NIWA and its partners have begun critical research to understand how to halt the spread of a tiny clam which threatens to do millions of dollars of damage to New Zealand’s freshwater ecosystems.
NIWA received $10.2m funding in September for a five-year research programme into ways to support the response to the invasive clam that was recently discovered here.
The freshwater gold clam, or Corbicula fluminea, is native to eastern and southeast Asia but was found in several locations in the Waikato River catchment in May 2023. Without intervention, large-scale invasion of corbicula could result in significant and irreversible economic, social, cultural and ecosystem losses. NIWA Principal Scientist - Freshwater Ecology Dr Deborah Hofstra is leading the MBIE-funded research programme. She says the first stage of the project is focussed on understanding the clam’s impact in New Zealand.
“We worked with Raukawa, Ngāti Korokī Kahukara and MPI last year to select five sites to survey at Lake Karāpiro and Lake Maraetai. We found the clams in all the sites, with densities of up to 1,500 clams per square metre.
“We’re now developing models to predict their dispersal and future establishment, and also a suite of interventions (tools) to reduce the risk of transfer and manage the clams at different scales,” she says.
As well as working with the clams in the field, research is being conducted at NIWA’s Hamilton ecotoxicology lab to determine the best ways to kill the clams and also clean equipment, supporting MPI’s Check, Clean, Dry procotols.
The overall aim is to understand the clam’s impacts on New Zealand’s waterways and develop effective methods that can be used by councils, management agencies, community groups and others to control the clams.
Funding for the project has been awarded by MBIE as part of their Endeavour Fund, which supports research excellence and science with high impact potential.
The Ministry for Primary Industries (MPI) declared corbicula an Unwanted Organism in New Zealand under the Biosecurity Act 1993 in August 2023 and has already implemented a programme of actions to help prevent the spread.
