New Undaria discovery in Fiordland

Members of a joint-agency response team have been disappointed to discover mature Undaria pinnatifida (Undaria) plants at a new site in Fiordland.

Environment Southland biosecurity manager Richard Bowman said 16 plants were discovered at Beach Harbour in Breaksea Sound as part of a recent marine compliance trip. This is the first significant find outside the Sunday Cove area which has been the subject of an intensive search and destroy programme for Undaria since 2010.

The Beach Harbour infestation is 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.

Undaria is an invasive Asian seaweed that was first discovered in New Zealand waters in 1987. During a routine marine biosecurity inspection in early 2010, Department of Conservation (DOC) staff spotted a single mature Undaria plant on a mooring rope in Sunday Cove at Breaksea Sound, Fiordland.

Environment Southland, DOC, and the Ministry for Primary Industries (MPI) with support from the Fiordland Marine Guardians swiftly launched a joint-agency response, finding hundreds of juvenile Undaria plants in Sunday Cove, but none elsewhere. An intensive removal programme was undertaken and monitoring continues.

Richard said the latest find is disappointing, but further information needs to be gathered before a final plan of action is 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.”

He said it is an extremely timely reminder about the importance of all vessel operators being vigilant when coming into this very special area.

“We have recently launched the Fiordland Marine Regional Pathway Management Plan which specifically addresses reducing the ways pests such as this are getting into Fiordland.”

The plan requires all vessels entering within one nautical mile of the landward boundary of the Fiordland Marine Area to abide by clean vessel, clean gear and residual seawater standards, as well as hold a Clean Vessel Pass.

“We know the damage a marine pest such as Undaria or Mediterranean fanworm could do to the ecology and economy of this area, so we all need to do everything possible to prevent pests making it in. The latest Undaria finding is a crucial reminder of the need for vigilance.”

Further information on the Fiordland Marine Regional Pathway Management Plan and how you can protect Fiordland can be found at

Page reviewed: 26 Apr 2017 1:00pm