Putting your tau in the water - Training at NIWA

Putting your tau in the water

Kōura. (Photo: W. J. Crawford)

Hauling up a tau to see how many kōura have colonised it. The blue net catches any kōura that try to drop off as the bundle of bracken fern emerges from the water. (Photo: Steph Parkyn)

Kōura (freshwater crayfish) were a traditional staple in the diet of the Te Arawa people of the Rotorua Lakes area. However, despite their cultural and ecological importance in these lakes, there is no long-term monitoring information on kōura populations on which to base management decisions or evaluate the effects of potential threats. These threats include invasion by exotic weeds and expansion of existing weed beds, fishing pressure, and water-quality problems, such as deoxygenation of the lake bottom.

A collaborative project between NIWA and Te Arawa has begun to address this lack of information and has evaluated a range of monitoring tools. We have concluded that a traditional tau-kōura fishing method (tau is pronounced 'toe') is likely to be the best tool for use by iwi. This involves laying a long-line of bundles of bracken fern along the lake bed for the kōura to colonise. The bundles are retrieved after a few weeks in the water and the kōura that have inhabited the fern bundle are counted and measured. This provides information on the populations (size range, sex ratio, number of individuals) in relation to environmental conditions.

We've developed a sampling protocol that is already being used by Ngāti Pikiao for monitoring the effects of the Ohau Channel diversion in Lake Rotoiti. This protocol will be used further in new collaborative research between Te Arawa and NIWA to underpin sustainable management of the traditional fisheries of Te Arawa lakes, a project funded by the Health Research Council and the Foundation for Research, Science & Technology.

For further information on the tau-kōura method, see:
www.niwascience.co.nz/maori/research/monitoring_koura
or contact: Ian Kusabs, Horohoro, RD1, Rotorua,
Ian@kusabs.co.nz
or Dr Stephanie Parkyn

For further information on the NIWA/Te Arawa lakes project, contact:
Dr Ngaire Phillips

Training at NIWA

NIWA staff teach a number of courses over a wide range of subjects. The courses are geared particularly to meet the needs of council and other agency staff. Some of the courses are held at NIWA and others are staged as in house training at an agency’s premises.

This year’s calendar of training courses is proving extremely popular; most of the classes held so far have been fully subscribed. We will be running the following courses in the next six months; each of them still has spaces available.

  • Identification of Algae in Rivers and Lakes
    Christchurch. 26-27 January
  • Identification of Wetland Sedges and Rushes
    Hamilton. 31 January-1 February
    Christchurch. 15-16 February
  • Identification of Aquatic Macrophytes
    Wellington. 8-9 February
  • General Environmental Datalogging
    Christchurch. 15-16 February
  • Taxonomy and Monitoring of Estuarine Invertebrates
    Hamilton. 21-22 February
  • Introduction to Stream Invertebrates
    Hamilton. 26 April
  • Introduction to Freshwater Pests (Biosecurity)
    Hamilton. 10-11 May

For further information on these and other courses, see:
education-and-training
or contact training@niwa.co.nz