More Undaria found in Fiordland

The discovery of more invasive Undaria plants in the waters of Fiordland has been described as a ‘‘kick in the guts’’ by an Environment Southland boss.

Undaria plants have been found at a second location in Fiordland, raising the possibility the invasive Asian seaweed may have spread further afield.

Environment Southland biosecurity manager Richard Bowman remained hopeful it could be contained, but said: ‘‘It’s a bit of a kick in the guts unfortunately, but we have to move on and get on with it now.’’

Sixteen Undaria plants have been found at Beach Harbour in Breaksea Sound, Fiordland, he said.

It was the first significant find of Undaria outside the Sunday Cove area of Fiordland which had been the subject of an intensive search and destroy programme since 2010.

The Beach Harbour infestation was about 2km east of the Sunday Cove site.

‘‘All plants were attached to a mooring line, and six of them were reproductively mature, meaning they could have been releasing spores and spreading the plant in the area,’’ Bowman said.

Undaria was first discovered in New Zealand waters in 1987.

Bowman said it was an exotic plant from northern Asia which liked living in sheltered and highly productive environments where it became dominant and disrupted to the normal functioning of an ecosystem.

Bowman said it could become dominant if it got onto a rocky coastline.

‘‘It’s like gorse on a hillside, it very quickly takes it over.’’

When Undaria was discovered at Sunday Cove at Breaksea Sound in 2010, a multi-agency response was swiftly launched and hundreds of juvenile Undaria plants were found in the area, but none elsewhere.

An intensive removal programme was undertaken and monitoring continues. Bowman said the latest find was disappointing, but further information needed to be gathered before a final plan of action was developed.

‘‘A thorough area survey will be carried out soon to determine the scale of the problem and identify new habitat that will need to be inspected.

‘‘This is concerning, but we don’t know the extent yet and are hopeful it can be contained.’’