The main goal of any stocking programme would be to preserve the genetic integrity of Taupo trout, which are unique in the world.
Department of Consevation are presently rearing 30,000 Lake Otamangakau rainbow trout fry at the Tongariro National Trout Centre hatchery, as well as 10,000 slightly larger fish from Rotorua stock until it has done a risk assessment to decide which source of trout is the safest to use. If both are safe, then the young trout will be reared until they reach about 10cm in length. Young rainbow trout of this size will have a better chance of survival as they are less likely to be preyed on by brown trout, and would also be fast enough to prey on smelt or bullies in Lake Taupo.
The fish would also be split into two groups, with one group released in Lake Taupo and the second in the upper Tongariro, Waipa Stream and Whitikau Stream. The stocked fish would be marked so that they could later be monitored through the trap, anglers' bags and fish counts to identify the best release location.
Dr Dedual says manipulating fish populations by stocking is one of the most controversial approaches to fisheries management, as there are many risks associated with it; and in the most serious cases the consequences of stocking have actually led to a smaller number of fish.
He says that Department of Conservation's stocking project would be classed as `restoration stocking' aimed at rebuilding an early rainbow trout run, but routine and on-going stocking in Taupo would be `enhancement' stocking, and would mean the end of the current wild Taupo trout population.
Department of Conservation sought anglers' feedback on stocking through its draft review of the Taupo Sports Fishery Management Plan but Dr Dedual says that out of about 10,000 season licence holders, only 90 submissions (0.9 percent of licence holders) were received, which were split almost equally between those in favour of stocking and those opposed.
``It's always a problem if you only have one or two per cent of the people responding and you have to decide based on that ... what about the 98 percent left? If the anglers don't want it then we won't do it but if they do, then we will, unless there's the danger of altering part of the run.''
The full article is available to read in the current edition of Target Taupo.