Science Centres: Fisheries

Paranephrops planifrons

Freshwater crayfish or koura are an important kai (food) resource for Māori and a vital component of healthy natural freshwater ecosystems. To better understand this resource, NIWA scientists have studied koura habitat preferences in almost 800 locations in 30 North Island rivers and streams.

The resulting research has produced models that correctly predicted the presence/absence of koura at 75% of locations using various habitat characteristics.

Not surprisingly for creatures that feed at night and hide from predators by day, koura were strongly associated with cover, such as tree roots and leaf litter, and were most likely to be found at the stream edge. They were commonest in streams less than about 6 m wide, in still or slow-flowing water. This may be a reflection of small streams having more cover.

The research will assist in stream management for the enhancement of koura for kai, in stream protection, and especially in restoration of degraded streams. It will also provide information relevant to koura aquaculture.