On 1 July 2025, NIWA merged with GNS Science to become Earth Sciences New Zealand.

December 2025 Update

Welcome to the December programme update from the Stopping the Gold Clam research team.

Ngā mihi o te tau hou. Welcome to the December programme update from the Stopping the Gold Clam research team. In this update we report on research activities over the last five months including a visit from Prof Frances Lucy and a new resource – the ‘Silent super spreaders” video.  

In this update

  • Deborah Hofstra  Programme Lead update

    In this update… New clam breeding insights, the Silent Super Spreaders video, and fresh collaborations to protect NZ waters.
  • a single D shaped clam larvae in natural sample with detritus and phytoplankton viewed under 100x magnification.

    Seasonal feeding trials and condition assessments

    Seasonal lakeside trials track Corbicula fluminea feeding & health - spring sampling now complete.
  • Sample from Lake Maraetai, Phytoplankton in Dec 2025 and it show measurements being taken down a microscope in µm of two species;  a Diatom, Fragilaria (the long cells joined together) and a Cyanobacteria, Dolichospermum (the round cells) two of the dominate large species at this time. Photo ESNZ

    Ecological impacts of the invasive gold clam on planktonic communities

    Investigating the ecological impacts of the invasive clam Corbicula fluminea on planktonic communities in Lake Karaapiro and Lake Maraaetai.
  • Clams team banner

    Visiting Irish professor calls for teamwork in fighting invasive clams

    Prof. Frances Lucy says connecting people and communities is key to managing the gold clam in New Zealand
  • NIWA Freshwater Fish Ecologist, Michele Melchior, using a NIWA-designed clam net to efficiently collect gold clams at Bob's Landing, Waikato river.

    Annual invasive gold clam population surveys in lakes Karaapiro and Maraetai

    Two-year dive surveys (2024–25) in Lakes Karaapiro & Maraetai track invasive gold clam impacts on native kaakahi.