A search team – including two Tauranga-based chemical experts – is scouring a roughly 400 square kilometre area north-east of the Poor Knights Islands for drifting packages of magnesium phosphide, a potentially hazardous chemical used to fumigate ships.
The group is operating from the 44-metre Navy vessel Manawanui and is part of a multi-agency response team based in Whangarei that is working to recover the packages.
Response team Incident Controller Ian Niblock says the Manawanui arrived in the search area about 1.30pm today and began looking for an estimated 40 packages believed to be drifting there. The search team - aided by spotters in a hired civilian helicopter – managed to recover 13 packages before fading light halted their efforts.
Mr Niblock says some of the recovered packages had still been giving off small amounts of gas, but not at a level considered harmful. However, given the potentially dangerous nature of the chemical concerned, the search team was continuing to adopt a precautionary approach.
“This chemical produces a poisonous gas on contact with moisture and in cases of serious exposure can lead to increasing chest tightness, breathlessness and collapse.
Mr Niblock says the Manawanui will remain at sea overnight with the search for the remaining packages expected to resume in daylight tomorrow.
He says the search for the orange coloured packages has been made more difficult because of the presence of similar coloured algal blooms in the search area.
Mr Niblock says the recovered packages are orange flat cardboard tubes, approximately two-metres long, 150mm wide and 25mm thick.
They are being lifted on to the Manawanui in a controlled manner and placed in a designated, safe area aboard to allow any gas to vent safely to air.
“It’s intended that the recovered packages will then be taken from the Manawanui to a secure land-based hazardous chemical storage area at Marsden Pt to allow the venting process to continue safely.”
That process could take several days, with options for final disposal including burial of the remaining inert matter at a suitable location.
No packages were believed to have come ashore today, however, Mr Niblock repeated earlier warnings that anyone who did encounter a package –either on land or at sea – should stay clear and make no attempt to recover it themselves.
“People encountering what they think may be one of these packages should telephone 111 immediately and advise the Fire Service, which will arrange for its safe removal. Alternatively, boaties encountering packages could contact Maritime Radio on Channel 16 to report their position.”
Mr Niblock says the Maritime Safety Authority is continuing its investigations into how the packages found their way into the sea, where they were discovered by boaties at the weekend.