The study stands in contrast to earlier studies suggesting that coccolithophores would fail to build strong shells in acidic waters. The world's oceans are expected to become more acidic as human activities pump increasing amounts of carbon dioxide into the Earth's atmosphere.
This is an image of the coccolithophore, Emiliania huxleyi, taken by lead author Ina Benner using the San Francisco State University FE-Scanning Electron Microscope.
Credit: Ina Benner
But after the researchers raised one strain of the Emiliania huxleyi coccolithorphore for over 700 generations, which took about 12 months, under high temperature and acidified conditions that are expected for the oceans 100 years from now, the organisms had no trouble producing their plated shells.
"At least in this experiment with one coccolithophore strain, when we combined higher levels of CO2 with higher temperatures, they actually did better in terms of calcification." said Jonathon Stillman, associate professor of biology at San Francisco State University, who along with Ed Carpenter, professor of biology, and Tomoko Komada, associate professor of chemistry, led a team of researchers at the University's Romberg Tiburon Center for Environmental Studies. The research was performed by postdoctoral scientist Ina Benner, masters students Rachel Diner and Dian Li and postdoctoral scientist Stephane Lefebvre.
Coccolithophores sequester oceanic carbon by incorporating it into their shells, which provide ballast to speed the sinking of carbon to the deep sea. These little organisms are central to the global carbon cycle, a role that could be disrupted if rising levels of atmospheric carbon dioxide and warming temperatures interfere with their ability to grow their calcified shells.
In previous experiments, the same SF State researchers found that the same strain of coccolithophores grown for hundreds of generations under cool and acidified water conditions grew less shell than those growing under current ocean conditions. In a short-term study by other researchers that examined the combined effects of higher temperatures and acidification, the same strain also had smaller shells under warmer and acidified conditions. However, results from this new long-term experiment suggest that this strain of coccolithophores may have the capacity to adapt to warmer and more acidic seas if given adequate time.
Stillman said the study underscores the importance of assessing multiple climactic factors and their impact on these organisms over a long time, to understand how they may cope with future oceanic environmental changes.
"We don't know why some strains might calcify more in the future, when others might calcify less," he said. Recent evidence indicates that the genetic diversity among coccolithophores in nature may hold part of the answer as to which strains and species might be "pre-adapted for future ocean conditions," Stillman added.
While these results indicate that coccolithophore calcification might increase under future ocean conditions, the researchers say that it's still unclear "whether, or how, such changes might affect carbon export to the deep sea."
The researchers received another surprise when they used recently developed genomic approaches to compare the expression of genes related to calcification in coccolithophores grown under current and future seawater conditions. "We really expected to see a lot of genes known to be involved in calcification to change significantly in the cells that thrived under high temperature and high acidity," Stillman said, "given their increased levels of calcification."
But the researchers found no significant changes in the expression of genes known to be involved in calcification from prior studies comparing strains with dramatically different calcification levels. It could be that these genes work as a sort of "on-off switch" for calcification, Stillman suggested. There may be other genes at work that control calcification in more subtle ways, affecting the degree of calcification.
The study by the RTC scientists was supported by the National Science Foundation and published in the August 26 issue of the Philosophical Transactions of the Royal Society B.
SF State is the only master's level public university serving the counties of San Francisco, San Mateo and Marin. The university enrolls more than 30,000 students each year. With nationally acclaimed programs in a range of fields -- from creative writing, cinema and biology to history, broadcast and electronic communications arts, theatre arts and ethnic studies -- the University's more than 140,000 graduates have contributed to the economic cultural and civic fabric of San Francisco and beyond.
Nan Broadbent | EurekAlert!
How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH
A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology