Professor Michael Bunce

Professor Michael Bunce, EPA Chief Scientist, standing in front of the valve tower, Lower Lake, Zealandia

Professor Michael Bunce, EPA Chief Scientist, in front of the valve tower, Lower Lake, Zealandia

"Science and regulation sit side by side in our work. They may not follow the same pathways, but they share similarities."

This year we launched our environmental DNA (eDNA) programme: Wai tūwhera o te Taiao - Open Waters Aotearoa.

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. eDNA describes all genetic material recovered from water, organic material, sediment, and soil.

As creatures pass through or over the environment they leave behind traces of themselves in the form of organic material such as skin, hair, feathers, urine, faeces, or decomposing organisms. By analysing this genetic material we can survey what is living, or has lived, in a particular environment. We can also measure changes over time, in response to stressors or changing conditions. 

Working with school children and community groups from the greater Wellington region, we have collected water samples from over 20 streams, estuaries and oceans, and generated millions of tiny DNA 'barcodes' (this refers to the tiny fraction of a creature's DNA needed to identify which species it came from – kind of like the barcodes we find on our groceries that are scanned at the checkout).

We then compare the barcodes with a database made up from a wide range of species, looking for matches. This is practical, sound science. Our survey of waterways in Zealandia ecosanctuary in Wellington identified almost 400,000 barcodes, 1,312 of which were unique. We can identify some of these to a distinct species, but some will remain unknown until we further study the biology and the ecosystems.

"At its heart, our eDNA programme is about building bridges between people and nature. It uses eDNA testing to connect communities to their environment: they can literally see the environment through a new lens and get firsthand experience of how science can inform our understanding of waterway health."

This in turn offers people insight into the decisions that we have to make, often in the face of uncertainty.

In 2019/20, we partnered with Zealandia to work with seven local community and iwi stream care groups, as well as the educational resource organisation House of Science and students from Wellington High School.

We have generated reports on eDNA findings at:

  • Zealandia Te Māra a Tāne
  • Owhiro Stream
  • Te Awarua-o-Porirua.

More about our eDNA project