What genetic testing, if any, has been undertaken in waterways adjacent to, or near, known Corbicula fluminea infestations, including sampling locations, dates of sampling, and detection thresholds?

Answer

I am advised that environmental DNA surveillance for Corbicula fluminea has been undertaken in high-risk waterbodies adjacent to known incursions and that no Corbicula fluminea has been found to date. Sampling has been undertaken in the Waikato River and, most recently, Lake Rotomanu in New Plymouth aiming to establish an early detection threshold. Most recently in the last six months: • For the Waikato region: o November 2025 / January 2026 – Upper Waikato River o September 2025 – Lake Taupō • For the Taranaki region o November/December 2025 - Lake Rotomanu and the Waiwhakaiho River o December 2025 – Lake Ratapiko o December 2025 – Waitara catchment Additionally, visual surveillance in waterways is being undertaken in adjacent regions.