Time and again, news and tabloid have reported occurrences of oil spill accidents across the globe. The most recent confirmed oil spill would be the MV Wakashio oil spill. This disaster shaped up at a gradual pace but it started from the offshore of Pointe d’Esny, south of Mauritius, after Wakashio (a Japanese bulk carrier) ran aground on a coral reef in the Indian Ocean on 25th July, approximately at 16:00 UTC. Estimation is that, about 1000 tonnes of oil was discharged into the ocean. The incident has been termed as the worst environment disaster in Mauritius.
India also had faced such disaster in the recent past. In 2017. The Ennore oil spill took place outside the Kamarajar Port in Ennore, near Chennai, Tamil Nadu. The incident took place on 28 January 2017, due to the collision between an outbound empty tanker BW Maple and An inbound loaded oil tanker Dawn Kanchipuram, at 04:00 local time.The spillage quantity is estimated to be 251 tonnes.
Needless to say, these accidents cost us humans in many ways. Some, which we don’t even realise now. So, what is the extent of damage and carnage caused by these incidents? Let’s find out.
What makes up the pollutant ?
The pollutant which causes all these environmental mayhem is crude oil. Also, known as liquid petroleum. The constituent chemical composition includes hydrocarbons of various molecular weights and also other organic compounds. It is a leading base source of numerous types of fuels and is formed due to compression of large quantities of dead organisms (mostly zooplankton and algae) under sedimentary rocks accompanied by intense heat and pressure conditions over a very large period of time.
Crude oil, especially the lighter grades (has lower density) are preferred as they contain a good balance of hydrogen and carbon. Due to their density, they tend to float over the saline water.
The slowly building adverse effects on the environment that are now being recognized and associated with fuel consumption. This includes global warming and ocean acidification due to CO2. On the other hand, short-term oil spill causes immediate and visible effects on the environment too.
What does it cost the environment?
The intensity of damage of oil spills, be it crude or refined oil, is more severe in oceans than on land. The layer of oil can spread up to hundreds of nautical miles and therefore forms a thin layer over the water surface. The nature of the adverse effects depends on the amount of oil spilled, type of oil,speed of the discharge of oil in the ocean, location of the spill, with respect to geographic and marine conditions, the oceanic circulation pattern and the local climatic conditions, and so on.
The immediate effects on marine biodiversity includes chemical toxicity, interference with physiological processes of the animals, loss of organisms from a community etc. In fishes, it leads to starvation (due to pollution of food sources), impaired respiration and reproduction, habitat destruction and toxicity due to oil ingestion.Also, certain species have sensitive reactions to the chemical composition of oil. All these build up to a high mortality rate in fishes and larvae. Also, deformities might arise in present and/or subsequent generations.
Birds are affected as they on consumption, these pollutants harm their lungs, liver and kidney. Also, due to oil trapped in their feathers, they cannot effectively fly or float, due to compression of the feathers. The feathers also provide insulation to the birds and in such cases, the feathers cannot effectively protect the under skin. Sea birds, which come in contact with water, have water residuals attached to their skin and might die due to hypothermia.
Animals like whales, dolphins, otters and sea turtles are also not immune to the oil spill adversity. They encounter physiological complexities.like tissue damage of various organs, low immunity, ingestion and inhalation of oil causing respiratory inflammation, ulcers, gastrointestinal irritation etc.
Several other classes of animals and the plant kingdom too are affected and suffer from various short and long term effects. Coral reefs, in particular, are very hard hit due to this pollutant. As for contact with large quantities of oil can damage and impede the growth, development and reproduction of the corals reefs. The oil cover also destroys the thriving ecosystem surrounding the reefs.
What’s done to reign in and restore the damage?
Cleaning up the oil spill can be difficult, as the methods and effectiveness vary with different factors like type of oil spilled, temperature of the water, and types of marine landforms involved. Also, some techniques themselves have adverse effects on the environment (eg. controlled burning). Other methods involve: Bioremediation, Dredging, Skimming, Solidifying etc. Also, in some courses of actions,’wait and watch’ approach is the best solution.
As the saying goes around, ‘Prevention is better than cure’. Hence, the focus should be on preventing such disastrous accidents rather than speedy clearance procedures. For now where we stand, any damage, even be it a small one, to the environment might hit us worse than we can think of.