The Central South Island Fish and Game Council is to ask Meridian Energy Ltd to fund spawning surveys of sockeye salmon for three to five years, which could lead to a management plan.
"In order to effectively manage this unique fishery, it is important to be able to measure it," fish and game officer Graeme Hughes said.
Sockeye salmon were introduced into the Waitaki River and Lake Ohau in 1901-02, but the construction of the upper Waitaki hydro canal scheme in the 1980s led to their demise.
It was thought the population had died out, cut-off from its traditional spawning streams, but in 2005 large numbers were seen again in Larch Stream, which flows into the Dobson River.
In 2007 they had migrated to the Ohau River and became established in the Haldon arm of Lake BenmoreThe Lake Benmore population grew from several hundred to about 10,000, spawning in the Ohau, Tekapo and Twizel Rivers.
However, this year very few were spotted.
Flooding this year in January and February spread the population into the lower lakes and into the lower Waitaki River, where they spawned in the Awakino and Hakataramea Rivers.
Mr Hughes said the resurgent population had added another species to the Waitaki catchment fishery and had recently created angler interest.
"Their frenetic activity at the peak of spawning can be a spectacular sight and, for the angler, a mature male sockeye salmon in full spawning colour has high trophy value," he said.
An additional value was their contribution to the food chain with fry a food source for predatory trout.
At present, the spawning waters for sockeye salmon were the high country tributaries of Lakes Ohau, Benmore and Aviemore. Lake Waitaki salmon used the Aviemore spawning race.
In large or less accessible spawning areas, aerial surveys using a helicopter gave the best results.
