In 1996, a large oil tanker, the “Sea Empress”, ran aground, spilling almost 70,000 tonnes of oil off the coast of England.
What followed next is a familiar story and a disturbing sight. A large oil slick in the ocean, oil soaked pelicans and otters, seals, dying turtles, and colonies of oil-smeared sea-bird eggs that would never hatch. Later on, pictures in magazines would show the magnified images of tiny sea creatures in laboratory glass beakers, bloated with sacs of oil.
An oil spill spells disaster for hundreds of creatures in the sea and on land. Even people and fishing communities aren't spared — a study has shown that eye problems, skin irritation, depression and worry over the loss of a livelihood are common.
In the case of the “Sea Empress”, experts say her cargo of North Sea crude light was a “light oil”, and didn't cause very heavy damage.
But it was the earlier instance, that of the “Exxon Valdez”, in 1989, which raised concerns about the state of the world's fleet of tankers. The “Exxon Valdez”, another giant tanker, ran aground in Alaska's Prince William Sound, spewing out an estimated 11 million gallons of “heavy crude” into one of the world's best marine ecosystems. Exotic species of birds, mammals and fish were killed and the land spoiled. Many more died, eating contaminated fish, or by the residual oil on their breeding beaches. The most serious damage was inflicted on fish breeding areas, especially those of salmon and trout. A new generation was nearly wiped out, a food chain disrupted.
More recently, the BP oil well case and the oil spill after two ships collided off the coast of Mumbai once again highlight the havoc that unfolds in an oil spill. And the detergents, dispersants and other chemicals used to clean up sites polluted by spills also cause problems.
Wildlife is endangered when it eats, gets coated with, absorbs and even breathes oil or oil-coated fish and plankton. Oil causes harm to wildlife through physical contact, ingestion, inhalation and absorption. While fish eat and absorb the oil, birds, mammals and other sea creatures eat these fish and the damage continues. You could be even eating such fish.
The U.S. Fish and Wildlife Service adds that scientists have still to study long-term damage but, in wildlife, oil is shown to affect “the immune system, damage organs and the adrenal system, cause skin irritation and ulceration, and behavioural changes that affect the ability to look for food and avoid predators.” It also has an impact on breeding and the next generation.
Most spills are man-made — ships collide or, in most cases, run aground in bad weather. A solution say experts, is to gradually ensure that oil tankers are built to be “double-hulled” as a better way to prevent accidents. Let's hope the world comes up with better solutions and shows a little more concern for and care about our environment.
Two decades later
A research paper says, that even today, a visitor to Prince William Sound may think that everything is normal. Everything he looks at is what one sees in picture postcards. But scientists will point out the missing and hidden horrors.
Pockets of oil — and that's gallons — remain buried in the earth and coast. Fish species, like herring, which are in top position in the food chain, have still not recovered. Many show “genetic damage, curved spines, lowered growth, liver damage, eye tumours and damaged brains”. Fishermen are affected as hatcheries have been badly hit and commercial fishing is still a question mark. Bird species like the harlequin duck, the common loon, the pigeon guillemot, the pelagic red-faced cormorant and the double-crested cormorant are yet to recover. Killer whales and sea otters, on the other hand, are a bit better off.
Five groups
Oil falls into five groups, “from very light to very heavy”. Once it is released into the sea or ocean as a spill, it starts being subject to a process called “weathering”, or a reaction to changes with the environment. “Weathering” generally cuts down the toxic part of the oil, but then again, this depends on factors like the weather and temperature.
It is “medium and heavy oils” (most types of crude oil fall into these two categories) that cause the maximum damage. As their names suggest, they do not readily mix with water and “weather” very slowly. A clean-up of such oil spills takes a very long time.
Heavy oils can also “float, mix, sink, or hang” in the water. In such cases, oyster beds and feeding areas get affected as the oil sinks and mixes with the sediment at the sea bed. The result is that it's long-term devastation as young fish and eggs get affected. With time, plankton on the water surface generally recover.
Big damage
When you see an oil coated pelican, it's the beginning of serious damage. Oil coats the feathers of birds and the fur of mammals. The first thing it does is to destroy the insulating properties of feathers and fur. Birds instinctively try to remove the oil with their beaks and ingest it in the process. In the case of sea otters, they no longer feel warm and in many cases die of hypothermia. Many birds also die because the oil ‘layers' them so completely that they start to sink and drown. The horror continues. If birds and animals manage to survive even after gulping so much oil, they could still face lung, liver and kidney damage.
