LAND AND WATER

New Zealand Mail, Issue 1613, 28 January 1903, Page 57

LAND AND WATER

(By “Dalbiac.”)

By the courtesy of Mr T. E. Donne, superintendent cf tJh e Tourist Department, I am enabled to give a full extract from a very interesting report by Mr F. T, .Ayson on the decrease of trout in Lake Wakatipu. Mr Ay son says:—“The secretaiy of the Lakes Acclimatisation Society informs me that licenses to net trout were first issued about twenty years ago, and that netting has been allowed ever y sea son since then down to the present time. From the time netting was first allowed np to about seven years ago trout were being taken in large quantities in the nets. Fish varying from five to twenty-five pounds were very plentiful, and in splendid condition. During the last seven years, however, there lias been a great falling'off in the quantity, size and condition of the fish taken, and at the present time they are small as compared with what they were in former years, and in such poor condition that many of them are scarcely fit for food. I am informed that the fish taken at ihe Lead of the lake are larger and in better condition than those got in any other part. This difference can probably be accounted for by the fact that the fish have a better supply of food brought down by the two large rivers which flow into the lake at tire head. One lot of twelve fish which I examined, the result of a nighFs fishing at Queenstown with six nets, would not average more than three pounds in weight. The largest fish measured 17 inches in length and only weighed silb. A fish of the same length fifteen years ago would have scaled from ten to twelve pounds. With regard to the decrease in quantity and the deterioration in size and condition of trout in this lake, I am of opinion that the following are the principal causes:—(l) The depletion of the principal food supply for trout; (2) tlio wholesale, unrestricted and uncontrolled netting of trout for market; and (3) the wholesale poaching that has been carried on, principally in the spawning season, when trout run up the streams from the lake. From the insight I have gained into the conditions obtaining in Lake Wakatipu I am of opinion that the principal cause of the deterioration of trout is due to the main food supply becoming almost exhausted. It is very probable that our snow-fed mountain lakes contain very little surface feed for trout, and that the principal supply consists of certain small fish and insects which inhabit only the shallow water. Mr Lucas and party, who have just completed a scientific survey of the lake, inform me that on an average Lbe ten-fathom line is within a chain of the shore, so that the bottom feeding area for trout in this lake would bo very limited indeed, and it can easily be understood that the large number of trout which it formerly contained would soon exhaust

the supply of natural feed on such a limited area. As the natural feed decreased, the trout would prey on each other, the larger trout would live on the. fry and yearlings, and this to a very great extent would account for the tiecrease in the quantity ol trout in. tlie lake. The uncontrolled and unrestricted netting for market which has been allowed in Lake aWkatipu for about twenty years has undoubtedly assisted mauei iai l> in reducing tlie quantity of trout. As the conditions existing in a good many ol our lakes vary considerably, no fixed rule dealing with the fish, in them can be made to apply to all. The value of our lake trout as a sport fish has not as yet been properly tested. I think that, at any rate in some of tlie smaller trout will prove to be an excellent sport fish. The trout inhabiting our lakes should be dealt with in the way most profitable for the people of the colony, whether it is by reserving the whole or part of any lake for angling purposes, or allowing tho fish to be netted for food for local residents, visiters or for market. I am convinced that it is possible to idlow netting, in the larger lakes at any rate, without doing any injury to the supply of fish in the lake itself or-to- the - angling interests m the streams . wn:cli flow into the lakes. It is the unrestiicred and uncontrolled netting which injures the fisheries in any locality. Wholesale poaching, particularly in the spawning season, seems to be prevalent throughout the lakes district. Thi» is an -evil which is becoming only too common in a good many other districts, and requires to be put down- with a strong hand. The loss caused by the destruction of the parent fish on the spawning bed is very great. Specially severe penalties should be provided for this offence. The local acclimatisation society does not seem to be able to put down reaching as it should do. Acclimatisation societies are no/w finding that a good many rivers in their dstricts do not now carry anything like the same head of trout that they did some years ago. This is no doubt caused by the trout exterminating certain insects and small fish which was part of their food supply. I may state that at Lakes Te Anau and Mana-pouri I found that trout were very plentiful and in splendid condition. One fish taken in a net at Te Anau measured 22 inches in length and weighed 211 b. • Considering the character of the country surrounding these lakes and other conditions obtaining there, I d:o not think that there is much risk of the food supply for trout becoming exhausted for a. great many years.” This is the most important part or Mr Ayson’s report. Much of it is of local interest. but as his statements on netting and trout generally are of such importance to the colony as a whole, I am fortunate in being able to give them in full. The one hundred and fifty lapwing which were being imported from Engl aim by the Wellington Acclimatisation Society were reduced on the voyage and after landing in an emaciated condition to twenty-eight. The survivors after careful feeding in an aviary, were, liberated the other day near the Wairarapa Lake, where they appeared to take off satisfactorily. The locality is eminently suitable for lapwings.