Dr Yu Cao
NIWA hosted a visiting scientist, Dr Cao, from the Wuhan Botanic Gardens, Chinese Academy of Sciences over January and February 2025.
Associate Professor Dr Cao has a research background on the structure and function of freshwater ecosystems and worked with the NIWA Aquatic Plants Group to investigate native plant response to high nitrogen levels. High nitrogen levels (ammonia) are anticipated with high densities of the invasive clam (Corbicula fluminea) and can be toxic to aquatic plants. We want to understand what those nitrogen thresholds are, so that we can predict likely impacts from the clams.
A lakeside clam hui, held at Bob’s Landing-Lake Karāpiro, in February 2025, was attended by representatives from Ngāti Koroki Kahukura, Raukawa, Nga muka, Tūwharetoa and Te Arawa Lakes Trust. This was an opportunity to see the invasive clams firsthand and to share perspectives on the clam with NIWA staff and Dr Cao (visiting scientist).
Strong themes from the korero included a desire for collaboration and the need for iwi monitoring methods for the invasive clam.
Professor Frances Lucy
Clam expert Professor Frances Lucy from Ireland visited New Zealand in late 2025 and pointed out that the country’s fight against the invasive gold clam has a lot in common with battles against invasive species elsewhere.
She said plenty is happening in New Zealand to tackle the problem, but that working together is the only way to succeed.
Read more: Visiting Irish professor calls for teamwork in fighting invasive clams.
