Nord Stream spews high levels of methane, likely to affect marine life

Dissolved methane transforms back into a gaseous form when it reaches the surface 

By Arya Rohini
Published: Tuesday 11 October 2022

Methane levels near Russia’s ruptured Nord Stream natural gas pipeline system were 1,000 times higher than normal, according to a new research.

The methane gas leak under the Baltic Sea was discovered 26 September 2022. Since then, it has continued to leak into the water, according to the University of Gothenburg’s scientific investigation team.

“In the water samples, we could see that the methane levels were up to 1,000 times higher than normal. The distribution pattern of the methane from the leak was difficult to explain,”  said Katarina Abrahamsson, a marine chemist at the University of Gothenburg and coordinator for the expedition, in a press note.

The research vessel Skagerak returned to Gothenburg after a five-day expedition. The hurriedly planned mission to the Nord Stream leaks in the Baltic Sea is over and the researchers are happy with their work.

The researchers needed to get to the location as soon as possible to quantify the impacts of this significant discharge and gather crucial data.

“In less than 48 hours, we got the researchers and equipment we wanted onboard,” said Abrahamsson. The team collected some 100–200 water samples over 54 hours. They couldn’t measure the whole discharge as the vessel was not permitted beyond Swedish waters.

Methane gas, dissolved in water, transforms back into a gaseous form when it reaches the surface and is emitted into the atmosphere. The ocean currents and the duration of the leakage determine its persistence in the Baltic Sea.

The impact of these high methane levels on marine life is obscure. For instance, there are bacterias in the water that proliferates by oxidising methane gas.

“I have filtered water samples during the expedition to see if there’s any growth of these types of bacteria at elevated methane levels in the water,” said Carina Bunse, a marine biologist at the University of Gothenburg.

If these methane-eating bacterias expand at the expense of other plankton species, it might impact the local food chain. But we are unable to predict the outcome. Conclusions can be drawn only after conducting a DNA analysis of the components in the water samples, said Bunse.

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