One year on from the Deepwater Horizon disaster it should be possible to get some perspective on just how serious this episode has been. But as I mentioned in a previous article, it is in nobody’s interest to say that things are basically OK. But in fact they are. Scientists will certainly be able to detect effects of the oil spill for years to come. But that’s not because the effects are so significant, its just that scientists are so damn clever!
One year ago approximately 1 million cubic metres – a cube 100 m × 100 m × 100 m – of oil was spilled into the Gulf of Mexico: enough to keep the USA going for almost 6 hours.
- If mixed uniformly with the waters of the Gulf, this would correspond to an impurity concentration of approximately 1 part per billion – which for most purposes is not biologically significant.
- As a surface slick 1 mm thick, it could have covered at most 0.1% of the surface area of the Gulf – significant, but not catastrophic.
- But when the oil reaches the shore, it is sufficient to deposit 300 kg of oil on every metre of shoreline.
Now I know that the oil will not mix uniformly with the entire mass of water in the Gulf, and I know that if you are a sea bird landing on a slick – it is clearly disastrous. But the basic facts above highlight that it is the oil landing on shore that presents the really significant hazard to people and wildlife. Much oil did come ashore – but mostly it has been removed from the places where this would not cause undue damage, and in the other places it will naturally degrade.
The BBC are keen – like other news outlets – to imply there is a continuing problem: The headline BP oil spill: Fishermen woes persist, one year on implies there is a continuing pollution problem. There is not. This story is about the widespread death of oysters caused by increasing the flow of the Mississippi river. Apparently oysters are very sensitive to salinity and cannot survive in fresh water. This decision was taken to drive oil from the shore – and was probably smart – but it was obviously unpopular with the oyster farmers. A similar effect will probably occur due to the current flooding of the Mississippi.
However, tests (pdf document) on fish show that pollutants are not just at safe levels – they are undetectable. You can find links to other environmental reports here. The site hosts links to lots of data including links to environmental impact assessments on turtles. If you know of any surviving bad effects I would be very interested to hear from you.
So people are still suffering from the loss of their livelihood – but the Gulf of Mexico is basically back to normal – possibly better than normal after taking a break from fishing. But now our focus has shifted, and our improved gaze may now detect the massive amounts of oil that are leaking into the Gulf anyway. The Scientific American magazine bizarrely claimed that ‘Science stopped the Gulf disaster‘. I don’t agree. But I do agree, that Science will eventually uncover exactly how bad the situation is.
However the whole episode really serves to expose our cultural addiction to oil. And despite this disaster, we will go right on trying to extract every last drop we can, no matter how deep or cold or hostile the terrain. Even the dear President Obama is unable to to say to ‘No’,