The Deepwater Horizon oil spill at the petroleum rig owned by British Petroleum and built by Transocean has dominated the news for the past one month. As the blame game continues and everyone worth their salt has expressed opinions as to why such a calamity has happened, the environmental impacts of this man made disaster are coming to light. This oil spill is the largest in human history and as a giant slick of oil spreads through the Gulf of Mexico, it sweeps away with it a significant portion of the flora and fauna inhabiting these waters. Many organisms of various species are left dead or maimed as efforts to contain the spill go on. Images of birds and various animals clogged in brown crude oil are circulating around the Internet and other visual media, the gruesome truth is being nailed in to the public conscience.
When the well was proposed BP had to draft an environmental impact analysis. In that analysis, the said that if at all a spill does occur, “water quality would be temporarily affected by the decomposed components and small droplets” and that “currents and microbial degradation would remove the oil from the water column or dilute the constituents to the background level”. They claimed to have observed “no adverse activities to fisheries and no danger to endangered or threatened marine mammals and no adverse impact to birds”. BP has finally accepted that the buck stops at their desk and has thus put a temporary end to the blame game. The government of the U.S.A has said that BP will have to pay for all clean up operations carried out to limit the damage. BP themselves have carried out attempts to help control the fast spreading oil slick.
Petroleum toxicity and oxygen depletion are the main factors which threaten to lead to an environmental disaster at Deepwater Horizon. Oil floating on the surface of water can affect a plethora of sea organisms. One of the main victims will be plankton, which includes algae, fish eggs and larvae of invertebrates. This poses a great danger as many organisms in the sea feed on a variety of plankton. From small fish to the whales, plankton is staple food to many aquatic fauna. Plankton affected by the oil spill will carry the adverse effects across the food chain of which they are a vital part. The effect on organisms at lower trophic levels is harder to assess as of now. The effect might be seen for years to come.
Oil can cause harm to organisms through absorption, ingestion, inhalation and physical contact. Birds face a high degree of risk of getting affected by an oil spill. As birds float on water or dive through water to catch fish, their wings, tail and body might become clogged with oil floating on the surface of the water. This impedes their ability to fly And they could ingest oil during preening as well.
Benthic organisms, like star fish and sea cucumber which grow on the ocean floor will be severely affected as significant portions for the sea bed gets coated with crude oil. Sea Turtles swim to the shore to nest and they too will have to bear the brunt of this human error. Turtle eggs may be damaged if an oiled adult sits on top of them. Scavengers such as bald eagles, gulls and raccoons too will be poisoned by oil if they feed on the carcass of oil clogged dead animals.
Oil can potentially persist in an environment long after the spill has occurred. Oil ingestion can cause damage to the immune system and also cause organ damage, skin irritation and ulceration. The area affected by the Deepwater Horizon spill is home to some for the world’s richest marine and coastal ecosystems. Southern Louisiana, the state on the coast off which Deepwater Horizon is located, accounts for almost 40% of the United States’ coastal wetlands. These wetlands are quite useful in the sense that they provide flood control, water purification, storm buffer, wildlife habitat, serve as a nursery ground for aquatic organisms and can be used as recreational areas.
The timing of the spill has also alarmed wildlife conservationists and scientists. The months of June and July are traditionally breeding seasons of many invertebrate species, fish, sea turtles and many birds. These creatures would have just laid their eggs or would be caring for their young in vital stages. The oil spill will spread widespread destruction of the young fauna in those parts.
This time of the year is also the Trans-Gulf migration season, when millions of birds migrate from the Yucatan Peninsula and South America to the U.S Gulf Coast. The spill has occurred close to the peak of the migration season. This time also happens to be the hurricane season on the eastern shores of the United States. June 1 was officially earmarked as the start of the hurricane season. A big, rough storm could complicate matters to a very large extent and spread the oil slick to a much wider area.
Scientists estimate that the area containing Deepwater Horizon (the area is officially known as NNE Octant of the Gulf) is home to 8,332 species of plants and animals. Including only the major taxa (taxon is one unit of organisms) of animals at all depths in the region of the spill, there are 1,461 mollusks, 604 polychaetes, 1503 crustaceans, 1,270 fish, 4 sea turtles, 218 birds and 29 marine mammal species to be found in the region. Many endangered species like the Kemp’s Ridley Turtle also inhabit the area.
Moreover, many national Refuges (American equivalent of the national parks in India) situated near the danger zone are at a high risk. In the National Refuges facing the maximum risk, about 34,000 birds have been counted, including gulls, pelicans, roseate spoonbills, egrets, terns, and blue herons. A large number of dead animals and birds have already been found in these parts. The tally consists of 1131 dead birds, 331 sea turtles, 38 dolphins and other mammals, and 1 reptile. As you read, more and more animals are being discovered dead or well clogged in oil everyday.
The Southeast Louisiana Refuge Complex is the refuge facing the highest risk. This national refuge houses nesting wading birds and seabirds, songbirds, raptors, as well as wintering shorebirds and waterfowl. The wetlands in the Refuges and other coastal regions also support a diversity of fish and shellfish species. These include Speckled trout, redfish, flounder, blue crabs and shrimp.
Coral reefs, those beautiful underwater structures, stand to incur a lot of damage from the spill. There are two significant coral reef structures in the Gulf of Mexico, the Flower Garden banks and Florida Reef tract. Studies have shown that the dispersant and dispersed oil droplets are much more toxic to the coral reefs than the crude oil itself. The dispersant oil caused ‘significant harm’, including quick, extensive death and stoppage of growth rates, to the coral colonies.
Birds and sea turtles seem to be on the priority list of conservationists as they are the ones most likely to be drastically affected. Endangered and threatened species at risk from the disaster include West Indian manatees, whooping cranes, Mississippi sand hill cranes, wood storks and four species of sea turtles.
The Deepwater Horizon disaster occurred because of negligence on the part of BP as well as the U.S government. It is up to all of us as world citizens to ensure that such disasters do not happen again. For that, the governments across the world have to be pressurized in to ensuring that strict regulation is enforced and no company is allowed to cross the line.
The Deepwater Horizon accident has put in peril the precious natural diversity of the Gulf of Mexico, but BP does not even seem sorry for their negligence. Rather, they have tried to blame other parties involved. We can only hope for the best as efforts to limit the damage and save what is remaining of the Gulf of Mexico’s flora and fauna go on.
Aju Basil James