A slimy, tube-shaped marine pest from Australia is seriously threatening Auckland's under water environment.
The Australian droplet tunicate (Eudistoma elongatum) grows in clusters around beaches, foreshores, marine farms and wharves.
Auckland Council said it has now been found in Mahurangi Harbour, Sandspit and Oakura Bay on Waiheke Island.
Because the pest can attach to boat hulls, rocks and pontoons, it can quickly smother marine environments and destroy sea life, it said.
The council said it was difficult to eradicate because the tubes grew back and spread in broken pieces.
Boat owners must start checking and cleaning boat hulls thoroughly before summer to stop its spread, Auckland Council marine biosecurity advisor Samantha Happy said.
"This pest will change our beautiful foreshores forever, and is nearly impossible to control once established," Ms Happy said.
"Preventing the pest spreading is something every Kiwi, especially seafarers and boat owners, need to be part of, so we can keep our treasured marine playground pest-free for future generations."
A Waiheke-based oyster farmer Nat Upchurch said the marine pests posed a real threat to marine farming.
"As a marine farmer you're on the front-line when it comes to facing new pests," he said.
"In the past we've been hit hard by new organisms that have had a massive impact on the business and my work. We need everyone to take action to stop it getting to that stage."
The council biosecurity team is urging anyone who comes across white tubes to call them on 09 301 0101 or [biosecurity@aucklandcouncil.govt.nz to email for advice].
Auckland Council suggests the following actions:
- If you have a bio-fouled hull, check and get it cleaned before travelling
- Plan ahead for summer and book in with boat maintenance facilities in advance
- If your boat is heavily bio fouled, haul it out and clean it appropriately - cleaning in-water will only spread any pests
- Keep antifoul fresh
- Find out more about other region's rules at the Marine Pests website.