Download or read book Ocean Acidification Affects Larval Swimming in Ostrea Lurida But Not Crassostrea Gigas written by Shannon Buckham and published by . This book was released on 2015 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecophysiology and Ocean Acidification in Marine Mollusks written by Youji Wang and published by Elsevier. This book was released on 2024-08-23 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecophysiology and Ocean Acidification in Marine Mollusks: From Molecule to Behavior provides an extensive overview of the latest research on the various ecophysiological effects of ocean acidification on marine mollusks. This book synthesizes historical information and recent findings on the effects of environmental change, ocean warming, and acidification on key mollusks and their life-history. It also discusses the underlying mechanisms underpinning the effects of ocean warming and acidification. Written by internationally recognized experts in the field of marine biology, this book systematically examines the effects of ocean acidification on the reproduction, growth and development, physiological metabolism, immunity, and behavior of marine mollusks. The book concludes by discussing the implications of current research, acknowledging data limitations in the field, and proposing future research directions, providing a better understanding of the potential impacts of ocean acidification on mollusks and the global aquaculture industry and inspiring new thinking for future research practices. It will be an indispensable resource for researchers, practitioners, undergraduate and graduate students, conservationists, and aquaculturists alike who are interested in marine environmental change, ecology, physiology, and marine biology. Describes the causes and consequences of ocean acidification in the marine environment Summarizes our modern understanding of the impact of ocean acidification on the physiology and behavior of marine mollusks Discusses the limitations of existing studies Proposes future research directions on ocean acidification and marine mollusks

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.

Download or read book Ocean Acidification Influences on Physiology and Epigenetics in the Pacific Oyster Crassostrea Gigas written by Yaamini Ranjani Venkataraman and published by . This book was released on 2021 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: As ocean acidification continues to impact marine ecosystems at unprecedented rates, phenotypicplasticity may allow organisms to withstand more stressful conditions. Genomic methods can elucidate molecular mechanisms that contribute to phenotypic plasticity, allowing for a deeper understanding of how physiological processes will be impacted by low pH. My dissertation examines the effects of ocean acidification on the Pacific oyster (Crassostrea gigas) stress response and reproduction; elucidate how exposure history impacts phenotype; and explore the role of functional role DNA methylation in somatic and reproductive tissue. I investigated the effect of regional environmental variation on the molecular physiology of C. gigas outplanted at five different estuarine sites (four in Puget Sound, one in Willapa Bay) in Washington, USA using gel-free proteomic methods. While there was no difference in survival, or any protein abundances due to pH differences between sites, C. gigas outplanted at the site with the highest temperature had significantly higher abundances of antioxidant enzymes and molecular chaperones, elucidating the molecular underpinnings of thermotolerance. In a hatchery setting, I explored the impact of ocean acidification on reproductive maturity and output. A seven week low pH exposure did not affect sex ratio or maturation stage; however, it did significantly affect survival of larvae. Even though adult oysters spent four months in ambient pH conditions between low pH exposure and strip spawning, larvae from females that experienced low pH conditions had significantly higher mortality. Finally, I conducted the first investigations examining the effect of ocean acidification in C. gigas methylomes. To investigate the role of environmentally-responsive methylation in reproductive tissue, I analyzed gonad methylomes of female C. gigas exposed to low pH. A total of 1,599 differentially methylated loci (DML) were found in gene bodies. The genic DML were associated with cilium movement, development, and cytoskeletal processes, implying a need to regulate cellular growth in the gonad in response to low pH. I then explored the influence of low pH on the somatic tissue methylome using diploid and triploid oyster ctenidia. Differences in ploidy status yielded 154 DML. These ploidy-DML were associated with cell-cell adhesion and dephosphorlylation processes, which are not commonly associated with methylome changes in organisms that undergo natural polyploidization. The 178 pH-DML were associated with processes commonly observed in oysters exposed to ocean acidification, including apoptosis, protein ubiquitination, zinc ion binding, and cytoskeletal processes. In both reproductive and somatic tissue, the enrichment of DML in genes with multiple transcripts could indicate a role for methylation to regulate gene expression via alternative splicing. Investigating the molecular underpinnings of responses to ocean acidification in C. gigas will provide a thorough understanding of this global aquaculture product’s ability to withstand future ocean conditions.

Download or read book Potential Transgenerational Effects of Ocean Acidification and Hypoxia on the Olympia Oyster Ostrea Lurida written by Bryanda J. T. Wippel and published by . This book was released on 2017 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean acidification (OA) is decreasing the pH of surface waters in Puget Sound, Washington, an area already prone to low pH from natural processes such as upwelling, freshwater inputs, and high respiration/decomposition rates. High rates of production and long residence times in Puget Sound can also lead to low dissolved oxygen (DO) levels (hypoxia) in some areas. Studies have shown the negative effects of these stressors on marine organisms, particularly calcifiers. I examined how changes in pH and oxygen in seawater affect adult fecundity and larval survival of the native Olympia oyster (Ostrea lurida). Through three discrete trials, I observed the following trends: Adult oysters conditioned at ~400 μatm released significantly more larvae than those conditioned at higher pCO2 levels ranging from 1000 to 2475 μatm pCO2. Larval survival decreased in two multi-stressor treatments when challenged with varying combinations of pCO2 and DO. Offspring of parents conditioned under high pCO2 experienced reduced survival when exposed to both high pCO2 and low DO (14.7% survival). In addition, progeny of adults conditioned under low pCO2 died when exposed to high pCO2 and high DO (22% survival). Our results suggest that elevated pCO2 negatively affects fecundity in O. lurida but that the synergistic effects of high CO2 and low DO on larval survival is more complicated than previously reported. Multigenerational, multi-stressor studies such as this are important in determining how species will respond to an environmental change in the ocean.

Download or read book Proteomic Analysis of Oyster Larvae Reveals Molecular Mechanism of Ocean Acidification and Multiple Stressor Effects written by Dineshram Ramadoss and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Proteomic Analysis of Oyster Larvae Reveals Molecular Mechanism of Ocean Acidification and Multiple Stressor Effects" by Dineshram, Ramadoss, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The increase in carbon dioxide emissions due to human activities has led to drastic variations in global climate. In addition to global warming and extreme weather patterns, the high CO2 levels have been leading to progressive ocean acidification. Compounded with other climate change related stressors, ocean acidification will hinder the ability of marine organisms to adapt to the ensuing changes and might affect human dependence on oceans as a source of food. Most marine organisms have complex life cycles, involving metamorphosis from larval to adult forms. In the early stages of life, oysters have calcium carbonate shells that are particularly sensitive to low pH, and the rapid climatic changes can compromise their metamorphosis. High temperature, low salinity and low pH resulting from ocean acidification are detrimental to both native and cultivated oyster populations. Although mechanistic studies to understand the tolerance responses of closely related species would be significant in this context, none have been reported to date. Therefore, this thesis aims to reveal the mechanisms that distinguish the "winners" from the "losers" among the selected aquatic species of commercial importance, in withstanding the stress induced by climate change. The present study employed molecular approaches to evaluate the interactive and cumulative effects of multiple stressors on large-scale cultures of pediveliger larvae from two oyster populations, Crassostrea hongkongensis and Crassostrea gigas. The study undertook transcriptomic and proteomic profiling of changes induced by ocean acidification in the larvae. The results revealed that oyster larvae could adopt an energy 'trade-off' strategy through metabolic suppression and adjust cell signalling pathways to overcome the stress induced by ocean acidification. Information from the oyster genome database facilitated the shotgun proteomics investigations on oyster larvae remarkably revealed over 1350 proteins in both the species. The study identified species- and stressor-specific tolerance responses, and survival mechanisms that preserved calcification, in oyster larvae. The larvae showed depletion of energy reserves due to enhanced metabolism, oxidative damage-induced immune response and metabolic suppression. The study reveals the existence of tolerance mechanisms in oysters that help them adapt to stresses resulting from climate change. It pioneered the use of a proteomics approach to understand the impact of multiple stressors on oyster larvae and the molecular mechanisms underlying their successful adaptation to them. Highlighted several potential possible biomarkers in this study will likely to play an important role in identifying oyster species showing heritable tolerance for future aquaculture. DOI: 10.5353/th_b5317012 Subjects: Ocean acidification Oysters - Effect of stress on

Download or read book Consequences of Global Change for Early Life Stages of the Olympia Oyster written by Annaliese Hettinger and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The nearshore marine environment is characterized by a multitude of natural and human-induced stressors. The interactive effects of stressors may complicate predicting ecological effects of global change on marine organisms. This dissertation focuses primarily on how altered seawater chemistry (ocean acidification), derived from increased atmospheric carbon dioxide, interacts with other environmental factors to influence the early life stages of Olympia oysters (Ostrea lurida). Initial laboratory experiments demonstrated that exposure of oyster larvae to high-CO2 caused lower growth rates and smaller size at settlement compared to individuals reared in ambient-CO2. Impacts were more pronounced a week after settlement, with juveniles exhibiting a larger decrease in shell growth rate compared to the negative effect on larval growth rate. The effects on juveniles arose regardless of the CO2 level oysters experienced as juveniles, indicating a strong carry-over effect from the larval phase. A combined laboratory and field approach addressed the duration of carry-over effects and how effects might be moderated in the natural environment. Juvenile oysters reared in laboratory cultures under ambient and high-CO2 as larvae were outplanted to field sites at two intertidal shore levels that differed in emersion time and temperature regime. Larval exposure to high-CO2 led to reduced growth in juveniles. Juveniles outplanted to the more stressful shore level also exhibited reduced growth compared to individuals in more benign conditions. Effects persisted halfway to reproductive age, the duration of the study. To determine if the negative effects from ocean acidification would be exacerbated or ameliorated in a low or high food environment, respectively, oyster larvae were reared at two CO2 and three food levels. Larval growth was reduced in low food and in elevated-CO2 conditions, but these factors operated additively, indicating that the effects of high-CO2 on growth did not depend on the food regime. Settlement was lower in elevated-CO2 conditions compared to ambient, and this was especially true in low food conditions. High food levels did not completely eliminate negative effects of high-CO2 on growth. A final experiment demonstrated that moderate temperature increases buffered larval and juvenile oysters from the damaging effects of high-CO2. Ocean acidification negatively impacts multiple early life history stages of Olympia oysters, and may contribute to substantial declines at the population scale. Responses are not uniform across the life cycle, and thus assessments of population responses to environmental perturbation must consider how effects propagate across life-history transitions.

Download or read book The Eastern Oyster written by Victor S. Kennedy and published by University of Maryland Sea Grant Publications. This book was released on 1996 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1966 Congress passed the National Sea Grant College Program Act to promote marine research, education, and extension services in institutions along the nation's ocean and Great Lakes coasts. In Maryland a Sea Grant Program -- a partnership among federal and state governments, universities, and industries -- began in 1977, and in 1982 the University of Maryland was named the nation's seventeenth Sea Grant College. The Maryland Sea Grant College focuses its efforts on the Chesapeake Bay, with emphasis on the marine concerns of fisheries, seafood technology, and environmental quality. The first comprehensive review of the biology of the eastern oyster in more than thirty years. The twenty-one chapters synthesize every aspect of oyster biology -- for instance, general anatomy, physiology, the circulatory system, reproduction, genetics, diseases -- and issues related to management and aquaculture.

Download or read book Examining Multigenerational Effects of Ocean Acidification on the Pacific Oyster written by Daniel Jacob Gillon and published by . This book was released on 2018 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ocean Acidification and Disease written by Elene Marie Dorfmeier and published by . This book was released on 2012 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrio tubiashii (Vt) is a causative agent of vibriosis in molluscan bivalves. Recent re-emergence of vibriosis in economically valuable shellfish, such as the Pacific oyster (Crassostrea gigas) in Washington State, has increased the urgency to understand the ecology of this pathogen. It is currently unknown how predicted environmental changes associated with ocean acidification, such as elevated surface seawater temperature, increased partial pressure of CO2 (pCO2), and Vt abundance will impact marine organismal health and disease susceptibility. This study investigates how environmental cues predicted with ocean acidification influence physiological changes and pathogenicity in Vt. Using laboratory experiments to manipulate temperature and pCO2, we examined how these environmental factors influenced pathogen growth. Larval susceptibility to vibriosis was determined by exposing C. gigas larvae to a combination of elevated pCO2 and Vt concentrations. These experiments provide insight into the environmental parameters that may drive pathogenicity or influence proliferation of the bacterium. Investigation of single and multivariate parameters such as temperature, pCO2, and pathogen levels will help assess how predicted shifts in ocean conditions can impact shellfish survival and disease resistance.

Download or read book Effects of Ocean Acidification on Early Developmental Stages of the Pacific Oyster Crassostrea Gigas in an Aquaculture Setting written by Manon Picard and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Ocean Acidification on Otoliths of Larval Estuarine and Marine Fish written by Andrea Therese Stoneman and published by . This book was released on 2016 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Early Life Stages Under Ocean Acidifcation written by Ackley Charles Lane and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Early Life Stages Under Ocean Acidifcation: Direct Effects, Parental Influence, and Adaptation" by Ackley Charles, Lane, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Anthropogenic carbon dioxide (CO2) emissions are forcing shifts in seawater carbonate chemistry. Having already caused the global average oceanic pH to drop from from 8.2 to 8.1, the trend is expected to continue in the coming centuries resulting in pH levels as low or lower than 7.4. This anthropogenically driven process is called ocean acidification, or OA. Reduced calcium carbonate due to OA threatens calcifiers as it is the building block used to calcify. For most species the process of OA will encompass many generations, and biological responses to OA will be shaped by evolutionary adaptation as the centuries progress. Adaptations to new environments can occur over tens of generations, and as such, evolution may provide an escape for some ostensibly vulnerable animals. So it is important to consider factors like multigenerational change and the potential for evolutionary adaptation when estimating the likelihood of success for any given species. In this thesis I present 1 study on the early life stages of the barnacle Balanus amphitrite and 4 studies on the early life stages of the calcifying tube worm Hydroides elegans and how they are affected by OA. By combining several controlled experiments that include quantitative genetics, fertilization kinetics, and multigenerational responses I present an in-depth, multi-perspective study of how an economically important biofouling species may fare as conditions shift over a relatively long period of time. (1) Larval survival, metamorphosis, and post-larvae calcification in response to multiple levels of seawater pH in both species. (2) Parental influence on fertilization success under future OA conditions in the broadcast spawning tube worm H. elegans. (3) Quantitative genetic analysis of multiple life history parameters, using offspring from a total of 48 mated pairs from 20 males and 13 females of H. elegans. (4) Influence of parental pH environment on performance of offspring in H. elegans. Major findings: (1) Observable effects of OA on the early life stages were only apparent in the tube worm H. elegans where growth at low pH (7.9) was reduced. This contrasted with B. amphitrite where low pH responses were only observed at the lowest, most extreme, pH (7.4). (2) Fertilization success in H. elegans was not affected by conservative OA scenarios, however, fertilization rates in different male/female combinations responded differently to different pH's. (3) H. elegans performance is significantly affected by their parents' pH environment, both maternal and paternal, however the effects of low pH were only apparent when offspring were raised at high (ambient) pH. Additionally, parental low pH experience effect on offspring revealed that maternal and paternal influence were independent, opposite and additive. (4) Lastly, metamorphosis success and growth rates in H. elegans are heritable in low pH conditions. Survival was not. Interestingly, in the lower pH environment, heritability of metamorphosis increased while heritability of growth decreased. These two ecologically and economically important biofouling species show distinct responses to low pH conditions, the barnacle being ostensibly robust to low pH while the tube worm proved sensitive to relatively conservative low pH scenarios. Using a multi-generational approach and estimating the genetic link to variation in pH r

Download or read book The Ecology of Intertidal Oyster Reefs of the South Atlantic Coast written by Leonard M. Bahr and published by . This book was released on 1981 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alien Species Alert written by Laurence Miossec and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Combined Effects of Ocean Acidification with Water Flow and Temperature on Tropical Non calcareous Macroalgae written by Maureen Ho and published by . This book was released on 2016 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vulnerability of coral reefs has substantially increased in the past few decades due to accelerating human-driven global change. The effects of ocean acidification (OA) and global warming individually and interactively have resulted in varying degrees of responses in benthic reef organisms. For non-calcareous macroalgae, the physiological and ecological responses to physical environmental changes can alter their relative abundances, which are often used as an indicator of the overall coral reef status. To better understand how fleshy macroalgae will respond to various physical parameters, three separate experiments were conducted from June 2014 to July 2015 in Moorea, French Polynesia. An important physical driver in transferring nutrients and dissolved gases to benthic reef organisms is water motion. In 2014, I tested the hypothesis that increased water motion and elevated pCO2 would benefit Amansia rhodantha (a CO2 user) more than Dictyota bartayresiana and Lobophora variegata (HCO3- users). The highest and lowest growth rates were at the intermediate and highest flow speed, respectively, for all three species. A. rhodantha exhibited the greatest reduction in biomass at reduced flow under ambient pCO2, indicating high sensitivity to mass transfer and carbon limitation. In 2015, the interactive effects of temperature and OA were tested in a two-part study on the metabolic (i.e. photosynthesis and respiration) and growth responses of D. bartayresiana and A. rhodantha. The first study in January 2015 showed that net photosynthesis in both species was affected by high pCO2 but not temperature, and the combination of temperature and OA affected respiration rates. In the second study in July 2015, metabolic rates were affected by temperature but not pCO2. Net photosynthesis and respiration of A. rhodantha were highest under OA conditions at 27.5 oC, but were reduced at 30 oC. There was no effect on metabolic rates of D. bartayresiana across all temperature treatments. The relative growth rates for D. bartayresiana were higher than A. rhodantha in the first study, while both species exhibited varying responses to treatments in the second study. Lastly, from May to June 2015, massive Porites spp. was paired with D. bartayresiana in competitive interactions at low and high flow speeds under ambient and elevated pCO2 levels. I tested the hypothesis that increased water flow would increase algal growth rates, enhancing the competitive ability of the alga against the coral. For corals, I predicted that OA and reduced water flow would negatively affect the corals, thus increasing susceptibility to algal overgrowth. Net calcification and the photosynthetic efficiency of corals were used as a proxy for fitness and health status, respectively, however neither was affected by water flow or OA. On the contrary, growth rates of D. bartayresiana were significantly reduced under low flow. The negative effects of reduced water motion on macroalgae may potentially compromise the ability of the alga to compete. The variation in water motion can affect resource acquisition and when combined with OA, can have significant implications on species interactions. These results indicate the importance of water motion in influencing macroalgal growth and provide insights to the varying responses in fleshy macroalgae to global change. Furthermore, their physiological responses may be attributed to their different carbon uptake strategies, as A. rhodantha was more sensitive to reduced flow and temperature than D. bartayresiana.

Download or read book Restoration Guidelines for Shellfish Reefs written by Simon Branigan and published by . This book was released on 2019-09-25 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: The restoration of habitat has become a priority for many citizens and governments as the ecological and societal benefits of these habitats have been become more widely recognised. This publication is intended to provide foundational information to serve as a useful starting pointfor shellfish reef restoration.