Scientists have warned of a potential environmental disaster after a cargo ship struck an oil tanker carrying 142,000 barrels of jet fuel off the coast of Yorkshire.
The US-flagged tanker MV Stena Immaculate was carrying over 18,000 tonnes of jet fuel when it was struck by the Portugal-flagged container ship, MV Solong yesterday morning.
Now, as that jet fuel leaks into the Humber Estuary, scientists and marine pollution experts have revealed how rescue teams could tackle the growing oil spill.
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.
Thankfully, experts say that the type of fuel currently entering the Humber Estuary could evaporate quickly before it causes any serious damage.
Professor Tiago Alves, of Cardiff University, says: ‘Environmentally, jet fuel evaporates easily and also combusts easily, as we have witnessed. Any impact depends on the volume of jet fuel spilled and if it was almost completely combusted during the ensuing fire.’
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.
Although the MV Stena Immaculate’s cargo was jet fuel, both ships are now understood to have been carrying ‘bunker fuel’, a type of heavy fuel oil used to power their engines.
This type of fuel is far heavier, meaning it is less likely to disperse naturally through evaporation, burning, or mixing with the water column.
Professor Alves says: ‘The environmental impacts depend on the volume of jet fuel spilt, and if any bunker fuel was or is already spilt.’
That means the first step in dealing with an oil spill is making a careful plan about what to do next.
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.’
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. The ship was carrying 18,000 tonnes of jet fuel, equivalent to 142,000 barrels
‘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.
Until that mathematical modelling is complete, the authorities won’t know the most effective places to deploy the cleanup operation’s resources.
As MailOnline’s step-by-step graphic shows, the first stage is to physically prevent the oil from spreading any further.
Cleanup crews can deploy specialised floating barriers called booms which corral the oil into more controllable areas.
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.
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
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 absorbent 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.
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 – absorbent 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.
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
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 harm local wildlife.
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.
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
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.
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 begins 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.
The dramatic fires seen blazing at the crash site are likely the product of the jet fuel igniting which, although concerning, may mean less fuel actually enters the environment.
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.’
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
This is helped by the fact that weather conditions today are relatively windy, which means that wave action should help more jet fuel evaporate before it reaches the shore.
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 bigger concern is not the oil, but the 15 containers of highly toxic sodium cyanide carried on the MV Solong, according to Lloyd’s List Intelligence.
This has now raised concerns of a mounting ecological disaster as the toxic and water-soluble compound could have entered the wildlife-rich waters near the crash.
Dr Jonathan Paul, of Royal Holloway, University of London, says: ‘The plume of sodium cyanide, which we now know is present, is likely to be localised to the spill and removed from the water within 12-15 days as it volatilises to cyanide gas in the atmosphere.
‘There is a potential immediate risk to humans and wildlife from this toxic gas, which depends on the volume released.’
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. However, the bigger concern is the toxic sodium cyanide which was being transported on the MV Solong
If the sodium cyanide continues to spread, it could cause widespread ecological damage to the wildlife living in the area.
Dr Tom Webb, a marine biologist from the University of Sheffield says: ‘The wildlife of the Yorkshire coast and Humber Estuary is of immense biological, cultural and economic importance.
‘Chemical pollution resulting from incidents of this kind can directly impact birds, and it can also have long-lasting effects on the marine food webs that support them. We have to hope that any spills can be quickly contained and pollution minimised.’
However, it is not yet clear how much, if any, of the sodium cyanide has entered the water.
