LIBERATION OF TROUT.

Hauraki Plains Gazette, Volume XXXX, Issue 5435, 14 June 1929, Page 2

LIBERATION OF TROUT.

PROPOSED BREEDING RACE. WAITAWHETA STREAM MOOTED The liberation of trout fry in the streams stocked by the Auckland Acclimatisation Society has caused that body a good deal of thought, and an alternative is sought. Fry have not been altogether a success, and it has been estimated that one fish aged from five months to one year is worth upwards of one hundred fry. Added to this fact, the Railway Department is now charging for the conveyance of fry, whereas previous to this year it carried fry free. This means that extra care must be taken with the conserving of stock available. Therefore a proposal has been put forward of a method which it is thought will be far more economical and infinitely more satisfactory. Instead of being liberated willynilly in a stream to fend for themselves, and be the easy prey of their host of enemies, the fry will be placed in a breeding race. The Ohinemuri Acclimatisation Club expects to construct one of these races adjacent to the Waitawheta stream. A side stream running into the main one has been selected, and parallel to this will be constructed a race fitted with wire netting protected sluice-gates at either end and joined to the side stream by connecting channels. The fry will be released in this and the whole covered over with wire netting to guard against birds, etc. For the first six weeks the embryo trout will be fed with liver. After they have passed that period in their lives a change of diet will be introduced. “High” rabbits will be placed on the wire netting so that when they rot and begin to disintegrate the resulting myriads of maggots will drop into the race and thereby provide food for the growing fish. At four months the upper sluicegate will be closed, and when the water has been lowered to a convenient level for netting the inmates the lower one will also be shut. A goodly portion of the fish will then be netted and carefully conveyed to the main stream for liberation. The gates will be opened again and the remainder of the stock left until they are seven months old before they, too, are liberated after their brethren, either bynetting or through the lower sluicegate. This releasing at two ages will serve a double purpose —the proving of which is the better age for liberation and the allowing of more room in the race as the fish increase in size. Through this method handling of fry may be eliminated altogether. Another manner of solving the question which the Ohinemuri Acclimatisation Club proposes to try is the placing of ova, by means of special tubes, in selected secluded spots along the banks of the streams. The spots chosen will be those which conform as nearly as possible to the natural spawning grounds of the adult fish.