My Account
Local government and tangata whenua kaitiaki are gearing up to prevent an invasive freshwater clam from reaching and potentially devastating the internationally significant Kai Iwi Lakes.
The Northland Regional Council and Kaipara District Council are working with Te Roroa iwi and Te Kuihi hapū to keep gold clam out of the lakes, including popular Lake Taharoa.
The clam was found in the Waikato River in May and has already spread down the river between Lake Maraetai, near Mangakino, and Hamilton City.
A single clam can produce 400 juveniles a day under favourable conditions and has never been eradicated from an invaded location before. The clams are already being reported at a density of hundreds of individuals per square metre in the Waikato, and at highly-infested sites overseas, that density can reach up to 20,000 clams per square metre.
Regional council chair Geoff Crawford, who also chairs the council’s Biosecurity and Biodiversity Working Party, says normal ‘Check, Clean, Dry’ methods don’t work for gold clam, which can survive for up to 10 days out of water.
He says kayaks and boats, especially wake boats with their internal ballast tanks, are the highest risk of spreading the clam.
Kaipara District Mayor Craig Jepson says widespread education is needed to prevent the clam reaching Kai Iwi Lakes, in particular Lake Taharoa, which is much loved by locals and popular with campers and as a summer playground for powered craft.
“The invasive freshwater clam could have significant ecological and economic impacts if it becomes established in the lakes,” Jepson says.
Biosecurity New Zealand’s newly-announced gold clam measures mean that legally, wake boats that have been used on the stretch of Waikato River from the Whakamaru Dam to the river mouth at Port Waikato cannot be used in any other waterways outside that controlled area, including Northland.
Up to 2000 people a day visit the Kai Iwi Lakes during summer. Visitors now need to follow new ‘Check, Clean, Dry’ procedures before they leave home.
Councils and tangata whenua will carry out biosecurity checks of boats and gear at the Kai Iwi Lakes between December 22 and February 6. The lakes are home to the nationally critical lake plant Trithuria inconspicua that is at high risk of extinction, and the at-risk fish, dune lakes galaxias.
Under Kaipara’s Taharoa Domain Bylaw 2018, the owner or master of a vessel or power-driven vessel can be denied access to the lakes if they refuse to undertake a biosecurity check if requested.
The NRC has allocated $300,000 towards the summer initiative and its staff, as well as Kaipara council and tangata whenua representatives, will be on site to answer any questions people have about gold clam.
Further information about gold clams is available from: www.biosecurity.govt.nz/freshwaterclams
