Exploring the hidden life of our streams: Whangateau eDNA community workshop

CSI for streams (but without the crime!)

On Saturday, 22nd February, an enthusiastic group gathered at Leigh Hall to take part in an eDNA stream testing workshop, hosted by Whangateau HarbourCare in collaboration with Mountains to Sea, and lead by Pattle Delamore Partners (PDP) and Healthy Waters. This brand new, hands-on workshop was a deep dive into how environmental DNA (eDNA) can support conservation efforts and catchment remediation, offering an exciting new tool for monitoring biodiversity and stream health. Whangateau HarbourCare was one of three catchment care groups in Auckland chosen for this project - huge thanks to Healthy Waters for making it happen.

Unlocking the secrets of our streams

The workshop began with a presentation from PDP, who introduced participants to the science of eDNA—how species leave traces of DNA in the water, allowing us to detect and monitor biodiversity with remarkable accuracy. We also explored the prototype eDNA GIS map viewer, a new tool designed to help communities make data-driven decisions about restoration and conservation using eDNA results.

After the session at Leigh Hall, we headed into the field to put our knowledge into action.

Sampling at Birdsall Stream: A snapshot of life

In a beautiful section of Birdsall Stream, under the cover of the ngahere, we collected 120 water samples to capture environmental DNA and gain a snapshot of what’s living in or near the stream. As we worked, we were surrounded by native fish - inanga (whitebait) resting in the ripples and bullies lounging on rocks—including a strikingly unusual light pink bully!

Alongside the eDNA sampling, Briar and Sarah from Mountains to Sea led water quality testing and macroinvertebrate surveys, revealing that Birdsall Stream is in excellent health. The discovery of species such as the flat mayfly and smooth case caddisfly—both indicators of clean water—was an exciting confirmation that this stream supports a thriving freshwater ecosystem.

What happens next?

With our first samples collected, the newly formed Stream Team will select four additional streams in the catchment for sampling. Once all samples are processed, WilderLab will conduct eDNA analysis to identify the species present in the samples, giving us a unique view of the biodiversity in our waterways - from fungi to fish; from pests to precious native species - some of which we might not be able to confirm without this analysis.

Why this matters

Understanding what species rely on our streams helps us to:

✅ Prioritise restoration actions based on ecological need.
✅ Track long-term changes in stream health and biodiversity.
✅ Inspire community action by revealing the incredible wildlife living in our awa.

We’re eagerly awaiting the results and look forward to sharing them with the community. This is just the beginning of using eDNA as a powerful tool for conservation in Whangateau!

Stay tuned for updates - our streams have so much more to reveal! 🌿💧🔬

Ngā mihi nui to Auckland Council and Access to Experts (Ministry for the Environment) for funding this project.