The Effects Of Nutrient Addition And Ocean Acidification On Tropical Crustose Coralline Algae

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The Effects of Nutrient Addition and Ocean Acidification on Tropical Crustose Coralline Algae

Author : Bridget Francine Shayka
Publisher :
ISBN 13 :
Total Pages : 97 pages
Book Rating : 4.:/5 (122 download)

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Book Synopsis The Effects of Nutrient Addition and Ocean Acidification on Tropical Crustose Coralline Algae by : Bridget Francine Shayka

Download or read book The Effects of Nutrient Addition and Ocean Acidification on Tropical Crustose Coralline Algae written by Bridget Francine Shayka and published by . This book was released on 2018 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the global population increases, the occurrence of multiple anthropogenic impacts on valuable coastal ecosystems, such as coral reefs, also increases. These stressors can be global and long-term, like ocean acidification (OA), or local and short-term, like nutrient runoff in some areas. The combination of these stressors can potentially have additive or interactive effects on the organisms in coral reef communities. Among the most important groups of organisms on coral reefs are crustose coralline algae (CCA), calcifying algae that cement the reef together and contribute to the global carbon cycle. This thesis studied the effects of nutrient addition and OA on Lithophyllum kotschyanum, a common species of CCA on the fringing reefs of Mo'orea, French Polynesia. Two mesocosm experiments tested the individual and interactive effects of OA and short-term nitrate and phosphate addition on L. kotschyanum. These experiments showed that nitrate and phosphate addition together increased photosynthesis, OA had interactive effects with nutrient addition, and after nutrient addition ended, calcification and photosynthetic rates changed in unpredictable ways in different OA and nutrient treatments. Because the results of the first two experiments showed impacts of nutrients even after addition stopped, two more mesocosm experiments were conducted to study the changes in photosynthesis and calcification over hourly time scales more relevant to a single nutrient pulse event. These two experiments revealed the existence of diurnal variation in light-saturated photosynthetic rate, but not calcification rate, under ambient and elevated pCO2. This pattern of increased maximum photosynthesis in the middle of the day can have important implications for how the time of nutrient runoff events during the day impacts CCA physiology. Finally, a field experiment was conducted to determine the effects of short- and long-term nutrient addition on L. kotschyanum. The results showed that a series of short-term nutrient additions did not increase photosynthesis or calcification rates above those in ambient nutrient conditions, but continual nutrient enrichment for 6 weeks increased photosynthetic rates. This increase in photosynthesis under only long-term enrichment shows the need for consideration of specific nutrient addition scenarios on coral reefs when predicting how the community will be affected.

Ocean Acidification

Author : National Research Council
Publisher : National Academies Press
ISBN 13 : 030916155X
Total Pages : 200 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Ocean Acidification by : National Research Council

Download or read book Ocean Acidification written by National Research Council and published by National Academies Press. This book was released on 2010-09-14 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean reviews the current state of knowledge, explores gaps in understanding, and identifies several key findings. Like climate change, ocean acidification is a growing global problem that will intensify with continued CO2 emissions and has the potential to change marine ecosystems and affect benefits to society. The federal government has taken positive initial steps by developing a national ocean acidification program, but more information is needed to fully understand and address the threat that ocean acidification may pose to marine ecosystems and the services they provide. In addition, a global observation network of chemical and biological sensors is needed to monitor changes in ocean conditions attributable to acidification.

The Effect of Ocean Acidification on the Ecology of Two Tropical Crustose Coralline Algae (phylum Rhodophyta)

Author : Joshua Caraher-Fergusson Manning
Publisher :
ISBN 13 :
Total Pages : 92 pages
Book Rating : 4.:/5 (119 download)

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Book Synopsis The Effect of Ocean Acidification on the Ecology of Two Tropical Crustose Coralline Algae (phylum Rhodophyta) by : Joshua Caraher-Fergusson Manning

Download or read book The Effect of Ocean Acidification on the Ecology of Two Tropical Crustose Coralline Algae (phylum Rhodophyta) written by Joshua Caraher-Fergusson Manning and published by . This book was released on 2017 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crustose coralline algae (CCA) are important members of coral reef communities. They accrete and consolidate the calcium carbonate framework of coral reefs, and some species are an important settlement substratum for coral larvae. CCA community composition is shaped, at least in part, by herbivory and competition. However, ocean acidification (OA) is negatively affecting CCA, with potential to affect CCA responses to herbivory (wounding) and their ability to compete for space. Changes in seawater chemistry because of OA cause reductions in the recruitment, abundance, and net calcification of CCA. In this thesis, the effects of OA on net calcification, regeneration of wounds, and competition was quantified for two species of CCA common in the back reefs of Mo'orea, French Polynesia; Porolithon onkodes and Lithophyllum insipidum. Three separate experiments were conducted in four flowing seawater tanks (flumes), each set to a different target pCO2 level representative of ambient (~ 400 μatm) or predicted end of the 21 century pCO2 (~ 700, 1000, and 1300 μatm). P. onkodes, was found to be the most abundant species of CCA in the back reefs of Mo'orea, followed by L. flavescens and L. insipidum. The abundance of P. onkodes is likely a direct result of its competitive ability. P. onkodes is thicker on average than the other common CCA in the back reefs of Mo'orea, and thicker species generally become dominant in areas of intense herbivory, such as coral reefs. In a flume experiment conducted from January to March 2016, net calcification declined 85% in P. onkodes at elevated pCO2 compared to a decline of 42% in L. insipidum, indicating that P. onkodes may be more negatively affected by OA. The differential responses to OA found here could alter the outcome of competitive interactions between P. onkodes and L. insipidum, leading to changes in the abundances of these species in CCA communities. Few studies have quantified the potential for OA to interact with natural disturbances, such as wounding of the thallus by herbivores. A flume experiment conducted from May to July 2016 found that there was a 58% reduction in the rate of vertical regeneration of artificial wounds within P. onkodes at elevated pCO2. This result could have important implications for the response of P. onkodes to grazing by excavating herbivores like parrotfish and sea urchins. Inability for CCA to recover from wounding, could increase the susceptibility of CCA to further wounding. In addition, the reductions in vertical regeneration of the wounds could also be indicative of reduced vertical growth rates. CCA with thicker thalli generally outcompete thinner CCA. Reduced vertical growth rates could reduce thallus thickness, and affect the outcome of competitive interactions among CCA. A flume experiment conducted from June to July 2016 found that there was no effect of elevated pCO2 on the outcome of competitive interactions between P. onkodes and L. insipidum. It is likely that this result may have been due to the relatively short duration of this experiment (one month). There was, however, an effect of the identity of the competitor on the proportion of live tissue remaining in focal individuals of P. onkodes. The proportion of live tissue remaining in focal individuals of P. onkodes was significantly lower in intraspecific pairings than in interspecific pairings or when paired with non-living substrate (controls). This result highlights the importance of including both intraspecific and interspecific interactions in future studies of the effects of OA on competition. Experiments of longer durations may elucidate the potential for elevated pCO2 to affect competition among CCA. CCA are ecologically important members of coral reefs. Changes in the community composition of CCA on coral reefs, because of altered competitive abilities under elevated pCO2, could affect the roles that CCA play in building and maintain coral reef ecosystems.

The Effects of Light, Temperature, and Ocean Acidification on the Physiology and Ecology of Tropical Crustose Coralline Algae

Author : Amy A. Briggs
Publisher :
ISBN 13 :
Total Pages : 127 pages
Book Rating : 4.:/5 (124 download)

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Book Synopsis The Effects of Light, Temperature, and Ocean Acidification on the Physiology and Ecology of Tropical Crustose Coralline Algae by : Amy A. Briggs

Download or read book The Effects of Light, Temperature, and Ocean Acidification on the Physiology and Ecology of Tropical Crustose Coralline Algae written by Amy A. Briggs and published by . This book was released on 2016 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt:

The Effects of Ocean Acidification, Elevated Temperature and Herbivory on Tropical Crustose Coralline Algae

Author : Maggie Dorothy Johnson
Publisher :
ISBN 13 :
Total Pages : 240 pages
Book Rating : 4.:/5 (8 download)

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Book Synopsis The Effects of Ocean Acidification, Elevated Temperature and Herbivory on Tropical Crustose Coralline Algae by : Maggie Dorothy Johnson

Download or read book The Effects of Ocean Acidification, Elevated Temperature and Herbivory on Tropical Crustose Coralline Algae written by Maggie Dorothy Johnson and published by . This book was released on 2011 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Marine Animal Forests

Author : Sergio Rossi
Publisher : Springer
ISBN 13 : 9783319210117
Total Pages : 0 pages
Book Rating : 4.2/5 (11 download)

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Book Synopsis Marine Animal Forests by : Sergio Rossi

Download or read book Marine Animal Forests written by Sergio Rossi and published by Springer. This book was released on 2017-08-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last decades there has been an increasing evidence of drastic changes in marine ecosystems due to human-induced impacts, especially on benthic ecosystems. The so called “animal forests” are currently showing a dramatic loss of biomass and biodiversity all over the world. These communities are dominated by sessile suspension feeder organisms (such as sponges, corals, gorgonians, bivalves, etc.) that generate three-dimensional structures, similar to the trees in the terrestrial forest. The animal forest provide several ecosystem services such as food, protection and nursery to the associated fauna, playing an important role in the local hydrodynamic and biogeochemical cycles near the sea floor and acting also as carbon sinks. The present book focus its attention on these three dimensional animal structures including, for the first time, all the different types of animal forests of the world in a single volume.

Characterizing the Response of Coralline Algae to Ocean Acidification and Nutrient Changes in the California Current System

Author : Sandy Letzing
Publisher :
ISBN 13 :
Total Pages : 42 pages
Book Rating : 4.:/5 (866 download)

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Book Synopsis Characterizing the Response of Coralline Algae to Ocean Acidification and Nutrient Changes in the California Current System by : Sandy Letzing

Download or read book Characterizing the Response of Coralline Algae to Ocean Acidification and Nutrient Changes in the California Current System written by Sandy Letzing and published by . This book was released on 2013 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean acidification (OA) has emerged as an important focus of research and policy in this decade. Ocean acidification specifically refers to changes in the inorganic carbon system in the ocean resulting from its absorption of human-released CO2 from the atmosphere. Anthropogenic atmospheric CO2 levels are rapidly increasing; much of this is dissolved and absorbed in the ocean (~30%) where it reacts with seawater altering fundamental properties including pH, pCO2 and saturation state of carbonate minerals. This change is of concern because of the potential of OA to disrupt biological processes, particularly those processes associated with calcification (Byrne, 2011; Diaz-Pilido, Anthony, Kline, Dove, & Hoegh-Guldberg, 2012). For this study, I chose to investigate red coralline algae as a model organism because OA is predicted to have effects on calcification and photosynthesis, and because of the importance of coralline algae as an ecological engineer, which can be found in shallow water habitats globally. While the response of coralline algae to OA is a serious concern, there remains very limited data on the interactions of OA with other ocean conditions (e.g., temperature, nutrients, and light) that may alter or modify the effects of low pH on coralline algae communities. One nutrient in particular, phosphorus is known to have inhibiting effects on calcification in long-term studies. My objective was to describe the short-term effects of a range of elevated pCO2 and phosphorus levels both alone, and together, on calcification and photosynthetic rates of Corallina vancouveriensis. I exposed these algae to a range of pCO2 and phosphate concentrations and measured changes in total alkalinity, pH, and DO in acute exposure trials (

The Combined Effects of Ocean Acidification with Fleshy Macroalgae and Filamentous Turfs on Tropical Crustose Coralline Algae

Author : Lansing Yun Perng
Publisher :
ISBN 13 :
Total Pages : 111 pages
Book Rating : 4.:/5 (124 download)

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Book Synopsis The Combined Effects of Ocean Acidification with Fleshy Macroalgae and Filamentous Turfs on Tropical Crustose Coralline Algae by : Lansing Yun Perng

Download or read book The Combined Effects of Ocean Acidification with Fleshy Macroalgae and Filamentous Turfs on Tropical Crustose Coralline Algae written by Lansing Yun Perng and published by . This book was released on 2019 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Coralline Algae: Globally Distributed Ecosystem Engineers

Author : Laurie Carol Hofmann
Publisher : Frontiers Media SA
ISBN 13 : 2889638316
Total Pages : 159 pages
Book Rating : 4.8/5 (896 download)

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Book Synopsis Coralline Algae: Globally Distributed Ecosystem Engineers by : Laurie Carol Hofmann

Download or read book Coralline Algae: Globally Distributed Ecosystem Engineers written by Laurie Carol Hofmann and published by Frontiers Media SA. This book was released on 2020-07-08 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:

The Combined Effects of Ocean Acidification with Morphology, Water Flow, and Algal Acclimation on Metabolic Rates of Tropical Coralline Algae

Download The Combined Effects of Ocean Acidification with Morphology, Water Flow, and Algal Acclimation on Metabolic Rates of Tropical Coralline Algae PDF Online Free

Author : Sarah Merolla
Publisher :
ISBN 13 :
Total Pages : 135 pages
Book Rating : 4.:/5 (119 download)

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Book Synopsis The Combined Effects of Ocean Acidification with Morphology, Water Flow, and Algal Acclimation on Metabolic Rates of Tropical Coralline Algae by : Sarah Merolla

Download or read book The Combined Effects of Ocean Acidification with Morphology, Water Flow, and Algal Acclimation on Metabolic Rates of Tropical Coralline Algae written by Sarah Merolla and published by . This book was released on 2017 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are currently facing multiple stressors that threaten their health and function, including ocean acidification (OA). OA has been shown to negatively affect many reef calcifiers, such as coralline algae that provide many critical contributions to reef systems. Past studies have focused on how OA independently influences coralline algae, but more research is necessary as it is expected that the effects of OA on coralline algae will vary depending on many other factors. To better understand how algal morphology, water flow, and algal acclimation interact with OA to affect coralline algae, three studies were conducted in Moorea, French Polynesia, from June 2015 to July 2016. In January 2016, I tested the hypothesis that algal individuals with higher morphological complexity would exhibit faster metabolic rates under ambient pCO2 conditions, but would also demonstrate higher sensitivity to OA conditions. For three species of crustose coralline algae, Lithophyllum kotschyanum, Neogoniolithon frutescens, and Hydrolithon reinboldii, algal individuals with more complex morphologies demonstrated faster rates of calcification, photosynthesis, and respiration in the ambient pCO2 treatment than individuals with simpler morphological forms. There also appeared to be a relationship between morphology and sensitivity to OA conditions, with calcification rates negatively correlated with higher morphological complexity. In the summers of 2015 and 2016, I conducted three experiments examining the effects of water flow and OA on different morphologies of coralline algae to test the hypotheses that increased flow would enhance metabolic rates and mitigate the effects of OA, and that algae with more complex morphologies would be more responsive to increased water flow and more sensitive to OA conditions. A field experiment investigating the effects of water flow on Amphiroa fragilissima, L. kotschyanum, N. frutescens, and H. reinboldii detected enhanced rates of calcification, photosynthesis, and respiration with increased flow, and this relationship appeared to be the strongest for the crustose algal species with the highest structural complexity. A flume manipulation examining the combined effects of water flow and OA on A. fragilissima, L. kotschyanum, N. frutescens, H. reinboldii, and Porolithon onkodes suggested that coralline algal species with high structural complexity were the most sensitive to OA conditions. Finally, A. fragilissima and L. kotschyanum were maintained in different pCO2 and water flow conditions in a long-term mesocosm experiment, which indicated that flow was unable to mitigate the effects of OA on coralline algae. In the summer of 2016, I investigated the acclimation potential of A. fragilissima and L. kotschyanum to OA, and predicted that the original treatment conditions would induce phenotypic modifications that would influence algal responses to the end treatment. There were negative effects of long-term exposure of coralline algae to elevated pCO2 conditions on calcification and photosynthesis, though partial acclimation in calcification to OA was observed. The instantaneous exposure of elevated pCO2 had negative impacts on algal calcification, but had a nominal effect on photosynthesis. No effects of long-term or instantaneous exposure to elevated pCO2 were observed for respiration. The results of these studies indicate that the coralline algal response to OA conditions will likely be complex and depend on numerous factors including water flow, morphology, and acclimation potential. Therefore, it is critical that future studies further investigate the effects of these factors; specifically examining the mechanisms that underlie these responses in order to better predict the future of coralline algae and thus coral reef ecosystems in a more acidic ocean.

Tropical Crustose Coralline Algal Community and Individual Growth Responses to Light and Elevated PCO2

Author : Elizabeth A. Dutra
Publisher :
ISBN 13 :
Total Pages : 39 pages
Book Rating : 4.:/5 (986 download)

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Book Synopsis Tropical Crustose Coralline Algal Community and Individual Growth Responses to Light and Elevated PCO2 by : Elizabeth A. Dutra

Download or read book Tropical Crustose Coralline Algal Community and Individual Growth Responses to Light and Elevated PCO2 written by Elizabeth A. Dutra and published by . This book was released on 2015 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crustose coralline algae (CCA) are important reef stabilizers and their susceptibility to anthropogenic climate change and ocean acidification (OA) is of concern. Ocean acidification effects on benthic algal communities were determined by the response of CCA, fleshy macroalgae and microalgae to the interaction of pCO2 and light. I examined if elevated pCO2 and light influences CCA dominance by assessing their growth, recruitment and calcification. Elevated pCO2 under natural reef diurnal CO2 cycles did not significantly affect CCA percent cover, calcification rates or survival of adult CCA lobes. No significant community pCO2 effects were observed, rather light controlled dominance. The percent cover of microalgae increased in highlight, while CCA increased in the shade. My results indicate that algal response to irradiance is a more significant driver of reef benthic algal change than pCO2 levels predicted for 2100; however, this conclusion should be corroborated in longer-term and in field experiments.

Assessing Ocean Acidification Impacts on the Reef Building Properties of Crustose Coralline Algae

Author : Merinda Catherine Nash
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (144 download)

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Book Synopsis Assessing Ocean Acidification Impacts on the Reef Building Properties of Crustose Coralline Algae by : Merinda Catherine Nash

Download or read book Assessing Ocean Acidification Impacts on the Reef Building Properties of Crustose Coralline Algae written by Merinda Catherine Nash and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crustose coralline algae (CCA), and in particular Porolithon onkodes, play an important reef-building role in modern tropical coral reefs. CCA form thick crusts of Mg-calcite and grow over corals and loose substrate to bind these together. This binding and cementing process is fundamental to the development of structural reefs that are capable of withstanding the high-energy waves in the shallow to inter-tidal areas of the reef. As anthropogenic CO2 emissions continue to increase, the oceans absorb part of this extra CO2 and become more acidic, a process known as Ocean Acidification (OA). There are concerns that OA will have a negative affect on the reef-building capacity of coral reef organisms, in particular on CCA. This is because Mg-calcite is meta-stable and more susceptible to dissolution than aragonite, the mineral used by corals to build skeletons. The goal of this thesis work was to firstly understand the physical and mechanical properties that enable the CCA to cement the reef and withstand damage from high-energy waves, bioerosion and chemical dissolution. Secondly, to anticipate how OA may interfere with these reef-building properties. These goals were pursued by setting clear aims with associated specific objectives designed to elucidate information relevant to these questions. Methods were developed for X-ray diffraction to identify the mineral composition of CCA. Nanoindentation was investigated as a tool for determining the mechanical properties of CCA and the measurement of fracture toughness was found to return physically meaningful information relevant to structural reef development. Study of CCA calcification showed that cell wall Mg-calcite exhibited radial crystal morphology in agreement with published studies on temperate species. However, high-resolution imaging showed the radial crystals were made of banded stacked sub-micron grains within an organic framework. Dolomite was found not only as cell lining by submicron rhombs, but also as the primary calcification of hypothallial cell walls. Dolomite is shown to be resistant to bacterial erosion. A model is developed whereby it is proposed that dolomite formation is dependent on polysaccharide accumulation. Using nanoindentation, P. onkodes are found to be extraordinarily tough, on par with the measured fracture toughness for metamorphic minerals quartz and corundum. The fracture toughness is enabled by the presence of dolomite cell lining. Contrary to the literature, bacterial erosion is found to be a constructive, not destructive, process. A survey of P. onkodes from Heron Island fore reef and reef flat showed that dolomite was present in all the fore reef crusts but none of the reef flat crusts. The reef flat crusts did not have fracture resistance except where remineralised. The presence of dolomite cell lining was shown to decrease skeletal dissolution rates by an order of magnitude. OA experiments showed that skeletal dissolution rates increased with elevated pCO2, but dolomite continued to confer resistance to dissolution. pCO2 levels did not affect the skeletal Mg content or dolomite formation in living CCA. Of concern, and in agreement with the literature, bacterial erosion is accelerated under a combination of elevated pCO2 and temperatures, suggesting this may be the main threat to CCA reef-building in the future. The experimental findings were corroborated by results of a field survey along a natural pCO2 gradient. In summary, dolomite was found to be an essential component of modern reef development via its contribution to enabling CCA P. onkodes thick crust development and persistence. Reef building by CCA P. onkodes is likely to continue as pCO2 rises up until a tipping point is reached whereby bacterial erosion switches from constructive to destructive.

Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions

Download Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions PDF Online Free

Author : Ashtyn Lynné Isaak
Publisher :
ISBN 13 :
Total Pages : 98 pages
Book Rating : 4.:/5 (131 download)

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Book Synopsis Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions by : Ashtyn Lynné Isaak

Download or read book Investigating the Photophysiology of a Tropical Crustose Coralline Alga at Different Depths Under Ocean Acidification Conditions written by Ashtyn Lynné Isaak and published by . This book was released on 2021 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean acidification (OA) negatively affects marine calcifying organisms and can alter many chemical and physiological processes. Crustose coralline algae (CCA), such as Porolithon onkodes, are important structural calcifying components on coral reefs and they grow across a range of depths. This research investigated the interactive effects of light quantity, spectral quality and pCO2 on P. onkodes to determine if CCA are impacted differentially by OA as a function of depth. In the first experiment, I tested the effects of increased pCO2 on Porolithon onkodes collected from two different depths. Light filters were utilized to simulate light quality at shallow back reef environments at 2-m depth and deeper fore reef environments at 17-m depth in manipulative mesocosm experiments at both ambient and elevated pCO2 treatments (400 μatm pCO2 and 1000 μatm pCO2). Results of this experiment showed no effects of OA on photosynthesis, respiration, calcification, or most photosynthetic pigment concentrations (except for phycoerythrin). Photosynthesis also did not differ between depths suggesting that photosynthesis in this species is not stimulated by blue wavelengths of light and may saturate at low levels of photon flux density (PFD). However, samples from shallow water calcified 64.7% faster than samples from the deep environment over the experiment, which is likely due to increased PFD and also indicates that photosynthesis and calcification may not be as tightly coupled as previously thought. The second set of experiments investigated the differences in photochemical efficiency of P. onkodes under OA conditions in a mesocosm experiment, and also by changes in algal orientation in relation to sunlight at different depths in a field experiment. The effective quantum yield of photosynthetic energy conversion (fluorescence yield), and the relative rate of electron transport through PSII (rETR) were quantified using a PAM fluorometer. Fluorescence yield was greatest in low-PFD environments in both the mesocosm and field experiments by 29.8% - 46.4% compared to the high-light environments. rETR were between 11.0% - 49.4% less than samples from high-PFD compared to low-PFD environments. OA at 1000 μatm pCO2 compared to 400 μatm pCO2 resulted in a decrease of fluorescence yield by 6.7% in the deep treatment, and by 21.7% in the high-PFD environment, which may be attributed to decreases in phycoerythrin pigment concentration. Overall, this study suggests that increased PFD is more important than spectral quality for P. onkodes, and although this study found no effects of OA on photosynthesis, respiration, or calcification rates, it did impact the concentration of the photosynthetic pigment phycoerythrin in low-PFD environments. Decreases in phycoerythrin in elevated pCO2 in low-PFD environments suggests that P. onkodes may be more impacted by OA in a fore reef compared to a back reef environment. Future studies should conduct longer experimental periods to determine if this pattern will ultimately result in decreases in photosynthesis and calcification.

Ecophysiology of Coral Reef Primary Producers

Author : Maggie Dorothy Johnson
Publisher :
ISBN 13 :
Total Pages : 176 pages
Book Rating : 4.:/5 (959 download)

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Book Synopsis Ecophysiology of Coral Reef Primary Producers by : Maggie Dorothy Johnson

Download or read book Ecophysiology of Coral Reef Primary Producers written by Maggie Dorothy Johnson and published by . This book was released on 2016 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural heterogeneity and global change are key environmental drivers of ecosystem structure and function in both terrestrial and marine ecosystems. At the foundation of all food webs are the primary producers, which require macronutrients and photosynthetic substrate in order to fix inorganic carbon into organic sugars and fuel energy transfer into food webs. This dissertation is an examination of the ecophysiology, or the interaction of organismal physiology with the environment, of key benthic primary producers on coral reefs. Reef-building corals and algae are the most abundant primary producers on coral reefs, and I use coarse functional groupings categorized as reef-building corals, fleshy macroalgae, calcareous macroalgae, crustose coralline algae (CCA) and turf algae assemblages. I assessed the influence of, 1) a natural gradient in inorganic nutrient availability, and, 2) simulated global change on the ecophysiology of corals and algae by functional group. The Southern Line Islands are an archipelago of islands that span the equatorial upwelling region and demonstrate predictable heterogeneity in inorganic nutrient availability. The dominant species of corals and algae demonstrated higher pigment concentrations and photosynthetic efficiency across the archipelago as a function of increasing inorganic nutrient concentrations. This suggests that natural fluxes of inorganic nutrients have an important positive influence on primary producers. I then conducted laboratory experiments on Palmyra Atoll and in Moorea, French Polynesia to test the effects of ocean acidification (OA) and warming on different functional groups of algae. Across a suite of species, OA increased the growth of fleshy macroalgae and turf algae assemblages, but decreased growth and calcification of calcareous macroalgae and CCA. Ocean acidification had a stronger effect than warming on the biomass of turf algae assemblages. Positive effects of OA on turf algae metabolism were increased by warming. These findings suggest that fleshy and calcifying algae respond differently to global change stressors. Ocean acidification has the potential to increase growth and productivity of fleshy algae, while concurrently decreasing growth and calcification of calcifying algae. Anthropogenic activities are increasingly altering the natural environment, and the results of this dissertation improve our ability to predict the response of corals and algae to increasing exposure to nutrients, OA and warming in the near-future ocean.

Encyclopedia of Modern Coral Reefs

Author : David Hopley
Publisher : Springer Science & Business Media
ISBN 13 : 904812638X
Total Pages : 1226 pages
Book Rating : 4.0/5 (481 download)

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Book Synopsis Encyclopedia of Modern Coral Reefs by : David Hopley

Download or read book Encyclopedia of Modern Coral Reefs written by David Hopley and published by Springer Science & Business Media. This book was released on 2010-11-26 with total page 1226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are the largest landforms built by plants and animals. Their study therefore incorporates a wide range of disciplines. This encyclopedia approaches coral reefs from an earth science perspective, concentrating especially on modern reefs. Currently coral reefs are under high stress, most prominently from climate change with changes to water temperature, sea level and ocean acidification particularly damaging. Modern reefs have evolved through the massive environmental changes of the Quaternary with long periods of exposure during glacially lowered sea level periods and short periods of interglacial growth. The entries in this encyclopedia condense the large amount of work carried out since Charles Darwin first attempted to understand reef evolution. Leading authorities from many countries have contributed to the entries covering areas of geology, geography and ecology, providing comprehensive access to the most up-to-date research on the structure, form and processes operating on Quaternary coral reefs.

Oceanic Acidification

Author : Ronald Eisler
Publisher : CRC Press
ISBN 13 : 1439896313
Total Pages : 249 pages
Book Rating : 4.4/5 (398 download)

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Book Synopsis Oceanic Acidification by : Ronald Eisler

Download or read book Oceanic Acidification written by Ronald Eisler and published by CRC Press. This book was released on 2011-10-04 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book critically examines the available literature on oceanic acidification, including a historical review of pH and atmospheric CO2 levels over the millennia; natural and anthropogenic sources of CO2 to the atmosphere and sea surface; chemical, physical, and biological mode of action; biological effects of acidification to marine plants and an

The Great Barrier Reef

Author : Pat Hutchings
Publisher : CSIRO PUBLISHING
ISBN 13 : 0643099972
Total Pages : 396 pages
Book Rating : 4.6/5 (43 download)

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Book Synopsis The Great Barrier Reef by : Pat Hutchings

Download or read book The Great Barrier Reef written by Pat Hutchings and published by CSIRO PUBLISHING. This book was released on 2008-11-07 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Great Barrier Reef Marine Park is 344 400 square kilometres in size and is home to one of the most diverse ecosystems in the world. This comprehensive guide describes the organisms and ecosystems of the Great Barrier Reef, as well as the biological, chemical and physical processes that influence them. Contemporary pressing issues such as climate change, coral bleaching, coral disease and the challenges of coral reef fisheries are also discussed. In addition,the book includes a field guide that will help people to identify the common animals and plants on the reef, then to delve into the book to learn more about the roles the biota play. Beautifully illustrated and with contributions from 33 international experts, The Great Barrier Reef is a must-read for the interested reef tourist, student, researcher and environmental manager. While it has an Australian focus, it can equally be used as a baseline text for most Indo-Pacific coral reefs. Winner of a Whitley Certificate of Commendation for 2009.