Lake Ōkataina in Rotorua is closed for fishing and boating throughout October while protections against invasive gold clams are installed. Photo / Andrew Warner
Lake Ōkataina in Rotorua is closed for fishing and boating throughout October while protections against invasive gold clams are installed. Photo / Andrew Warner
OPINION
Will access to idyllic spots around the country end as local communities seek to protect them from invasive pests? Sparkling rivers and tranquil lakes are taonga and sources of wellbeing for many of us, but are they at risk of closure because of a lack of a robust, joined-up national response to protect them? Fish & Game New Zealand chief executive Corina Jordan highlights concerns.
A pretty lake in the Rotorua region could be the spark that starts a fiery and divisive national debate about access to lakes and rivers throughout New Zealand.
Lake Ōkataina holds a special place in the hearts of anglers as one of the premier trophy rainbow trout lakes within the Rotorua lakes fishery. Its pristine environment, surrounded by lush bush and distanced from urban areas, ensures it remains one of the cleanest lakes in the region. Every year, about 7000 angler days are recorded at this cherished destination.
But for Fish & Game, it has also raised significant questions about the national response to this biosecurity incursion at the heart of the Waikato River catchment.
We understand and respect mana whenua concerns surrounding this issue. And we understand why they took the action to seek the lake’s closure. The lake is a taonga of great cultural, spiritual and ecological importance to the people of Ngāti Tarāwhai.
In response to their request, the Ministry for Primary Industries announced at the end of September it was issuing a Controlled Area Notice to close the lake for a month based on the perceived biosecurity threat from gold clams.
The freshwater gold clam, from eastern Asia, was first identified along a segment of the Waikato River in May.
As filter feeders, gold clams have the potential to compete with native species for resources.
These clams reproduce rapidly, forming sizeable populations that can obstruct water-related infrastructure, including electricity generation facilities, irrigation systems, and water treatment plants. As filter feeders, they have the potential to compete with native species for resources. Scientists say one of the most effective ways of killing the clams is in warm water — 45C water for 15 minutes.
Unfortunately, since the clams were confirmed in the Waikato River, there has not been the level of action we or our anglers expect from MPI.
As the country’s leading freshwater advocate, we are deeply troubled by what we believe has been MPI’s failure to take more comprehensive action from the moment the gold clams were first found.
We are perplexed that MPI supports the closure of Lake Ōkataina as a preventive measure while, in our opinion, failing to adequately manage the issue at its source, which is the Waikato River. This inconsistency raises concerns about the overall protection of our waterways.
A good analogy would be a doctor recommends complete bed rest and isolation for a patient with a mild cough while neglecting to prescribe antibiotics for a patient with a severe infection. We believe it’s a perplexing approach that fails to address the real problem.
The closure of Lake Ōkataina has left anglers nationwide disheartened. Photo / Stephen Parker
Addressing this incursion cannot rely on ad-hoc closures of individual lakes and rivers nationwide.
What is always required in the initial stages of a biosecurity incursion is a strategy that combines immediate action with a long-term plan to safeguard our water bodies, in this case from the gold clam invasion.
The present national watch-and-see approach — which centres on a surveillance programme to “determine how widely the clams are distributed”, among other actions — leaves our cherished lakes and rivers vulnerable to further infestations.
The absence of cleaning stations at infected rivers and lakes when gold clams were initially confirmed is one glaring oversight.
Furthermore, we must promptly address the risk posed by boats carrying ballast water, particularly wake boats travelling from Lake Karapiro and Lake Maraetai to other lakes. Many of these boats still retain litres of residual water even when fully drained.
Biosecurity New Zealand’s Technical Advisory Group Report into the threat of gold clams identified internal ballast water in boats or the online trade of aquarium animals as possible ways the invasive species spreads. Examples of vessels with ballast systems are some wake boats used for water skiing and wakeboarding. However, these activities have continued unrestricted.
For many New Zealanders, heading to the sparkling lake to catch some fish is a way of life and a much-loved family tradition. But local communities may start closing access to more lakes and rivers, and this will inevitably lead to tension.
Fish & Game NZ chief executive Corina Jordan.
There’s still time to get ahead of this, but it needs immediate and focused attention.
The true impact of this invasive species on our environment remains uncertain, making this issue of great concern to our organisation and the anglers we represent.
The focus must be on improving the response to this issue, ensuring that resources are effectively directed towards finding solutions, strong communications with stakeholders and communities, and collaboration.
The closure of Lake Ōkataina serves as a poignant reminder that a comprehensive, science-led approach is imperative to combat the gold clam invasion effectively.
Corina Jordan is chief executive of Fish & Game New Zealand.
