The oceans' sensitive skin
Ocean acidification affects climate-relevant functions at the sea-surface microlayer
2014-11-11
(Press-News.org) Like a skin, the sea-surface microlayer separates the ocean from the atmosphere. The exchange of gases and the emission of sea-spray aerosols - two functions that are crucial for climate - take place in this boundary film. A mesocosm experiment by scientists from GEOMAR Helmholtz Centre for Ocean Research Kiel, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Bremerhaven (AWI) and the Institute for Baltic Sea Research Warnemünde (IOW) reveals for the first time how ocean change might affect the special physical, chemical and biological characteristics of the ocean's uppermost boundary. The results are published in the "Journal of Geophysical Research: Oceans". First author is Dr. Luisa Galgani who conducted the study as part of her PhD at GEOMAR and AWI.
"Experiments have shown how ocean acidification, a change in the ocean chemistry due to the uptake of man-made carbon dioxide, influences the growth and efficiency of marine bacteria as well as the sinking of carbon-rich particles", Dr. Luisa Galgani resumes. "We know that organic material and microorganisms accumulating in the sea-surface microlayer are similar to those found in the water column below. So we expected that ocean acidification-driven changes in ocean biogeochemistry in the water column can also be reflected in the microlayer. It is important to understand changes in this microenvironment, because it might have consequences for air-sea interactions that are relevant for our climate."
To investigate consequences of ocean acidification on marine systems, future ocean scenarios have been simulated with the KOSMOS mesocosms (KOSMOS: Kiel Off-Shore Mesocosms for future Ocean Simulations) at Raunefjord, Norway. These nine large floating structures, each of which isolates 75.000 litres of seawater, were brought to different carbon dioxide (CO2) levels as to be expected for upcoming decades and centuries. For one month, the surface of six mesocosms was sampled daily with a glass plate.
Analyses of the samples verified that organic compounds in the sea-surface microlayer reflected the temporal development of phytoplankton growth in the water column. Also, at higher CO2 levels, the concentrations of bacterioneuston, marine bacteria inhabiting the surface, increased. More acidic conditions promoted changes in the dynamics of organic matter. Especially proteinaceous marine gels became smaller but more abundant probably because they served as a nutritional substrate in the sea-surface microlayer, where higher abundances of microorganisms were more efficient in degrading the organic material accumulated during a phytoplankton bloom.
"From previous studies we know that the activity of marine bacteria is stimulated at high CO2", Dr. Galgani explains. "Based on our observations in the sea-surface microlayer, we think that this could be very important as it may imply a positive feedback on atmospheric CO2 from oceanic sources, that is, from microbial metabolism at the air-sea interface."
Additionally, stimulated bacterial degradation might heavily affect the organic composition of nascent sea-spray particles, upon which relies the ability of marine aerosols to interact with the climate system. In the era of climate change, the contribution of marine aerosols is still poorly understood. "There is a long way ahead before we can determine how the ocean provides raw material for clouds formation", Prof. Dr. Anja Engel, head of the research group Microbial Biogeochemistry at GEOMAR, states. "However, we think that our study provided an additional piece of the puzzle and we are directing our research in investigating more the structure and the dynamics of the air-sea interface to better estimate ocean-atmosphere interactions in a high CO2 world."
INFORMATION:
The work was supported by the projects SOPRAN (Surface Ocean Processes in the Anthropocene) and BIOACID (Biological impacts of Ocean Acidification), both funded by the Bundesminsterium für Bildung und Forschung (BMBF) and is a contribution to the international SOLAS project (Surface Ocean - Lower Atmosphere Study).
Original publication:
Galgani, L., Stolle. C., Endres, S., Schulz, K. G., Engel, A. (2014), Effects of ocean acidification on the biogenic composition of the seasurface microlayer: Results from a mesocosm study, J. Geophys. Res. Oceans, 119, doi:10.1002/2014JC010188.
Links:
GEOMAR Helmholtz Centre for Ocean Research Kiel
BIOACID (Biological Impacts of Ocean Acidification)
SOPRAN (Surface Ocean Processes in the Anthropocene)
SOLAS (Surface Ocean - Lower Atmosphere Study)
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Bremerhaven
Leibniz Institute for Baltic Sea Research Warnemünde
Images:
Images are available for download at http://www.geomar.de/n2158-e. Video footage on request
ELSE PRESS RELEASES FROM THIS DATE:
2014-11-11
Using community pharmacies to identify undiagnosed cases of chronic obstructive pulmonary disease (COPD) at an early stage could save £264 million a year according to new research from the University of East Anglia (UEA).
A report published today shows the value of pharmacies in addressing diseases at an early stage. It reveals that case-finding would provide "significant NHS and societal benefits" and save the NHS more money than the service costs to deliver.
The research shows that more than half (57 per cent) of people screened by pharmacies were identified ...
2014-11-11
A tool to help multinational companies assess the business bribery risks faced when conducting business in foreign countries and tailor compliance policies to address those threats has been created by researchers from the RAND Corporation and TRACE International.
Called the TRACE Matrix, the tool improves upon previous methods of risk assessment by incorporating approaches that are better designed to help businesses predict bribery risk and similar threats, researchers say. The tool is free and is available on the TRACE International website.
Researchers say corruption ...
2014-11-11
CLEVELAND, Ohio (Monday, November 10, 2014)--After menopause and before age 65, women who have normal bone density have a very low risk of fracture, shows a new study from the Women's Health Initiative (WHI) published online in Menopause, the journal of The North American Menopause Society. That means these women don't need another bone mass density (BMD) test before age 65.
This study followed up 4,068 postmenopausal women ages 50 to 64 who had a BMD test, weren't taking hormones or calcium and vitamin D supplements in the trial, and didn't already have an osteoporotic ...
2014-11-11
Research during the past 30 years has found many benefits of skin-to-skin contact between mothers and newborns immediately after birth, particularly with aiding breastfeeding. However, in some hospitals, skin-to-skin contact following cesarean birth is not implemented, due to practices around the surgery. A recent Quality Improvement (QI) project demonstrated that women's birth experiences were improved by implementing skin-to-skin contact after cesarean surgery.
Women who give birth by cesarean often have more difficulty with breastfeeding, and skin-to-skin contact can ...
2014-11-11
Consumers place great faith in weight loss pills and remedies, buying and using them more than ever before. American obesity rates, however, are skyrocketing. According to a new study in the Journal of Public Policy & Marketing, false beliefs about these drugs are causing Americans to gain more weight.
"Weight management remedies that promise to reduce the risks of being overweight may undermine consumer motivation to engage in health-supportive behaviors," write authors Lisa E. Bolton (Pennsylvania State University), Amit Bhattacharjee (Dartmouth College) and Americus ...
2014-11-11
Why do some chemical farmers resist a profitable conversion to organic methods? A new study in the Journal of Marketing suggests it may be because making that change feels like switching belief systems.
"The ideological map of American agriculture reveals an unfolding drama between chemical and organic farming," write authors Melea Press (University of Bath), Eric Arnould (Southern Denmark University), Jeff Murray (University of Arkansas) and Katherine Strand (McGill University). "Chemical farmers argue that to make money, one must follow chemical traditions; when organic ...
2014-11-11
As obesity rates rise, health professionals and policy makers scramble to help consumers resist unhealthy eating choices, often focusing on better labeling and improved nutritional knowledge. According to a new study in the Journal of Marketing Research, however, training people to pay attention to their emotions is a far more powerful strategy.
"Consumers are often mindless," write authors Blair Kidwell (Ohio State University), Jonathan Hasford (Florida International University) and David M. Hardesty (University of Kentucky). "We not only demonstrate that emotional ...
2014-11-11
The American obesity epidemic is out of control, and health advocates are working hard to ensure that food labels clearly list calorie content and all unhealthy ingredients. But according to a new study in the Journal of Marketing Research, labeling alone contributes little to healthier eating decisions unless the item also costs more.
"Obesity rates have more than doubled in the past two decades, and large-scale interventions are necessary to dissuade people from consuming unhealthy food," write authors Avni M. Shah (Duke University), James R. Bettman (Duke University), ...
2014-11-11
Cities around the world are pouring money into beautiful bicycle paths in hopes of convincing citizens to drive less and bike more. According to a new study in the Journal of Public Policy & Marketing, however, getting people to go from four to two wheels isn't quite that simple.
"Although bicycling is a widely accepted way to travel around cities in Germany, Denmark, and the Netherlands," write authors Marius C. Claudy (University College, Dublin) and Mark Peterson (University of Wyoming), "it is still the most underutilized form of transportation in countries such as ...
2014-11-11
Reserve's borders have erroneously moved 50 kilometers
New species, named after the Luama Katanga Reserve, is now threatened by cattle ranches and forest destruction
NEW YORK (November 11, 2014) - WCS scientists in the Democratic Republic of Congo (DRC) have discovered a new species of plant living in a remote rift valley escarpment that's supposed to be inside of a protected area. But an administrative mapping error puts the reserve's borders some 50 kilometers west of the actual location. Now the new species, along with 900 other plant varieties and 1,400 chimpanzees, ...
LAST 30 PRESS RELEASES:
[Press-News.org] The oceans' sensitive skin
Ocean acidification affects climate-relevant functions at the sea-surface microlayer
