Just over a year after the Rena struck the Astrolabe Reef in the Bay of Plenty, containers of hazardous substances still lie
beneath the water.
The Minister of Transport, Gerry Brownlee, has confirmed the contents of three containers of cryolite, a byproduct of the
aluminium smelting process, have been lost at sea.
The location of a further 17 containers with cryolite is not known.
Mr Brownlee said it was not possible to state with certainty how many of these containers remained within the wreck in
Twenty had been stowed below deck in Hold 3, from where the ship was ripped in half during a January storm, while the
other had been stowed below deck in another hold.
A risk assessment provided to the Government stated cryolite posed "both an immediate and long-term pollution hazard to
marine organisms and plants". But scientists had advised Maritime New Zealand that a number of factors suggested the risk
could be reduced.
Cryolite was only slightly soluble in water and the rate of release was expected to be diminished because of packaging. It
broke down to naturally occurring elements - mainly aluminium and fluoride - which became less harmful in seawater
because of reactions with other naturally abundant elements.
Maritime New Zealand began an investigation when it found cryolite had been loaded onto the Rena in Bluff without being
classified as a dangerous substance.
The agency decided not to prosecute the manufacturer after it alerted authorities to the error and co-operated to address
the gap in its processes.
The contents of containers carrying ferrosilicon and one of potassium nitrate are also thought to have been lost at sea.
Another container of 5400kg of trichloroisocyanuric acid was on the seabed next to the wreck in March, but has not been
The Government has been notified of 11 "near misses" involving ships since the disaster.
Foreign tankers and passenger ships were among vessels involved.
Between the Rena's grounding in the Bay of Plenty a year ago and late last month, Maritime New Zealand was told of two
near misses involving passenger vessels, four involving container vessels, two involving tanker vessels, two involving cargo
vessels and one involving a bulk carrier vessel. All the ships were foreign-owned.
A near-miss is defined as any incident where a crash was avoided by luck or recovery.
The numbers, provided to the Green Party by Transport Minister Gerry Brownlee, come amid renewed calls for compulsory
shipping lanes for New Zealand - a concept backed by the disgraced captain of the Rena.
The Government has previously ruled out lanes, saying they are expensive to set up and police.
But one shipping expert, who told the Herald he had tracked dozens of ships sailing dangerously close to the coast, said
having a better system was a "open and shut case".
Marico Marine senior partner John Riding believed that although the Rena disaster had been a warning, ship captains had
become complacent again.
"We also tracked a passenger vessel - a cruise liner 280m long and capable of carrying 2500 people - going straight through
the Mercury Islands, and so close to Mercury Rock that they were probably navigating beyond the accuracy of the charts."
He felt the need for a compulsory GPS-routing system was "bleedingly obvious".
Green MP Gareth Hughes accused the Government of "downplaying" the risk of further incidents such as the Rena disaster,
saying it was not focusing on how to make coastal shipping safer.
He believed the issue should have been addressed in a review Maritime New Zealand is making of its response to the Rena
Transport Ministry officials have told the Herald compulsory shipping lanes do not guarantee compliance with regulations
or prevent navigational errors.
They said New Zealand already had guidelines for coastal navigation and a range of navigation technology to ensure safe
passage and enable ships to be tracked.