Healthy coastal ecosystems serve as effective carbon sinks

The researchers in this project are examining the extent to which Baltic Sea coasts can take up carbon dioxide from the atmosphere, thereby acting as carbon sinks. One key question is whether the ability to sequester carbon is affected by the health of an ecosystem, and whether eutrophied and degraded environments instead release carbon dioxide and methane into the atmosphere. If so, action taken to reduce Baltic Sea eutrophication may play a key role for the climate.

In order to mitigate climate change, we must reduce our emissions of greenhouse gases. But capture of carbon dioxide from the atmosphere is also under discussion. There has been much talk of forests as a key factor in carbon capture, but recent research suggests that coastal ecosystems may be important carbon sinks as well.

However, monitoring of greenhouse gas emissions performed by Stockholm University Baltic Sea Centre has shown that emissions of methane – a powerful greenhouse gas – from Baltic coasts may be significant, potentially vitiating the sequestration of carbon dioxide from the atmosphere. There are also clear signs that these emissions increase as habitats are impacted by eutrophication. The researchers’ basic hypothesis is therefore that a healthy coastal ecosystem serves as an effective carbon sink, or as a “powerhouse of climate mitigation”, fixing carbon and contributing to a good carbon balance in the ecosystem. If a coastal sea is impacted by eutrophication, it may instead become a carbon source, emitting carbon dioxide and methane into the atmosphere.

CoastClim – a joint Swedish–Finnish research project – will be evolving over the next few years, supported by the Swedish Research Council and the Finnish Academy. The aim is to attract a critical mass of researchers and build up the scientific infrastructure needed to study the “powerhouse hypothesis”, i.e. to ascertain how various processes in the Baltic marine and coastal environments interact with processes in the atmosphere, i.e. the mutual impact between sea and climate. CoastClim will give the researchers unique opportunities for collaboration on questions of the marine environment and atmospheric chemistry at two field stations: the Askö Laboratory in Sweden and Tvärminne Zoological Station in Finland. 

Funding from the Foundation will be used to establish a postdoc position to study fundamental processes and to measure emissions of carbon dioxide and methane from macroalgae and other vegetated coastal environments, using microbial analyses to identify:

• the organisms that are present by conducting genetic studies of various coastal habitats;
• the factors that increase or reduce microbial activity; temperature and human disturbance such as eutrophication by taking samples from habitats at various stages of influence, as well as possible controlled laboratory studies, transcriptomics and proteomics to determine the level of activity in various processes.