MV Rena: Responding to New Zealand’s biggest environmental disaster
On 5 October 2011, at 02:14 hours, the cargo ship MV Rena ran aground on Ōtāiti (Astrolabe) Reef as it approached Tauranga Harbour. The 47,000 tonne, 236 metre ship was carrying 1700 tonnes of heavy fuel oil and 1368 containers.
What followed would become New Zealand’s worst environmental disaster as 350 tonnes of fuel oil spilled into the ocean, affecting more than 50kms of coastline.
Maritime New Zealand immediately assessed the situation as Tier 2 - of national importance - and took responsibility for leading the response to the incident.
On the night of 5 October, an oil leak was detected from the wreck, and the National Oiled Wildlife Response Team (NOWRT) was mobilised quickly. This team, which included experts from Massey University’s Wildbase and the Department of Conservation (DOC), began preparing for wildlife rescue and rehabilitation efforts. Eventually hundreds of volunteers would contribute towards the clean-up.
By 8 October, the first samples of seawater, sediment and shellfish from Motiti Island had arrived at Hill Labs for urgent testing. They would be the first of thousands of samples that would be sent to them in the ensuing weeks, months and years.
Ara Heron, Hill Labs Senior Client Services Manager, helped lead the testing effort.
“Samples were sent to us very quickly. Within a few days we had our first batch to test and we initially concentrated on analysing the heavy fuel oil. Most of our Environmental testing team was involved in some capacity.”
The oil then reached beaches in Mount Maunganui and Papamoa, and more samples of shellfish, sediment and water were sent to Hill Labs.
“We tested urgent seawater samples for Total Petroleum Hydrocarbons (TPH) in the days and weeks after the Rena went aground to help determine when beaches could reopen,” says Ara, whose team also worked on characterising the antifouling agents used on the many layers of paint on the ship’s hull.
“After a week, it was apparent the oil spills couldn’t be contained as hoped, and oil was flowing heavily into the ocean. The greatest fear was that it would enter the food chain. Thousands of samples of fish and shellfish from in and around the wreck were sent to us, which we tested for petroleum hydrocarbons, heavy metals and Tributyltin to help officials determine when it was safe to be collected again, which was in early 2016.”
The Rena grew more unstable on the reef, and as it listed to the side in stormy weather, its containers began to tumble into the ocean, spilling debris that would wash up on beaches. Samples from these were also sent to Hill Labs for contaminant testing.
While the ultimate aim of the recovery operation was to get the Rena removed off the reef, it would prove too difficult, and in January 2012 the ship split in two and eventually sank. In 2016 the ship owners’ application for resource consent to keep the remains of the Rena, its equipment and cargo, on the reef, was granted.
The clean-up of the Rena cost $700 million; the second most expensive salvage operation in global maritime history. Today, the environment is recovering well, and experts conclude that the shipwreck should not have any long-term effects on the Bay of Plenty beaches and coastal fisheries.
Hill Labs remains involved in ongoing testing of samples, specifically for heavy metals and Tributyltin (TBT) from the ship’s hull, which remains on the reef.
