That was one of the main questions raised at a workshop, recently arranged by our research school in Arctic Marine Geology and Geophysics. Oceans are covering over 70 percent of our home planet´s surface. It is therefore important to understand how greenhouse gases affected ocean life in the past, and how they may affect it in the future.
Text: Maja Sojtaric
The workshop presented students with relevant methods for measurement of greenhouse gases in the ocean. Changes in the quantity of greenhouse gases such as CO2 and methane can have a profound effect on marine environments. Increase of these gases in the ocean can among other things cause ocean acidification, which can be devastating for many ocean environments, such as corals.
Since our planet is mostly ocean, it is important to understand how these gases affected ocean life in the past, and how they may affect it in the future.
Greenhouse gases recorded in fossil shells
Today we can measure concentrations of greenhouse gases by using different instruments. But the longest instrumental record of CO2 reaches some 60 years back in time. To be able to reconstruct the amounts of greenhouse gases in the distant past the scientists use proxies – indirect measurements of preserved physical characteristics such as fossilized shells of single celled organisms that also live today.
Plaktonic / living in the water column), and benthic ( living in and on the seabed) foriaminifera are species with shells that are easily affected by the environment. Chemical traces which covary with climatic changes, such as quantities of particular isotopes, can be recovered from these shells and measured to uncover changes in temperature and environment of the oceans in the past. Their fossils are well preserved in ocean sediments all over the world.
The AMGG workshop aimed to help PhD and master students understand the scope and significance of this kind of research.
Impacts caused by human activity
“They got an insight into geochemical and biological processes connected to ocean acidification and climate change, and impacts on marine ecosystems caused by human activity. Factors controlling benthic foraminifera and ostracods, two types of organisms living on the seafloor, were also one of the subjects at the meeting.” sais the coordinator Kasia Zamelczyk, researcher at CAGE.
“We also looked into effects of methane on marine environment. For instance, how methane escaping from the sea floor can change the chemistry of the water masses above and therefore the structure and composition of benthic and planktonic foraminiferal shells.”
Studies of paleoproductivity, the ocean productivity in the distant past, and storage of organic carbon were also presented. These studies are the key to understand the cycle of greenhouse gasses in the past on both a regional and global scale.
“In addition, we discussed technology, innovations and effort it takes to conduct culture studies and experiments both in the lab and in the field.The workshop program offered more than 25 hours of lectures and exercises focused on theoretical and practical applications of methods. Talks given during the meeting raised a wide range of subjects related to climate change research focused on marine sediments and foraminifera.” sais Zamelczyk.
The workshop was organised with financial support from The Norwegian Research School in Climate Dynamics (ResClim).
List of invited speakers:
Joan M. Bernhard – Woods Hole Oceanographic Institution, USA
Jelle Bijma – Alfred Wegener Institute, Germany
Jochen Knies – CAGE and Geological Survey of Norway, Norway
Helen Findlay – Plymouth Marine Laboratory, UK
Jutta Wollenburg – Alfred Wegener Institute, Germany
Moriaki Yasuhara – University of Hong Kong, China
Giuliana Panieri – CAGE (Centre for Arctic Gas Hydrate, Environment and Climate), Norway
Agneta Fransson – Norwegian Polar Institute, Tromsø, Norway
