Download or read book The Distribution and Demography of the Invasive Pacific Oyster Crassostrea Gigas and Native Olympia Oyster Ostrea Lurida in the San Diego River written by Jason Langevin and published by . This book was released on 2019 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Even though the introduction of the Pacific Oyster, Crassostrea gigas, to the west coast of North America, happened roughly a century ago, it has only been in the past 15 to 20 years that C. gigas has started to become an established and conspicuous species along Southern California's coast. The establishment of C. gigas in Southern California has the potential to heavily influence many native species, as it has done globally. In Southern California, this invasion is particularly relevant for the native Olympia Oyster, Ostrea lurida. The Olympia oyster has both historical and present-day threats to its population, due to overfishing, pollution, and exotic species introductions. Understanding the distribution and demography of both species at the relatively early stage of C. gigas establishment is important for future management of both species. In order to address this, sampling was conducted along the rip rap of the San Diego River, near its connection with the Pacific Ocean. Transects were laid down at the high, mid and low intertidal, and quadrats along these transects were sampled quarterly for one year. Densities, biomass, Condition Index, length frequencies, and Von Bertalanffy growth constants were used to look at the growth of the two species over this time period. For C. gigas, growth lines were also used as a tool to estimate age and growth. This work demonstrated that O. lurida densities were in fact much greater than those of C. gigas, but that these native oysters had greater numbers in the low intertidal and diminished as tidal height increased. Crassostrea gigas numbers also decreased with increase tidal height, although less dramatically than O. lurida. Even though there is a large size difference between the two species, growth rate constants found using the Von Bertanlaffy growth model (k) in the low- and mid-intertidal combined were found to be very similar, indicating similar growth rates. Further analysis of growth rates of C. gigas across tidal zones, using growth lines, demonstrated that the growth rate decreased as tidal elevation increased. This study on the demography on native and invasive oysters in San Diego provides a foundation of baseline scientific information against which future change can be assessed, and can also inform future research directions, such as investigations of how each species interacts independently with their environment and with one another.
Download or read book Vertical Distribution of Olympia Oyster Ostrea Lurida Larvae in Fidalgo Bay WA written by Brooke A. McIntyre and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Restoring populations of native Olympia oyster (Ostrea lurida) in the Salish Sea is ecologically and socially valuable. Olympia oysters disperse as planktonic larvae that control their depth with swimming and sinking behaviors, which can affect the currents that carry them and ultimately determine dispersal. Understanding larval dispersal patterns can help prioritize restoration efforts and establish a self-sustaining network of oyster populations in the region. The purpose of this study was to determine which factors (temperature, chlorophyll-a, larval size, current speed, tidal stage) influence the vertical distribution of Olympia oyster larvae in Fidalgo Bay, which is a Washington state priority restoration area. On four consecutive days in July 2017, we collected and analyzed Olympia oyster larvae from four depths over the tidal cycle in combination with temperature and chlorophyll-a measurements. We also measured current velocities profiles in the main channel. Mixed effects modelling results indicate that larvae were distributed significantly shallower when current speeds exceeded ~25 cm s-1 and were deeper when currents were below ~25 cm s-1, but it is unclear whether distribution was due to passive or active larval movement. If larvae were behaviorally controlling their depth, they did not distribute at depth-specific temperature or chlorophyll-a conditions. Larvae did not perform tidally-timed vertical migrations and it remains unclear whether larvae exhibited an ontogenetic vertical migration strategy. Fidalgo Bay does not exhibit a two-way flow or strong vertical shear, so Olympia oyster larval vertical distribution likely has little to no effect on their transport through the main channel of the bay. These results should not be generalized to other restoration areas due to the unique conditions of this location and the possibility of larval behavioral plasticity between distinct populations of Olympia oysters. Results can inform a Fidalgo Bay larval transport model to predict dispersal patterns and prioritize Olympia oyster restoration efforts.
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:
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.
Download or read book Species Profiles written by David Couch and published by . This book was released on 1989 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Some Observations on the Pacific Oyster Ostrea Gigas Thunberg and the Native Oyster Ostrea Lurida Carpenter in Willapa Bay written by Theodore Woodruff Holway and published by . This book was released on 1934 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anthropogenic Impacts on Native Olympia Oysters written by Jillian Margaret Bible and published by . This book was released on 2016 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of anthropogenic global change on organismal performance and ecosystem functioning have been investigated across many systems. However, our ability to project future effects is limited by many uncertainties. For example, there is a pressing need to understand how multiple stressors interact and how populations of the same species vary in their response to environmental stress. This dissertation assesses impacts of anthropogenic stressors on the native Olympia oyster (Ostrea lurida), a foundation species of conservation concern in west coast estuaries. In particular, I tested whether populations of Olympia oysters are differentially susceptible to low salinity and predation pressure from invasive species and whether the timing of multiple climate-related stressors affects oyster survival. First, using oysters raised under common laboratory conditions for up to two generations, I assessed whether populations of Olympia oysters are locally adapted to their home sites and whether such adaptive differentiation leads to some oyster populations that are more tolerant than others of extreme low salinity. Field experiments revealed results that were consistent with local adaptation and laboratory experiments demonstrated that second-generation oysters from the site that experienced low salinity most frequently were more robust in the face of extreme low salinity events than oysters from other sites. These results suggest that environmental conditions may select for robust phenotypes in certain regions. Second, I tested whether Olympia oysters could detect and respond to invasive predator cues and whether the response varied among populations based on their evolutionary histories with the predators. All oyster populations detected waterborne predator cues and responded with antipredator morphological changes. However, the magnitude of the response differed among populations with laboratory-reared, second-generation oysters originating from the site with the highest predator density exhibiting the greatest response. The evidence suggests that some oyster populations may have undergone rapid evolution of cue sensitivity in the face of an invasive predator. Lastly, I examined the effects of multiple stressors (low salinity and high air temperature) and different amounts of time between stressors on Olympia oyster survival. When applied coincidentally, these stressors resulted in synergistic effects, with oysters exhibiting higher mortality than expected based on adding single stressor effects. However, when stressors were decoupled by two or four weeks, the synergistic effects were eliminated, suggesting that the temporal patterns of stressors in nature may have profound effects for the vulnerability of organisms. Collectively, my dissertation chapters further our understanding of factors that mediate the response of coastal marine organisms to stress. In particular, the fact that populations of the same species may respond differently to stress is critical in predicting anthropogenic impacts and managing species of concern. Additionally, an understanding of temporal patterning of multiple stressors will likely improve projections regarding how organisms and ecosystems will fare in a rapidly changing world.
Download or read book Alien Vs Predator written by Emily W. Grason and published by . This book was released on 2010 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evolutionary History Predation and Coastal Upwelling Interactively Influence Native Oyster Habitat in Tomales Bay California written by David Lloyd Kimbro and published by . This book was released on 2008 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physiological Cost of Climate Change in the Native Olympia Oyster Ostrea Lurida written by Sara Elizabeth Boles and published by . This book was released on 2014 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book From Introduced to Invasive and Iconic written by Kathrin S. Hauptfeld and published by . This book was released on 2013 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The resilience framework is increasingly used to understand the dynamics of sustainability in coupled social and ecological systems. Resilient ecological systems exhibit high levels of diversity, including species and habitat diversity, and redundancy, all of which are thought to help maintain the system within a domain of attraction. Numerous studies demonstrate the threat posed to natural systems by the introduction of invasive species on a global scale. Over the past century, biological invasion has caused changes in biological diversity and alterations to the structure and function of ecosystems. In Puget Sound, the non-native Pacific oyster (Crassostrea gigas) has been used as a commercial aquaculture species for over a century, despite increasing evidence that its spread threatens ecological resilience of the nearshore system. Interestingly, recent changes in ocean conditions that lessen the invasion threat have been met with alarm in Washington, as they jeopardize the social resilience built on the culture of Pacific oysters. In this case study, I discuss conflicts between social and ecological resilience, and the values that drive those conflicts. I then discuss social adaptation strategies as options to retain social-ecological resilience within the system.
Download or read book Response of Olympia Oysters Ostrea Lurida to Changing Environmental Conditions written by Jake Heare and published by . This book was released on 2014 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Olympia oyster is an iconic oyster species in the Pacific Northwest with special significance in Puget Sound, WA. Oyster populations in the region were decimated to historic lows during the 20th century due to a number of factors including overharvest, habitat loss, and invasive species. Restoration projects have seen limited success, likely due to the limited information on stock structure within Puget Sound, especially in regards to adaptive abilities and habitat suitability. Chapter one of this study investigates population related fitness measures (ie. mortality, growth, reproduction) within three resident populations from geographically isolated locations in Puget Sound. Using a reciprocal transplant experiment with Ostrea lurida populations from Fidalgo Bay, Dabob Bay, and Oyster Bay, we found that two of the three populations (Dabob Bay and Oyster Bay) express significant phenotypic signatures related to the population. Using this information we offer restoration strategies catered to population phenotypes in an effort to improve restoration projects in the Puget Sound. In Chapter two, we ran a thermal and mechanical stress experiment due to differences in mortality between populations observed in Chapter 1 to investigate expression of genes (via qPCR) related to survival. We found differences in expression related to gene transcription, which indicates possible phenotypic plasticity previously unknown in the study populations though further investigation is required.
Download or read book Population Status and Molecular Systematics of the Olympia Oyster Ostrea Lurida Carpenter 1864 written by Maria Polycarpou Polson and published by . This book was released on 2008 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Efforts to introduce non native oyster species to the Chesapeake Bay and the National Research Council s report titled Non Native Oysters in the Chesapeake Bay written by United States. Congress. House. Committee on Resources. Subcommittee on Fisheries Conservation, Wildlife, and Oceans and published by . This book was released on 2004 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Behaviour of the Pacific Oyster Crassostrea Gigas in Polluted and Unpolluted Environments written by Wilfredo A. Almarzah G. and published by . This book was released on 1992 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Re establishment of the Native Oyster Ostrea Conchaphila in Netarts Bay Oregon USA written by Pamela Emily Archer and published by . This book was released on 2009 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Olympia oysters, "Ostrea conchaphila," were once common along the west coast of North America. A popular delicacy, native oyster populations began to decline in the late 1800's due to over-harvest, degraded water quality, and habitat loss. Interest in re-establishing the native oyster in a small Oregon estuary, Netarts Bay, culminated in a partnership among The Nature Conservancy, the National Oceanic and Atmospheric Administration, the Oregon Watershed Enhancement Board, and Oregon State University. This study was designed to assess the reestablishment progress of the Olympia oyster restoration in Netarts Bay along with subsequent impacts of the restoration on eelgrass ("Zostera marina"), an important estuarine species. Two brood years (2005 & 2006) of cultch, consisting of O. conchaphila set on clean "Crassostrea gigas" shell substrate, were outplanted within an extensive, relatively uniform eelgrass bed. Cultch was placed in two experimental locations to determine the effect of cultch cover on native oyster survival, growth, and eelgrass abundance. The percent cover of cultch varied among treatments: "control" (no cultch), "low" (4% cultch cover), "medium" (11% cultch), and "high" (19% cultch). Research objectives were: (1) determination of O. conchaphila density, growth, and reproduction; and (2) quantification of the response of "Z. marina" abundance and reproduction to cultch cover. Results from 2007 demonstrated that Olympia oysters were capable of growth, reproduction, and recruitment within their former habitat. Cultch cover within treatments did not change throughout the summer and there was minimal shell export out of the experimental location. Oyster size increased from March-September, 2007: the mean size of the 2005 brood year increased by 10.5 mm, while the 2006 brood year increased by 16.2 mm. Sperm and larvae were found in individuals from both brood years, indicating that oysters were reproductively active. Declines in eelgrass mean percent leaf cover and shoot density were observed with increasing cultch cover. The mean eelgrass percent leaf cover was 15-22% lower and shoot density was 27-36% lower in high treatment (19% cultch) plots than in control plots. There were no discernable patterns in the eelgrass response variables of flowering shoot count, blade length, or blade width. The medium treatment (11% cultch), in which oyster densities were statistically similar to the high treatment (19% cultch), did not have statistically significant impacts on eelgrass percent cover or shoot density. We recommend continued testing of the medium treatment (11% cultch), as well as other cultch densities, such as a 50% cultch treatment. Additional monitoring will be needed to determine what, if any, long-term impacts occur to the eelgrass bed. We also recommend long-term monitoring of both oysters and eelgrass beds to detect any additional changes at the re-establishment site.
Download or read book The Growth of a Population of Pacific Oysters Crassostrea Gigas when Transplanted to Three Different Areas in the State of Washington written by Kenneth K. Chew and published by . This book was released on 1963 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
