For the past days Mauritius witnessed the local government “handling” a 203,130 deadweight tons, 300-meter long and 50-meter wide cargo ship stranded on the reefs of Pointe d’Esny. The ship was carrying 200 tons of diesel and 3800 tons of heavy oil. On day 12, the “worst case scenario” happened. Knowing that water was already entering the lower engine rooms, was an oil spill that unpredictable?
The region of ‘Madagascar and the Indian Ocean islands’ is one of the 34 biodiversity hotspots around the globe because of its rich biodiversity and high endemism. The Western Indian Ocean is recognized as one of the most widely-used routes for shipping. According to a report published by World Bank in 1998, c. 30% of the world’s petroleum production either pass near the waters or through the coastal waters of the Indian Ocean islands each year. The study also concluded that accidents in that region where very large vessels carry crude oil (heavy oil) would likely overload the local authorities and could have disastrous consequences on the ecosystems, biodiversity and communities along the coastal regions.
Oil is considered the fastest way of damaging the oceans – more dangerous than waste. Heavy oils are non-volatile and cleaning them up under all conditions is very difficult. As a consequence the impacts are severe and long term. Diesel, on the other hand, is considered a light oil. The latter is moderately volatile (evaporates easily) and therefore is toxic once present in the air. Inhalation can have acute toxic effects. Furthermore, both of them have a strong odour which can damage the respiratory system. Oil does not only affect life directly through the skin (physical contact) or mouth (ingestion), but also through the nose (inhaling).
An oil spill can impact an ecosystem or species on the short term and long term through physical smothering impairing physiological functions (oil in seabirds’ feathers), chemical toxicity causing sub-lethal effects (damages in reproduction or breeding), ecological changes when keystone species are lost, and other indirect effects such as loss of shelter. While some species (seagrass, adult fish) can survive the contamination by oil, others such as mangroves, sea turtles and seabirds will not be so lucky.
Previous observations showed that fish usually swim away to avoid exposure. In fact, the vulnerable marine species might die because they were unable to move, to breathe, to eat or to undergo photosynthesis. Long-term exposure can cause liver damage and cancer. In some cases, the toxins from an oil spill can be stored in the tissues of an organism and pass from the prey to the predator. As a consequence, the predator also becomes contaminated – including humans, upon consumption. Humans are part of the natural ecology and cannot be ignored when talking about the impacts. Just like other animals, humans can be contaminated in cases of oil spill and develop severe health issues – symptoms varying depending on the period of the exposure and intake.
The South East of Mauritius, known for having the largest lagoon around the island, is particularly rich in biodiversity with the Ramsar site, the Blue Bay Marine Park and the ‘Ile aux Aigrettes’. In addition to the ecological and health complications that might result from an oil spill, there are social and economic implications as well. In Mahebourg / Pointe d’Esny, the local communities depend heavily on the sea for their livelihood – from fishing to touristic activities. Since the national lockdown (COVID-19), many businesses in the tourism sector (dive centers, hotels, tour operators) took a hit as well as fishers who were not allowed to fish for weeks / months. The burden of an oil spill further drowns the people employed in the sectors.
The key factors that have to be taken into consideration before and while cleaning up an oil spill is the source of the spill (if it is contained or not); the type and quantity of oil spilt; the duration of the spill; the location of the oil spill (ecological, social and economic importance); the physico-chemical conditions and water dynamics (temperature, wind direction, wave actions and currents). There are various methods to contain the oil spill or prevent further spread – biological or physico-chemical, for example, booms which have already been used by the authorities; the use of chemicals to mineralize petroleum or to break down the oil into smaller particles that will mix with the water; bioremediation – microorganisms that degrade hazardous organic pollutants to non-poisonous compounds like carbon dioxide, methane or water vapor; hair mats to absorb the oil and act as a sponge; manually (especially heavy oils).
Unfortunately, an oil spill does not end with the removal of the oil from the ecosystems. Ecologists, conservationists and scientists will have a huge post-Wakashio work in order to monitor the health of the organisms so as to detect changes in the health of those organisms or alterations in the ecology. The impacts of an oil spill do not only affect the environment, but also human health, food security, people’s safety, livelihood, children’s development, psychosocial development and cause further exhaustion from the clean ups, toxic exposures, and potential injuries. Moved by the people risking their lives to save Pointe d’Esny and many more eager to lend a helping hand out of love for their country, this is my message to you – please, be careful. The people should not pay the price for the government’s amateurism.