Three decades of careful monitoring, unique safeguards and community advocacy have ensured Lake Taupō is relatively healthy compared to degraded waterways seen elsewhere.

But a new environmental threat is emerging which Taupō’s Lakes and Waterways (TLAW) charitable trust is determined to keep at bay.

Freshwater gold clams (also known as Asian gold clams or Asian clams) are a small shellfish that reproduce rapidly, forming large groups that can clog water pipes and out-compete native species.

It was first discovered upstream in the Waikato River in May 2023 and hasn’t yet reached Lake Taupō. Efforts are now underway by multiple agencies, including Biosecurity New Zealand, Waikato Regional Council, DOC, NIWA and TLAW, to ensure this clam infestation is contained and doesn’t make it into the lake itself.

Growing Awareness

Thanks to a $7500 grant towards operational costs from BayTrust, TLAW is currently running a summer speaker series. Their November meeting focused on the freshwater gold clam incursion and drew a record-sized crowd which delighted TLAW Chair Paul White.

“It was probably our biggest meeting in years so we’re very thankful for BayTrust’s backing. The grant has enabled us to raise more awareness and generate more community engagement – more than we’ve ever been able to do.”

Adult clams are just 2–3cm wide and their juveniles and spat are virtually impossible to see. They are typically dirty white, yellow or tan in colour and have an obvious ribbed texture on their shell. They thrive in freshwater or near river mouths, living on top of sandy or muddy surfaces, buried within them and even within weed beds.

Paul says the clam’s incredible reproductive abilities mean they could potentially take over any lake from the surface right down to 12m of depth.

“Previously sandy environments will just become cockle beds. They’ll compete directly with our native kākahi (freshwater mussel), which is a taonga. They’re very effective filter feeders so they may enable lake weed growth to explode. It’s a finely balanced ecosystem, so there’s great peril. Stopping its spread is our only hope.”

TLAW is helping promote a public awareness campaign this summer to encourage people to wash and dry all boating equipment – and even swimming togs – if they’ve been in the affected downstream areas of the Waikato River before entering Lake Taupō.

“There was a lot of great information presented at our recent meeting. Rather than catastrophising, everybody realised that this is stoppable. Alongside agencies’ actions, it will come down to deeply personal actions – challenging our friends, family and all visitors to check their gear and follow the appropriate clean and dry procedures to protect the lake.”

Proud Record

This latest campaign is in keeping with TLAW’s long history of advocating for the health of Lake Taupō. Since the mid-1990s members have led discussions on science relating to water quality, political processes, stakeholder activities in the catchment, sustainable land uses and ecological restoration initiatives. “We link, amplify and promote initiatives across the catchment and community,” Paul explains. “Our goal is to unite people for the benefit of protecting Lake Taupō’s natural environment. We acknowledge and wish to support the lake owners and all those who are kaitiaki.”

Lake Taupō is the only freshwater lake in the world to have a nitrogen cap in place which limits land use activities (including farming, fertiliser inputs and sewage systems), to reduce the nutrient load. TLAW was instrumental in the establishment of this nitrogen cap as part of the Lake Taupō Protection Project – a land and water management milestone in New Zealand.

Thanks to these positive actions, the water quality is doing okay. “Everyone is watching with interest. Fingers crossed; things are looking good.”

But complacency is a risk in itself. Long-time TLAW trustees are among the few who hold institutional knowledge that stretches back to when there were grave fears for the lake’s health.

“Taupō’s community is at a crossroads because many have forgotten about the millions and millions of central and regional government money that was poured into problem solving for the lake. Twenty five years on, agencies and local authorities may no longer have any institutional memory of it. People and the community’s personal and economic sacrifices are in danger of being forgotten.”

But Paul says with regular monthly meetings, and funding from supporters like BayTrust, TLAW can continue to shine a spotlight on important issues as they emerge and help ensure Lake Taupō is well-looked-after for generations to come.