The sabotage of Nord Stream pipelines may have affected the Baltic cod stocks, Sweden’s State Veterinary Institute (SVA) has said in its recent analysis.
Having compared fish caught in the vicinity of the leaks with that caught outside of the affected area, the researchers noticed a possible side effect of exposure to methane, the main constituent of natural gas.
"The cod sampled closest to the discharges have a higher incidence of a certain change in their gills. Similar but milder changes have been demonstrated in experimentally-caused oxygen deficiency," acting State Veterinarian Charlotte Axen said in a press release.
According to the SVA, the sample of the analysis (a total of 29 fish) is too small for detailed conclusions, but the deviations may nevertheless be caused by methane replacing oxygen in the water.
The coming spring, the SVA will follow up on the findings by including gills checks in the regular monitoring of the cod stock.
At the end of September, four leaks were discovered on the gas pipelines Nord Stream 1 and 2 that ran between Russia and Germany through the Baltic Sea following what was later determined to be an act of industrial sabotage. Large amounts of methane poured out of the destroyed pipelines, and shortly after the blasts, levels were measured up to a thousand times higher than normal. Four months later, the levels dropped considerably. A subsequent analysis by the University of Gothenburg showed that the levels at the beginning of January were around five times higher than normal.
The blasts halted deliveries of affordable Russian gas to Europe ahead of the cold season, prompting a gas price hike and a scramble for alternative sources across the European Union.
Germany, Denmark and Sweden each launched separate investigations into the suspected sabotage, amid reported trust issues between the three EU nations. The Russian Chief Prosecutor's Office opened an inquiry on suspicion of international terrorism as well. According to Russian Foreign Ministry spokeswoman Maria Zakharova, the investigation of the terrorist attacks cannot be considered reliable and objective unless Moscow takes part in the probe.
However, Sweden notably refused to include Russia in its investigation or disclose its findings, prompting a harsh reply from Zakharova. “Withholding the established facts irrefutably testifies to the obvious: the Swedish authorities are hiding something,” Zakharova concluded earlier in January.