Rena spill: oil on coastal ecosystems – experts respond

The SMC received the following comments from experts on various aspects of the oil spill. Feel free to use these quotes or contact the SMC to follow up with these and other experts.

The latest update from Maritime New Zealand is available here.

Impact of the oil spill:

Dr Norm Duke, Professorial Research Fellow, Mangrove Hub, James Cook University comments:

“There needs to be great care taken in mitigating the impacts of large oils on coastal ecosystems – and in selecting the chemicals and methods applied.

“Petroleum oil will naturally break down – but this takes time and oxygenation. So, the longer the oil remains floating at sea – the safer it becomes. And, the rougher the weather – the better also.

“My results in Australia and in Panama with studies of major oil spills – and experimental studies – clearly show that oil can persist in tidal sediments for 20-30 years. And, the effect of this persistence is longer term impacts on biota growth – and its genetic makeup. For the latter, we know for instance, that there are mangrove plants can have increased genetic mutations with increased levels of oil in sediments.”

Dr. Barbara Bollard-Breen, senior lecturer in marine conservation biology at AUT University’s School of Applied Science comments:

“This morning Maritime New Zealand indicated that up to 350 tonnes of oil have spilled from the Rena and more is expected over the next several hours.””While the oil spill from the Rena has placed the marine and coastal regions in the Bay of Plenty at great risk, all of New Zealand’s coastal areas are vulnerable to this sort of disaster.”

“It highlights the urgent need to develop rapid response protocols for ship groundings and oil spills and mechanisms to prevent this from occurring again. It also highlights the need for a more comprehensive approach to marine ecosystem management in New Zealand.

“This has turned into an environmental disaster with widespread implications. It has the potential to not only affect some of our most pristine coastal areas in the Bay of Plenty region, but also estuaries and already threatened marine habitats, sea birds, shellfish, marine mammals and other marine life.It will also impact upon commercial, amateur and customary fishing, tourism, surfing and other recreational activities in the area.”

Legal jurisdiction under the Resource Management Act:

Joanna Mossop, Senior Lecturer and maritime law expert, School of Law, Victoria University comments:

“My understanding is that [Rena] is within the territorial sea because it is less than 4 nautical miles from Motiti Island which generates its own territorial sea of 12 nautical miles.

“The RMA provisions in respect of pollution offences applie up to 12nm. Beyond that, the Maritime Transport Act contains offences in relation to pollution. As far as I can tell, section 65 is not limited to beyond the territorial sea because the MTA is the primary source of regulation of shipping and maritime activities.”

Previously issued this morning:

Dr. Simon Boxall, National Oceanography Centre, University of Southampton, comments:

“The main concern now is securing the containers on the ship. A couple of years ago the container ship Napoli ran aground off Devon and Dorset in England and lost a significant number of containers. These are potentially more worrying now than the fuel oil leaking from the ship. Once they break away from the ship they present a hazard to shipping – often floating just below the surface and difficult to see and track until they finally fill with water and sink.

“Containers can remain afloat for weeks at a time. There should also be concern as to the contents of the containers. This could range from household good to chemicals and in the case of Napoli there were several tonnes of herbicides amongst other materials. The emergency will remain until the vessel is finally towed to safe haven.”

On the growing oil spill:

“The volumes of oil have evidently increased over the past two days but even at 350 tonnes, when this is 12km offshore the damage will be short term. The focus should be on securing the ship and its cargo and dealing with oil as and when it reaches shore. There will be blobs of material (emulsified oil we often call mousse) on the beach which will require mechanical collection by hand.”

On use of dispersant Corexit 9500:

“Scientists will argue over the use of dispersants, for and against, but given the one used in this case the discussion is rather academic. [That is because Corexit 9500] is one of the less toxic dispersants and the volume used so far (under two tonnes) should not cause undue concern.”