Undaria exemption areas
Under the Southland Regional Pest Management Plan 2019, it is prohibited to harbour Undaria, including having Undaria growing on a vessel’s hull, within the Southland region.
Two exemption areas are where Undaria has already established.
The exemption areas do not prevent vessels from entering, but do put in place the following requirements when leaving exemption areas:
- vessels must be free of Undaria when they leave the Southern Undaria Exemption Area and the Breaksea Sound Undaria Exemption Area;
- all marine gear and equipment, including but not limited to lobster pots, mooring lines and dive gear, must be free of Undaria when it leaves the Southern Undaria Exemption Area and the Breaksea Sound Undaria Exemption Area;
- all on-board residual seawater collected in the Exemption Area must be treated or discarded within the Southern Undaria Exemption Area and the Breaksea Sound Undaria Exemption Area.
Note: A controlled area was previously declared within Breaksea Sound, but revoked in 2019 as it was superseded by rules under the Southland Regional Pest Management Plan.
What is Undaria?
Undaria is an invasive seaweed that forms dense stands, it can grow up to 3cm a day and be found at high densities making it able to outcompete native species for light and space which can lead to their exclusion or displacement. Due to Undaria's ability to rapidly spread and growth in the marine environment it is often referred to as the gorse of the sea.
Undaria is native to Japan and Korea where it is grown for human consumption as seaweed salad or miso soup. It looks similar to Ecklonia radiata, a native species, however mature Undaria plants grow up to 2 meters tall and have with a distinct mid-rib.
A marine pest such as Undaria has the potential to significantly impact the ecology and economy of Southland, especially the unique and precious Fiordland Marine Area.
Undaria is widespread and dense around the southern coast of Southland and Stewart Island. It has also established in Breaksea Sound, with high densities found around Beach Harbour and Johns Islands.
With the current tools available, containing the spread of Undaria and stopping its establishment in other areas of Southland is the best management option at this stage.
Undaria’s grows from spores released into the water column which attach to vessel hulls. If a vessel is moored for extended periods of time within areas harbouring Undaria, there is a high likelihood that Undaria will be growing on the hull and being moved outside the area when the vessel moves.
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 rules in the Fiordland Marine Regional Pathway Management Plan. All vessels entering within one nautical mile of the landward boundary of the Fiordland Marine Area are required to hold a Clean Vessel Pass and to comply with clean vessel, clean gear and residual seawater standards.
You can find out more about the Plan and the Clean Vessel Pass here.