A parasite that has the potential to harm the oyster industry has been found in Foveaux Strait but there is hope the systems in place to ensure boats and equipment are clean will help to ensure it doesn’t spread further.
On 25 March 2021, three wild oysters from Foveaux Strait were confirmed infected with Bonamia ostreae, a parasite that infects flat oysters, including New Zealand’s flat (Bluff or dredge) oysters, which can cause widespread oyster deaths.
Within five days, Ngāi Tahu and Biosecurity New Zealand enacted a rāhui and a Controlled Area Notice to the specific geographical area where the infected oysters were found, to reduce the risk of the disease spreading. Sampling of other sites is also underway.
Choosing the right antifouling coating for your boat depends on a large number of factors including how you use the boat and where it is moored, says Brent Wilson of Marsden Cove Marina. He says it’s important to talk to specialists about what you need because a product that works well on a boat in one location may not work well on the same boat in a different part of the coast.
Antifoul is considered our best line of defence against marine pests, but it's not the only option.
Antifouling coatings are still our best weapon against marine pests. But many of the traditional formulas come with unwanted side effects for our environment and health and that leaves boat owners concerned about how they can safely – and cost effectively – keep their boat protected from fouling. It’s not a challenge we face alone in New Zealand. We talk to three industry experts about how the antifoul industry is working to find solutions.
Early evidence reported by the teams surveying boats at anchor in Northland is that around 85% of boats, both local and visiting the region, are free of marine pests.
It confirms a steady increase in the number of vessels ensuring their boat’s hulls are clean and free of marine pests
“It shows that most of our boatyards and haulouts not only in Northland but in regions where visiting vessels originate are doing a great job of cleaning,” Kathryn Lister of Northland Regional Council. “Boat owners are also to be credited and thanked for understanding the need to complete this maintenance before they arrive.”
Kathryn says this is in large part due to work done in the regions, including Auckland and Bay of Plenty in both education and surveillance. For example, Auckland Council run a summer Outreach programme that sees friendly ambassadors at marinas and busy boat ramps, raising awareness with boaties and the public on marine biosecurity.
Rules were introduced to Northland in 2010 to help ensure that marine pests could not be transferred to pristine places on moving vessels. Since then, the councils involved in the marine biosecurity partnership have worked hard to educate and inform boaties about marine pests, the harm they can do, and the need to check and clean boats.
Many thousands of boats visit Northland each summer, many from Auckland. Some marine pests are prevalent in Auckland, but are not present in the majority of Northland’s harbours. Boats entering Northland or moving between the regions different harbours can have no more than a slime layer and small patches of visible fouling, according to the region’s biofouling rules.