49: Oil Spills

In June 2020 news came from Russia that there was a national emergency. The melting of permafrost leading to the ground subsiding had caused a tank at a power plant in Norilsk to collapse, spilling 20,000 tonnes of oil into nearby water sources. The rivers turned red with oil, and Putin quickly dispatched a team to clean up the mess. This raised questions however on whether melting permafrost in the Arctic might increase the risk of oil spills, as so many oil extracting and refining services are in this region.

The impacts of permafrost are to some degree speculative, as we don’t yet know exactly where and what changes are going to happen to permafrost in the next few years. However, as it’s a pretty current topic, this week we are going to explore oil spills, looking at what they are, how they can impact the environment, what some of the biggest disasters have looked like and finally what can be done to deal with them. It should make for some slick reading! (sorry not sorry, puns have to be squeezed in occasionally…).

*A satellite image from May 2020 showing shows the extent of the oil spill, in red, near a power plant in the Siberian city of Norilsk (Picture: ESA/Royalty Free)*

Oil

For starters oil is a bit of an oversimplification. Oil is any thick liquid which does not mix with water but mixes with other oils. They are generally quite flammable and have high levels of carbon and hydrogen atoms within them. This includes things like olive oil which you can cook with, or lubricants for your car. However, we’re not interested in those, as when we speak about an oil spill we’re usually thinking specifically about crude oil products.

For more info on how crude oil is formed read plog 33: Fossil fuels, but for a brief overview this is created by the decomposition of plant and marine life over millions of years and is held in pockets underground. Some of this is under land, and lots is also under the sea. Through oil rigs this crude oil is extracted, put on an oil tanker and then shipped off to refineries, or on land sent through oil pipelines. Here through heating the oil to different temperatures, different products can be extracted. This includes things like diesel, gasoline, jet fuel and many others. These are then often either transported over land to a new destination, or put back into a boat and shipped there depending on what is easiest or most cost effective.

Usually this process goes smoothly, but occasionally one of these ships filled to the brim with some sort of oil has a bit of an issue. Perhaps something breaks, or it crashes into something and whatever kind of oil it contains starts leaking out. This is where the big problems begin…

*Crude oil can be refined in to a variety of different products by heating it to different temperatures*

The effects of a spill

Water and oil don’t fully mix with one another, but they can sort-of mix. When oil spills happen in the ocean the oil and water can create what is called ’mousse’. This can be a temporary state or last quite a while. The issue with mousse is that it is an extra sticky oil substance, and as it hasn’t fully mixed with the water it floats on the water surface. This means anything it comes into contact with, like a beach, bird or seal gets coated in the stuff, and due to its super sticky nature the oil mousse very hard to clean off.

Being covered in oil comes with a variety of problems. It may cause a bird’s feathers to clump together preventing them from flying. Alternatively for something like a seal it might break down the fluffy structure of its fur, this structure being super important for trapping air for insulation, meaning the seal is at risk of hypothermia. For egg laying animals like birds and reptiles, they have been seen to lay eggs with thinner shells when exposed to an oil spill, putting the chicks at risk. Oil can also have problems on the inside. If small fish or algae get covered in oil, and are then eaten by other animals such as seals, this can poison the seals. Imagine drinking a glass full of diesel- it would not do wonders for your digestion.

Animals can be severely affected by oil spills. This pelicans feather structure has been destroyed by the oil, preventing it from flying and stopping it from being able to insulate itself. It may die from starvation, poisoning or hypothermia.

Past disasters

How extensive have oil spills been? In 1979 The Atlantic Empress, an oil tanker, got caught up in a storm near the Islands of Trinidad and Tobago. Unfortunately, another ship called the Aegean Captain was also caught up in the storm and the two vessels collided, causing the Atlantic Empress to spill around 90 million gallons of oil into the Atlantic Ocean. Not only this but both ships caught fire in the collision lighting the oil aflame too. The boat burned for two weeks after the disaster before sinking. The environmental damage close to shore was quite minimal as the winds pushed the oil out to sea, but the impact it had on wildlife further out is still unknown.

Thanks to a recent Hollywood blockbuster, another more well known oil spill is that from the Deepwater Horizon oil rig in the Gulf of Mexico which happened in 2010. A surge of natural gas broke through some concrete in the oil platform allowing the oil they were drilling to spill out. The oil platform sank and it took many months before BP, the owning company, managed to put a cap on the oil well to stop the flow of oil. Within this time 134 million gallons of oil poured into the sea, and it was reported that around 2,100 km of the US coastline from Texas to Florida was covered in oil, not to mention all the ocean area that the oil coated.

Deepwater Horizon is probably the largest accidental oil spill, but thanks to some politics some major environmental damage was done in an intentional oil spill. In 1990 Saddam Hussein, Iraq’s leader at the time, was intent on invading Kuwait to capture its significant oil reserves. However, during his campaign into Kuwait he was met with a large international coalition of countries who fought to keep him out. At the start of 1991 Saddam Hussein’s forces retreated but as they left they set fire to hundreds of the incredibly flammable oil wells within Kuwait, these fires burning for months even after the troops had left, wasting monumental amounts of oil and gas.

To prevent the coalition from attacking them by sea, Hussein’s troops used the chaos created by oil to their advantage, pouring somewhere between 350-520 million gallons of it into the Persian Gulf. This decimated the biodiversity killing hundreds of thousands of birds and many mammals in the area. It also leached into groundwater making it undrinkable and contaminated soil making parts of the coast uninhabitable to people still today. In parts of the desert where oil leaked from oil wells, this mixed with the sand creating a layer of ‘tarcrete’ that was up to 9 feet deep, killing all plant life.

These are all massive events that have included millions of gallons of oil. However, one litre of oil can contaminate thousands of litres of water, so even simple things like regularly spilling petrol on the ground at petrol pumps can cause issues when this is washed away with the rain into water sources. Of course there can be big issues when oil spills happen on land too, such as from oil pipelines. This is why many indigenous communities in Canada are against the construction of oil pipelines through their traditional lands where they hunt and fish, as not only does it block the migration routes animals like caribou, but it brings with it a risk of spills which could destroy all kinds of wildlife.

Saying this, many oil platforms, tankers and pipelines transport oil and gas from A to B every day with no issues and no spillages. It’s simply a high stakes game- it’s usually fine, but when it goes wrong it goes really wrong.

On the left the Deepwater Horizon disaster, the largest accidental oil spill in history caused by issues at an oil platform on an oil well in the Gulf of Mexico. On the right workers at Kuwait’s Burgan oil field in 1991 trying to stem the flow of oil from a well destroyed by Saddam Hussein’s retreating forces. Many of these destroyed wells created huge oil lakes around them on land.

How to get rid of oil

Whilst the environmental impact of oil can be disastrous, there are many things that can be done to limit it. Luckily one of the properties of oil is that it floats on the water’s surface so for a small and relatively contained spill, oil booms can be used. These are basically a fence that can be put around the oil preventing it from floating out further so it can be contained and collected. This doesn’t work for large spills or in choppy water however. Skimmers, giant oil vacuums, can then be used to remove the surface oil. This is especially liked as an option as the oil can be separated out and still used after being collected, though it gets a little tricky and the skimmers can get jammed if there is also a lot of debris in the water.

Sorbents, so absorbent materials, are another good option to soak up the oil and can be useful for smaller spills or the leftover traces of a spill. They do get heavier when they absorb so it’s important to keep an eye on them and collect them so they don’t sink to the ocean floor and create issues of their own.

A quick and dirty method which can be used to get rid of up to 98% of oil is to just set it on fire. Sounds a bit rough and ready but it is effective if the oil is still relatively thick and fresh. It can release a lot of gases that are harmful to the environment though and it definitely needs to be done in a controlled way. For really big oil spills harsh chemicals can be used to speed up the breakdown of the oil, chemicals called dispersants, though these can have toxic effects on wildlife themselves.

When the spill approaches the shoreline the two main methods to cope with it are microbes and manual labour. Microbes such as bacteria and fungi can break down the oil into safer products. This takes a lot longer than using skimmers and booms, but can be useful when the oil is harder to collect. Finally, the probably best known images of oil spills is lovely people on beaches scrubbing away at an oil coated puffin. This, as well as literally getting a shovel and scooping up oil in sand and on rocks can be hugely helpful to cleaning up beach though of course takes time and a lot of people-power.

*Manual power as well as simple technologies like oil booms can be used to clean up oil spills*

Oil spills, clearly are not good. Of course in most cases no one wants them, and it is unfortunate accidents that usually lead to oil leaking out into oceans as well as onto land, though we didn’t explore on-land spills much here. There is also the interesting example of oil spills being used as a political tool, a decision which still has ramifications on people and wildlife around the Persian Gulf today. Whilst there are methods to clean up these spills, damage is always done so ensuring that oil doesn’t spill again should be a big priority for oil companies. Global oil production and consumption has been steadily rising over the last few years, yet with the sudden drop in demand caused by the COVID 19 lockdowns, many are considering this to be a prime opportunity to move away from fossil fuels and towards renewable energy sources. This may mean that, if indeed these changes happen, the risk of oil spills in the future is decreasing. Good news for Mother Nature.