An area of Fiordland’s Breaksea Sound has become a Controlled Area to prevent further spread of the marine pest Undaria pinnatifida.
Environment Southland biosecurity manager Richard Bowman said the notice issued for Breaksea Sound will not prevent access to the area, but would put restrictions in place for mooring, equipment and anchoring.
Some of the restrictions in place mean that vessels in the controlled area can occupy it on a mooring for no more than 48 hours, and that anchoring in the area is prohibited.
Undaria is common around New Zealand ports. It was first identified in Fiordland in 2010 and a multi-agency eradication response has been underway ever since. In 2017, a survey found Undaria to be widespread in the Beach Harbour and John Islands area of Breaksea Sound.
Research suggests that the risk of Undaria being carried out of the area will be highest when vessels or equipment are inactive for prolonged periods prior to moving to a new location.
Mr Bowman said if vessels sat idle for extended periods of time in a place that had Undaria, there was a high likelihood the seaweed would attach itself to the vessel and leave with it. With the current tools available, reducing its spread was the best option at this stage, he said.
“We are continuing to explore all options and we will meet with our partners and University of Otago marine scientists in the New Year to explore the possibility of an intensive control programme for Undaria.”
The introduction of the Fiordland Marine Pathway Plan in April 2017 was a major step in reducing the transport of marine pests like Undaria into the Fiordland marine area.
Fiordland Marine Guardians chairwoman Dr Rebecca McLeod said the Guardians felt it was imperative to push for a Controlled Area at the site of the Undaria infestation in Breaksea Sound.
“With the exception of Undaria in Breaksea Sound, Fiordland is one of the last coastal marine areas of New Zealand that remains free of invasive species. We argue that this status is worth fighting for.”
The restrictions within the Controlled Area are:
• Vessels may occupy the Controlled Area on a mooring for a maximum duration of 48 hours.
• Anchoring in the Controlled Area is prohibited.
• No marine gear or equipment, including lobster pots, mooring lines and any other equipment to establish new moorings, may be transported out of the Controlled Area.
- Dive gear used within the Controlled Area must be treated or dried prior to use outside of the Controlled Area, using one of the following methods:
- Dishwashing detergent 5% solution soak for one minute;
- Bleach 2% solution for one minute; or
- Hot water >60oC for one minute.
• All on-board residual seawater collected in the Controlled Area must be treated as above or discarded within the Controlled Area.