Priority Freshwater Areas for Invasive Clam Monitoring

Introduction Invasive freshwater clam, also known as freshwater gold clam (Corbicula fluminea), is an introduced freshwater mollusc that has become a biosecurity concern in New Zealand (Northland Regional Council [NRC], n.d.). It can threaten rivers, lakes, infrastructure and native biodiversity, and its spread is strongly linked to the movement of watercraft, trailers and other wet equipment between waterways (Ministry for Primary Industries [MPI], 2025; NRC, n.d.). Northland has many freshwater environments, including rivers, lakes, wetlands and recreational water access sites, which makes prevention and early monitoring important (LINZ Data Service, 2026). This project, Priority Freshwater Areas for Invasive Clam Monitoring, uses GIS to identify freshwater areas in Northland that may be higher priority for monitoring based on their location near access points, roads and recreational freshwater sites. The aim is to support biosecurity planning by showing where monitoring and awareness efforts could be focused before invasive clam becomes established in the region.