Climate change: Atlantic plankton bloom reflects soaring carbon dioxide levels, scientists say

Photo credit: Rex

Photo credit: Rex

Scientists say growth of coccolithophores, a microscopic marine alga, could be ‘canary in the coalmine’ for climate change.

A microscopic marine alga with a shell-like skeleton has increased more than tenfold in the North Atlantic over the past 50 years in response to rising levels of carbon dioxide, scientists have discovered.

The dramatic “bloom” of coccolithophores since the 1960s is unprecedented and marine biologists said they are both astonished and mystified by such a sharp increase in microscopic phytoplankton.

An analysis of more than 81,000 plankton samples collected over the past half century has found that the percentage of coccolithophores has increased from about 2 per cent to more than 20 per cent, with a dramatic acceleration occurring after the late 1990s.

Continue reading ‘Climate change: Atlantic plankton bloom reflects soaring carbon dioxide levels, scientists say’

Rapid plankton growth in ocean seen as sign of carbon dioxide loading

A microscopic marine alga is thriving in the North Atlantic to an extent that defies scientific predictions, suggesting swift environmental change as a result of increased carbon dioxide in the ocean, a study led a by Johns Hopkins University scientist has found.

What these findings mean remains to be seen, however, as does whether the rapid growth in the tiny plankton’s population is good or bad news for the planet.

Published Thursday in the journal Science, the study details a tenfold increase in the abundance of single-cell coccolithophores between 1965 and 2010, and a particularly sharp spike since the late 1990s in the population of these pale-shelled floating phytoplankton.

“Something strange is happening here, and it’s happening much more quickly than we thought it should,” said Anand Gnanadesikan, associate professor in the Morton K. Blaustein Department of Earth and Planetary Sciences at Johns Hopkins and one of the study’s five authors.

Continue reading ‘Rapid plankton growth in ocean seen as sign of carbon dioxide loading’

Multidecadal increase in North Atlantic coccolithophores and the potential role of rising CO2

As anthropogenic CO2 emissions acidify the oceans, calcifiers generally are expected to be negatively affected. However, using data from the Continuous Plankton Recorder, we show that coccolithophore occurrence in the North Atlantic increased from ~2 to over 20% from 1965 through 2010. We used Random Forest models to examine >20 possible environmental drivers of this change, finding that CO2 and the Atlantic Multidecadal Oscillation were the best predictors, leading us to hypothesize that higher CO2 levels might be encouraging growth. A compilation of 41 independent laboratory studies supports our hypothesis. Our study shows a long-term basin-scale increase in coccolithophores and suggests that increasing CO2 and temperature have accelerated the growth of a phytoplankton group that is important for carbon cycling.

Continue reading ‘Multidecadal increase in North Atlantic coccolithophores and the potential role of rising CO2’

Two decades of inorganic carbon dynamics along the West Antarctic Peninsula (update)

We present 20 years of seawater inorganic carbon measurements collected along the western shelf and slope of the Antarctic Peninsula. Water column observations from summertime cruises and seasonal surface underway pCO2 measurements provide unique insights into the spatial, seasonal, and interannual variability in this dynamic system. Discrete measurements from depths > 2000 m align well with World Ocean Circulation Experiment observations across the time series and underline the consistency of the data set. Surface total alkalinity and dissolved inorganic carbon data showed large spatial gradients, with a concomitant wide range of Ωarag (< 1 up to 3.9). This spatial variability was mainly driven by increasing influence of biological productivity towards the southern end of the sampling grid and meltwater input along the coast towards the northern end. Large inorganic carbon drawdown through biological production in summer caused high near-shore Ωarag despite glacial and sea-ice meltwater input. In support of previous studies, we observed Redfield behavior of regional C / N nutrient utilization, while the C / P (80.5 ± 2.5) and N / P (11.7 ± 0.3) molar ratios were significantly lower than the Redfield elemental stoichiometric values. Seasonal salinity-based predictions of Ωarag suggest that surface waters remained mostly supersaturated with regard to aragonite throughout the study. However, more than 20 % of the predictions for winters and springs between 1999 and 2013 resulted in Ωarag < 1.2. Such low levels of Ωarag may have implications for important organisms such as pteropods. Even though we did not detect any statistically significant long-term trends, the combination of on\-going ocean acidification and freshwater input may soon induce more unfavorable conditions than the ecosystem experiences today.

Continue reading ‘Two decades of inorganic carbon dynamics along the West Antarctic Peninsula (update)’

An automated monitoring and control system for flow-through co-cycling hypoxia and pH experiments

Acidification research has exploded in recent years, however, experiments testing effects of co-cycling hypoxia and pH on ecological and physiological processes are rare, despite the pervasiveness and potential importance of co-varying fluctuations in these parameters. Co-cycling dissolved oxygen (DO) and pH are difficult to precisely control, as gases used for manipulation influence both parameters. We successfully developed a LabVIEW™-based system capable of monitoring and controlling co-varying DO and pH in raw seawater flow-through aquaria. Using feedback from Oxyguard DO probes and Honeywell ion sensitive field effect transistor Durafet pH sensors, our system controls ratios of nitrogen, oxygen, carbon dioxide, atmospheric air, and CO2-stripped air within a total gas flow rate through mass flow controllers, to achieve target co-cycling DO and pH values in five treatments. Our system performed well in two long-term experiments investigating effects of diel-cycling hypoxia and pH on eastern oyster (Crassostrea virginica) feeding, growth, fecundity, Perkinsus sp. (Dermo) infection dynamics and immune response. In our 2013 adult oyster experiment, the severe low DO treatment averaged only 0.04 mg L−1 higher than the 0.50 mg L−1 target, and the moderate hypoxia averaged only 0.05 mg L−1 higher than the 1.30 mg L−1 target over 48 d of cycles. Mean pH for the hypercapnia plateau was within 0.02 above the 7.00 target. In our 2013 spat experiment, daily minimum DO in the severe and moderate hypoxia treatments were both within 0.06 mg L−1 of the 0.50 and 1.3 mg L−1 targets, respectively; hypercapnia plateau pH values were within 0.01 of our 7.00 target.

Continue reading ‘An automated monitoring and control system for flow-through co-cycling hypoxia and pH experiments’

CO2 Modeller brings climate change and emissions targets within touching distance

Scientists and computer engineers at the University of Southampton have developed an interactive climate app – CO2 Modeller – which can fit in your pocket and help you to gauge the future effects of carbon emissions around key sensitivities of the Earth’s climate.

The new app, CO2 Modeller, provides an interactive tool to allow anyone – from members of the public to policy makers – to explore for themselves the implications of delaying emission reductions on their tablet or smartphone.

Using an easy-to-follow touchscreen, users of the app can review how carbon emission targets and outcomes will impact four key areas of climate change – future global warming, sea level rise, ocean acidification and CO2 concentration – over the next 85 years.

The app’s developers, from Ocean and Earth Science and Electronics and Computing Science, at the University of Southampton, believe that making climate modelling tools so accessible in this way will help us gain a greater understanding of the carbon emission targets and reduction policies proposed at international policy forums, such as the forthcoming COP21 Paris climate talks.

Continue reading ‘CO2 Modeller brings climate change and emissions targets within touching distance’

OA-ICC technical meeting on the management of biological response to ocean acidification data, 17-18 November 2015, Monaco

The IAEA Ocean Acidification International Coordination Centre (OA-ICC) organized a technical meeting on the management of biological response data related to ocean acidification, focusing specifically on the discovery and access of these data via a common data portal. The meeting was hosted at the IAEA Environment Laboratories in Monaco, November 17 – 18, 2015 and was a follow-up to two previous meetings held at the facility:

The meeting brought together scientific and technical experts actively involved in the dissemination or use of ocean acidification data via web based portals, and technical experts providing similar technical capabilities in support of other areas of research.

The objectives of the meeting were to:
1. Provide updates on metadata and portal activities from:
a. 2014 workshop: “Technical meeting on management of biological data related to ocean acidification: international cooperation and development of standards”
b. 2015 workshop: “Technical meeting: Towards a GOA-ON data portal”
2. Finalize the direction for addressing ocean acidification portal needs with a specific focus on biological effects data
3. Develop a plan and establish commitments for completing the portal activity

The meeting provided an opportunity for researchers to communicate the vision for what a common portal should provide, a one-stop shop for the discovery and harmonized access to ocean acidification data.

Continue reading ‘OA-ICC technical meeting on the management of biological response to ocean acidification data, 17-18 November 2015, Monaco’

Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 877,594 hits

Ocean acidification in the IPCC AR5 WG II

OUP book


Get every new post delivered to your Inbox.

Join 1,222 other followers