Undaria found in Dusky Cove, Tamatea/Dusky Sound, Fiordland

Media release - 16 November 2022

Undaria found in Dusky Cove, Tamatea/Dusky Sound, Fiordland

A new discovery of the invasive seaweed Undaria pinnatifida in Fiordland is disappointing but it should not discourage people from following the rules set out in the Fiordland Marine Regional Pathway Management Plan.

Environment Southland biosecurity and biodiversity operations manager Ali Meade said the new discovery on the south side of Resolution Island in Tamatea/Dusky Sound was very disappointing.

“We are unsure if it jumped from our containment zone to the south side of Resolution Island, or if it is a new incursion.”

Environment Southland has met with its partners, Biosecurity New Zealand, the Department of Conservation and the Fiordland Marine Guardians.

“Divers have been surveying the area since the discovery on 9 November to determine the spread of Undaria. We are working together to manage this invasive marine pest, and, for now, that means understanding what we’re up against. Once the survey results have been collated, we can work together on a response plan,” Mrs Meade said.

Although this is the first find in this area, Environment Southland, the Department of Conservation and Biosecurity New Zealand, with support from the Fiordland Marine Guardians, have been working together on an intensive control programme for Undaria in Te Puaitaha/Breaksea Sound since 2010.

“A further discovery was made in Taiari/Chalky Inlet in 2019, which has now been brought under control and is looking good for full elimination from Northport,” Mrs Meade said.

In 2020, Environment Southland received $2 million in Jobs for Nature funding to aid in the battle against Undaria. With this, a team of divers were trained and have spent the past year removing Undaria.

Biosecurity New Zealand has appointed a supplier to be part of a two-year trial piloting a suppression tool on Undaria in Te Puaitaha/Breaksea Sound, and work has begun.

Mrs Meade said the latest discovery reinforced just how important it was for all vessels to abide by the rules of the Fiordland Marine Regional Pathway Management Plan to stop pests getting into the pristine waters of Fiordland.

“The plan requires all vessels entering within one nautical mile of the landward boundary of the Te Moana o Atawhenua/Fiordland Marine Area to hold a Clean Vessel Pass, and to comply with clean vessel, clean gear, and residual seawater standards.”

Fiordland Marine Guardians chair Rebecca McLeod said the group were devastated by the news.

“While we are uncertain about what this will mean for the Undaria work already underway in Te Puaitaha/Breaksea Sound, vessels must continue to be vigilant about marine pests when they travel into the fiords.“

“Undaria is just one of several highly invasive marine pests in New Zealand waters, and we need to make every effort to reduce the risk of anything being carried into the Fiordland Marine Area. In the case of Undaria, we don’t want to hasten its spread by shifting it outside of an infested area,” Dr McLeod said.

On Undaria pinnatifida

Undaria pinnatifida is a threat to Fiordland’s marine environment with its ability to quickly establish and outcompete native marine species. Pests like Undaria and other fouling species can hitchhike to new locations on dirty boat bottoms and marine equipment. All vessels should check, clean and dry mooring lines and buoys, fishing or dive gear, kayaks and other recreational equipment before travelling to Fiordland. For more on Undaria visit here. For more on the Fiordland Marine Pathway Plan visit here.