The Chinese owners of a floating dock which broke up in Cyclone Lusi, threatening marine life off Northland's east coast, have been ordered to clean up a chain of islands by midnight tonight.
The polystyrene-filled dock was swept away from Motukawaiti Island, part of the Cavalli group off Matauri Bay, in last month's cyclone and later smashed apart on nearby rocks.
The largest chunks have washed up on Kahangaro Island but countless polystyrene fragments have washed up on other islands, including Motukawanui, the largest of the spectacularly scenic Cavallis. Polystyrene can be fatal to seabirds, fish and marine mammals such as dolphins, which can mistake it for food.
Northland Regional Council harbourmaster Jim Lyle said the island resort's owners initially reported the dock had been blown away in the cyclone. With its whereabouts unknown it was a potential navigation hazard.
It was subsequently found broken into pieces concentrated on three to four beaches on nearby islands. Council staff travelled to the islands on April 15 and were now treating it as an environmental incident.