A growing oil spill in the Humber Estuary has sparked concerns of an environmental disaster after an oil tanker and cargo ship crashed off the Yorkshire coast.
At least 36 people have been rescued after the US-flagged tanker, MV Stena Immaculate, was hit while at anchor by the Portugal-flagged container ship, MV Solong.
Now, as jet fuel leaks out into the estuary, scientists have revealed what can be done to contain the spill.
Nicky Cariglia, director of Marittima which specialises in marine pollution, told MailOnline: ‘This will all depend on a number of factors, the type of oil, the weather, the sea state, and how far out the spill is.’
Experts say floating barriers, oil-dispersing chemicals, and even giant sponges could be used to hold back the spreading oil.
By holding the fuel in one place for long enough, boats and specially designed ‘skimmers’ can suck the fuel back out of the water.
In exceptional circumstances, environmental agencies may even choose to burn the oil ‘in situ’ – lighting enormous fires on the open water.
However, experts say that the type of fuel currently entering the Humber Estuary could evaporate quickly before it causes any serious damage.
A growing oil spill in the Humber Estuary has sparked concerns of an environmental disaster after an oil tanker and cargo ship crashed off the Yorkshire coast. The US-flagged tanker, MV Stena Immaculate, was hit while at anchor by the Portugal-flagged container ship, MV Solong
From the moment the oil hits the water, experts and local environmental authorities will need to start making a plan to contain the spill.
Thicker oils, such as crude oil, behave very differently from lighter, more volatile refined oils like jet fuel.
Likewise, waves and currents might disperse the oil over vast distances while making it difficult for recovery vessels to make it out to sea.
That means the first step in dealing with an oil spill is making a careful plan about what to do next.
‘When there is a spill, such as has happened today, agencies and experts will undergo some modelling of the type of oil and the weather conditions to understand what its behaviour might be and what kind of measures would be suitable,’ says Ms Cariglia.
‘There will be a lot of preparation going on at any time for different phases of the operation.’
Generally speaking, the first step of a cleanup operation is to physically prevent the oil from spreading any further.
Cleanup crews deploy specialised floating barriers called booms which corral the oil into more controllable areas.
US-flagged tanker, MV Stena Immaculate (pictured), was hit while at anchor by the Portugal-flagged container ship, MV Solong, off the coast of Humber Estuary, Hull, this morning.
How the spill is contained will depend on the weather and the type of oil. However, the process typically begins by deploying inflatable barriers called booms which sit on the surface and stop the oil escaping. Pictured The Marine Spill Response Corporation puts down a boon to protect the beach at Chrissy Fields from oil contamination November 8, 2007 in San Francisco
Booms are also deployed near beaches and in other sensitive areas as a protective barrier against the oil spill. Pictured: Booms float on the Talbert Marsh, California following an oil spill in 2021
While there are different designs the most common booms are long cylindrical flotation devices attached to a weighted ‘skirt’ that extends beneath the water.
Since oil doesn’t mix with water it floats to the surface, so these booms can be used to ‘sweep’ it up or protect sensitive areas.
Ms Cariglia says: ‘You can either wait down current for the oil to collect it there, or you can sometimes sweep up the oil and gather it up like that.’
In some cleanup operations, booms will be towed alongside one or two boats to funnel the oil into a point where it can be collected.
Once the oil is contained, the next stage is to ‘recover’ the oil so that it can be safely disposed of or recycled.
This is primarily done using skimmers which float along the surface of the water and suck up the oil like vacuum cleaners.
These have several different designs including suction pumps, conveyor belts of sponges of absorbant sponges, and ‘weir’ skimmers which sit just below the waterline and drain the oil off the surface with gravity.
After the BP Deep Horizon oil spill, hundreds of skimmers were used to scoop up oil from the water’s surface.
Cleanup crews also use skimmers (pictured) which pull oil off the surface of the water after it has been collected
Skimmers sit at the surface of the water and pull oil off so that it can be disposed of safely or recycled
However, these proved much less effective than expected and only recovered about three per cent of the oil on the surface.
Cleanup crews might also use ‘sorbents’ which are absorbant materials which soak up liquids like giant household sponges.
These sorbents, usually made of natural materials like wool or clay, are dropped into the water to clean small amounts of oil in places skimmers can’t reach.
Some types of sorbents can even be fished out of the water and squeezed out to recover the oil and allow them to be used again.
In addition to these standard approaches, cleanup operations also have a few more drastic options available.
The first is to add chemical or biological ‘dispersing agents’ to the oil slick, usually in the form of powders or liquids dropped from helicopters.
Ms Cariglia says: ‘It’s essentially like how dish detergent works to cut through grease, it makes the oil slick go into smaller particles.
This helps the oil disperse naturally under the force of the wind and waves making it less likely to reach the shore where it could cause an environmental disaster.
Absorbent pads called sorbents are also used to catch oil in areas that skimmers can’t reach. These soak up the oil like giant sponges so that it can be removed. Pictured: A worker retrieves an absorbent pad following an oil spill in San Francisco
In some cases, oil-dispersing chemicals will be dropped from planes or helicopters to help the oil naturally disperse. These act like washing detergents to break the oil down into smaller droplets. Pictured: A U.S. Air Force plane drops an oil-dispersing chemical onto an oil slick on the Gulf of Mexico in 2010
However, Ms Cariglia says that these compounds are only suitable for very specific applications and types of oil.
Finally, the last and most controversial way of removing an oil spill is to set it on fire.
In-situ burning, as the technique is formally known, works by collecting the oil into a layer which is thick enough to burn using fire-resistant booms and then setting it alight.
This can only be done when the oil is two to three millimetres thick and when the waves are smaller than three feet.
Although this can be extremely effective at removing oil from the surface, it comes with its own set of concerns.
Dr Vikas Nandwana, founder and CTO of Coral Innovations which produces oil cleaning products, told MailOnline: ‘Controlled burning is sometimes used to rapidly remove large volumes of oil when other methods are ineffective.
‘It is not the preferred method, as it releases CO2 and other toxic gases, contributing to air pollution. Because of these environmental concerns, in-situ burning is only viable under specific conditions where containment is possible.’
However, in some circumstances, none of these methods are needed.
In extreme cases, the oil can be removed through in-situ burning. The oil is collected using fire-resistant booms and then ignited. Pictured: Crews conduct a controlled burn on an oil spill in the Gulf of Mexico
The oil spilt in today’s collision (pictured) is likely to disperse quickly because it is volatile jet fuel. This means the environmental risk is lower than it would have been for a fuel like crude oil
If the oil spill is far enough away from populated areas or sensitive marine areas the wind and waves will naturally disperse the oil as parts of it begin to evaporate.
This process is especially fast in cases such as the Humber Estuary spill where the fuel is a highly refined, volatile, form of oil like jet fuel.
Dr Hark Hartl, of Heriot-Watt University, says: ‘Whilst the images look worrying, from the perspective of the impact to the aquatic environment it’s less of a concern than if this had been crude oil because most of the jet fuel will evaporate very quickly.’
Likewise, over time, microbes will start to feed on the oil, breaking it down and helping to remove the spill.
Professor Mark Sephton, of Imperial College London, says: ‘The fact that it is jet fuel is significant. Jet fuel is dominated by relatively small hydrocarbons, compared to the more diverse and sometimes larger organic structures found in crude oil.
‘Smaller hydrocarbons are very attractive to bacteria who will degrade them more quickly than larger molecules – called “biodegradation”.
‘The fact that we are moving into warmer temperatures will also speed up biodegradation rates. In the end it all depends on the rate of introduction of fuel and the rate of destruction by bacteria. Let’s hope the latter wins out.’
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