Russian experts and environmentalists are battling to clean up a massive oil spill in Siberia, amid fears it could reach the Arctic Ocean. After a storage tank in Norilsk, northern Russia, collapsed in late May, 20,000 tonnes of diesel fuel was released into the environment. Strong winds caused the oil to spread more than 12 miles from the source, contaminating the nearby rivers, lakes and surrounding soil. The spill perhaps didn't get enough attention but it is a major disaster with serious implications.
Experts of Arctic ecosystems are worried about the long-term impacts of this diesel spill. Considering the harsh and untouched conditions of Arctic ecosystems, life is limited and there is a low biodiversity of organisms. While bacteria is known to "clean up" oil spills elsewhere in the world, the population of bacteria is much lower in the Arctic. Additionally, conditions force a much slower rate of bacterial activity. This means that diesel products can linger for decades.
A diesel spill differs from other oil spills -
Major oil spills such as that of the Exxon Valdez in 1989 or Deepwater Horizon in 2010 typically involve thick, gloopy crude oil that sits on the surface of seawater. For these sorts of spills, clean-up best practice is well known. However, the recent Norilsk spill involved thinner, less gloopy diesel oil in freshwater, making clean-up more difficult.
Diesel oil contains between 2,000 and 4,000 types of hydrocarbons (the naturally occurring building blocks of fossil fuels) that each break down differently in the environment. About 50% or more can evaporate within hours and days, harming the environment and causing respiratory problems for people nearby. Other, more resistant chemicals in diesel oil can bind with algae and microorganisms in the water and sink, creating a toxic sludge on the bed of the river or lake.
How different part of ecosystem respond -
Soils in the Russian Arctic harbour fewer organisms than elsewhere in the world, but nonetheless, these soils are still teeming with life and badly affected by oil spills.
Oil spills disrupt the food chain. At the bottom of rivers and lakes are microscopic plants and algae that use photosynthesis to create energy. As primary producers, they need sunlight. When oil first enters the water it sits on the surface and forms a sort of oily sunblock, acting as a barrier between them and their food, leading to a rapid decrease in population of these organisms.
The zooplankton that feed on them eventually will die off. As time passes, wind and currents help disperse this oily layer, and when the oil that has combined with algae sink to the bottom, algae will be able to feed and return in even greater numbers without competition from the zooplankton.
Initially, oil coats soil particles, reducing their ability to absorb water and nutrients, negatively affecting soil organisms as they are unable to access food and water essential for survival. This oily coat can last for years as it is very hard to wash off, so often the soil has to be physically removed.
As of July 6, Nornickel, the mining company that owned the storage tank, says it has removed 185,000 tonnes of contaminated soil (about 14 times the weight of the Brooklyn Bridge). The soil is being stored on site to be "cleaned" by certified contaminant experts by early September which will then likely be returned to its original site.
Additionally, 13 Olympic swimming pools' worth of fuel-contaminated water has been pumped from the river to a nearby industrial site where harmful chemicals will be separated and “cleaned”. This “clean" water will be returned to the river.
However, toxins will likely remain in both the water and soil. Over months and years, these toxins will build up within the food chain, starting with the microscopic organisms and eventually causing health problems in larger organisms such as fish and birds.
Some of these small, largely invisible organisms in both the soil and freshwater can in theory be part of the solution. Diesel contains carbon (which is essential for all life) and some microorganisms actually thrive on fuel spills, helping to break down contaminants by using the carbon as a food source.
Normally, cold Arctic conditions hinder microbial activity and biodegradation. The current Arctic heatwave may speed up this process initially, enabling oil-degrading microorganisms to grow, reproduce and consume these contaminants more rapidly than normal. But due to the region's lack of water and the nitrogen and phosphorous needed for growth, a heatwave can only help these microorganisms so much.
May 2020 temperatures compared to the longer-term average. Norilsk is right in the dark red area. Credit: Copernicus Climate Data Source, CC BY-SA
This will probably happen again
Russian authorities have blamed the collapse on the poor state of the fuel tank and have requested Nornickel pay "voluntary compensation" for environmental damage. Nornickel denies negligence and says the fuel tank failed due to rapidly thawing permafrost.
This spring saw Siberia experience temperatures 10°C warmer than average and, with permafrost underlying most of Russia, the region is highly vulnerable to climate warming. Indeed, 45% of oil and gas extraction fields in the Russian Arctic are at risk of infrastructure instability due to thawing permafrost.
Without more stringent regulations to improve existing infrastructure then more spills are likely to occur, especially given how rapidly permafrost is melting in these areas causing unstable ground.
While nature and her oil-degrading microbial communities can help clean up our mess, we should avoid relying on a largely invisible force that we don't fully understand to fix a much larger human-generated problem. And how can an environment already on the edge of devastation ever fully recover?
Written by Lisa Siddiqui
@lisasiddiquii on Instagram
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