New Zealand Freshwater Sciences Society Ngā Kohinga Wai o Aotearo - Native fish crisis deepens
Scientists call for urgent action at Christchurch conference.
The native fish crisis
A hum filled the Te Pae Convention Centre in the first week of December 2025 as more than 400 freshwater scientists from across New Zealand and Australia gathered for the annual New Zealand Freshwater Sciences Society conference. The event showcased cutting-edge research and collaboration, but a sobering reality dominated discussions: Our native fish are in serious trouble.
A new report revealed that nearly two-thirds of our freshwater fish species are at risk:
- 28% (22 species) are now threatened with extinction
- 32% (25 species) are at risk of becoming threatened
- Only 8% (just 6 species) are considered not threatened
Among the most alarming declines is the state of īnanga—a common species of whitebait—which has shifted from ‘At Risk – Declining’ to ‘Threatened – Nationally Vulnerable’ – the same threat level as the great spotted kiwi. More dramatic is the decline of Stokell’s smelt, found mainly in Canterbury, which has plummeted from ‘At Risk – Naturally Uncommon’ to ‘Threatened – Nationally Critical’, the last step before extinction.
“New Zealand has already lost at least one freshwater fish to extinction (the grayling) and we face now the serious reality of losing another species within the decade,” says Dr Joanne Clapcott, President of the Freshwater Society. “These findings are a wake-up call. Restoring lowland streams and wetlands is critical if we want to give our native fish a fighting chance at survival.”
Whatever we have been doing in the past is not working for our fish.
Why it matters
Freshwater fish are woven into the fabric of New Zealand life. Species like īnanga are central to the whitebait tradition and have been cherished by communities for generations. For Māori, these fish hold deep cultural significance as taonga and as kin. Many of our freshwater fish are found nowhere else in the world, losing them reduces our unique biodiversity and cultural heritage, and degrades the health of our waters.
Fish play vital roles in freshwater ecosystems and without them there are devastating effects on other species that we value. For example, iconic longfin eels stop growing, and bitterns starve to death when key foods like īnanga are gone. Streams near the coast are spawning habitats for īnanga and many other species, but with only 100 hectares of īnanga spawning grounds estimated to be left in New Zealand, their survival is uncertain.
Scientists warn that habitat loss, poor land-use practices, and barriers to migrating fish are driving population declines in some species and worsening conservation status in others. Wetlands—once abundant—have been drained for agriculture and development, stripping fish of critical nursery habitats. We have already lost 90 % of our wetlands and most of our īnanga spawning grounds, we cannot afford to lose one more metre.
What you can do
- Go to your local river and explore, take the kids, find out what lives in your stream.
- Protect lowland rivers by fencing stock out, preventing trampling of īnanga eggs that are laid in the grass of riverbanks.
- Report piped streams and culverts that fish can’t swim up to your local council. Barriers with downstream drops or waterfalls cut fish off from upstream habitats.
- Plant native vegetation along stream edges to improve habitat, don’t mow or use pesticides or herbicides along river margins.
- Support wetland creation and restoration on your property or in your community. Contact your local council to find out where community action is going on in your area.
For advice or questions, NZFSS welcomes the public to reach out at info@freshwater.science.org.nz
Media Contact:
Dr Joanne Clapcott, President, NZFSS
Joanne.Clapcott@cawthron.org.nz | 027 246 0517
Dr Richard Allibone, Vice-President, NZFSS
waterwayscon@gmail.com | 021 904 950