The recent explosions that occurred near the Nord Stream gas pipelines in the Baltic Sea have raised concerns about the safety of marine life. The blasts, which released over 100,000 tonnes of methane into the sea and the atmosphere, threw up sediment from the sea bed, returning it to the water column. This sediment, which contains toxins and chemical warfare agents from the Second World War, could pose a threat to marine life for more than a month.
A team of environmental scientists at Aarhus University in Denmark recently analyzed the impact of these explosions on the marine ecosystem. Using decades of monitoring data of the sediment in the Bornholm Basin and hydrological models of sediment transport, the team estimated that the explosions threw up a total of 250,000 tonnes of sediment, which reached up to 30 metres below sea level.
The researchers took into account the known concentrations of various contaminants in the sediment, including heavy metals and tributyltin (TBT), an endocrine disruptor used to protect ship hulls. Based on their findings, any more than 5.8 milligrams of sediment re-suspended per litre of seawater was predicted to be harmful to marine life. The contaminants in the sediment, such as lead and TBT, accounted for most of the toxicity, with lead and TBT alone responsible for 75% of it.
The sediment thrown up by the Nord Stream 1 blast contained contaminants that breached the threshold safety level at depths of between 95 and 53 metres for 15 days, and the threshold for Nord Stream 2 was breached for 34 days at depths of between 78 and 42 metres. The blasts contaminated 11 cubic kilometres of seawater for over a month, potentially affecting the region’s animals, including the cod and harbour porpoises.
According to Hans Sanderson, the lead researcher of the study, “there are high concentrations for a long duration in a large area. It could potentially have a quite significant impact” on cod stock. Additionally, the presence of TBT is “not good news for these organisms,” he says. It is possible that the blasts damaged the porpoises’ hearing, and so their ability to communicate, which is concerning since there are estimated to be only 500 harbour porpoises left in the Baltic Sea.
The team’s research highlights the need to address sediment content alongside any activity that stirs up the sea bed, such as installing pipelines, wind turbines, or fishing. Environmental impacts of conflicts also need clarification. A comprehensive understanding of the impact of explosions on the marine ecosystem can help develop appropriate measures to protect marine life while reducing the risk of future incidents.
In conclusion, the explosions that occurred near the Nord Stream gas pipelines pose a significant threat to marine life in the Baltic Sea. The analysis conducted by the team of environmental scientists highlights the need to address sediment content in tandem with any activity that stirs up the sea bed. Implementing appropriate measures to protect marine life can help to reduce the risk of similar incidents in the future.#Nord #Stream #Pipeline #Blasts #Stirred #Toxic #Sediment