FISH SCALES

Hokitika Guardian, 21 September 1929, Page 6

FISH SCALES

A GUIDE TO AGE

DECLINE IN TROUT-FISHING

CHRISTCHURCH, Sept. 20

Just as it is possible to tell the age of a tree by the rings in the grain, so the age of a fish can be gauged by its scales.

This is a work which Mr A. W. Parrott who has been doing research work for the North Canterbury Acclimatisation Society, has been engaged on. From time to time anglers have sent him the scales of trout, and by studying these he has been able to te the age of the fish and its average growth per year over a series of years. ( Data thus produced have been- graphed, and frpm these curves there are indications that over a period of fifteen or sixteen years there has been an appreciable decline in the rate of growth of trout in the Selwyn river. Professor Pereival, of Canterbury College, explained yesterday that this work was only a small part of the research, which, it was honed, would be done in connection with trout in New Zealand. He hoped the present Dominion conference of Acclimatisation Societies would agree to the scheme to pool their resources in this cause. If our trout-fishing had declined and they were going to find out why, it would take a good many years’ continuous research. Perhaps, even then, they might not be able to produce much conclusive evidence. In attacking the problem from the viewpoint o' pure science tlioy were hampered by having little literature, as nothing of this kind had been attempted in New Zealand before. In some of its phases the problem was the same as in America and England, and much good would accrue from exchanging information gleaned in this way. It might be that the solution of the problem in New Zealand would come from discoveries made in other countries, but it was only possible to obtain this by exchanging other evidence for it.