Despite the recent headlines about the oil spill in the Gulf of Mexico, the good news is that the overall number of oil spills since 1960 has actually decreased due to a combination of tougher penalties and improved ship design.
The operative word there being decreased but not eliminated.
Just how bad is it? In the prior decade of the 1990s, an average of 150,000 tons of oil spilled into the world's waterways each and every year.
Seeing the after-effects on the evening news of such disasters as the Exxon Valdez catastrophe in 1989 and the current mess we are experiencing in the Gulf, witnessing the countless birds and aquatic mammals suffering, covered in oil, made me wonder exactly how do experts clean up oil spills? Time is the critical factor, along with waves, currents, and weather.
If a crew can reach a spill within an hour or so, containment and skimming are employed.
The oil will generally rise to the surface and then slowly spread out forming a thin sheen.
If crews can get to work in time then they can employ long, buoyant booms with skirts that float on the water and contain the slick.
The oil can then be skimmed and placed into containment tanks.
This approach obviously requires calm seas in order to be successful.
But sometimes time is not on our side.
And in that case other more advanced methods have to be tried.
One such approach is bio remediation: the use of microorganisms or biological agents to break down or remove oil.
Another approach involves the use of a bio remediation accelerator: a hydrophobic chemical (containing no bacteria) which chemically bonds to hydrocarbons.
The effect is a herding agent that floats these molecules to the surface of the water.
A sheen can be eliminated literally within minutes.
The resulting nutrient-rich emulsion creates a perfect environment for hydrocarbon-consuming bacteria.
These bacteria break down the hydrocarbons into water and carbon dioxide.
Another approach that is used is controlled burning.
However this method is restricted to low wind conditions and can cause air pollution.
Not an ideal solution near coastal cities.
The use of dispersants is another approach.
They act as detergents, clustering around oil globules and allowing them to be carried away in the water.
Just like what happens in your washing machine.
One problem with this however is that the dispersed oil droplets infiltrate into deeper water and can lethally contaminate coral.
For some oils, those denser than water, dredging is used.
And finally there are sorbents - large sponges that can absorb the oil from the water.
All very expensive solutions.
Which reminds me of what my mother used to say...
"an ounce of prevention is worth a pound of cure".