community dominated by Planctomyctes occurred in Lake Caillou oyster stomachs. Gut communities for oysters from both sites differed from stomach communities, and harbored a relatively diverse assemblage of phylotypes. Phylotypes most closely related to Shewanella and a Chloroflexi strain dominated the Lake Caillou and Hackberry Bay gut microbiota, respectively. While many members of the stomach and gut microbiomes appeared to be transients or opportunists, a putative core microbiome was identified based on phylotypes that occurred in all stomach or gut samples only. The putative core stomach microbiome comprised 5 OTUs in 3 phyla, while the putative core gut microbiome contained 44 OTUs in 12 phyla. These results collectively revealed novel microbial communities within the oyster digestive system, the functions of the oyster microbiome are largely unknown. Finally, a comparison of microbiomes from Louisiana oysters with bacterial communities reported for other marine invertebrates and fish indicated that molluscan microbiomes were more similar to each other than to microbiomes of polychaetes, decapods and fish.

  5. Angiotensin I-Converting Enzyme Inhibitor Derived from Cross-Linked Oyster Protein

    PubMed Central

    Xie, Cheng-Liang; Kim, Jin-Soo; Ha, Jong-Myung; Choung, Se-Young

    2014-01-01

    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. PMID:25140307

  6. The role of tissue-specific microbiota in initial establishment success of Pacific oysters.

    PubMed

    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. PMID:26695476

  7. Effects of oyster harvest activities on Louisiana reef habitat and resident nekton communities

    USGS Publications Warehouse

    Beck, Steve; LaPeyre, Megan K.

    2015-01-01

    Oysters are often cited as “ecosystem engineers” because they modify their environment. Coastal Louisiana contains extensive oyster reef areas that have been harvested for decades, and whether differences in habitat functions exist between those areas and nonharvested reefs is unclear. We compared reef physical structure and resident community metrics between these 2 subtidal reef types. Harvested reefs were more fragmented and had lower densities of live eastern oysters (Crassostrea virginica) and hooked mussels (Ischadium recurvum) than the nonharvested reefs. Stable isotope values (13C and 15N) of dominant nekton species and basal food sources were used to compare food web characteristics. Nonpelagic source contributions and trophic positions of dominant species were slightly elevated at harvested sites. Oyster harvesting appeared to have decreased the number of large oysters and to have increased the percentage of reefs that were nonliving by decreasing water column filtration and benthopelagic coupling. The differences in reef matrix composition, however, had little effect on resident nekton communities. Understanding the thresholds of reef habitat areas, the oyster density or oyster size distribution below which ecosystem services may be compromised, remains key to sustainable management.

  8. Flat oyster follows the apoptosis pathway to defend against the protozoan parasite Bonamia ostreae.

    PubMed

    Gervais, Ophélie; Chollet, Bruno; Renault, Tristan; Arzul, Isabelle

    2016-09-01

    The in vitro model Ostrea edulis hemocyte - Bonamia ostreae is interesting to investigate host-parasite interactions at the cellular level. Indeed, this unicellular parasite infects the flat oyster Ostrea edulis and multiplies within hemocytes, the central effectors of oyster defenses. Apoptosis is a mechanism used by many organisms to eliminate infected cells. In order to study the potential involvement of this mechanism in the oyster response to B. ostreae, in vitro experiments were carried out by exposing hemocytes from the naturally susceptible oyster O. edulis and a resistant oyster species Crassostrea gigas to live and heat-inactivated parasites. Hemocyte apoptotic response was measured using a combination of flow cytometry and microscopy analyses. Whatever the host species was, the parasite was engulfed in hemocytes and induced an increase of apoptotic parameters including intracytoplasmic calcium concentration, mitochondrial membrane potential or phosphatidyl-serine externalization as well as ultrastructural modifications. However, the parasite appears more able to infect flat oyster than cupped oyster hemocytes and the apoptotic response was more important against live than dead parasites in the natural host than in C. gigas. Our results suggest that O. edulis specifically responds to B. ostreae by inducing apoptosis of hemocytes. PMID:27431587

  9. Introduction, establishment and expansion of the Pacific oyster Crassostrea gigas in the Oosterschelde (SW Netherlands)

    NASA Astrophysics Data System (ADS)

    Smaal, A. C.; Kater, B. J.; Wijsman, J.

    2009-03-01

    The Pacific oyster Crassostrea gigas was first introduced as an exotic species by oyster farmers in 1964 in the Oosterschelde estuary (SW Netherlands). The initial phase is not well documented but first natural spatfall was recorded in 1975. Excessive spatfall occurred in 1976 and this is considered the start of the expansion phase of the wild oysters. Oyster beds in intertidal and subtidal areas of the Oosterschelde estuary have been growing since. The development in the intertidal area has been reconstructed by using aerial photography, validated by ground truth in 2000-2002. In the subtidal areas extensive oyster beds have been detected by using side scan sonar; on hard substrates along the dikes coverage with oysters up to 90% locally has been recorded by scuba diving surveys. Expansion has also occurred into adjacent water bodies including the Wadden Sea. By forming resistant reefs the oysters induce structural changes in the ecosystem. It is concluded that bed area is still expanding while decrease of the fraction live animals may indicate adjustment of the stock size to the local conditions.

  10. Mortalities of Eastern and Pacific Oyster Larvae Caused by the Pathogens Vibrio coralliilyticus and Vibrio tubiashii

    PubMed Central

    Watson, Michael A.; Needleman, David S.; Church, Karlee M.; Häse, Claudia C.

    2014-01-01

    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 × 104 to 3.0 × 104 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 × 104 and 4.0 × 104 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 × 104 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. PMID:25344234

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

    PubMed

    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. PMID:21488516

  12. Modeling and Prediction of Oyster Norovirus Outbreaks along Gulf of Mexico Coast

    PubMed Central

    Wang, Jiao; Deng, Zhiqiang

    2015-01-01

    Background: Oyster norovirus outbreaks often pose high risks to human health. However, little is known about environmental factors controlling the outbreaks, and little can be done to prevent the outbreaks because they are generally considered to be unpredictable. Objective: We sought to develop a mathematical model for predicting risks of oyster norovirus outbreaks using environmental predictors. Methods: We developed a novel probability-based Artificial Neural Network model, called NORF model, using 21 years of environmental and norovirus outbreak data collected from Louisiana oyster harvesting areas along the Gulf of Mexico coast, USA. The NORF model involves six input variables that were selected through stepwise regression analysis and sensitivity analysis. Results: We found that the model-based probability of norovirus outbreaks was most sensitive to gage height (the depth of water in an oyster bed) and water temperature, followed by wind, rainfall, and salinity, respectively. The NORF model predicted all historical oyster norovirus outbreaks from 1994 through 2014. Specifically, norovirus outbreaks occurred when the NORF model probability estimate was > 0.6, whereas no outbreaks occurred when the estimated probability was < 0.5. Outbreaks may also occur when the estimated probability is 0.5–0.6. Conclusions: Our findings require further confirmation, but they suggest that oyster norovirus outbreaks may be predictable using the NORF model. The ability to predict oyster norovirus outbreaks at their onset may make it possible to prevent or at least reduce the risk of norovirus outbreaks by closing potentially affected oyster beds. Citation: Wang J, Deng Z. 2016. Modeling and prediction of oyster norovirus outbreaks along Gulf of Mexico coast. Environ Health Perspect 124:627–633; http://dx.doi.org/10.1289/ehp.1509764 PMID:26528621

  13. The Effects of Storage Temperature on the Growth of Vibrio parahaemolyticus and Organoleptic Properties in Oysters.

    PubMed

    Mudoh, Meshack Fon; Parveen, Salina; Schwarz, Jurgen; Rippen, Tom; Chaudhuri, Anish

    2014-01-01

    During harvesting and storage, microbial pathogens and natural spoilage flora may grow, negatively affecting the composition and texture of oysters and posing a potential health threat to susceptible consumers. A solution to these problems would mitigate associated damaging effects on the seafood industry. The purpose of this study was to investigate the effects of storage temperature on growth of vibrios as well as other microbial, sensory, and textural characteristics of post-harvest shellstock Eastern oysters (Crassostrea virginica). Oysters harvested from the Chesapeake Bay, Maryland, during summer months (June, July, and August, 2010) were subjected to three storage temperatures (5, 10, and 20°C) over a 10-day period. At selected time intervals (0, 1, 3, 7, and 10 days), two separate samples of six oysters each were homogenated and analyzed for pH, halophilic plate counts (HPC), total vibrios, and Vibrio parahaemolyticus (Vp). Oyster meats shucked after storage were also organoleptically evaluated (acceptability, appearance, and odor). Texture analysis was performed using a texture analyzer on meats shucked from oysters held under the same conditions. The pH of the oyster homogenates showed no consistent pattern with storage time and temperature. The HPC (4.5-9.4 log CFU/g) were highest on day 7 at 20°C while olfactory acceptance reduced with time and increasing storage temperatures. The Vp counts increased over time from 3.5 to 7.5 log MPN/g by day 10. Loss of freshness as judged by appearance and odor was significant over time (p < 0.05). Toughness of oysters increased with storage time at 5 and 10°C from days 1 to 3 but was inconsistent after day 7. The results indicate that the length of storage and temperature had a significant effect on bacterial counts and olfactory acceptance of oysters but had an inconsistent effect on texture. PMID:24904911

  14. Localization of the bacterial agent of juvenile oyster disease (Roseovarius crassostreae) within affected eastern oysters (Crassostrea virginica).

    PubMed

    Boardman, Cynthia L; Maloy, Aaron P; Boettcher, Katherine J

    2008-02-01

    The bacterium Roseovarius crassostreae causes seasonal mortalities among commercially produced eastern oysters (Crassostrea virginica) grown in the Northeastern United States. Phylogenetically, the species belongs to a major lineage of marine bacteria (the Roseobacter clade), within which Roseovarius crassostreae is the only known pathogen to be isolated in laboratory culture. The objective of the current study was to determine the location and nature of R. crassostreae interactions with oysters affected by juvenile oyster disease (JOD). Scanning electron microscopy of diseased individuals revealed abundant colonization of the inner shell surfaces by bacteria which were morphologically similar to R. crassostreae. The same types of cells were also observed on and within layers of host-derived conchiolin on the inner valves. Most bacterial cells were alive as determined by the use of a fluorescent viability stain. Further, most were clearly attached at the cell poles, which is consistent with the ability of R. crassostreae to express polar fimbriae. When material from the pallial fluid, soft tissue and inner valve surfaces was cultured, the highest numbers of R. crassostreae were recovered from the inner valves. These samples also contained the greatest abundance of R. crassostreae as a percentage of total colonies. Cloning and sequencing of 16S rRNA genes provided culture-independent evidence of the numerical dominance of R. crassostreae among the bacterial consortia associated with the inner shell surfaces of JOD-affected animals. The ability of R. crassostreae to colonize shell and conchiolin is consistent with the described JOD-pathology and may aid the bacteria in avoiding hemocyte-mediated killing. PMID:17931651

  15. Perkinsus sp. infecting oyster Crassostrea rhizophorae (Guilding, 1828) on the coast of Bahia, Brazil.

    PubMed

    Brandão, Rosana Pinho; Boehs, Guisla; Sabry, Rachel Costa; Ceuta, Liliane Oliveira; Luz, Mariane Dos Santos Aguiar; Queiroga, Fernando Ramos; da Silva, Patrícia Mirella

    2013-02-01

    This study investigated the occurrence of the protozoan Perkinsus in the oyster Crassostrea rhizophorae on the coast of Bahia State, Brazil. The oysters (n = 900) were collected in February-March and July-August 2010. The Ray's fluid thioglycollate medium (RFTM) analysis of gills and rectum revealed hypnospores of Perkinsus sp. with a high mean prevalence (63%). The infection intensity varied from very light to advanced. The polymerase chain reaction confirmed Perkinsus in 87.2% of the RFTM-positive oysters. Histological analysis showed trophozoites and schizonts phagocytized by hemocytes, mainly in the intestine and the stomach epithelium. PMID:23201453

  16. Oyster resource zones of the Barataria and Terrebonne estuaries of Louisiana

    USGS Publications Warehouse

    Melancon, E., Jr.; Soniat, T.; Cheramie, V.; Dugas, R.; Barras, J.; Lagarde, M.

    1998-01-01

    A 1:100,000 scale map delineating the subtidal oyster resource zones within the Barataria and Terrebonne estuaries was developed. Strategies to accomplish the task included interviews with Louisiana oystermen and state biologists to develop a draft map, field sampling to document oyster (Crassostrea virginica), Dermo (Perkinsus marinus), and oyster drill (Stramonita haemastoma) abundances, use of historical salinity data to aid in map verification, and public meetings to allow comment on a draft before final map preparation. Four oyster resource zones were delineated on the final map: a dry zone where subtidal oysters may be found when salinities increase, a wet zone where subtidal oysters may be found when salinities are suppressed, a wet-dry zone where subtidal oysters may be consistently found due to favorable salinities, and a high-salinity zone where natural oyster populations are predominantly found in intertidal and shallow waters. The dry zone is largely coincident with the brackish-marsh habitat, with some intermediate-type marsh. The wet-dry zone is found at the interface of the brackish and saline marshes, but extends further seaward than up-estuary. The wet zone and the high salinity zones are areas of mostly open water fringed by salt marshes. The dry zone encompasses 91,775 hectares, of which 48,788 hectares are water (53%). The wet zone encompasses 83,525 hectares, of which 66,958 hectares are water (80%). The wet-dry zone encompasses 171,893 hectares, of which 104,733 hectares are water (61%). The high salinity zone encompasses 125,705 hectares, of which 113,369 hectares are water (90%). There is a clear trend of increasing water habitat in the four zones over the past 30 years, and oysters are now cultivated on bottoms that were once marsh. The map should be useful in managing the effects upon oysters of freshwater diversions into the estuaries. It provides a pre-diversion record of the location of oyster resource zones and should prove helpful in

  17. Differential proteomic responses of selectively bred and wild-type Sydney rock oyster populations exposed to elevated CO2.

    PubMed

    Thompson, E L; O'Connor, W; Parker, L; Ross, P; Raftos, D A

    2015-03-01

    Previous work suggests that larvae from Sydney rock oysters that have been selectively bred for fast growth and disease resistance are more resilient to the impacts of ocean acidification than nonselected, wild-type oysters. In this study, we used proteomics to investigate the molecular differences between oyster populations in adult Sydney rock oysters and to identify whether these form the basis for observations seen in larvae. Adult oysters from a selective breeding line (B2) and nonselected wild types (WT) were exposed for 4 weeks to elevated pCO2 (856 μatm) before their proteomes were compared to those of oysters held under ambient conditions (375 μatm pCO2 ). Exposure to elevated pCO2 resulted in substantial changes in the proteomes of oysters from both the selectively bred and wild-type populations. When biological functions were assigned, these differential proteins fell into five broad, potentially interrelated categories of subcellular functions, in both oyster populations. These functional categories were energy production, cellular stress responses, the cytoskeleton, protein synthesis and cell signalling. In the wild-type population, proteins were predominantly upregulated. However, unexpectedly, these cellular systems were downregulated in the selectively bred oyster population, indicating cellular dysfunction. We argue that this reflects a trade-off, whereby an adaptive capacity for enhanced mitochondrial energy production in the selectively bred population may help to protect larvae from the effects of elevated CO2 , whilst being deleterious to adult oysters. PMID:25689603

  18. Ingestion of Nanoplastics and Microplastics by Pacific Oyster Larvae.

    PubMed

    Cole, Matthew; Galloway, Tamara S

    2015-12-15

    Plastic debris is a prolific contaminant effecting freshwater and marine ecosystems across the globe. Of growing environmental concern are "microplastics"and "nanoplastics" encompassing tiny particles of plastic derived from manufacturing and macroplastic fragmentation. Pelagic zooplankton are susceptible to consuming microplastics, however the threat posed to larvae of commercially important bivalves is currently unknown. We exposed Pacific oyster (Crassostrea gigas) larvae (3-24 d.p.f.) to polystyrene particles spanning 70 nm-20 μm in size, including plastics with differing surface properties, and tested the impact of microplastics on larval feeding and growth. The frequency and magnitude of plastic ingestion over 24 h varied by larval age and size of polystyrene particle (ANOVA, P < 0.01), and surface properties of the plastic, with aminated particles ingested and retained more frequently (ANOVA, P < 0.01). A strong, significant correlation between propensity for plastic consumption and plastic load per organism was identified (Spearmans, r = 0.95, P < 0.01). Exposure to 1 and 10 μm PS for up to 8 days had no significant effect on C. gigas feeding or growth at <100 microplastics mL(-1). In conclusion, whil micro- and nanoplastics were readily ingested by oyster larvae, exposure to plastic concentrations exceeding those observed in the marine environment resulted in no measurable effects on the development or feeding capacity of the larvae over the duration of the study. PMID:26580574

  19. Larviphagy in native bivalves and an introduced oyster

    NASA Astrophysics Data System (ADS)

    Troost, Karin; Kamermans, Pauline; Wolff, Wim J.

    2008-10-01

    Introduced Pacific oysters Crassostrea gigas have expanded rapidly in the Dutch Oosterschelde estuary, while stocks of native bivalves declined slightly. As a consequence, total filtration pressure increased significantly, which may affect the mortality of bivalve larvae. Better escape abilities in Pacific oyster larvae might be a contributing factor to their rapid geographic expansion. To study whether C. gigas larvae are filtered less than larvae of native bivalves, we investigated filtration and ingestion of the larvae of the native Mytilus edulis and introduced C. gigas by the adults of C. gigas and M. edulis as well as the native Cerastoderma edule. We measured filtration rates of C. gigas and M. edulis larvae by the adult bivalves ( C. gigas, M. edulis and C. edule), and compared these to filtration rates of algae. Additionally, we studied the fate of filtered larvae. All three adult species filtered both C. gigas and M. edulis larvae. M. edulis larvae were filtered by all three bivalve species with the same filtration rates as algae, whereas filtration rates of C. gigas larvae were roughly 50% lower than filtration rates of algae. This suggests that C. gigas larvae can somehow reduce their filtration risk, whereas larvae of M. edulis cannot. The majority of filtered C. gigas and M. edulis larvae were ingested.

  20. Aeromonas hydrophila Sepsis Associated with Consumption of Raw Oysters

    PubMed Central

    Goldman, John; Cheriyath, Pramil; Nookala, Vinod

    2014-01-01

    Introduction. Aeromonas hydrophila is a gram negative bacillus that is native to aquatic environments that is increasingly reported in humans. This case is remarkable for A. hydrophila with an initial presentation of acute pancreatitis. Case Presentation. A 61-year-old male presented to the emergency department with nausea, vomiting, and abdominal pain for two days. His past medical history was significant for alcohol abuse. Initial laboratory examination showed an elevated white blood cell count, elevated lipase, and elevated liver function tests (LFT). Computer tomography (CT) showed peripancreatic inflammatory changes and retroperitoneal free fluid, suggestive of acute pancreatitis. The patient was treated with intravenous (IV) fluids and IV meropenem. After two days, the patient developed sepsis and respiratory failure and was intubated. Blood cultures were positive for Aeromonas hydrophila sensitive to ciprofloxacin which was added to his treatment. Additionally, it was discovered that this patient had recently vacationed in Florida where he consumed raw oysters. He was discharged home on the eighth day of the hospital admission. Conclusion. This is a rare case of A. hydrophila sepsis in an elderly patient with acute pancreatitis and a history of consumption of raw oysters. This case suggests that A. hydrophila can cause disseminated infection in immunocompetent individuals. PMID:25506003

  1. Aeromonas hydrophila Sepsis Associated with Consumption of Raw Oysters.

    PubMed

    Nikiforov, Ivan; Goldman, John; Cheriyath, Pramil; Vyas, Anix; Nookala, Vinod

    2014-01-01

    Introduction. Aeromonas hydrophila is a gram negative bacillus that is native to aquatic environments that is increasingly reported in humans. This case is remarkable for A. hydrophila with an initial presentation of acute pancreatitis. Case Presentation. A 61-year-old male presented to the emergency department with nausea, vomiting, and abdominal pain for two days. His past medical history was significant for alcohol abuse. Initial laboratory examination showed an elevated white blood cell count, elevated lipase, and elevated liver function tests (LFT). Computer tomography (CT) showed peripancreatic inflammatory changes and retroperitoneal free fluid, suggestive of acute pancreatitis. The patient was treated with intravenous (IV) fluids and IV meropenem. After two days, the patient developed sepsis and respiratory failure and was intubated. Blood cultures were positive for Aeromonas hydrophila sensitive to ciprofloxacin which was added to his treatment. Additionally, it was discovered that this patient had recently vacationed in Florida where he consumed raw oysters. He was discharged home on the eighth day of the hospital admission. Conclusion. This is a rare case of A. hydrophila sepsis in an elderly patient with acute pancreatitis and a history of consumption of raw oysters. This case suggests that A. hydrophila can cause disseminated infection in immunocompetent individuals. PMID:25506003

  2. Polynuclear aromatic hydrocarbons in oyster tissue around three coastal marinas

    SciTech Connect

    Marcus, J.M.; Stokes, T.P.

    1985-12-01

    Marinas present the potential for introduction of various pollutants into the surrounding waters such as coliform bacteria, primary pathogens, heavy metals, and petroleum hydrocarbons. Little data have been presented specifically addressing the effects of recreational marinas on petroleum hydrocarbon levels or, for that matter, other constituent levels in oysters near those marinas. In order to obtain such data, a comprehensive assessment of water and oyster quality around three coastal marinas was conducted by the South Carolina Department of Health and Environmental control (SCDHEC) during 1983. Polynuclear aromatic hydrocarbons (PAH) were selected as the petroleum hydrocarbon fraction of interest since they are mainly of pyrogenic origin; have been shown to be the most toxic/carcinogenic fraction of oil; have been shown to affect the respiration and heart rates of mussels; and have been shown to be linked to neoplasia in clams and proliferative disorders in mussels. C. virginica was chosen as the mollusc of interest because of its widespread distribution in the estuaries of South Carolina, its importance as an economic and recreational resource, and its suitability as a sentinel organism for monitoring coastal pollution.

  3. Heavy metals in oyster tissue around three coastal marinas

    SciTech Connect

    Marcus, J.M.; Thompson, A.M.

    1986-04-01

    The past decade has presented an unprecedented period of growth and development along the coastline of South Carolina. The majority of this development has been to serve the recreation and tourism industry and, as such, has included the construction of numerous recreational marinas in the coastal waters of the State. Various plans have been presented for the siting of marinas in pristine estuarine waters. This has raised much concern due to the possible impacts of such development on the plentiful oyster resource found in those waters. Marinas present the potential for the introduction of pollutants such as heavy metals into the surrounding waters. This investigation was conducted by the South Carolina Department of Health and Environmental Control (SCDHEC) during 1983, and yielded a multifaceted data base composed of physiocochemical and bacteriological analyses from water, chemical analyses from sediment and chemical/bacteriological physiological analyses from the American oyster, Crassostrea virginica (Gmelin). C. virginica was chosen as the organism of interest due to its wide distribution in the estuaries of South Carolina, its importance as an economic and recreational resource and its suitability as a sentinel organism for monitoring coastal pollution.

  4. Richness and distribution of tropical oyster parasites in two oceans.

    PubMed

    Pagenkopp Lohan, Katrina M; Hill-Spanik, Kristina M; Torchin, Mark E; Aguirre-Macedo, Leopoldina; Fleischer, Robert C; Ruiz, Gregory M

    2016-08-01

    Parasites can exert strong effects on population to ecosystem level processes, but data on parasites are limited for many global regions, especially tropical marine systems. Characterizing parasite diversity and distributions are the first steps towards understanding the potential impacts of parasites. The Panama Canal serves as an interesting location to examine tropical parasite diversity and distribution, as it is a conduit between two oceans and a hub for international trade. We examined metazoan and protistan parasites associated with ten oyster species collected from both Panamanian coasts, including the Panama Canal and Bocas del Toro. We found multiple metazoan taxa (pea crabs, Stylochus spp., Urastoma cyrinae). Our molecular screening for protistan parasites detected four species of Perkinsus (Perkinsus marinus, Perkinsus chesapeaki, Perkinsus olseni, Perkinsus beihaiensis) and several haplosporidians, including two genera (Minchinia, Haplosporidium). Species richness was higher for the protistan parasites than for the metazoans, with haplosporidian richness being higher than Perkinsus richness. Perkinsus species were the most frequently detected and most geographically widespread among parasite groups. Parasite richness and overlap differed between regions, locations and oyster hosts. These results have important implications for tropical parasite richness and the dispersal of parasites due to shipping associated with the Panama Canal. PMID:27263626

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

    PubMed

    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. PMID:25054140

  6. Differential Response of Oyster Shell Powder on Enzyme Profile and Nutritional Value of Oyster Mushroom Pleurotus florida PF05

    PubMed Central

    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. PMID:25054140

  7. ESTABLISHING MINIMUM FLOWS AND LEVELS OF FRESHWATER IN THE CALOOSAHATCHEE RIVER, FLORIDA, USING RESPONSES OF OYSTERS.

    EPA Science Inventory

    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 ...

  8. Fresh Water Inflow and Oyster Productivity in Apalachicola Bay, FL (USA)

    EPA Science Inventory

    Apalachicola Bay lies at the mouth of the Apalachicola River, where seasonally variable freshwater inflows and shifting winds support an unusually productive and commercially important oyster fishery. While there is concern that upstream water withdrawals may impact the fishery,...

  9. Detection of enteric viruses in oysters by using the polymerase chain reaction.

    PubMed Central

    Atmar, R L; Metcalf, T G; Neill, F H; Estes, M K

    1993-01-01

    A procedure for the detection of enteric viral nucleic acid in oysters by the polymerase chain reaction was developed. Known quantities of poliovirus type 1 were seeded into oysters. Virus was extracted and concentrated by using organic flocculation and polyethylene glycol precipitation. Inhibitors of reverse transcription-polymerase chain reaction were present in the oyster extracts, preventing amplification of target viral nucleic acid. The use of cetyltrimethylammonium bromide precipitation sufficiently removed inhibitors to allow detection of as few as 10 PFU of poliovirus. Norwalk virus also could be detected after being seeded into oysters. This methodology may be useful for the detection of these and other shellfish-borne viral pathogens. Images PMID:8382024

  10. INFLUENCE OF SEASONAL FACTORS ON OYSTER HEMOCYTE KILLING OF VIBRIO PARAHEMOLYTICUS

    EPA Science Inventory

    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...

  11. A metabolomic investigation of the effects of metal pollution in oysters Crassostrea hongkongensis.

    PubMed

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

    2015-01-15

    Metal pollution has been of great concern in the estuaries in Southern China. In this study, metabolic differences between oysters Crassostrea hongkongensis from clean and metal-polluted sites were characterized using NMR-based metabolomics. We collected oyster samples from one clean (Jiuzhen) and two metal polluted sites (Baijiao and Fugong). The metal concentrations in oyster gills indicated that both the Baijiao and Fugong sites were severely polluted by several metals, including Cr, Ni, Cu, Zn, Ag, Cd and Pb. In particular, Cu and Zn were the major contaminants from the Baijiao and Fugong sites. Compared with those oysters from the clean site (JZ), metal pollution in BJ and FG induced disturbances in osmotic regulation and energy metabolism via different metabolic pathways, as indicated by different metabolic biomarkers. This study demonstrates that NMR-based metabolomics is a useful tool for characterizing metabolic responses induced by metal pollution. PMID:25499180

  12. The role of oyster restoration and aquaculture in nitrogen removal within a Rhode Island estuary

    EPA Science Inventory

    Coastal systems are increasingly impacted by over-enrichment of nutrients, which has cascading effects for ecosystem functioning. Oyster aquaculture and restoration are hypothesized to mitigate excessive nitrogen (N) loads via assimilation, burial, or benthic denitrification. Stu...

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

    PubMed

    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. PMID:24871274

  14. A metabolomic study on the biological effects of metal pollutions in oysters Crassostrea sikamea.

    PubMed

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

    2016-01-15

    Metal pollution has become a great threat to organisms in the estuaries in South China. In the present study, the oysters Crassostrea sikamea were collected from one clean (Jiuzhen) and five metal polluted sites (Baijiao, Fugong, Gongqian, Jinshan and Songyu). The tissue metal concentrations in oysters indicated that the five metal sites were polluted by several metals, including Cr, Ni, Co, Cu, Zn, Ag, Cd and Pb with different patterns. Especially, Cu and Zn were the major contaminants in Baijiao, Fugong and Jinshan sites. The metabolic responses in oysters C. sikamea indicated that the metal pollutions in BJ, FG, JS and SY sites induced disturbances in osmotic regulation and energy metabolism via different metabolic pathways. However, the metal pollution in GQ site mainly influenced the osmotic regulation in the oysters C. sikamea. This study demonstrates that NMR-based metabolomics is useful to characterize metabolic responses induced by metal pollution. PMID:26616746

  15. IN VITRO KILLING OF PERKINSUS MARINUS BY HEMOCYTES OF OYSTERS CRASSOSTREA VIRGINICA

    EPA Science Inventory

    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...

  16. THE EFFECT OF PCBS ON GLYCOGEN RESERVES IN THE EASTERN OYSTER CRASSOSTREA VIRGINICA. (R825349)

    EPA Science Inventory

    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...

  17. The role of oyster restoration and aquaculture in nutrient cycling within a Rhode Island estuary

    EPA Science Inventory

    Coastal ecosystems are increasingly impacted by over-enrichment of nutrients, which has cascading effects for other organisms. Oyster aquaculture and restoration are hypothesized to mitigate excessive nitrogen (N) loads via benthic denitrification. However, this has not been exam...

  18. WATER QUALITY AND OYSTER HEALTH (CRASSOSTREA VIRGINICA): AN INTEGRATED APPROACH TO DETERMINING HABITAT RESTORATION POTENTIAL

    EPA Science Inventory

    Volety, Aswani K., S. Gregory Tolley and James T. Winstead. 2001. Water Quality and Oyster Health (Crassostrea virginica): An Integrated Approach to Determining Habitat Restoration Potential (Abstract). Presented at the 5th International Conference on Shellfish Restoration, 18-21...

  19. EFFECTS OF FRESHWATER RELEASES AND SEASON ON OYSTERS (CRASSOSTREA VIRGINICA) IN CALOOSAHATCHEE ESTUARY, FLORIDA

    EPA Science Inventory

    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...

  20. EFFECTS OF SEASONAL AND WATER QUALITY PARAMETERS ON OYSTERS (CRASSOSTREA VIRGINICA) AND ASSOCIATED FISH POPULATIONS.

    EPA Science Inventory

    Influence of water quality and seasonal changes on disease prevalence and intensity of Perkinsus marinus, gonadal condition, recruitment potential, growth of caged juvenile oysters, and habitat suitability of reefs for fishes and macrobenthic invertebrates were measured in Callos...

  1. Modeling and Mapping Oyster Norovirus Outbreak Risks in Gulf of Mexico Using NASA MODIS Aqua Data

    NASA Astrophysics Data System (ADS)

    Deng, Z.; Wang, J.

    2015-12-01

    Norovirus is a highly infectious virus and the leading cause of foodborne disease outbreaks such as oyster norovirus outbreaks. Currently, there is no vaccine to prevent norovirus infection and no drug to treat it. This paper presents an integrated modeling and mapping framework for predicting the risk of norovirus outbreaks in oyster harvesting waters in the Northern Gulf of Mexico coast. The framework involves (1) the construction of three novel remote sensing algorithms for the retrieval of sea surface salinity, sea surface temperature, and gage height (tide level) using NASA MODIS Aqua data; (2) the development of probability-based Artificial Neural Network (ANN) model for the prediction of oyster norovirus outbreak risk, and (3) the application of the Local Indicators of Spatial Association (LISA) for mapping norovirus outbreak risks in oyster harvesting areas in the Northern Gulf of Mexico using the remotely sensed NASA data, retrieved data from the three remote sensing algorithms, and the ANN model predictions. The three remote sensing algorithms are able to correctly retrieve 94.1% of sea surface salinity, 94.0% of sea surface temperature, and 77.8% of gage height observed along the US coast, including the Pacific coast, the Gulf of Mexico coast, and the Atlantic coast. The gage height, temperature, and salinity are the three most important explanatory variables of the ANN model in terms of spatially distributed input variables. The ANN model is capable of hindcasting/predicting all oyster norovirus outbreaks occurred in oyster growing areas along the Gulf of Mexico coast where environmental data are available. The integrated modeling and mapping framework makes it possible to map daily risks of norovirus outbreaks in all oyster harvesting waters and particularly the oyster growing areas where no in-situ environmental data are available, greatly improving the safety of seafood and reducing outbreaks of foodborne disease.

  2. Depuration of metals by the green-colored oyster Crassostrea sikamea.

    PubMed

    Wang, Lei; Wang, Wen-Xiong

    2014-10-01

    The accumulation of metals (especially copper) in oysters has led to green-color now being found in Chinese estuaries. In the present study, the authors quantified the depuration of 8 metals (Ag, Cd, Co, Cr, Cu, Ni, Pb, and Zn) in green-colored oysters (Crassostrea sikamea) collected from an estuary that is heavily contaminated by metals as a result of industrial effluent releases. The oysters were depurated under laboratory conditions for 4 mo; the accumulated concentrations and the subcellular distribution of metals were measured at different time intervals. Results showed that the green color of oysters faded to light yellow (nearly normal) after 4 mo of depuration. Depuration of metals could be described by a first-order kinetic process. The calculated overall depuration rate constants of metals were in the range of 0.008 d(-1) to 0.024 d(-1) , with a biological retention half-life of 30 d to 70 d. The depuration rates of green-colored contaminated oysters were significantly higher for Cd, Cu, Cr, and Ni than the rates of oysters from a less contaminated site, whereas the depuration rates of Ag, Co, Pb, and Zn were comparable between the 2 populations. When corrected for the change of oyster tissue weight, the actual efflux rate constants of the metals (0.0708-0.1014 d(-1) ) were much higher than the overall depuration rate constants. Cellular debris and metallothionein-like proteins were the important fractions binding with the metals in the oysters. Significant changes in metal subcellular distribution were observed during the 4-mo depuration for Ag, Cd, Cu, and Zn. Metallothionein-like protein became more important in sequestering the metals during the depuration period, with a concomitant decrease in metals associated with the cellular debris fraction. PMID:25053576

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Transcriptome analysis of biomineralisation-related genes within the pearl sac: host and donor oyster contribution.

    PubMed

    McGinty, E L; Zenger, K R; Jones, D B; Jerry, D R

    2012-03-01

    Cultured pearl production is a complex biological process involving the implantation of a mantle graft from a donor pearl oyster along with a bead nucleus into the gonad of a second recipient host oyster. Therefore, pearl production potentially involves the genetic co-operation of two oyster genomes. Whilst many genes in the mantle tissue have been identified and linked to shell biomineralisation in pearl oysters, few studies have determined which of these biomineralisation genes are expressed in the pearl sac and potentially linked to pearl biomineralisation processes. It is also uncertain whether the host or donor oyster is primarily responsible for the expression of biomineralisation genes governing pearl formation, with only two shell matrix proteins previously identified as being expressed by the donor oyster in the pearl sac. To further our understanding of pearl formation, the pearl sac transcriptome of Pinctada maxima and Pinctada margaritifera was each sequenced to an equivalent 5× genome coverage with putative molluscan biomineralisation-related genes identified. Furthermore, the host and donor contribution of these expressed genes within the pearl sac were quantified using a novel approach whereby two pearl oyster species harbouring unique genomes, P. maxima or P. margaritifera, were used to produce xenografted pearl sacs. A total of 19 putative mollusc biomineralisation genes were identified and found to be expressed in the pearl sacs of P. maxima and P. margaritifera. From this list of expressed genes, species-diagnostic single nucleotide polymorphisms (SNP) were identified within seven of these genes; Linkine, N66, Perline, N44, MSI60, Calreticulin and PfCHS1. Based on the presence/absence of species diagnostic gene transcripts within xenografted pearl sacs, all seven genes were found to be expressed by the species used as the donor oyster. In one individual we also found that the host was expressing Linkine. These results convincingly show for the

  5. Using oysters as anthropogenic indicators to evaluate the occurrence of the wastewater contamination of the estuaries

    NASA Astrophysics Data System (ADS)

    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.

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

    USGS Publications Warehouse

    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.

  7. Fluxomics of the Eastern Oyster for Environmental Stress Studies

    PubMed Central

    Tikunov, Andrey P.; Stoskopf, Michael K.; Macdonald, Jeffrey M.

    2014-01-01

    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). PMID:24958387

  8. Identification of potential general markers of disease resistance in American oysters, Crassostrea virginica through gene expression studies.

    PubMed

    Nikapitiya, Chamilani; McDowell, Ian C; Villamil, Luisa; Muñoz, Pilar; Sohn, SaeBom; Gomez-Chiarri, Marta

    2014-11-01

    Several diseases have a significant impact on American oyster populations in the Atlantic coasts of North America. Knowledge about the responses of oysters to pathogenic challenge could help in identifying potential markers of disease resistance and biomarkers of the health status of an oyster population. A previous analysis of the transcriptome of resistant and susceptible American oysters in response to challenge with the bacterial pathogen Roseovarius crassostreae, as well as sequencing of suppression subtractive hybridization libraries from oysters challenged with the protozoan parasite Perkinsus marinus, provided a list of genes potentially involved in disease resistance or susceptibility. We investigated the patterns of inducible gene expression of several of these genes in response to experimental challenge with the oyster pathogens R. crassostreae, Vibrio tubiashii, and P. marinus. Oysters showing differential susceptibility to R. crassostreae demonstrated differential patterns of expression of genes coding for immune (serine protease inhibitor-1, SPI1) and stress-related (heat shock protein 70, HSP70; arginine kinase) proteins 30 days after challenge with this bacterial pathogen. Differential patterns of expression of immune (spi1, galectin and a matrix metalloproteinase) and stress-related (hsp70, histone H4, and arginine kinase) genes was observed in hemocytes from adult oysters challenged with P. marinus, but not with V. tubiashii. While levels of spi1 expression in hemocytes collected 8 and 21 days after P. marinus challenge were negatively correlated with parasite load in oysters tissues at the end of the challenge (62 days), levels of expression of hsp70 in hemocytes collected 1-day after challenge were positively correlated with oyster parasite load at 62 days. Our results confirm previous research on the role of serine protease inhibitor-1 in immunity and disease resistance in oysters. They also suggest that HSP70 and histone H4 could be used

  9. Pesticides and Ostreid Herpesvirus 1 Infection in the Pacific Oyster, Crassostrea gigas

    PubMed Central

    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. PMID:26107171

  10. Upregulation in response to infection and antibacterial activity of oyster histone H4.

    PubMed

    Dorrington, Tarquin; Villamil, Luisa; Gómez-chiarri, Marta

    2011-01-01

    Several histones and histone-derived peptides have been shown to have antimicrobial activity and a potential role in innate immune defenses. A histone H4 sequence was identified in a subtractive suppression library containing genes upregulated in American cupped oysters, Crassostrea virginica, in response to challenge with the protozoan parasite Perkinsus marinus. Oyster histone H4 protein levels significantly increased in hemocyte lysates and cell free hemolymph of oysters experimentally challenged with P. marinus. The complete histone H4 coding sequence of C. virginica was cloned into a Saccharomyces cerevisiae yeast expression system and recombinant expression was confirmed using SDS-PAGE analysis and western blot. Delivery of yeast cells expressing recombinant oyster histone H4 into the gut of brine shrimp, Artemia salinas, challenged with a streptomycin resistant strain of Vibrio anguillarum resulted in a significant and dose-dependent decrease in the load of V. anguillarum. Purified recombinant histone H4 showed antimicrobial activity against V. anguillarum and Escherichia coli at micromolar concentrations, but did not affect the viability of P. marinus in culture. These results support the role of histone H4 in the defense of oysters against bacterial infection and validate the use of a novel oyster antimicrobial H4 in a yeast feed-based delivery system for the treatment of bacterial infections in aquaculture applications. PMID:20883794