DECLINE IN TROUT

Dominion, Volume 7, Issue 2203, 16 July 1914, Page 8

DECLINE IN TROUT

THE DEEPER CAUSE INEVITABLE LAW OP NATURE PROFESSOR PRINCE ON SPORTINC FISH. Professor Prince, the Canadian fisheries expert, gave a Dominion reporter a summary of his recent inter-, view with the members of tho Wellington Acclimatisation Society. Among those present were: Messrs. L. 0. H. Tripp (president), H. H. Ostler, A. J. Sladden, W. Wakeman A. J. Rutherford, A. F. Lowe, L. G. Rcid, and M. G. Bagnall. Mr. Tripp explained to the visitor the exact nature of tho work of the society over a long period of years, and informed him that at; least four species of trout" had been introduced into New, Zealand—Canadian, English, and United States species—and acclimatised by the society, but, with the exception of the brown trout, the various species could not be said to have done well. Even the rainbow trout, which for a few years flourished and grew to a very largo size, had during the last few years fallen off very appreciably. Indeed, fishing all round had declined, as far as abundance of fish and tho sport they gave were concerned. The society desired to know, if possible, what the causes of the decline were likely to be. Professor Prince said it niight be duo to one or a combination of causes, but eels, which he had been told were superabundant in the streams of the Wellington district, might-be held to be responsible-for considerable inroads on the young fish. Shags, too, were most destructive, and these he understood were also fairly plentiful in New Zealand. Both of these causes could bo effectively dealt with. Some of tho mer.ibors of the society had mentioned that seagulls ! were a danger to trout, particularly in tho Wainui waters. It was tho first time ho had heard of it. The habit of the seagull was to feed on offal and waste fish, but-not to capture live fish. That was the characteristic of tho gannet, item, and some other seabirds. Professor Prince did not altogether admit that the seagull was blameless, but inferred that it might be possible for the gulls to have contracted bad habits in those parts; Then the admitted criminal use of dynamite and carbide explosives had been adduced as a contributing cause of the increased scarcity of trout in the streams. Better Patrol Wanted. • Professor Prince expressed tho view that a better system of patrol was required in tho district. He understood that the society only , had one paid ranger to look after tho whole area (with'the assistauce of the.police), but unloss there was a more efficient patrol it would:be a very, difficult matter to •restoro- the fish in abundance. ■ ■ A discussion took placojas to the advisability of introducing Aiew species of sporting fish into New Zealand waters, but Professor Prince advised the greatest caution in that regard. Canada's policy in that regard, Professor Prince meutioned, r was to' never hastily introduce new. game fish, some of were' likely to prove permanently harmful to the species already established. Tho black bass which had been introduced into Eastern Canada, was a very fine sporting fish, but it had been found to b>) as var-acious as a shark when it had been introduced into new waters, and,,all-other;.species of fish .had disappeared before it. There were some fine species of fish in tho Rocky Mqun-' tain rivers, notably the Bow River grayling, a .fine species of fresh-water white fish, which took the fly eagerly. Opinions wore expressed at the conference that good streams . and lakes "had suffered in lncalities where crayfish abounded, aud it was also 1 6tated that inunga (whitebait) and other small species of fish were far less abundant than formerly. The Deeper Cause. Professor Princo discussed the deeper cause that may undcrly the decline of trout in New Zealand. Wherever fish or" animals were introduced into a new country congenial to their natures, they increased in size under the exhilarating influence of a new environment until they reached a maximum,' and after that there ensued a falling-off both in sizo and .Quality. That, he thought, had been well illustrated in New Zealand. Some species of, trout that had been introduced had attained a size larger, than the; over had in their native waters, and have since shotvn a. diminution in length and weight. This was a natural law, and one that could not he readily overcome except by the introduction of now blood, The Only Way. Professor Prince thought that the obtaining of further supplies of the same species already established was the only efficient means of keeping up the average sizo if so desired. His personal view was that large trout were not desirable. Every overgrown fish must be more or loss predatious in its' habit, and would probably make great inroads on other schools of fish. The society had, during the conference, expressed great appreciation of' the work that had been done by Mr. Ayson (Government Fisheries Expert), and had further stated that in any future scheme of reorganisation only properly qualified officials should bo vested with authority, and tlie societies, which in ♦.ho past had established the fish almost solely by their own labours, should be given an authoritative standing. Finally Professor Prince was tendered a vary, hearty yoteof thanks and appreciation for his kindliness and courtesy in discussing so freely points of mutual interest.