Attempts to disperse Tauranga oil spill with chemicals courts controversy

Attempts to disperse Tauranga oil spill with chemicals courts controversy

As individuals and groups scramble to contain the oil spill from stranded vessel Rena, which last week struck the Astrolabe Reef off the coast of Tauranga, others are questioning methods being used to help clean up the oil. According to Maritime New Zealand’s latest update on the situation, there is a significant amount of oil leaking from the vessel and dispersants are being tested on the fresh oil leaking from the ship. One dispersant, called Corexit 9500, is the same one used in the BP Deepwater Horizon spill, which came under criticism for its level of toxicity.  

Greenpeace claims dispersants are chemicals themselves and don’t actually help clean up anything. 

“They only put it out of sight and often add to the harm by increasing the toxic load that wildlife are exposed to,” said Greenpeace campaigner Steve Abel. 

Meanwhile University of Southampton lecturer in oceanography Dr Simon Boxall, who has experience of the Erika oil spil on France’s Brittany coast in 1999, and the MV Braer oil spill in the Shetland Islands in 1993, advises “caution on use of dispersants”. 

“Some experts disagree on the dispersants. Dispersants do have a role to play but only in a few cases (but) there is a tendency to use them regardless. 

“Contrary to what is coming out, they are more harmful than the oil itself and they are NOT less toxic than dishwashing liquid! Fairy dishwashing liquid doesn’t carry hazchem advice and you don’t wear protective clothing and masks to do the washing up. In their raw form some dispersants can be very toxic and I believe will do more harm than good. Most of the Corexit dispersants were banned from use by the UK Government in 1998 for rocky shore areas and can only be used offshore after consultation with govt., and if no alternatives are available. Sweden has a blanket ban on all dispersants in the marine environment. In this case – with limited knowledge of the region.” 

CSIRO research scientist Professor Nic Bax, who leads the Biodiversity Hub at the University of Tasmania, said the problem with dispersants is that they don’t change the amount of oil in the environment, but rather redistribute it. 

Still, he takes a more optimistic view on their role. 

“Where they are used in deep water and high energy environments they also serve to spread the oil over a wider area (or volume), diluting it and reducing its immediate impact. Dispersants used to be quite toxic but now are considered to be much less toxic than the oil itself, so the main environmental decision regarding their use is determining where the oil will have least harm i.e. concentrated at the surface and on sensitive shorelines, or dispersed through the water column. There does not seem to be much evidence to indicate that dispersing oil leads to greater uptake by organisms, although this would be very hard to measure”. 

He adds that natural processes like microbial activity will also help break the oil down. 

Looking at the wider implications of the spill, Abel said despite the spill occurring at a slow pace, it still has New Zealand resources stretched, and that is something the government will need to address once the crisis has abated. 

“Once we are through this crisis period, serious questions need to be asked about the Government’s preparedness and ability to handle oil spills, even of this relatively small scale.” 

And with numerous off shore oil drilling permits being scoped out, it also beggars the question of how well New Zealand would be prepared if an event like the Deepwater Horizon spill were to happen near Kiwi shores. 

Not that John Key is buying into the argument. Speaking on TVNZ’s Breakfast programme this morning, Key denied that the latest spill highlighted how ill-prepared New Zealand is for a major oil spill from the Government’s planned deep sea oil programme, saying it was a “completely different … and not correlated issue.” 

But according to Abel, the only difference between the two incidences is scale. 

“John Key admits that this spill, at less than 100 tonnes so far, is a catastrophe, and yet it is minuscule compared to an underwater blow-out of a deep water rig, such as that in the Gulf of Mexico, which leaked millions of barrels of oil,” said Abel. 

Well over 1500 tonnes of oil have so far leaked from the ship,and the WWF is concerned about the threat this poses to marine wildlife, in particular, seabirds and dolphins. 

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