The MV Wakashio ran aground on a coral reef, at Pointe d’Esny, Mauritius on July 25, 2020. Within two weeks, the tanker had split in half and started leaking oil into the surrounding waters affecting, according to a UN report, up to 30 kilometres of shoreline. Around a week after that, images of dead dolphins surfaced, sparking protests at an inefficient and intransparent government response.
In contrast, the Sri Lankan government responded to the spills from the MT New Diamond within a few hours, involving the Air Force and Coast Guard, and detailing public meteorological forecasts. These human factors may control the ramifications of many oil-spills, which contrasts to the natural forces which can alleviate, reinforce, or be affected by the harms that can occur. This article will examine the role science plays in the aftermath of oil spills, looking at the effects it has and the remedies it provides.
Oil spills can have drastic environmental effects on many levels. For instance, the oil can lead to the suffocation of fish and animals. The effect on seabirds is particularly stark, as the oil coats their wings, which makes it impossible to fly, and removes the protective thermal coating, leaving many birds vulnerable to hypothermia or overheating. As the birds try to preen their feathers to clean them, they often swallow some oil, which ends up poisoning them. The Exxon Valdez spill is said to have killed over a quarter of a million birds. The oil can also damage natural habitats such as coral reefs and mangroves. This leads to a lack of shelter and sustainability in these areas, which endangers local wildlife populations. In small scales, the damage is not so great, but in large quantities, such as the 10.8 million gallons released in the Exxon Valdez, the effects can be drastic.
Moreover, the oil is often toxic to a wider degree, due to the vapours such as benzene, toluene, and poly-aromatic hydrocarbons that it releases. These can react with oxygen in the air to form small particles that can penetrate lung tissue when inhaled. These effects not only contribute actively to climate change but also pose a threat to animal and human life in the vicinity of the spill. Crude oil is also very flammable and thus poses a fire hazard. When this risk is left unmitigated, it can cause accidents such as the Kuwait oil fires, or the Deepwater Horizon explosions.
When dealing with oil spills, scientists and response teams can utilise a variety of countermeasures. The use of bioremediation is gaining traction, especially after its supposed efficacy in the Deepwater Horizon spill. The idea behind it is that the introduction of bacteria that can consume the oil will lead to its breakdown or removal. These can then be incorporated into accelerators, which transfer hydrocarbons out of the water and into gels, where they are broken down by microorganisms. However, scientists disagree on the extent to which it solves the issue, as some academics such as David Valentine claim that the microbes only address the natural gas emissions from oil slicks, whereas others claim that the breakdown of hydrocarbons is hundreds of times faster than natural decomposition.
Another common tool used to combat oil spills is the use of dispersants. These are chemicals that emulsify and disperse large amounts of oil, which are meant to be reduced to safe levels. However, even at these concentrations, oil droplets can sink and reach fish eggs, killing them, or penetrate the outer layer of corals, bleaching them. Moreover, the chemicals used often are poisonous, and in the case of the Deepwater Horizon spill, actually exacerbated the harms of the oil spill, as the toxic materials in the dispersant failed to remove the oil and instead just spread it further.
Human hair is being used as material to absorb oil, as it has good ‘adsorbing’ qualities, where the oil sticks to the outside of the hair. This is used both as a barrier to prevent oil from spreading and as a sort of sponge, used to remove oil from the water. More technologically advanced forms of this idea are being developed, which specialise in using nanotechnology to take in several times the sponge’s mass in oil. Water can also be removed and turned in a centrifuge to separate the water from oil. Whilst this method does take out lots of oil, maximum efficiency is prevented since the remaining contaminants are hard to remove, and environmental legislature bans the reintroduction of polluted water to the areas it was taken from.
Overall, science is being used in many different ways to solve the complex issues brought forward by oil spills. These can have drastic effects if not tackled well, and although much of the response is dependent on sufficient technology being available, it is impossible not to count out the human and political forces which can aid or hamper recovery efforts.