FISH RESEARCH

Press, Volume LXXI, Issue 21415, 6 March 1935, Page 7

FISH RESEARCH

TO THE EDITOB OF 1111. Sir,—As "Black Gnat" ha? been unable to substantiate any of the claims that he has made on the value of the work of his friends, the lish research staff, we must no longer take him seriously when this subject is under discussion. We have given him every opportunity to do so: but he has utterly failed to advance even one piece of work accomplished by the research stall' that has been of any practical benefit to the angler. His last effort, is most disappointingly feeble. We will now part with "Black Gnat" with this further piece of advice: he should keep to angling notes, as he will be more at his ease there than in venturing into fish research. This is a matter upon which he would appear to have no opinion of his own. but. is content to act the part of Die blind follower. Now, I would like to make some comments on the proposed two yeais work as set out by Professor Pereival. (1) Extension of survey of age and growth to complete examination of the whole Dominion—They have been engaged upon this work ever since they started operations, and the value to the angler to date has been nil. Any further time and money spent on this work will have the same result. For the practical angler and his friend, the fish culturist, were acquainted with all that is to be known in this matter, in regard to the possible benefits to the angler, before those at present at work upon it were born. f 2) Continuation of study of fate ot particular year classes for elucidation of problems connected with variation in quality for fishing from year to year —This will ever be a matter of Guesswork and will be governed by fhe climatic conditions prevailing throughout the year, such as a favourable or unfavourable spawning season, floods which may carry the fry out to sea, or droughts that may kill thousands in drying up pools. Over climatic conditions we have no control. . (31 Study of relation between rate of growth and time of first maturity What benefit study of this matter is going to prove to the angler is difficult to follow, as trout may come to maturity at any period of growth from approximately nine inches to two feet or more and at any weight from four ounces to four pounds or more. This matter of growth is almost entirely governe'd by the available food supply. (4) Determination of condition factors throughout the Dominion with the object of classifying streams arid elucidation of causes of difference between condition and stocks of fish.— Here again, what benefit is going to accrue Lo the angler from the classification of the different streams is difficult to determine. Every angler knows that the different streams contain fish of varying condition, and that this varying condition is caused entirely by the amount and quality of the food available in the different waters. C 5) Attempt to discover a means of differentiating hatchery produced and naturally produced fish, to determine efficiency of artificial stocking.—lt would appear that this is a work which it is proposed to undertake with the object of trying to bolster up Professor Percival's preconceived idea that natural reproduction is all that is required in connexion with our trout fisheries. The efficiency of artificial stocking of waters has also long been proved, and we in South Canterbury had a very practical illustration of the benefits to be derived from a hatchery in the restocking of the upper waters of our streams, which had become depleted. Except for the satisfying of idle curiosity, it matters not whether the numbers of hatchery produced fish and those from natural reproduction are 50 : 50 or 90 : 10, either way. We have this assurance with a hatchery, that we can keep up the supply of young fish. Whether or not they develop into five and 10pounders is another matter; that is dependent on a variety of factors. (6) Prosecution of work on natural reproduction in special regions with the ultimate object of an examination of the whole Dominion, so as to map. if necessary, streams incapable of natural regeneration. —There is no occasion for the research staff to be wasting the angler's money in this direction, as if the members of the councils of the different societies have not sufficient knowledge to know this, their curators and rarfgers have. (7) Prosecution of investigation into causes resulting in small summer population in rivers which provide extensive stocks of fry.—"-I am not acquainted with any stream in South Canterbury where this takes place, with the exception of the small streams that the trout frequent for the purpose of spawning. The environment in these streams not being suitable for the larger fish to remain in, after having completed the process of reproduction, they seek more suitable quarters. It would naturally follow that the fish, having made use of these waters to spawn in, such waters would carry a population of fry which would also seek a more suitable environment as they grew larger. This is what is termed the valuable work to which'the fish research staff is going to devote two years, and on which, incidentally, a large amount of the angler's money is to be spent. As I have endeavoured to show in the criticism of this proposed two years' work, all that needs to be known, from the point of view of benefits to the angler, in ponnexion with these

matters, is already known by most competent anglers and our rangers and especially the fish culturist, And it is for that reason that South Canterbury is taking up its present attitude. As we have had no practical results to date from fish research and can see no value in the proposed work ahead, it is only a commonsense proposition that we should spend our money in some quarter that will give the angler a better return of value. Scientific research should be based on practical foundations, and its findings should be such as the practical man can work on. To say that-the results of any work are valuable is foolish and misleading, if there is no value to be found in it. Research can only justify itself by results.—Yours, etc., J. McDONALD, Chairman, South Canterbury Acclimatisation Society. Geraldine, March 4. 1935.