Polluted shellfish found in Maungatapu

Clean-up after the Mobil spill in Tauranga Harbour. Photo/Andrew Warner

Polluted shellfish has been found in Maungatapu following an oil spill in Tauranga Harbour in April.

Following questions asked by the Bay of Plenty Times, the Bay of Plenty Regional Council said in a media release today that early results from initial sampling on April 29, three days after the oil spill, showed levels of oil-related pollutants in shellfish at Maungatapu Bay were higher than baseline levels on that date.

All other monitoring sites, including the Port, Bridge Marina, town reach and Motuopuhi Island, had results within typical average levels for Tauranga Harbour, regional on scene commander Adrian Heays said.

"This suggests that initial impacts of the oil spill on shellfish were localised, affecting only heavily-oiled shoreline areas.

"Current contaminant levels and longer term oil spill impacts on shellfish can't be assessed until at least six weeks of sampling has been completed at the end of June."

Clean-up operations have finished at the worst affected area, Matakana, and at Rangiwaea Island, Pilot Bay and Sandy Bay.

The council has invoiced Mobil for a total of $691,766 in clean-up costs so far.

Mr Heays said there was still work to be done.

"A minor amount of oil remobilised at Bridge Marina last week, so we have reactivated clean-up efforts with prop washing and booms, recovering oil from the water, waterline scraping and solvent cleaning of dry marina structures.

"We've been wiping down the pier surface and using divers to clean difficult surfaces under water."

At the port, pile cleaning continues with a final washing off to contain and remove any oil that may be trapped in pockets in rocks under the wharf.

At Maungatapu and Motuopuhi Island, Mobil staff and local hapu are checking shorelines regularly, and a remediation plan is being developed for oiled seawalls and jetties.

The clean-up will continue until all areas have reached an acceptable end state, rather than an end date, Mr Heays said.

"Once we get to the point that transferable oil is largely removed from the affected areas we can terminate the response phase of the clean-up.

"Independent environmental monitoring will continue, and it is expected that Mobil will lead the affected parties through an appropriate recovery and mitigation process."