Trout Stocking Programme

Lakes in the Auckland/Waikato region are stocked with rainbow trout and brown trout from the Eastern Fish & Game hatchery at Ngongotaha.  Trout are stocked in autumn when they are 10 months old and 12-15 cm long.  Lake Pupuke is stocked with two-year old trout that average 35-45cm.  The accompanying table shows the trout releases that occur in a “typical year”.

Trout releases in the Auckland/Waikato

Lake Number of fish Species
Pupuke 1000 Rainbow trout
  100 Brown trout
Whatihua 200 Rainbow trout
Parkinson 50 Rainbow trout
Mangatangi 500 Rainbow trout
Moano-nui 200 Rainbow trout
Karapiro 1500 Rainbow trout
  500 Brown trout
Arapuni 4000 Rainbow trout
  500 Brown trout

The rainbow trout are from the selective breeding programme carried out by the Ngongotaha Hatchery using trophy sized trout from Lake Tarawera as the breeding stock.  The advantage of these fish over other strains is that they do not reach maturity until their third or fourth year.  The growth rate of rainbow trout slows considerably after maturity is reached, and many fish fail to recover condition after spawning and die.  Therefore, late maturing trout have a considerable advantage with some of these fish achieving one to two years extra growth, resulting in very large trout!

Stocked brown trout are of Lake Waikaremoana strain.  Although brown trout are hard to catch, they live long and can grow much larger than rainbows.

Lake Waipapa and the Mangatawhiri Reservoir hold abundant trout populations from natural recruitment and do not require stocking.

Lake fisheries monitoring programme

Trout are released into Auckland/Waikato lakes to enhance angling opportunities.  Therefore, it is important that the fisheries are closely monitored to ensure that good growth rates are achieved.  The overstocking of lake fisheries can result in poor growth rates with few fish reaching a size acceptable to anglers.  On the other hand, if too few fish are stocked then catch rates can decline.

All hatchery-reared rainbow trout can be identified by the absence of one fin, either an adipose or pelvic fin.  These fins are removed at the hatchery so that each year class can be clearly identified.  The subsequent growth and condition of these fish are not affected by this procedure.

New to freshwater fishing?

Local tackle shops should be able to tell you what are the most popular lures and fishing techniques for lakes in their area.  Fish & Game also has a pamphlet “Getting Started in Freshwater Fishing” that is aimed at assisting the complete novice.