Scientists explore dispersant impact

University of Waikato Professor Chris Battershill says the true environmental impact of the dispersants used during the Rena oil spill should be known by Christmas.

The Rena ran aground on the Astrolabe Reef in October and leaked about 350 tonnes of crude oil into the ocean.

Dispersants were used to help break up the oil before it washed ashore, but the action was criticised by some scientists.

“This is the first big oil spill in New Zealand’s history,” says Chris, “and we’ve quickly realised what isn’t known in this country about oil dispersants and toxicology.”

Dispersants are chemicals put on an oil spill and work a bit like dishwashing detergent on grease by breaking down the slick into millions of tiny oil droplets.

“Unfortunately, we know little about the toxicology of the dispersants on New Zealand species.

“Right now we need to learn more about the coastline and the food chain implications.”

During the spill, more than 20,000 birds are thought to have been injured or killed and studies are still being conducted into the impact on underwater ecology.

“The relevance of dispersant toxicology on New Zealand species is a huge gap in our knowledge.

“We are using similar dispersants used in the Gulf of Mexico disaster and are in the dark as to the short-term lethal effects versus the long-term effects on the food chain and ecology.

“It’s the unknowns that are the big problem now for New Zealand,” says Chris.

Research conducted by the university’s Coastal Marine Group in the wake of the Rena disaster is aiming to determine how future marine disasters should be managed.

“The spill globally isn’t much, but because of the pristine coastline we have here, and the iwi and community’s cultural connection to the coast, the impact is significant.

“By Christmas we will know what the degree of impact is and the scenario for cleaning it up.”

Coastal Marine Group doctoral students are researching aspects of Tauranga harbour and summer research scholarship students have realigned their work to examine the impacts of the Rena spill.

Chris says the university will soon have a clearer picture of how long the marine environment will take to recover, following results of chemistry studies of samples. These were taken during initial response surveys two days after the Rena ran aground and the weeks that followed.

The information has added to data gathered by local councils over the last 20 years and builds a good picture of marine habitats prior to any oil being spilled.

“Having this accurate data to hand is a rare circumstance globally.

“In most other cases of oil pollution it has been difficult to quantify the extent of impact and even harder to determine when the ecology will get back to normal, as elsewhere there is little or no ‘before impact’ information making it difficult to know what ‘normal’ is.”

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Posted on 25-11-2011 21:03 | By SCARLET PIMPINEL

A few minutes online would would have known what has been known for decades already, that the dispersents used are toxic, they are bad new PERIOD. If you had previously looked at the reported ex the Gulf of Mexico you would see that the affects are HUGE on the environment and people, that is how it has always been. For you this is a simple case of "put brain in gear before open mouth ..." AGAIN! PS are you on the payroll of the ol companies perhaps ?

Hey Claypole...

Posted on 25-11-2011 16:24 | By Tauranga Tazmin

Me against education and past mistakes? lol, you should change your name to tadpole if you beleive that! The evils and toxicity of this particular dispersant were well known prior to the use in NZ, and a few hours in front of google would have told the government that, but they still went ahead and used it! Read my first comment again and maybe you will learn something!

back it up

Posted on 25-11-2011 16:21 | By justice

The dispersent used was bassically vegetable oil? yet we continue to use and not worry about the slow painfull deaths that 1080 creates neverlone land,river,stream and eventually sea contamination that our government condones!!!!


Posted on 25-11-2011 15:02 | By overit

No good on them for looking into the toxicity issues. There was a lot of information for the pro’s & con’s-lets find out the truth because if it was bad we don’t want to use it again. Some brands were better than others.


Posted on 25-11-2011 14:57 | By BUSH WACKER

Just look online mate, all the info you will ever need is there about the BP messes made in the Gulf of Mexico, ELASTOL is US approved and best with no environmental affects yet these people continue to buy and abuse our environment with harmful products as supplied by the Oil industry.


Posted on 25-11-2011 14:50 | By Donnaw

Im with TT on this one, there should have been no lesson to is common knowledge that this toxic dispersent is seriously destructive, hence why other countries that have trialed it in the past have totally banned it. The spraying of this "dispersent" was done pretty damn quickly and pretty damn quietly...."Accidents" such as these should not happen, yes we all learn from them but its wether or not we take notice is the real issue....and in this instance....they just went ahead and done it knowing full well what can happen, so really there is no structure to your response.

It was an....

Posted on 25-11-2011 13:19 | By claypole

’accident ’ so when the next one happens here or overseas, lessons can be learnt. TT, there is no structure to your argument, maybe you are against education and learning from past mistakes?


Posted on 25-11-2011 11:04 | By Tauranga Tazmin

What is done is done, you cannot undo it! Just don’t do it again and stop spending money on trying to prove what was done in the past was wrong!

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