Archive for April, 2012

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Hatchery, OSU scientists link ocean acidification to larval oyster failure

Published 12 April 2012 Science Closed

Corvallis, Ore. – Researchers at Oregon State University have definitively linked an increase in ocean acidification to the collapse of oyster seed production at a commercial oyster hatchery in Oregon, where larval growth had declined to a level considered by the owners to be “non-economically viable.”

A study by the researchers found that elevated seawater carbon dioxide (CO2) levels, resulting in more corrosive ocean water, inhibited the larval oysters from developing their shells and growing at a pace that would make commercial production cost-effective. As atmospheric CO2 levels continue to rise, this may serve as the proverbial canary in the coal mine for other ocean acidification impacts on shellfish, the scientists say.

Results of the research have just been published in the journal, Limnology and Oceanography.

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Ocean acidification lesson plan

Published 12 April 2012 Science , Web sites and blogs Closed

Want to learn more about ocean acidification? Do this lab experiment to learn how a decrease in the ocean’s pH can effect shelled organisms.

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Inquiétude croissante autour de l’acidification des mers (in French)

Published 12 April 2012 Media coverage Closed

Des scientifiques font le point en Méditerranée

Il y a 65 millions d’années, l’acidification de l’océan a conduit à l’extinction massive des organismes marins calcaires dont les récifs coralliens, composante du réseau trophique marin, ont disparu. Il leur a fallu des millions d’années pour se reconstituer. Heureusement, il n’y avait pas d’hommes, en ce temps-là, pour pâtir de cette situation.

Que se passerait-il si le scénario se reproduisait à cause de l’augmentation d’émission de CO2. L’acidité́ des océans a cru de 30 % depuis le début de la révolution industrielle. C’est 100 fois plus rapide que celle subie par les organismes marins depuis au moins 20 millions d’années. A ce rythme, l’océan deviendra corrosif pour les coquillages de nombreux organismes marins d’ici à la fin du siècle. Cela rendrait la plupart des régions océaniques inhospitalières pour les récifs coralliens, affectant le tourisme, la sécurité́ alimentaire, la protection du littoral et la biodiversité́.

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CO2 is messing with coral skeletons

Published 11 April 2012 Science Closed

An international scientific team has carried out the world’s first analysis of the impact of ocean acidification on every gene in the coral genome, throwing new light on the likely fate of corals under climate change.

This prodigious research undertaking, involving more than 250 million ‘reads’ of genetic material and their detailed interpretation, was carried out by researchers from Australia, France, Netherlands and South Korea using powerful new genetic analysis tools.

In recent years declines in coral calcification have been reported around the world, matching the steady rise in carbon emissions to the atmosphere from human activity.

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Whole transcriptome analysis of the coral Acropora millepora reveals complex responses to CO2-driven acidification during the initiation of calcification

Published 11 April 2012 Science Closed
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The impact of ocean acidification (OA) on coral calcification, a subject of intense current interest, is poorly understood in part because of the presence of symbionts in adult corals. Early life history stages of Acropora spp. provide an opportunity to study the effects of elevated CO2 on coral calcification without the complication of symbiont metabolism. Therefore, we used the Illumina RNAseq approach to study the effects of acute exposure to elevated CO2 on gene expression in primary polyps of Acropora millepora, using as reference a novel comprehensive transcriptome assembly developed for this study. Gene ontology analysis of this whole transcriptome data set indicated that CO2-driven acidification strongly suppressed metabolism but enhanced extracellular organic matrix synthesis, whereas targeted analyses revealed complex effects on genes implicated in calcification. Unexpectedly, expression of most ion transport proteins was unaffected, while many membrane-associated or secreted carbonic anhydrases were expressed at lower levels. The most dramatic effect of CO2-driven acidification, however, was on genes encoding candidate and known components of the skeletal organic matrix that controls CaCO3 deposition. The skeletal organic matrix effects included elevated expression of adult-type galaxins and some secreted acidic proteins, but down-regulation of other galaxins, secreted acidic proteins, SCRiPs and other coral-specific genes, suggesting specialized roles for the members of these protein families and complex impacts of OA on mineral deposition. This study is the first exhaustive exploration of the transcriptomic response of a scleractinian coral to acidification and provides an unbiased perspective on its effects during the early stages of calcification.

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CO2 effects on coral ‘complex, disturbing’

Published 11 April 2012 Media coverage Closed

Warmer oceans will have both positive and negative effects on coral development, a massive international study has found.

The study, undertaken by scientists from James Cook University (JCU) in Queensland, France, the Netherlands and South Korea, involved 250 million “reads” of coral genetic material and tested the effects of increased carbon dioxide levels.

JCU Professor David Miller says the study found some surprising results about the calcification of coral skeletons.

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Recent and upcoming ocean acidification workshops

Published 11 April 2012 Newsletters and reports , Science Closed

The NOAA Ocean Acidification Program Office has been working with the University of Washington and the Integrated Ocean Observing System (IOOS) Regional Association, the Northwest Association of Networked Ocean Observing Systems (NA-NOOS), to convene two invitational workshops in 2012, one on integrating ocean acidification (OA) data management for the nation, and one
on defining a global network for OA monitoring. Libby Jewett (NOAA OA), Dick Feely (NOAA PMEL), and Jan Newton (UW & NANOOS) are working with others to plan and conduct these two workshops.

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Local researcher to reveal problems of acidic oceans

Published 10 April 2012 Media coverage Closed

The problems of increasing ocean acidity and its impact on regional marine life will be the subject of the first of a free lecture series hosted by the CCMI and Little Cayman Research Centre later this month. Emma Camp who is currently working on her PhD with the University of Essex and who works for CCMI as a researcher and lab manager will share her specialist knowledge on the subject and the day to day discoveries in the field. The oceans have absorbed excessive CO2, which has resulted in changes to the chemistry of surface seawater. As a result of increased ocean acidification, the future of a variety of critical species and ecosystems is in doubt an important factor for Cayman’s reef life.

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The Pacific oyster, Crassostrea gigas, shows negative correlation to naturally elevated carbon dioxide levels: implications for near-term ocean acidification effects

Published 10 April 2012 Science Closed
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We report results from an oyster hatchery on the Oregon coast, where intake waters experienced variable carbonate chemistry (aragonite saturation state < 0.8 to > 3.2; pH < 7.6 to > 8.2) in the early summer of 2009. Both larval production and midstage growth (∼ 120 to ∼ 150 µm) of the oyster Crassostrea gigas were significantly negatively correlated with the aragonite saturation state of waters in which larval oysters were spawned and reared for the first 48 h of life. The effects of the initial spawning conditions did not have a significant effect on early-stage growth (growth from D-hinge stage to ∼ 120 µm), suggesting a delayed effect of water chemistry on larval development.

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The acid test: armor-covered plankton adapt to warming world

Published 10 April 2012 Media coverage Closed

Tiny armor-covered creatures that float along with the ocean’s currents may adapt and survive, if badly, as their watery world warms and becomes more acidic, a new study finds.

Even so, the plankton may become flimsier and could turn into more of a “french fry” than a nutritious snack for its consumers.

As more carbon dioxide, a greenhouse gas, gets pumped into the atmosphere, and ultimately dissolves in the oceans, the seas are becoming more acidic. How this will impact life in the oceans is not known, though various studies have undertaken the challenge to find out.

In the new study, a trio of scientists at the Helmholtz Center for Oceanographic Research in Kiel, Germany, bred a variety of phytoplankton, called Emiliania huxleyi, to tolerate higher levels of carbon dioxide dissolved in the water.

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Marine life ‘has warming defences’

Published 10 April 2012 Media coverage Closed

Marine life may be more tolerant of climate change than previously thought, with new research showing the world’s most important calcifying organism can adapt to ocean acidification.

In a study published in the journal Nature Geoscience today, German scientists found the key micro-organism, a species of coccolithophore important in burying carbon in rocks, evolved a tolerance to higher carbon-dioxide levels over multiple generations, whereas previous studies had tended to look only at a single generation.

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Commentary: Ocean acidification: invisible now, soon to become obvious

Published 10 April 2012 Media coverage Closed

As I look out on Kachemak Bay, I know that the waters of the Bay, Cook Inlet, and the Gulf of Alaska are teeming with organisms that nourish the fish that I depend on to make a living and to fill my freezer.

Some days, the water is too rough to go fishing, but still, I know the fish are there waiting for when I can go. For more than 30 years, my family and I have enjoyed some of the most sought-after and prized foods in the world, harvested right at our doorsteps. It is only in the last five years that I have learned that the very food web that supports this luxury and sustenance is under attack from a silent killer.

Ocean acidification is the result of the ocean absorbing carbon dioxide from the atmosphere. As the world population has increased, so has the use and demand of energy that is produced by many different methods and fuels. Most of these methods result in the emission of carbon in the atmosphere. As the ocean absorbs this carbon dioxide, the acidity in seawater is increased and this reduces the availability of calcium carbonate minerals, which are the building blocks of shells and skeletons for many marine organisms.

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Evolution at the sea – long-term experiments indicate phytoplankton can adapt to ocean acidification

Published 10 April 2012 Media coverage Closed

Fossil fuel derived carbon dioxide has a serious impact on global climate but also a disturbing effect on the oceans, know as the other CO2 problem. When CO2 dissolves in seawater it forms carbonic acid and results in a drop in pH, the oceans acidify. A wealth of short-term experiments has shown that calcifying organisms, such as corals, clams and snails, but also micron size phytoplankton are affected by ocean acidification. The potential for organisms to cope with acidified oceanic conditions via evolutionary adaptations has so far been unresolved. Scientists of the Helmholtz Centre for Ocean Research Kiel (GEOMAR) have now for the first demonstrated the potential of the unicellular algae Emiliania huxleyi to adapt to changing pH conditions and thereby at least partly to mitigate negative effects of ocean acidification. These results raised by the biologists Kai Lohbeck, Prof. Ulf Riebesell und Prof. Thorsten Reusch are published in the current issue of Nature Geoscience.

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Adaptive evolution of a key phytoplankton species to ocean acidification

Published 10 April 2012 Science Closed
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Ocean acidification, the drop in seawater pH associated with the ongoing enrichment of marine waters with carbon dioxide from fossil fuel burning, may seriously impair marine calcifying organisms. Our present understanding of the sensitivity of marine life to ocean acidification is based primarily on short-term experiments, in which organisms are exposed to increased concentrations of CO2. However, phytoplankton species with short generation times, in particular, may be able to respond to environmental alterations through adaptive evolution. Here, we examine the ability of the world’s single most important calcifying organism, the coccolithophore Emiliania huxleyi, to evolve in response to ocean acidification in two 500-generation selection experiments. Specifically, we exposed E. huxleyi populations founded by single or multiple clones to increased concentrations of CO2. Around 500 asexual generations later we assessed their fitness. Compared with populations kept at ambient CO2 partial pressure, those selected at increased partial pressure exhibited higher growth rates, in both the single- and multiclone experiment, when tested under ocean acidification conditions. Calcification was partly restored: rates were lower under increased CO2 conditions in all cultures, but were up to 50% higher in adapted compared with non-adapted cultures. We suggest that contemporary evolution could help to maintain the functionality of microbial processes at the base of marine food webs in the face of global change.

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Recognising ocean acidification in deep time: an evaluation of the evidence for acidification across the Triassic-Jurassic boundary

Published 10 April 2012 Science Closed
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While demonstrating ocean acidification in the modern is relatively straightforward (measure increase in atmospheric CO2 and corresponding ocean chemistry change), identifying palaeo-ocean acidification is problematic. The crux of this problem is that the rock record is a constructive archive while ocean acidification is essentially a destructive (and/or inhibitory) phenomenon. This is exacerbated in deep time without the benefit of a deep ocean record. Here, we discuss the feasibility of, and potential criteria for, identifying an acidification event in deep time. Furthermore, we investigate the evidence for ocean acidification during the Triassic-Jurassic (T-J) boundary interval, an excellent test case because 1) it occurs in deep time, beyond the reach of deep sea drilling coverage; 2) a potential trigger for acidification is known; and 3) it is associated with one of the ‘Big Five’ mass extinctions which disproportionately affected modern-style invertebrates.

Three main criteria suggest that acidification may have occurred across the T-J transition. 1) The eruption of the Central Atlantic Magmatic Province (CAMP) and the associated massive and rapid release of CO2 coincident with the end-Triassic mass extinction provide a suitable trigger for an acidification event (full carbonate undersaturation in the surface ocean is possible but improbable). 2) Tentative evidence for a global paucity of carbonate across the end-Triassic mass extinction versus the adjacent stratigraphy is consistent with a predicted sedimentary response to acidification. 3) The end-Triassic mass extinction was particularly selective against acid-sensitive organisms (more so than perhaps any other extinction event) and temporarily eliminated coral reefs. Therefore multiple lines of evidence are consistent with a T-J ocean acidification event within our current resolution to recognise such events in deep time. The conclusion that the end-Triassic extinction was influenced by acidification implies that short-term acidification perturbations may have long-term effects on ecosystems, a repercussion that has previously not been established.

Although anthropogenic emissions are more rapid than any event in the geologic record, events such as the T-J can serve as partial analogues for the present anthropogenic carbon release. Since the T-J was such a pronounced crisis for both modern-style marine invertebrates and scleractinian reefs, it is of particular interest in terms of informing projections about the effects of modern ocean acidification.

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SCCOOS projects – 2012 Ocean Acidification

Published 10 April 2012 Projects Closed

What is ocean acidification?

As the ocean absorbs increasing levels of carbon dioxide (CO2) from the atmosphere, it causes changes in ocean chemistry. When carbon dioxide reacts with water, it creates carbonic acid, decreasing pH and carbonate ion concentration. Lower levels of pH in the ocean result in higher levels of acidity, causing “ocean acidification.”

Click here to view Part 1 and Part 2 of Scripps Institution of Oceanography Professor Andrew Dickson’s “Introduction to CO2 Chemistry in Seawater” lecture on UCTV.

What are the potential impacts?

Ocean acidification can have significant impacts on marine species, especially organisms that rely on calcium carbonate to build and maintain their shells and skeletons, such as clams, oysters, sea urchins, crabs, lobsters, and corals. Ocean acidification can both reduce amounts of calcium carbonate and prove corrosive to shells and corals.

What is SCCOOS doing?

SCCOOS plans to add ocean acidification monitoring to its ongoing observations of the coastal ocean. Sensors that monitor pH, CO2, and dissolved oxygen can be added to pier stations and gliders. These observations will allow for continuous measurements of acidification in the Southern California Bight and will allow for improvements to be made to the models that forecast climate change.

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Marine life sandwiched by rising CO2

Published 10 April 2012 Web sites and blogs Closed

The oceans have absorbed almost 50 % of the CO2 humans released into the atmosphere, which has driven CO2 in the oceans to rise, causing – because of the effect of increasing CO2 in producing carbonic acid – a decline in ocean pH, termed ocean acidification. Ocean acidification has been argued to threaten calcifying organisms, such as corals and planktonic calcifiers, as coccolhitophores and pteropods.

However, CO2 does not only affect pH, but also affects the efficiency of aquatic aerobic respiration, which depends on the relative partial pressures of oxygen and CO2 in the water with which the organisms are to exchange their gases. In addition, reduced pH reduces the binding affinity for oxygen in blood. As a result, increased partial pressure of CO2 reduces the efficiency of aerobic respiration of aquatic organisms and, most importantly, raises the thresholds of oxygen required to support respiration.

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Biodiversity stability of shallow marine benthos in Strait of Georgia, British Columbia, Canada through climate regimes, overfishing and ocean acidification

Published 10 April 2012 Science Closed
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The highest human population density in British Columbia, Canada is situated around the shores of the Strait of Georgia, where current government policy is focusing early efforts toward achieving ecosystem-based management of marine resources. Climate regime shifts are acknowledged to have affected commercial fishery production in southern British Columbia (McFarlane et al., 2000), and overfishing is well documented in the Strait of Georgia region for a variety of important species, to the extent that Rockfish Conservation Areas have been created (Marliave & Challenger, 2009). As CO2 levels rise in the atmosphere, the oceans become progressively more acidic. While ocean acidification is predicted to be a great threat to marine ecosystems, little is known about its ecosystem impacts. Few taxpayer-funded studies have committed to long-term monitoring of full ecosystem biodiversity. This document presents results of over forty years of private taxonomic monitoring of shallow seafloors in the region centering on the Strait of Georgia.
Also presented are records of ambient ocean acidity levels (pH), documented continuously by the Vancouver Aquarium through the same time period. Biodiversity data are summarized in ways that enable visualization of possible relationships to climate regimes and ocean acidification. This work does not attempt statistical analyses, in the hope that the data trends can be incorporated into future models.

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Effect of ocean acidification and temperature increase on the planktonic foraminifer Neogloboquadrina pachyderma (sinistral)

Published 10 April 2012 Science Closed
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The present study investigated the effects of ocean acidification and temperature increase on Neogloboquadrina pachyderma (sinistral), the dominant planktonic foraminifer in the Arctic Ocean. Due to the naturally low concentration of CO32− in the Arctic, this foraminifer could be particularly sensitive to the forecast changes in seawater carbonate chemistry. To assess potential responses to ocean acidification and climate change, perturbation experiments were performed on juvenile and adult specimens by manipulating seawater to mimic the present-day carbon dioxide level and a future ocean acidification scenario (end of the century) under controlled (in situ) and elevated temperatures (1 and 4 °C, respectively). Foraminifera mortality was unaffected under all the different experiment treatments. Under low pH, N. pachyderma (s) shell net calcification rates decreased. This decrease was higher (30 %) in the juvenile specimens than decrease observed in the adults (21 %) ones. However, decrease in net calcification was moderated when both, pH decreased and temperature increased simultaneously. When only temperature increased, a net calcification rate for both life stages was not affected. These results show that forecast changes in seawater chemistry would impact calcite production in N. pachyderma (s), possibly leading to a reduction of calcite flux contribution and consequently a decrease in biologic pump efficiency.

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European Free CO2 Enrichment Experiment (eFOCE)

Published 10 April 2012 Projects , Science Closed

The objective of the eFOCE project is to develop, validate and implement experimental systems that enable scientists to investigate the long-term effects of acidification in situ on benthic marine communities – i.e. those organisms which live on or near the seabed. The project will be carried out in cooperation with the Monterey Bay Aquarium Research Institute (MBARI), which has recently developed a number of prototypes, and in partnership with several European laboratories involved in two projects – EPOCA and MedSeA – being co-funded by the European Commission. Over a 3-year period, the aim of the project is to develop and test systems which can be used in relatively long (> 6 month) experiments in the Mediterranean Sea. The ultimate goal is to increase the number of these systems and make them available to the international scientific community via an international network.

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