A Controlled Area has been declared within Breaksea Sound in Fiordland to reduce the spread of the Asian seaweed Undaria pinnatifida (Undaria), in accordance with section 131 of the Biosecurity Act 1993.
Read the notice here.
What does this mean?
The Controlled Area does not prevent vessels from entering the Sound, but does put in place the following restrictions:
- 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.
What is Undaria?
Undaria is an opportunistic invasive seaweed that forms dense stands underwater, giving it the potential to compete for light and space which may lead to the exclusion or displacement of native species. Due to Undaria's ability to rapidly spread in the marine environment it is often referred to as the gorse of the sea.
Undaria is native to Japan where it is grown for human consumption. It looks similar to Ecklonia, a native species, however mature Undaria plants which can grow 1-2 meters tall are characterised by a distinct mid-rib.
A marine pest such as Undaria has the potential to do significant damage to the ecology and economy of a precious and unique area of Fiordland.
Why is the Controlled Area being put in place?
Since 2010 Environment Southland (ES), the Ministry for Primary Industries (MPI) and the Department of Conservation (DOC) have been working to eradicate the Asian seaweed Undaria from Sunday Cove, located in Breaksea Sound, Fiordland.
However, in April 2017 during a routine joint-agency surveillance and compliance trip, Undaria was discovered by divers on a mooring line in Beach Harbour.
The discovery initiated a Breaksea Sound delimiting survey to determine the extent of Undaria in this area. The survey found Undaria to be widespread and dense in the Beach Harbour and John Islands area of Breaksea Sound.
With the current tools available, reducing the spread to other areas of Fiordland is the best option at this stage.
Research suggests that the risk of Undaria being carried out of the area is highest when vessels or equipment are inactive for prolonged periods, so the restrictions put in place by the Controlled Area address that risk.
Undaria has a growth of 1-3cm per day, so if vessels sit idle for extended periods of time within an area harbouring Undaria, there is a high likelihood of it attaching itself and being moved outside the area when the vessel moves.
In the event of an emergency situation, such as adverse weather, vessel malfunction or a health emergency, vessels may be permitted to seek refuge within the Controlled Area. Ensuring the safety of people at sea will always take priority. Please advise Environment Southland as soon as possible if such a situation occurs.
What else do I need to know if I am heading into the Fiordland Marine Area?
It's important to make yourself aware of the location of the Controlled Area and the restrictions that apply. The Fiordland Marine Regional Pathway Management Plan also has some rules that anybody entering the area must adhere to and all vessels, regardless of size, must hold a Clean Vessel Pass.
You can find out more about the Plan and the Clean Vessel Pass here.