Download or read book The Effects of Rising Ocean Temperature and PCO2 on the Physiology and Growth of Giant Kelp Macrocystis Pyrifera and Grazing by Purple Urchins Strongylocentrotus Purpuratus written by and published by . This book was released on 2013 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: As climate change rapidly alters the world's oceans, marine life will have to acclimate and/or adapt to warmer and more acidic conditions. While there is a growing body of literature on the individual effects of elevated temperature and CO2 on marine biota, few studies have examined the synergistic effects of these factors, especially regarding how they impact species interactions. In coastal environments of temperate latitudes, forests of kelp (large brown seaweeds in the Order Laminariales) provide habitat and food for numerous species, support enhanced biodiversity, and provide important ecosystem services. Consequently, impacts to these important ecosystem engineers can have disproportionately large effects on coastal ecosystem functioning. To determine how climate change might impact kelp forest ecosystems, I examined two of the more conspicuous and ecologically important kelp forest species, namely the giant kelp, Macrocystis pyrifera, and the purple sea urchin, Strongylocentrotus purpuratus. First, I performed three separate experiments in order to determine the effects of elevated temperature and pCO2 on M. pyrifera growth and photosynthetic performance. In my first experiment I cultured M. pyrifera meristematic tissues under three pCO2 levels (500, 1000, 1500 matm CO2) and examined how this impacted their growth, steady-state photosynthetic oxygen evolution, and changes in their tissue carbon:nitrogen ratios. In my second experiment, I used a fully factorial design with two temperatures (12°C and 15°C) and two pCO2 levels (500 matm and 1500 matm CO2), and examined how these impacted kelp growth, steady-state photosynthetic carbon uptake, and tissue carbon:nitrogen ratios. In my third experiment, I used the same fully factorial design (12°C and 15°C; 500 matm and 1500 matm CO2), but examined changes in kelp photosynthetic pigment composition and carbonic anhydrase activity (an estimate of their ability to use HCO3 - in photosynthesis). Counter to my expectations, elevating only pCO2 in the water had no effect on kelp growth rates, photosynthesis or tissue carbon:nitrogen ratios in either of the first two experiments. In contrast, in the second experiment, elevating only seawater temperature resulted in a significant reduction in both photosynthesis and growth, and an increase in tissue carbon:nitrogen ratios. However, when seawater temperature and pCO2 were increased together, the kelps exhibited significant increases in photosynthesis and growth relative to the other treatments. This suggested that rising ocean temperatures may interact with rising pCO2 to elicit responses that are different than when either of these factors is increased by itself. In my third experiment, elevating pCO2 in the water significantly reduced carbonic anhydrase activity, suggesting a reduction in HCO3 --based photosynthesis (i.e. a down regulation of carbon concentrating mechanisms) and an increase in CO2-based photosynthesis. In contrast, elevating temperature and/or CO2 alone had littleto- no impact on photosynthetic pigment concentrations. Following the experiments on M. pyrifera, I then examined how climate change will impact the interactions between S. purpuratus and M. pyrifera. Here, I cultured these two species separately under both "present day" conditions (i.e. 12°C and 500 matm CO2) and "future" conditions (i.e. 15°C and 1500 matm CO2) for three months. During this period, urchins were fed kelp from either their own water conditions or the alternate conditions, resulting in a fully factorial design with four treatment combinations (urchins held under either present day or future conditions being fed kelps grown under either present day or future conditions). My results indicate that urchins held under future conditions exhibited reduced feeding and growth rates, and smaller gonads than urchins held under present day conditions regardless of the conditions in which their food was grown. In contrast, urchins held under present day conditions and fed kelp grown under future conditions showed higher feeding and growth rates compared to similar urchins fed kelps grown under present day conditions. Together, my data suggest that M. pyrifera may benefit physiologically from a warmer, more acidic (i.e. higher pCO2) ocean while S. purpuratus will likely be impacted negatively. Given that S. purpuratus can exert a strong deterministic influence on M. pyrifera distribution and abundance, changes to either of their populations that might arise from climate change can alter how they interact and thus have serious consequences for many coastal environments.

Download or read book The Effects of Nitrate Limitation on the Growth and Physiology of the Giant Kelp Macrocystis Pyrifera Phaeophyta written by Charles Donald Kopczak and published by . This book was released on 1993 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elevated Temperature Drives Kelp Microbiome Dysbiosis While Elevated Carbon Dioxide Induces Water Microbiome Disruption written by and published by . This book was released on 2016 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global climate change includes rising temperatures and increased pCO2 concentrations in the ocean, with potentially deleterious impacts to marine organisms. In a four-week climate change mesocosm simulation, I tested the effects of elevated temperature, elevated carbon dioxide and future conditions (a combination of both temperature and carbon dioxide) on the microbiomes of an important foundation species, the giant kelp Macrocystis pyrifera, and the surrounding water column. The water and kelp microbiome responded differently to each of the climate stressors. In the water microbiome each condition caused an increase in a distinct microbial order, whereas the kelp microbiome exhibited a reduction in the dominant symbiont, Alteromondales. The water column microbiomes were most disrupted by elevated pCO2, as demonstrated by a significant increase in species richness (ANOVA, p ≤ 0.01) and a four-fold increase in Rhizobiales. Kelp growth was negatively associated with elevated temperature, with a 20 fold increase in Flavobacteriales and increase in degradation enzymes capable of metabolizing kelp derived alginate, sucrose, and sulfatases. In contrast, kelp growth was positively associated with future conditions, with a 28-fold increase in Planctomycetales. I demonstrate novel interplay between an important macroalgal host and its microbiome that is strongly impacted by climate change perturbations.

Download or read book Effects of Ocean Acidification Temperature and Copper on the Development of Early Life Stages of the Native Kelp Macrocystis Pyrifera and the Invasive Kelp Undaria Pinnatifida from Southern New Zealand written by Pablo P. ‡e author Leal Sandoval and published by . This book was released on 2016 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic activities have increased atmospheric CO2 concentrations from pre-industrial concentrations of 280 ppm to current values of 400 ppm. These atmospheric emissions of CO2 are responsible for the ongoing increase in seawater temperature and the reduction of pH in the ocean’ surface, phenomena known as ocean warming (OW) and ocean acidification (OA), respectively. Model-based projections indicate that the global ocean surface temperature will increase by 4°C whereas the pH will decrease from a current 8.10 to 7.74 by 2100. However, these two global events are not occurring in isolation because anthropogenic activities also threatens coastal environments at local levels. For instance, in coastal environments, natural concentrations of copper are low but are increasing due to human industrialization. In addition, the speciation and bioavailability of copper in seawater is highly dependent on seawater chemistry. Therefore, reductions in seawater pH due to OA will increase the toxic, free ionic form of copper in oceans by 20% by the end of the current century. These abiotic changes can have important impacts on marine biota and ecosystems. Fleshy (non-calcifying) macroalgae such as those that belong to the Order Laminariales are important components of coastal environments. Macroalgae, as sessile organisms, are exposed to constant changes in abiotic factors and the community dynamics (e.g., growth and reproduction) depend on their tolerance to stress. Despite their importance, few studies have focused on the effects of OW, OA and/or copper pollution on fleshy macroalgae and even less have focused on their early life stages. Early life stages have been reported to be the most sensitive phase of the macroalgal life cycle to stressors. Therefore, the main purpose of this work was to evaluate the separate and interactive effects of seawater temperature, pH and copper concentration on the development of microscopic stages of the native kelp M. pyrifera and the invasive kelp U. pinnatifida from southern New Zealand. The first result of this work was that, in M. pyrifera, sporogenesis occurred in basal sporophylls (specialized reproductive laminae) as well as in non-reproductive laminae such as pneumatocyst-bearing adult blade and young apical scimitars. The sorus surface area was greater on sporophylls (57%) than in adult blades and young scimitars (25%). Meiospore release was greater in apical scimitars, followed by adult blades and sporophylls. However, germination of meiospores from different laminae was not significantly different, indicating that meiospores produced in all types of fertile laminae were equally viable. The first climate change-related experiment consisted of monitoring meiospore development of M. pyrifera and U. pinnatifida cultured under four seawater pH treatments (pH 7.20, extreme OA predicted for 2300; pH 7.65, OA predicted for 2100; pH 8.01, ambient pH; and pH 8.40, pre-industrial pH) for 15 days. Reduced seawater pH (7.20 and 7.65) had no effects on meiospore germination but had positive effects on germling growth rates and gametophyte size of both species compared to higher pH (8.01 and 8.40). Gametophyte sex ratio was biased towards females under all pH treatments. Germling growth rate under OA was significantly higher in M. pyrifera compared to U. pinnatifida but gametophyte development was equal for both kelps under all seawater pH treatments, indicating that the microscopic stages of the native M. pyrifera and the invasive U. pinnatifida will respond similarly to OA. The second experiment climate change-related experiment consisted of monitoring meiospore development of M. pyrifera and U. pinnatifida cultured under four seawater pH treatments (pH 7.20, 7.65, 8.03, and 8.40) and two temperature treatments (12°C, ambient temperature; and 16°C, OW predicted for 2100) for 15 days. Reduced seawater pH and elevated temperature had no effects on meiospore development and positive effects on germling growth rates and gametophyte size of both species compared to higher pH (8.01 and 8.40) and lower temperature (12°C), whereas gametophyte sex ratio was not affected by the interaction between the two factors. Despite some small differences between species, results of this experiment suggest that microscopic stages of the native M. pyrifera and the invasive U. pinnatifida will respond similarly to OA and OW. The single effects of the local stressor, copper pollution, on the development of M. pyrifera and U. pinnatifida meiospore were examined. After settlement, meiospores of both kelps were exposed to five nominal copper treatments (control, 100, 200, 300 and 400 μg L-1 Cu) for 9 days. Analyses of total dissolved copper (CuT) concentrations in the blanks showed that nominal copper concentrations were reduced to 54, 91, 131 and 171 μg L-1 CuT (i.e., > 50% of the CuT was adsorbed onto the culture vessel walls). In the media with meiospores, the CuT also decreased: to 39, 86, 97 and 148 μg L-1 CuT in M. pyrifera, and to 39, 65, 97 and 146 μg L-1 CuT in U. pinnatifida (i.e., 6 – 15% of the dissolved copper was adsorbed by the cells). Meiospore germination decreased with increasing copper concentrations but gametogenesis was arrested under all copper treatments. The effective copper concentration causing 50% of arrested germination (Cu EC50) was higher for U. pinnatifida (231 μg L-1 CuT) than for M. pyrifera (157 μg L-1 CuT), suggesting ecological success for the invasive species in copper polluted environments; however, the subsequent inhibition of gametogenesis under all copper treatments indicated no difference in copper tolerance between both kelp early life stages. The reduction of CuT during the previous experiment occurred because copper might be adsorbed onto glass and/or plastic and this can be avoided using a proper trace metal clean procedure. Therefore, a review on the methodologies used in the literature on copper ecotoxicology of marine macro- and microalgae, specifically the use of trace metal clean procedures such as the labware used (glassware vs plasticware), methods of cleaning the labware (acid soaking and ultrapure water rinsing), stock solution preparation (copper source and acidification), and measurement and reporting of dissolved copper concentrations was performed. The main results of this review were that 50% of the articles did not specify the laboratory–ware, 25% used glassware and 25% plasticware; only ~30% of the studies specified cleaning protocols for labware to remove trace metal impurities; the copper form used to prepare the stock solutions was specified in ~80% of studies but acidification to stabilize the dissolved copper was performed in only ~20%; and the dissolved copper concentration was measured in only ~30% of studies. Based on these finding, a trace metal procedure was recommended for conducting copper ecotoxicological studies. A four-factor experiment was performed to investigate the interactive effects of OA, OW and copper pollution on the meiospore development of M. pyrifera and U. pinnatifida. Meiospores of both species were cultured under two seawater pH treatments (7.65 and 8.16), and two temperature treatments (12 and 16°C), and to the species-specific Cu-EC50 for 18 days. In both species, meiospore germination and germling growth rates significantly decreased in the copper treatment, irrespective of pH and temperature whereas gametophyte development for both species was inhibited by copper in all pH and temperature treatments. These results suggest that a local stressor (e.g., copper) is more important to the development of microscopic stages of M. pyrifera and U. pinnatifida than global climate change factors. In summary, results of this study indicate that meiospore development of M. pyrifera and U. pinnatifida will be able to tolerate future OA and OW. That tolerance might be related to: 1) macro- and microscopic stages of both kelps being able to use HCO3- and CO2 to support photosynthesis, therefore, the higher CO2(aq) availability due to OA (pH 7.20 to 7.65) will not affect their physiology; and 2) both M. pyrifera and U. pinnatifida have a wide temperature tolerance (4 to 30C°) which may allow them to perform well in a future warmer ocean (+ 4C°). In contrast, relatively high copper concentrations inhibited meiospore development of both kelp species. This finding indicates that local drivers (e.g., copper pollution) may be more important to physiological processes during meiospore development than global climate change factors. Furthermore, the responses of meiospores to the experimental abiotic factors (i.e., OA, OW and Cu) were similar between the study species, indicating that the invasive U. pinnatifida is unlikely to have an advantage over the native M. pyrifera in natural coastal environments.

Download or read book The Effects of the Operation of the San Onofre Nuclear Generating Station on the Giant Kelp Macrocystis Pyrifera written by and published by . This book was released on 1987 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seasonal Patterns in the Growth of the Giant Kelp Macrocystis Pyrifera written by Peter D Kirkwood and published by . This book was released on 1978 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Climate Change Effects on a Physiology and Trophic Transfer written by Laura E. Smith and published by . This book was released on 2018 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increased anthropogenic carbon dioxide (CO2) emissions have led to an increasingly acidified ocean and higher average global sea surface temperatures. This alteration of abiotic conditions is directly affecting aquatic organisms through physiological stress and indirectly through reductions in trophic transfer efficiency. Less efficient trophic transfer at the base of the food web would reduce the overall energy available to support higher trophic levels and could be detrimental to the dependent ecosystem. Estuarine ecosystems are subject to harmful algal blooms (HABs). They are also characterized by low species diversity, which lowers ecosystem resilience to environmental perturbations. This results in a system where changes in phytoplankton and their consumers can dramatically impact the health of the local community. Increased temperature and pCO2 are predicted to change nutritional adequacy and/or toxicity of some HAB species and their copepod consumers. Interactions between Karlodinium veneficum, a HAB species present in the Delaware Inland Bays, and its consumer Acartia tonsa, a locally-dominant copepod, were used to assess direct changes to physiology and/or indirect changes to trophic transfer. Acartia tonsa, toxic prey K. veneficum, and non-toxic prey Storeatula major were grown in multi-generational laboratory cultures at both ambient conditions (25 °C/400 ppm pCO2) and those predicted for year 2100 (29 °C/ 1000 ppm pCO2). Physiological changes were assessed using grazing, respirometry, egg production, and egg hatching success. Grazing experiments indicated there was not a direct toxic effect of the prey on A. tonsa. Respiration rates did not change significantly at higher temperature and pCO2 values, indicating physiological compensation. Egg production did not significantly differ between treatments, but a significant reduction in egg hatching success was found when A. tonsa were fed exclusively K. veneficum. Significant reduction of egg production and hatching also occurred as a result of higher temperature and pCO2. Significant reductions in efficiency of carbon transfer from prey to consumer offspring were found when A. tonsa ingested K. veneficum, and when A. tonsa ingested S. major at elevated temperature and pCO2. In summary, A. tonsa acclimated to the elevated pCO2 and temperature conditions, but changes in resource partitioning led to a lowered transfer of carbon to their offspring. Ingestion of K. veneficum also led to a lowered trophic transfer efficiency, irrespective of temperature and pCO2 level. This indicates that both HABs and increased temperature and pCO2 from climate change have the potential to alter ecosystem dynamics by reducing trophic transfer efficiency at the base of the food chain.

Download or read book Variation in Nitrogen Physiology and Growth Among Geographically Isolated Populations of the Giant Kelp Macrocystis Pyrifera Phaeophyta written by Charles D. Kopczak and published by . This book was released on 1991* with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seasonal Patterns in the Productivity of a Giant Kelp Macrocystis Pyrifera Forest written by Richard Carl Zimmerman and published by . This book was released on 1983 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Roles of Life Stage and Climate Change on the Persistence of Juvenile Giant Kelp Macrocystis Pyrifera Under Herbivory written by Crystal Ng and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Giant kelp forests are some of the most productive and biodiverse ecosystems in the world, but they are vulnerable to stressors associated with global climate change. As a foundation species, giant kelp (Macrocystis pyrifera) provides habitat, food, and refuge for hundreds of species, many of which are economically important. Much of what is known about giant kelp is focused on the adult stage and the abiotic factors influencing the persistence and recovery of this species. However, under increasing environmental variability, it is critical to understand the factors impacting the survival of juvenile kelp, which has direct implications for the success of the adults. One of the largest gaps in our knowledge of giant kelp forests is the role of a diversity of grazers on the early life stages of M. pyrifera, and virtually nothing is known about the impacts of climate change on these species interactions. In this dissertation, I use both laboratory and field experiments to quantify the impacts of four grazers on two life stages of juvenile kelp under ocean acidification and hypoxia. I found that grazers are a significant source of mortality on juvenile kelp, and that an often overlooked herbivore in the literature, the brown turban snail, emerges as a dominant grazer on both microscopic and macroscopic stages. Under climate change, consumption is significantly reduced, increasing estimated kelp survival, and hypoxia drives these decreases in consumption across all four grazing species. By utilizing natural variability regimes within an upwelling season, I found through field experiments that grazing rates decreased with high monthly oxygen variance, suggesting that cumulative impacts of more extreme conditions may also impact herbivore feeding behavior. Overall, the results of this dissertation demonstrate that herbivory can play a significant role influencing the persistence of giant kelp, and that under the threat of climate change, these species interactions will be significantly weakened, which has implications for kelp forest ecosystems and the transfer of primary productivity through these diverse food webs. This dissertation provides critical information on the ecology and persistence of giant kelp forests and gives us a greater understanding of climate change impacts on marine communities.

Download or read book Nutrients and Productivity of the Giant Kelp Macrocystis Pyrifera in the Nearshore written by George Anthony Jackson and published by . This book was released on 1976 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecophysiological Studies on the Giant Kelp Macrocystis written by William Neilson Wheeler and published by . This book was released on 1978 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Edible Sea Urchins Biology and Ecology written by John M. Lawrence and published by Elsevier. This book was released on 2001-05-21 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea urchins are a major component of marine environments found throughout the world's oceans. A major model for research in developmental biology, they are also of major economic importance in many regions and interest in their management and aquaculture has increased greatly in recent years. This book provides a synthesis of biological and ecological characteristics of sea urchins that are of basic scientific interest and also essential for effective fisheries management and aquaculture. General chapters consider characteristics of sea urchins as a whole. In addition, specific chapters are devoted to the ecology of 17 species that are of major commercial interest and ecological importance. Features include: • A synthesis of what is known about the basic biological characteristics of the sea urchin, useful for the direction of future research. • Case histories of 17 species that illustrate their ecological role in a variety of environments. • With the catastrophic decline in fisheries resulting primarily from over-fishing, it is essential that the populations be managed effectively and that aquaculture be developed. This book provides knowledge of the biology and ecology of the commercially important sea urchins that will contribute to these goals. • The only book available in present literature devoted to sea urchins. With this new title experts provide a broad synthetic treatment and in depth analysis of the biology and ecology of sea urchins from around the world, designed to provide an understanding of the group and the basis for fisheries management and aquaculture.

Download or read book Effects of Climate Change Across Ocean Regions written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The IPCC Fifth Assessment Report (AR5) highlighted that conditions within Earth's ocean are changing more rapidly than any of the time during the past 65 million years, and as a consequence, major changes are occurring in natural and human systems. While this major report as enhanced our understanding of the complexity of ocean issues, we propose this research topic as an opportunity to expand discussion on past, present and future changes across oceans regions.

Download or read book The Biology and Ecology of Giant Kelp Forests written by David R. Schiel and published by Univ of California Press. This book was released on 2015-05-01 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: The largest seaweed, giant kelp (Macrocystis) is the fastest growing and most prolific of all plants found on earth. Growing from the seafloor and extending along the ocean surface in lush canopies, giant kelp provides an extensive vertical habitat in a largely two-dimensional seascape. It is the foundation for one of the most species-rich, productive, and widely distributed ecological communities in the world. Schiel and Foster’s scholarly review and synthesis take the reader from Darwin’s early observations to contemporary research, providing a historical perspective for the modern understanding of giant kelp evolution, biogeography, biology, and physiology. The authors furnish a comprehensive discussion of kelp species and forest ecology worldwide, with considerations of human uses and abuses, management and conservation, and the current and likely future impacts of global change. This volume promises to be the definitive treatise and reference on giant kelp and its forests for many years, and it will appeal to marine scientists and others who want a better appreciation and understanding of these wondrous forests of the sea.

Download or read book Seaweed Ecology and Physiology written by Catriona L. Hurd and published by Cambridge University Press. This book was released on 2014-07-17 with total page 567 pages. Available in PDF, EPUB and Kindle. Book excerpt: A synthesis of concepts and examples of how physiological processes influence seaweed communities worldwide, authored by experts in the field.

Download or read book Ecophysiology of Photosynthesis written by Ernst-Detlef Schulze and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a world of increasing atmospheric CO2, there is intensified interest in the ecophysiology of photosynthesis and increasing attention is being given to carbon exchange and storage in natural ecosystems. We need to know how much photosynthesis of terrestrial and aquatic vegetation will change as global CO2 increases. Are there major ecosystems, such as the boreal forests, which may become important sinks of CO2 and slow down the effects of anthropogenic CO2 emissions on climate? Will the composition of the vegetation change as a result of CO2 increase? This volume reviews the progress which has been made in understanding photosynthesis in the past few decades at several levels of integration from the molecular level to canopy, ecosystem and global scales.