Undaria, also known as Asian kelp has been discovered in Aucklandâs Westhaven Marina. Dubbed the gorse of the sea it is listed as one of the 100 worst invasive species. A survey found colonies from the marina to Marsden Wharf and in the Viaduct Basin near the Team New Zealand base. The concern is that the kelp which can grow to around 1.8m and rapidly colonises the seabed, will spread into harbours at Great Barrier Island or into marine reserves further north such as the one at Goat Island, Leigh. It was first found in New Zealand in Wellington Harbour in 1987 and since then has been found at every major port except Tauranga. It has spread to Stewart Island, Kaikoura, Golden Bay and the Coromandel Peninsula but so far none has been found in Fiordland. The ARC estimates containing it in the Waitemata could cost $3000,000 in the first year and around $150,000each year after that. Ms Coney said the council would raise the issue with Biosecurity Minister Jim Sutton and Conservation Minister Chris Carter.