The invasive Asian seaweed undaria has been discovered growing on the Southland coast.
The weed was first spotted last month below the lighthouse at Waipapa Point, near Fortrose, Environment Southland biosecurity officer Derek Richard said yesterday. On Tuesday and Wednesday, Mr Richards and two others removed about 1600 plants.
Undaria was first discovered in New Zealand in 1987. Mr Richards said it was now well established at all New Zealand ports including Bluff, and had also been found at Hoopers Inlet, on Otago Peninsula.
However, it had not been thought to be thriving between Bluff and Dunedin.
''From the size of the plants, it looks like it's been there for years and we didn't know. It's a worry. It is difficult to quantify the impact it will have there, but we know it can build up very rapidly in rock pools and crowd out native seaweed species.''
Mr Richards is part of a multi-agency control group which is trying to eradicate undaria from Fiordland.
The Waipapa Point area would be monitored regularly from now on, he said.
