Koaro live to fight another day

Department of Conservation —  05/09/2013

By Rob Griffiths, Community Relations Ranger, Rotorua.

Just over a year ago, inspired by a Te Arawa Lakes Trust initiative, a small project team was formed with the ultimate goal of providing a sanctuary for koaro, a little native fish, in the upper reaches of Hamurana Springs near Rotorua.

The initial focus was on constructing a weir across the stream to help exclude trout, and then later to remove the trout from the upstream side of the spring.

A kaora being held over a bucket

Check out this little sucker

Projects that happen in streams, rivers or lakes around the Rotorua region are never simple! Generally you need resource consent from the regional council, approval from Te Arawa Lakes Trust (as they manage the beds), local iwi require consultation, and often approval is needed from Fish & Game and NIWA. Rather than going through the motions and pushing on alone, a working group that included all the associated organisations was formed and this collective expertise and commitment proved invaluable to the project.

Wading near the Hamurana Spring trout barrier.

Hamurana Spring trout barrier

DOC Ranger Kristina Thompson has been involved since the outset. She felt it was important to involve as many of the relevant organisations as possible as partners in the project. Their approval is one thing, but having them on board as partners in the project brought the added benefit of their skills and knowledge.

The weir is simple in design and construction, having a slightly sloped downstream side to allow koaro to climb, and a grate to repel trout from jumping over. A distinguishing feature of koaro is their ability to climb up very steep surfaces such as waterfalls, dams and even white-baiters’ buckets.

Wader training for iwi helpers.

Iwi wader training

To date, Kristina has been both surprised and delighted with the results of the project. It is the first structure of its kind in the Bay of Plenty and so far the results have been positive. Recent monitoring of koaro above the weir shows that numbers of koaro have sky rocketed, and the waterways they are now found are much more dispersed than previously reported.