Researchers are collecting DNA information from one of Aotearoa New Zealand's most threatened freshwater fish – the Canterbury mudfish (kōwaro) – in an effort to make it more resilient to future environmental change.

Levi Collier-Robinson sampling kōwaro (Canterbury mudfish) with students from Te Kura o Tuahiwi. Image: Ashley Overbeek.

Scientists will use the data to comprehensively assess the genetic diversity of the kōwaro. In general, species have better survival rates if their populations are more genetically diverse. The assessment will be used to build a framework that could underpin future decisions on where, when or whether to mix kōwaro populations to improve conservation outcomes.

Te Whare Wananga o Waitaha (University of Canterbury or UC) MSc student Levi Collier-Robinson is working with students from Te Kura o Tuahiwi to sample kōwaro at Tūhaitara Coastal Park in North Canterbury, as part of a BioHeritage Challenge project led by UC’s Associate Professor Tammy Steeves.

Levi says collecting samples from kōwaro throughout their Canterbury distribution is a critical first step towards building resilience in this taonga (treasured) species.

“Up to now, recommendations on how to best manage small, isolated kōwaro populations have been based on a single genetic marker and a limited number of sites. This work will provide us with tens of thousands of genetic markers from fish sampled across at least 20 sites.

“We’ll use this information to identify kōwaro populations at risk of local extinction. We’ll also use it to make recommendations about which populations to use to top up populations elsewhere, or to create new ones.”

“Our aim is to build genetically healthy kōwaro populations that can adapt to environmental change. As a rule of thumb, the more genetically diverse a population is, the better.”

Levi has strong links to Ngāi Tūāhuriri and, as a past student of Te Kura o Tuahiwi, he enjoys working with the school’s tamariki (children), especially because they are sampling at a culturally significant site on their takiwā (region).

In addition to kōwaro, the UC research team is collecting DNA from a declining mahinga kai species, kēkēwai (freshwater crayfish). Both projects are being conducted in partnership with Te Ngāi Tūāhuriri rūnanga.

Levi was one of three researchers to present research on kōwaro and kēkēwai at the recent Symposium on the Evolutionary Genomics of Adaptation at the University of Montana Flathead Lake Biological Station in Polson, Montana, and at the Society for Conservation Biology 5th Oceania Congress in Wellington.

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