On the 22nd of April the Deepwater Horizon rig suffered a large-scale explosion that killed 11 workers and cost the life of the rig itself. The sinking of the large platform has resulted in an environmental tragedy caused by the estimated five thousand daily leaking oil barrels. An oil spill is the effective release of large quantities of liquid petroleum hydrocarbon, a chemical that, because thicker than water, can spread across vast expanses of marine and coastal waters at very high rates. The present spillage, which has already reached the coasts of Mexico, Mississippi, Louisiana, Alabama and Florida, is forecasted to greatly damage the delicate and endangered ecosystem of the coastline.
Despite the 41 miles of floating boom to contain the expansion, the skimmers employed to remove 20,300 barrels of oil-water, the dispersant chemicals (soapy-solutions) being air-sprayed, some controlled burning, four robotic submarines and projects to create a drilling relief – the safety of the ecosystem is gravely plummeting.
The most at risk are the waterfowl, who at this time of year migrate to the warm coast of Mexico to breed and nest. After many days of non-stop travel the birds look for food and solace in the coastal shallows. Their feeding patterns entail plummeting into the sea and swimming deep into the water to find fresh fish for themselves and their newborns. The danger they encounter at this time is paramount, for in returning to the surface they are likely to find themselves covered in heavy and sticky oil. The oil penetrates their plumage, reducing its insulating ability making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. Worst of all, it impairs them from flying out, swimming down and escaping from predators. The species most at risk are the Clapper Rail, the Reddish Egret and the Caspian Tern.
Airborne animals are not alone; the millions of fish and aquatic mammals who inhabit these waters are all at great risk from the pollutant in the open water. Ingestion of the oil affects their digestive system, causes dehydration and, depending on the level of chemical concentration, can also be toxic. Aquatic plants and coral reefs, which are both home and nourishment to enormous marine ecosystems are obscured by the impenetrable, black floating oil. This affects their ability to carry out photosynthesis and phytoplankton (the main food element for fish).
The gravity of the situation is difficult to predict; the direction the oil will spread depends on the winds and currents; to the east are the seagrass beds – carpets of underwater meadows in the bays and estuaries of the Laguna Madre that are home to shrimp and shellfish, redfish and speckled sea trout. To the west are schools of bluefin tuna, dolphins, sperm whales, nesting sea turtles and manatees (or sea cows). Manatees are friendly, herbivorous sea mammals who can reach up to 4 metres in length. They are clumsy swimmers because of their small paddle-like flippers so spend most of their time munching on the seagrass. However they have been known to swim 30km per hour in search of the perfect meal. Because they only mate every two years, and gestation of a single calf lasts 12 months with weaning taking between 12-18 months, they are a highly endangered species. It is believed that less than 2500 manatees exist in the wild and they depend on the seagrass both as a food source and habitat.
The consequences of this environmental tragedy on humans are also grave. Much of the affected marine life is a source of food and income for the coastal populations spread across the entire area. Similarly, rare and interesting animal species have attracted vast waves of tourists. Not only is the presence of oil in itself a tourist deterrent, but the possible devastation of the ecosystem could have long-term impacts.