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Book Species Profiles

    Species Profiles

    Book Details:
  • Author : Gilbert B. Pauley
  • Publisher :
  • Release : 1988
  • ISBN :
  • Pages : 40 pages

Download or read book Species Profiles written by Gilbert B. Pauley and published by . This book was released on 1988 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Summer Mortality of Pacific Oyster Crassostrea Gigas

Download or read book Summer Mortality of Pacific Oyster Crassostrea Gigas written by Jean-François Samain and published by Editions Quae. This book was released on 2008-02-13 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mass oyster mortalities have been known for many years throughout the world, but no strictly pathological explication has been found. This book describes how environmental influences, reproduction, stress, genetics, pathogens and temperature contribute to oyster summer mortality in France. An interaction model is derived from the results and recommendations are made for forecasting and managing risk factors.

Book Species Profiles

Download or read book Species Profiles written by Gilbert B. Pauley and published by . This book was released on 1988 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Influence of Environmental Factors Upon the Growth and Survival of the Pacific Oyster Crassostrea Gigas Thunberg microform

Download or read book The Influence of Environmental Factors Upon the Growth and Survival of the Pacific Oyster Crassostrea Gigas Thunberg microform written by James R. Brown and published by National Library of Canada. This book was released on 1986 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Evaluation of the Deleterious Effects of Heavy Metals and Pesticides on Early Life Stages and Gametes of the Pacific Oyster Crassostrea Gigas

Download or read book Evaluation of the Deleterious Effects of Heavy Metals and Pesticides on Early Life Stages and Gametes of the Pacific Oyster Crassostrea Gigas written by Huong Mai and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The coastal areas are subject to multiple anthropogenic pressures including chemical pollution that can pose a real risk to the sustainability of aquatic species. The Arcachon Bay, macrotidal lagoon located on the French Atlantic coast, is the important ecosystem for oyster farming. But for several years, the oyster farms face lower recruitment and high mortality of oyster spat. Chemical contamination of the environment as a factor that may contribute to the observed effects on oysters has so far not been investigated.The present thesis aimed at evaluating through different approaches, of the potential toxicity of heavy metals and pesticides representative of the Arcachon Bay contamination on the early life stages of the Pacific oyster, Crassostrea gigas. Embryotoxicity, genotoxicity and expression levels of eleven targeted genes were studied. Firstly, different pesticides (S-metolachlor, irgarol, and diuron) and metals (copper and cadmium) were separately tested to determine their spectrum of effects. It were shown that exposure of gametes and embryos of oyster to environmental concentrations of pesticides and copper increased developmental abnormalities and DNA damage, and reduced fertilization success and affected offpring quality. Cadmium, meanwhile, showed no embryotoxic and genotoxic effects at the concentrations found in the Arcachon Bay. Metabolites of metolachlor, metolachlor ESA and metolachlor OA, are found in the Arcachon Bay at higher concentrations than their parent compound. The results showed that these metabolites were less embryotoxic and genotoxic on oyster embryos and spermatozoa than metolachor. Significant changes in expression of genes involved in antioxidant defense were observed for oyster larvae exposed to metolachlor and metolachlor ESA. Toxicity of mixtures of pesticides representative of the Arcachon Bay contamination with and without copper was then evaluated. Exposures of oyster embryos to these mixtures lead to development defects, DNA damage and changes in the expression of genes involved mainly in oxidative stress responses. Finally, mapping of toxicity of sediments from the Arcachon Bay was conducted for four seasons of 2011 with the oyster embryo-larvae assay. Sediments collected from Arguin exhibited low toxicity, regardless any season. In contrast, sediments from Le Tès showed higher toxicity in spring and summer seasons compared to winter season.From this work, it can be hypothesized that chemical contamination of the Arcachon Bay represents a threat for oyster reproduction and development.

Book Ecophysiological Tolerances of the Pacific Oyster Crassostrea Gigas with Regard to the Potential Spread of Populations in South Australian Waters

Download or read book Ecophysiological Tolerances of the Pacific Oyster Crassostrea Gigas with Regard to the Potential Spread of Populations in South Australian Waters written by Kathryn Wiltshire and published by . This book was released on 2007 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Effects of Ocean Acidification on Multiple Life History Stages of the Pacific Oyster Crassostrea Gigas

Download or read book The Effects of Ocean Acidification on Multiple Life History Stages of the Pacific Oyster Crassostrea Gigas written by Emma B. Timmins-Schiffman and published by . This book was released on 2014 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: As global climate change accelerates, due in large part to increasing emissions of carbon dioxide and other greenhouse gases from fossil fuel use, agriculture, and large-scale changes in land use, natural ecosystems bear the consequences. For marine systems these include increased mean seawater temperature, changes in carbonate chemistry equilibria, and increased pollutant loading due to non-point run-off, among other effects. Human-induced environmental changes will not have the same magnitude of effect in all regions, but on average the changes occurring are rapid and significant. Natural populations will either need to acclimatize and/or adapt, or shift their ranges to enable continued existence. This dissertation explores the effects of ocean acidification on the Pacific oyster, Crassostrea gigas. Oysters are sedentary and inhabit a naturally variable environment (the intertidal zone) and thus may be pre-adapted to withstand rapid environmental change. Oysters and similarly sedentary organisms are ideal for investigating the effects of environmental change on biology because they are not able to escape these changes, but must respond physiologically (acclimatize) if they are to survive. Due to this ecological history, oysters provide a model that allows us to explore potential physiological mechanisms that are needed in a response to specific environmental changes as well as the limits of these mechanisms. In the first chapter, the effects of elevated partial pressure of CO2 (pCO2, a major driver of ocean acidification) on oyster larvae are explored. Larvae were exposed to low pH during early development, a period that included the transition from energetic dependence on maternally derived lipids to dependence on exogenous resources. Larvae were found to experience a developmental delay at elevated pCO2, manifested as smaller size and slower rate of shell deposition. These significant effects of ocean acidification on early larval development may indicate a bottleneck in the oyster life cycle as the pH of marine waters decreases. Subsequent research has shown that these effects at early larval stages can carry over into later stages after settlement in another oyster species (Hettinger et al. 2012). In order to better understand the effects of environmental change on oyster physiology, we developed proteomic tools to explore changes in protein pathways in oyster gill (ctenidia) tissue. The second chapter explores the gill proteome (suite of expressed proteins) of adult oysters. Characterization of the proteome provides insight into the physiological mechanisms that may be available to the oyster during response to an environmental stress. The results revealed that the ctenidia proteome includes a diverse array of proteins that accomplish many functions and that it is a metabolically active tissue. The proteome sequencing lays the groundwork for exploring how ocean acidification affects various proteomic pathways in the tissue that acts as the interface between the oyster and its environment. Lastly, the adult oyster response to ocean acidification and a second stress are explored via proteomics, fatty acid profiles, glycogen content, shell microstructure, and mortality in response to heat shock. There was a significant impact of ocean acidification on oyster shell integrity, but no effects after one month of exposure on relative amounts of fatty acid, glycogen or response to acute heat shock. Through the proteomic analysis, we revealed an active and significant proteomic response to ocean acidification exposure, uncovering some of the mechanisms behind the observed macro-phenotypic changes. Additionally, the proteomic response to mechanical stimulation was largely altered between low and high pCO2, suggesting that ocean acidification can fundamentally change how oysters respond to a second stress.

Book Biological Effects of Contaminants

Download or read book Biological Effects of Contaminants written by J. E. Thain and published by . This book was released on 1991 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Regulation of Environmental Science

Download or read book Regulation of Environmental Science written by David E. Smith and published by . This book was released on 1993 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The native Chesapeake Bay oyster stocks and harvest are at their lowest level in history, and the Virginia oyster industry is being threatened with economic extinction. A number of factors have contributed to this decline, but the three most often cited are: overfishing; environmental degradation, such as diminished water quality and habitat loss; and oyster disease. Concern over the ecologic and economic impact of this decline has led some Virginia scientists to look for other oyster species which may in the long term be used as a substitute species for "Crassostrea virginica". The introduction of an exotic species of oyster into the Chesapeake Bay has social, economic, ecological and political ramifications. In early spring of 1990 the Virginia Institute of Marine Science (VIMS) of the College of William and Mary submitted a proposal to the Virginia Marine Resources Commission requesting permission to conduct an open water experiment using the Japanese oyster, "Crassostrea gigas", in the York River, one of the tidal rivers of the Chesapeake Bay. The controversy surrounding this proposal and its approval and denial described here, has involved representatives from several state governments, various components of the Chesapeake Bay oyster industry, non-​governmental organizations and public interest groups"--National Sea Grant Library publication website.