11 October 2011

Lessons from the New Zealand oil spill

What can we learn from the Rena oil spill now happening in New Zealand? How does this incident compare with the Changi East oil spill on 25 May 2010.
Container run aground in New Zealand, Oct 2010
from Science Alert - Rena oil spill
Although the New Zealand oil spill is a lot smaller than the one in Singapore, there has been lots of information provided by the New Zealand authorities and experts. There are also issues of volunteer involvement, and I learnt more about dispersants.

Comparison of New Zealand oil spill and Changi East oil spill
The Singapore oil spill was much bigger.

The container ship Rena ran aground on Astrolabe Reef off Tauranga in New Zealand on 5 Oct. Since then, an estimated 350 tonnes of heavy fuel oil has leaked from its ruptured hull into the Bay of the Plenty. More than 1300 tonnes and 200 tonnes of diesel is still on board.

The Changi East oil spill on 25 May involved a collision between a crude oil tanker and a bulk carrier which released about 2,000 tonnes of crude oil that affected the Singapore East Coast, Changi East, Chek Jawa at Pulau Ubin and parts of Johor.
From Singapore oil spill spread and clean up: a summary

Do container ships run aground in Singapore too?
Unfortunately, yes. In Sep 2009, a container ship ran aground in Singapore on Sebarok Beacon which is close to the Sisters Islands and Pulau Jong.
Container ship run aground in Singapore, Sep 2009
seen between the two Sisters Islands.

Timely information updates
I'm quite impressed by the enormous range of information provided by the New Zealand authorities on the oil spill. In the Changi East oil spill incident, ordinary people started and maintained a facebook page which attempted to provide real time information.

For the New Zealand oil spill, there are regular and thorough updates from the New Zealand Science & Technology Media Centre which was set up by the Ministry of Research, Science & Technology (MoRST — now MSI) aimed at "engaging New Zealanders with science and technology".

The site has set up a page on the Rena oil spill: Information and expert resources updated with information on these aspects:
  • Marine ecologist on the oil spill.
  • Experts on environmental impact, the clean-up ahead.
  • Expert comments on oil breakdown, collected by the SMC.
  • Maritime NZ media release site- the official source of information on developments.
  • Cawthron Institute guidelines for Maritime NZ on dispersants:
  • Northland Regional Council resource pack on oil spills.
  • Real time satellite location data for the Rena and nearby ships
  • American Academy of Microbiology FAQ on microbes and oil spills.
It also has a scrolling list of latest posts and reports on the issue.

Volunteer involvement
As in the Singapore oil spill, ordinary people in New Zealand were also moved to try to do something. The website stuff.co.nz has many articles about people going out to clean up the shores despite authorities attempting to prevent them from doing so. In Singapore, we need a plan for safe and effective volunteer involvement in the event of an oil spill. I posted earlier about what ordinary people can do.
Siva briefed Jim of NParks and me, about the proposal on Saturday.
N. Sivasothi has come up with a proposal for volunteer involvement, representing key volunteer groups. We await upcoming discussions to put this in place.

Other information about oil spills in general
There is lots of discussion as usual about the effectiveness of dispersants in dealing with an oil spill. This article below highlight some issues. I didn't know, for example, that dispersants "only worked on fresh oil and would not work on oil that had been in the ocean for more than three or four hours."

Dispersants 'worse than oil'
Michelle Cooke stuff.co.nz 11 Oct 11;

The dispersants being used to break up the hundreds of tonnes of oil leaking from the grounded Rena could be "more harmful than the oil itself".

Maritime New Zealand (MNZ) has used Corexit 9500 to help break up the oil, but University of Southampton oceanography lecturer Dr Simon Boxall said using dispersants could cause unnecessary harm.

The UK banned the use of Corexit dispersants in 1998 and Sweden has a blanket ban on all dispersants in the marine environment, Boxall said.

"In their raw form some dispersants can be very toxic and I believe will do more harm than good," he said.

"They are more harmful than the oil itself and they are not less toxic than dishwashing liquid.

"Dishwashing liquid doesn't carry hazchem advice and you don't wear protective clothing and masks to do the washing up. In this case - with limited knowledge of the region - I'd advise caution on use of dispersants."

But Environment Minister Nick Smith said Corexit was no more toxic than dishwashing liquid and had been approved by the Environmental Protection Agency.

He said at least 1800 litres of the chemical dispersant had been used with variable results.

In New Zealand, Corexit can be used in sea water but not fresh water.

Boxall has studied the Erika oil spill on France's Brittany coast in 1999 and the MV Braer oil spill in the Shetland Islands in 1993.

He said oil broke up naturally after the Erika oil spill and "little human intervention took place".

He estimated last night that it should take between four and six weeks for the oil to be naturally dispersed.

But another 300 tonnes have since leaked into the ocean, which means the natural process could take longer.

He said the stormy weather was "both a pro and con". While it hindered the salvage operation, it would also help disperse the oil.

MNZ started using Corexit last week to disperse the oil from the Rena, but was also looking at using alternative dispersants.

National on scene commander Rob Service said last week that despite initial indications that dispersant testing had proved effective, further analysis had confirmed Corexit was not dispersing the oil.

MNZ said on its website chemical dispersants were an "important option" and should always be considered in the most effective "first stage" of the response strategy.

A spokesperson for MNZ said results from a trial of Corexit on Thursday and Friday proved inconclusive and while it planned to use it this morning, the weather hindered that operation.

Corexit is dispersed from the air, but it was too cloudy to fly today.

Helicopters have been on standby all day, waiting for a break in the weather so spraying could continue.

The chemical only worked on fresh oil and would not work on oil that had been in the ocean for more than three or four hours.

"If it's still coming out tomorrow then we'll continue to use it," the spokesperson said.

Commonwealth Scientific and Industrial Research Organisation (CSIRO) research scientist Professor Nic Bax, who leads the Biodiversity Hub at the University of Tasmania, said nature would play its part but dispersants could also be helpful in breaking up the oil.

"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."

"Spilt oil that remains at the surface will gradually be dispersed by natural physical processes at least in high energy environments. Oil that reaches low energy environments or gets buried in sediments may persist for several years."

The University of Houston in Texas is currently researching new types of dispersants which are more environmentally friendly.

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