The researchers understood early that the autumn's hasty expedition to the Nord Stream leaks needed a return visit to measure the consequences of the methane gas release in the ocean. Thanks to an emergency research grant, the researchers at the University of Gothenburg will go on a new voyage to the southern Baltic Sea on 8 January 2023.
The research vessel Skagerak will return to the area east of Bornholm in early January for a follow up of the autumn's research voyage. Data measurements over time are important to be able to draw conclusions about the impact of the large gas release in the southern Baltic Sea, in the water and on biological life.
"It feels great that we have received this funding. Now we are able to find out what has happened with the methane after the leak: has it been broken down by bacteria, has it been diluted, or has it gone up into the atmosphere? We are going to measure the same things as we did during the autumn expedition, which are methane levels, pH, bacterial and plankton composition," says researcher Katarina Abrahamsson, who is once again the coordinator of the expedition.
Hurrying before classes start
It's roughly the same group of researchers who were on the first trip to the gas leak, who are leaving right after Epiphany to be away for a week. They would have liked to go already in December, but for various reasons that wasn't possible. Instead, there was an opportunity before the teaching of students starts for some of the joining researchers.
"We are also bringing our German colleagues and their equipment, which will allow us to distinguish between naturally occurring methane emissions in the sea and what are emanating from the gas pipelines, which is extremely important to be able to draw the right conclusions about the impact of the release," says Katarina Abrahamsson.
An application for an emergency grant was sent to the Swedish Research Council for Sustainable Development, Formas, shortly after the first research voyage ended. Now, the grant of SEK one million to the expedition comes as an early Christmas gift from Formas.
"Together with the measurements made by the ocean gliders from VOTO, the new expedition can disclose how much methane is still there in the water, and where the rest has gone, "says Katarina Abrahamsson.
Biological samples take time to analyse
The methane levels in the water can be attained relatively quickly. But the impact of the leak on biological life takes more time to study; the marine biologists are still analysing the samples from the autumn expedition. The new expedition will give a valuable addition of new samples that could reveal whether the bacterial and plankton composition in the ocean east of Bornholm are different than the normal composition.
Is there a need for more research trips to the area in the future?
"We don't know. There are no such ideas at the moment. VOTO still has two gliders in the area, which is an asset that will give us more data in the future.
The results from the research project on the Nord Stream leaks can lead to improved safety for pipelines on the seafloor, which could also have an impact on environmental and risk assessments of new gas pipeline projects. The results can also show the impact of methane emissions on the environment, in addition to climate effects.
"We will soon publish a shorter comment based on what we have found so far. But in the long term, we want to publish a more thorough study combining the results from both expeditions," says Katarina Abrahamsson.
