Don’t let Marine Pests harm Fiordland

The unique marine environment in Fiordland is vulnerable to the establishment of introduced marine pests and diseases.

Vessels travelling into the Fiordland marine area from other regions of New Zealand or internationally, have the potential to accidentally introduce marine pests via fouling on vessel hulls and equipment, or ballast water discharge.

All marine users can play a small but significant role in keeping pests out of Fiordland by following some simple biosecurity precautions. If you own a vessel and are about to sail into the Fiords or relocate marine equipment such as buoys, ropes or fishing gear, please:

• clean your vessel’s hull before entering Fiordland,
• dispose of anything removed from the hull on land (prevent it getting back into the water),
• ensure you regularly clean your hull and treat, where appropriate, with anti-fouling paint as per the product’s directions,
• check, clean and dry any mooring lines and buoys, fishing or dive gear, kayaks and any other equipment before using it in Fiordland waters.

For further information on hull cleaning, visit: www.biosecurity.govt.nz.

If you are visiting the area, particularly for diving, you can also help by reporting anything unusual you might see in the area’s waters.

Some particular pests to look out for are ones that are already established in New Zealand. They are:

Undaria pinnatifida

This Asian seaweed is already growing in a number of New Zealand areas, including Southland waters. It can form dense forests in sheltered reef areas, and grows on any hard surface including reefs, ropes, wharf piles and vessel hulls.

 

Styela clava

This ascidian, or sea squirt, was detected in Auckland and Lyttelton in 2005. It is known to be widespread throughout the Hauraki Gulf, in Lyttelton and in Tutukaka in Northland. This organism can potentially compete with native fauna, particularly mollusks, for food. It appears in colonies as a leathery-skinned, tubular organism that can grow up to 16 cm long.

Didemnum vexillum

A different ascidian, Didemnum vexillum is present in the Bay of Plenty and has recently appeared in the Marlborough Sounds and Nelson waters. Didemnum vexillum forms large colonies of yellowish, melted wax-like mats that can droop from marine structures. Its appearance would be unsightly in a high-value ecological and tourism area such as Fiordland.

If you spot any of these known pests, or something else you consider unusual, please:

• note its location,
• grab a sample if possible,
• immediately phone Biosecurity New Zealand’s free phone: 0800 80 99 66.

For further information on these pests or other marine pests that have not been detected in New Zealand, but which Biosecurity New Zealand is concerned about, please visit: www.biosecurity.govt.nz and click on the button marked "Marine Pests and Boat Cleaning".