NORTHERN ADVOCATE DAILY TUESDAY, AUGUST 15, 1933. SCIENCE IN FISHERIES

Northern Advocate, 15 August 1933, Page 4

NORTHERN ADVOCATE DAILY

TUESDAY, AUGUST 15, 1933. SCIENCE IN FISHERIES

Registered for transmission through the i post as a Newspaper.

A few days ago we reported the establishment of a fish canning industry in the Whangaroa district, and made reference to the widely held opinion that the Northern waters wore favoured for fishing. It is interesting- in this connection to know that estimation of the value of fishing grounds is uq logger a matter for rule of thurnh. Accurate forecasts of the abundance of sea fish are now becoming possible through the work of the Fisheries Laboratory of the British Ministry of Agriculture and Fisheries at Lowestoft. The methods have recently been proved successful in the ease of herring,

plaieo and hake; and this year they are to he extended for the first time to cover the cod fisheries of the North Sea. Counting rings on the scales of herrings through a microscope to tell their age; counting even smaller rings on a part of the ears of plaice and hake; a census of fish mortality at different ages —these are some of the methods used. The next stage of usefulness, which is already being approached, is the discovery of not only how many fish there will be, but of where they will he found. Changing currents, food supplies, and temperature may all drive fish from one ground to another to the mystification of fishermen, and in the case of herring it is known that a mass of small sea animals which they dislike may deflect their course. Such masses may extend as far as 150 miles and bo a real harrier to fish movement. Another development, of the future is the preparation of long range forecasts from the success of particular spawning seasons. The abundance of fish of special ages, it lias been found, is dependent almost entirely on the proportion which survive the first few weeks of life. Fish may be born just too soon or too late for the flowering of the minute sea plants on which they are to feed; the supply of these may be affected by the proportion of Atlantic or Arctic water which enters the North Sea round Scotland; and the rigid salts must be present for the plants to flower at all. The foregoing facts are particularly interesting in view of the efforts which are being made to develop the fishing industry in'the North. There would seem to be scope for useful research by scientists in order to assist those who are endeavouring to establish what should be a commercial enterprise of real value.