FRESH WATER FISH

Hokitika Guardian, 17 November 1932, Page 8

FRESH WATER FISH

RESEARCH WORK

KNOWLEDGE. GIVEN TO ANGLERS.

Since the 'setting up of a. Central Fresh. Water Research Committee '-by the New Zealand Acclimatisation Societies’ Association conference in September, 1929 ; great strides . have been achieved in problems affecting the ■well-toeing of tirout 'in the -rivers and lakes of the Dominion.

At the last conference the majority of the Acclimatisation 'Societies wer« brought to .see that there was a lack of: .something in their equipment where-' by they could be is t carry out what was not only -their legitimate work but also their ibounden duty as bodice having statutory authority to control utilisation, 'conservation and development of the fresh water fisheries of New Zealand. The thing lacking was a real understanding of the nature -of the fish they <vere supposed to be looking after, and of the surroundings into which the committee, or its predeceseoi'e -in office, had cast them.

The preliminary research work which had been undertaken by the Acclimatisation Societies of- Wellington and North Canterbury has gone far enough to - that such work had a real bearing on the fish problems .of acclimatisation societies and to point to the desirability of extending and increasing fishery research.

HELP GIVEN BY GOVERNMENT-

The .-New Zealand Government has been approached by the committee to grant a subsidy towards th e work. If times had been normal ) the Government would have seen its way to con-, tribute -to the scheme, probably through the Department of Internal Affairs and the -Marine Department, go far as the latter is concerned it may be -pointed out that, although no cash contributions have been made directly, the Department has helped to the extent of printing two reports, namely “The Age and" Growth < i Trout in New Zealand,” by A. W. Parrott as Fisheries Bulletin No,'4, rnd Professor P-ercival’s report, “On the Depreciation of Trout Fishing in' the Oreti, with remarks on conditions in other parts' of New Zealand,” as Fisheries Bulletin No. 5.. It has also printed Captain Phillips’ two reports as Bulletins No. 2 -and 3. At the conference a -resolution we s passed that each society should appoint a small ne.earch sub-committee, Which should assist the work as far, as possible and furnish research workers with information about its •districts and -put forward any local problems ; but it must be said that on the whole, the prosecution of local enterprise has not been what it might be. The necessity to cut .‘to a minimum expenditure on traveh und dncidentnls has‘-eraniped< the - development of local auxiliaries to the central committee. •

RESEARCH LABORATORY NEEDED/ The proposal :to establish a research laboratory in such locality aa the Central Research -Committee shall think, most suitable has been held in abeyance. This ‘is a question that involves many'• difficulties, -and these are -not only financial. -Sooner or later .q suitably equipped station must, be . tabli-shed.

Meanwhile bhfe laboratory and field operations which are being carried on by" Professor -Percival and Mr Parrott, with 'the" assistance of -local members, are necessary to throw light on factors that must be understood before one can usefully attempt that artificial improvement on natural conditions which constitutes pisciculture as distinguished from the “chuck • and' chance it” methods of acclimatisation.

' "-As-a result of the investigations of the ‘last few years ? a great deal- has been made known about the various forms of -life which are found in different types of trout water 5 and these constitute the fundamentals of_the conditions with which the committee and trout have to 'deal. Because two observers appear to draw different conclusions, it is not reasonable to consider that the value of thei r work is thereby nullified. 1 Especially with regard to such a complexity of factors as those : which make up the environment of a trout, it may eventually prove that both, conclusions ar e right—up to a certain point, or within the limits ol the conditions covered by the observations. WORK (OF INVESTIGATORS.

The job of "fishery investigators is to elucidate the factors which constitute the causes and to get a reliable measure of the effects of these causes. The. significance of the work that ha.s ibeen; carried on by the-'Ciogist, Mr Parrott, h? s had to do with the measuring of effects, i.e., of growth as an effect of the feeding conditions and of age t or survival, a« the effect of'all the hostile factors, including the angler, which trhut population is up against. • The. real value of tile scale investigations is-, °sal they give criteria by which growth can be compared as between one trout stock and another stock, either from, place to plabe or from time to time. A knowledge of the range and variations of temperatures throughout the year is - one of' the essentials of the. understanding of reproduction; growth and habits of- trout and of the organ-; jams on which they feed. The collection of such records depends almost entirely on local co-operation. These records require to b e extended so as to include- such factors a 3 heights of water as well as temperature, since the incidence of floods oh the one hand and very low water conditions on -the other hand conntituto conditions that vitally affect tro.nl- life fit every ttage.