The impact of ocean acidification and carbonation on microbial community structure was assessed during a large-scale in situ costal pelagic mesocosm study, included as part of the EPOCA 2010 Arctic campaign. The mesocosm experiment included ambient conditions (fjord) and nine mesocosms, with pCO2 range from ~145 to ~1420 μatm. Samples collected at nine time points (t-1, t1, t5, t7, t12, t14, t22, t26 to t28) in seven treatments (ambient fjord (~145), 2×~185, ~270, ~685, ~820, ~1050 μatm) were analysed for “free-living” and “particle associated” microbial community composition using 16S rRNA amplicon sequencing. This high-throughput sequencing analysis produced ~20 000 000 16S rRNA V4 reads, which comprised 7000 OTUs. The main variables structuring these communities were, sample origin (fjord or mesocosms) and the filter size fraction (free-living or particle associated). The community was significantly different between the fjord and both the control and elevated 2 mesocosms (which were not significant different) after nutrients were added to the mesocosms; suggesting that the addition of nutrients is the primary driver of the change in mesocosm community structure. The relative importance of each structuring variable depended greatly on the time at which the community was sampled in relation to the phytoplankton bloom. The size fraction was the second most important factor for community structure; separating free-living from particle-associated bacteria. When free-living and particle-associated bacteria were analysed separately at different time points, the only taxon pCO2 was found to significantly affect were the Gammaproteobacteria after nutrient addition. Finally, pCO2 treatment was found to be significantly correlated (non-linear) with 15 rare taxa, most of which increased in abundance with higher CO2.
Archive for 2012
Ocean acidification shows negligible impacts on high-latitude bacterial community structure in coastal pelagic mesocosms
Published 27 September 2012 Science ClosedTags: Arctic, biological response, community composition, field, mesocosms, molecular biology, prokaryotes
A new policy guide from the international Ocean Acidification Reference User Group was released in Monterey, California, on the closing day of the Third Symposium on the Ocean in a High CO2 World. The new guide is available in 5 languages: English, French, German, Spanish and Portuguese.
Continue reading ‘Ocean acidification – the knowledge base 2012’
Ocean acidification: finding new answers through National Science Foundation research grants
Published 27 September 2012 Projects , Science ClosedProjects address concerns for acidifying marine ecosystems
With increasing levels of carbon dioxide accumulating in the atmosphere and moving into marine systems, the world’s oceans are becoming more acidic.
The oceans may be acidifying faster today than at anytime in the past 300 million years, scientists have found.
To address the concern for acidifying marine ecosystems, the National Science Foundation (NSF) recently awarded new grants totaling $12 million in its Ocean Acidification program.
The program is part of NSF’s Science, Engineering and Education for Sustainability (SEES) investment.
The awards, the second round in this program, are supported by NSF’s Directorates for Geosciences and Biological Sciences, and Office of Polar Programs.
Something’s rotten in the ocean. And as it rots, the ocean acidifies making life tough for shellfish, coral, and other creatures.
Carbon dioxide released from decaying algal blooms combines with the ever increasing concentration absorbed from the atmosphere to give marine communities a double dose of ocean acidification, according to a new study published in Environmental Science and Technology. Areas, like the mouth of the Mississippi River, where nutrient rich water feeds gigantic masses of algae may experience up to 12 times the amount of acidification that they would from atmospheric carbon dioxide alone. The strength of the effect of rotting algae is more intense in areas with low salinity and temperature.
Official denies that Cook Islands is most vulnerable to ocean acidification
Published 27 September 2012 Media coverage ClosedA top official with the Cook Islands’ government denies the Pacific state is the most vulnerable nation to rising acidic oceans in a new report on climate change.
A new study released by the international environmental group Oceana says the Cook Islands is facing an imminent food crisis as climate change and ocean acidification destroy their fisheries.
Continue reading ‘Official denies that Cook Islands is most vulnerable to ocean acidification’
Ocean acidification occurring at unprecedented rates
Published 27 September 2012 Media coverage ClosedOcean acidification is the process of decreasing pH in the Earth’s oceans. This is mainly due to the absorption of carbon dioxide emitted by humans. As CO2 dissolves in seawater, hydrogen ion concentrations increase, thus lowering the ocean pH. Oceans are currently absorbing about a quarter of all CO2 that is released into the air and with the increasing acidity of these marine environments come many concerns about the future of these ecosystems.
This week, at the Third International Symposium on the Ocean in a High-CO2 World in Monterey, California, Dr. Daniela Schmidt of the University of Bristol’s School of Earth Sciences warns us that the current rates of ocean acidification are unlike any other in the Earth’s history.
Continue reading ‘Ocean acidification occurring at unprecedented rates’
Speed of ocean acidification concerns scientists
Published 27 September 2012 Media coverage , Science ClosedSpeaking at the Third International Symposium on the Ocean in a High-CO2 World this week in Monterey, California, Dr Daniela Schmidt, a geologist from the University of Bristol, warned that current rates of ocean acidification are unparalleled in Earth history.
Dr Schmidt of Bristol’s School of Earth Sciences said: “Ocean acidification has happened before sometimes with large consequences for marine ecosystems. But within the last 300 million years, never has the rate of ocean acidification been comparable to the ongoing acidification.
Continue reading ‘Speed of ocean acidification concerns scientists’
Genetic variability makes some marine organisms resilient to environmental change.
Monterey, California
Purple sea urchins can weather changes in ocean pH.
Rising acidity in the oceans is expected to have dire consequences for organisms like coral, but some sea urchins have the genetic tools to adapt to the inhospitable conditions, researchers have found. The result, presented Monday at the Third International Symposium on the Ocean in a High CO2 World in Monterey, California, is one of a few suggesting that some organisms are more resilient than others to changes in ocean acidity.
This week, scientists from around the world are meeting in Monterey to discuss what they call the “other” climate change problem: the acidification of Earth’s oceans. It happens as oceans absorb the carbon dioxide we add to the air through burning fossil fuels — and it can be bad news for oysters, mussels and the marine food web.
Continue reading ‘Scientists focus on ocean acidification (audio)’
WASHINGTON, Sept. 25 (UPI) — A U.S. lawmaker said fallout from ocean acidification won’t go away unless there’s widespread recognition of global climate change.
A study published by the National Ocean and Atmospheric Administration and the University of Georgia said there is a higher level of atmospheric carbon emissions coupled with carbon dioxide released by decaying algal blooms is leading to higher levels of ocean acidification.
NOAA said ocean acidification is putting the seafood industry at risk because of effects on the ecosystem.
Continue reading ‘Ocean acidification troubles U.S. lawmaker’
Report warns of global food insecurity as climate change destroys fisheries
Published 26 September 2012 Media coverage ClosedThe Persian Gulf, Libya, and Pakistan are at high risk of food insecurity in coming decades because climate change and ocean acidification are destroying fisheries, according to a report released on Monday.
Continue reading ‘Report warns of global food insecurity as climate change destroys fisheries’
Tom Jacobs last week cited current research showing that job applications attributed to female scientists were received less favorably by other scientists than those of applications they believed came from a man. The effect was true for both men and women.
Right now I’m at the Third International Symposium on the Ocean in a High-CO2 World, and a factoid that arose in the first day’s opening remarks offers some small hope for greater gender equality (at least in science). Looking over the participants and presenters of all three of these ocean-acidification gatherings—the first in Paris in 2004, the second in Monaco in 2008, and this one in Monterey, California—there has been a steady increase in the visibility of female scientists in this growing field.
Continue reading ‘Small steps toward scientific gender equity’
As field matures, ocean acidification scientists face new challenges
Published 26 September 2012 Media coverage ClosedMONTEREY, CALIFORNIA—Ocean acidification research is a bit competitive for Jean-Pierre Gattuso, and he likes it that way. Nearly 15 years ago, the biogeochemist at the French National Center for Scientific Research in Villefranche-sur-mer was one of just a handful of scientists worldwide examining how the buildup of carbon dioxide in the atmosphere might affect sea life by altering the chemistry of the oceans. When he published his first paper on the topic in 1998, few scientists were interested. “It just wasn’t a hot topic,” he says, adding that he was able to work at a leisurely pace. That first paper, for instance, took 4 years to go from experiment to publication. Gattuso didn’t worry that someone else might publish similar results first.
Continue reading ‘As field matures, ocean acidification scientists face new challenges’
Ocean species seeking cooler waters to survive may have to adapt to their new environments by changing their diet
Monterey, Calif.—As Earth’s atmosphere heats up due to global warming, the world’s oceans will warm, too. All kinds of creatures, from the smallest plankton to the largest fishes, will be forced to adjust. Some of them may be able to adapt by altering their body chemistries, but the most likely response—for those that are free to travel (unlike oysters, say)—is simply to move.
Continue reading ‘As fishes migrate, their food might not follow’
The swimming kinematics of larval Atlantic cod, Gadus morhua L., are resilient to elevated seawater pCO2
Published 26 September 2012 Science ClosedTags: biological response, fish, laboratory, North Atlantic, performance
Kinematics of swimming behavior of larval Atlantic cod, aged 12 and 27 days post-hatch (dph) and cultured under three pCO2 conditions (control-370, medium-1800, and high-4200 μatm) from March to May 2010, were extracted from swim path recordings obtained using silhouette video photography. The swim paths were analyzed for swim duration, distance and speed, stop duration, and horizontal and vertical turn angles to determine whether elevated seawater pCO2—at beyond near-future ocean acidification levels—affects the swimming kinematics of Atlantic cod larvae. There were no significant differences in most of the variables tested: the swimming kinematics of Atlantic cod larvae at 12 and 27 dph were highly resilient to extremely elevated pCO2 levels. Nonetheless, cod larvae cultured at the highest pCO2 concentration displayed vertical turn angles that were more restricted (median turn angle, 15°) than larvae in the control (19°) and medium (19°) treatments at 12 dph (but not at 27 dph). Significant reduction in the stop duration of cod larvae from the high treatment (median stop duration, 0.28 s) was also observed compared to the larvae from the control group (0.32 s) at 27 dph (but not at 12 dph). The functional and ecological significance of these subtle differences are unclear and, therefore, require further investigation in order to determine whether they are ecologically relevant or spurious.
Friday Harbor research apprenticeship on ocean acidification
Published 26 September 2012 Courses and training , Science ClosedOCN492
Friday Harbor Research Apprenticeship on Ocean Acidification
Spring Quarter 2013 (15 units)
Lead Instructor: James Murray (UW, Ocean)
Additional Instructors: Evelyn Lessard (UW, Ocean), Bob Morris (UW, Ocean), Robin Kodner (WWU, UW, Ocean)
Continue reading ‘Friday Harbor research apprenticeship on ocean acidification’
Effects of CO2 enrichment on photosynthesis, growth, and nitrogen metabolism of the seagrass Zostera noltii
Published 25 September 2012 Science ClosedTags: biological response, field, growth, mesocosms, phanerogams, photosynthesis, physiology
Seagrass ecosystems are expected to benefit from the global increase in CO 2 in the ocean because the photosynthetic rate of these plants may be Ci-limited at the current CO 2 level. As well, it is expected that lower external pH will facilitate the nitrate uptake of seagrasses if nitrate is cotransported with H+ across the membrane as in terrestrial plants. Here, we investigate the effects of CO 2 enrichment on both carbon and nitrogen metabolism of the seagrass Zostera noltii in a mesocosm experiment where plants were exposed for 5 months to two experimental CO 2 concentrations (360 and 700 ppm). Both the maximum photosynthetic rate (Pm) and photosynthetic efficiency (α) were higher (1.3- and 4.1-fold, respectively) in plants exposed to CO 2-enriched conditions. On the other hand, no significant effects of CO 2 enrichment on leaf growth rates were observed, probably due to nitrogen limitation as revealed by the low nitrogen content of leaves. The leaf ammonium uptake rate and glutamine synthetase activity were not significantly affected by increased CO 2 concentrations. On the other hand, the leaf nitrate uptake rate of plants exposed to CO 2-enriched conditions was fourfold lower than the uptake of plants exposed to current CO 2 level, suggesting that in the seagrass Z. noltii nitrate is not cotransported with H+ as in terrestrial plants. In contrast, the activity of nitrate reductase was threefold higher in plant leaves grown at high-CO 2 concentrations. Our results suggest that the global effects of CO 2 on seagrass production may be spatially heterogeneous and depend on the specific nitrogen availability of each system. Under a CO 2 increase scenario, the natural levels of nutrients will probably become limiting for Z. noltii. This potential limitation becomes more relevant because the expected positive effect of CO 2 increase on nitrate uptake rate was not confirmed.
Characterizing the effects of ocean acidification in larval and juvenile Manila clam, Ruditapes philippinarum, using a transcriptomic approach
Published 25 September 2012 Science ClosedTags: biological response, laboratory, molecular biology, mollusks, mortality, multiple factors, physiology, temperature
Ocean acidification as a result of anthropogenic carbon dioxide (CO 2) emissions and global climate change poses a risk to the ecological landscape of intertidal and shallow subtidal communities. The organisms that inhabit these waters will have to cope with changing environmental conditions through the appropriate modulation of physiological processes. Calcifying organisms are particularly at risk, as increased atmospheric levels of CO 2 in the atmosphere increase the partial pressure of CO2 (pCO2) in the oceans. Increased pCO2 reduces the saturation of carbonate minerals required to form calcified structures. Being able to cope with the increased energetic demand of maintaining these structures, in addition to other vital physiological processes, will be the key driver that determines which organisms will persist. Assessment of larval and juvenile Manila clam mortality and physiology in this study suggests that this species is capable of coping with elevated pCO2 conditions. The use of high throughput sequencing and RNA sequence analysis in larval clams revealed several physiological processes that play important roles in the Manila clam’s ability to tolerate elevated pCO2 conditions during this life stage. Exposure of juvenile Manila clams, acclimated to elevated pCO2 conditions, to a thermal stress revealed that this species might also be capable of coping with multiple stressors associated with global climate change. Manila clams could therefore represent a model for studying physiological mechanisms associated with successful acclimation of populations to ocean acidification.
The U.S. Ocean Carbon and Biogeochemistry (OCB) program, with support from the UK Ocean Acidification Research Programme (UKOA), has updated and expanded a list of frequently asked questions (FAQs) developed in 2010 by OCB, the European Project on Ocean Acidification (EPOCA), and UKOA. The FAQ is a concise, readable summary of the state of ocean acidification knowledge.
Carbon dioxide (CO2) released into the oceans as a result of water pollution by nutrients — a major source of this greenhouse gas that gets little public attention — is enhancing the unwanted changes in ocean acidity due to atmospheric increases in CO2. The changes may already be impacting commercial fish and shellfish populations, according to new data and model predictions published this week in American Chemical Society’s journal, Environmental Science & Technology.
Continue reading ‘CO2 pollution from water and air may harm oceans’
