TROUT IN LAKE TAUPO

New Zealand Times, Volume XXXVII, Issue 8362, 24 February 1913, Page 3

TROUT IN LAKE TAUPO

DETERIORATION OF THE RAINBOW. HOW IT MAY BE PREVENTED. (By Cecil A. Whitney.) I am glad to see from articles anu letters in some of the leading journals of the Dominion that the ”uo food and “shag” theory is fast being put m the background as the first and primary cause of the deterioration ot trout. To gain any kind o: _ renable information on this subject it is ntcessary to go up to taupe regularly eacn month from January to September to watch tho trout. When 1 first went to fish at Taupo the rainbow were perfect fish, due to the abnormal quantity of food-, and many fish were in such good condition in December that tney were on tno move to go up to spawn in February; now, few fish in February are in condition, and none in December, whilst the average size is hair wfiat it. was then, and few try to go up to spawn till April. X was looking at a basket of fish caught at Taupo on January 17th (one of a number of baskets tnat i examined of fish caught in Rotorua, Rotoiti, and Taupo), and a native who was standing by pointed out a very poor fish, and said, “No good; too late the spawn; kapai in three or four" weeks.” He was quite right, the fish had spawned in December, and this accounted for its weak and poor condition. 'There cannot be tho slightest doubt that the whole nature of tho fish is being altered by first, the use of minnow. and spoon-bait in the rivers; second, the continual harrying of the fish at tho mouths of the rivers by boats; third, the use of minnow and spoon at the mouths of • the rivers; fourth, the season being kept open in May, when enormous quantities ot oreeding fish are taken (this was specially prohibited by a very wise Act of Parliament, the close season being fixed as between April 30th and October Ist, but an -Order-in-Council upset this Act and for three seasons it has boon open in May); fifth, the destruction by spearing by the natives of the best breeding fish during the close season. All this tends to make the fish keep away from the rivers when the call of nature .bids them go up, and as a result they often retain the spawn till it is dead. Fish that have done this seldom again reach the same condition and are just ripe to catch any disease that inferior fish are subject tp. The most healthy fish go up to spawn early (or want to go up), but if kept back by fear till June there is a great rush of both early and late fish, and the rivers are so full that few fish get the chance of spawning properly,- and it is more than probable a large majority of the ova that mature are from the late and worst fish in the lake. Besides the fish are so thick in the upper reaches of the river, when the rivers are little more than small streams that one can nearly step across, that the best become an easy prey for the natives. The late spawning also affects the growth of the young fish, for if the early fish are allowed to go up to spawn in May the fry • from these fish can obtain quantities of food in the shape of ova from tho late spawning fish, and as a result ova spawned in the beginning of May would mature and the fry would flourish to such an extent that they would be fully nine inches long in December of tho same year. This is a fact 1 have seen continually-de-monstrated at Taupo and previously at Rotorua, before the slaughter of the best fish started the deterioration of the Rotorua fish. The fry that feeds on the spawn, of the late fish are doing the best thing possible for the fishing, because they are consuming the ova of the worst breeding fish, and thus, to a great extent, preventing inferior bred fry from going down to the lake; the few that do get down would be eaten by their larger and stronger brothers of the same season's spawning. The food supply in the rivers is very short, most oi it being supplied by the fish themselves, in the shape of ova and fry. In dry weather a fannumber of green butterflies, moths, crickets, grasshoppers, dragon hies, etc., fall into tne water and -are greedily taken by the fish, and in flood time quantities of tadfioles, frogs, worms, etc., got into tne rivers and afford a plentuul food supply, but tins only lasts just while the flood is on. vvnere, then, do the iish obtain the bulk of their feed '{ From careful study of the subject, I venture to say in the deep water of the fake. This is proved Uy deep trolling with the spoon, where the best fisn are taken in twenty to twenty-live feet of water. I have contended that good fly-flsmng could be ofl tamed of late years (especially since the natural Uabits of the hsh have been altered) in the deep water of the lake m December and January, because the best fish are then feeding and putting on condition lor the spawning season. A well-known fisherman, who spends six weeks or so each season at VVaihaha, \Vestern Bay, had the experience this year of obtaining splendid tiy-iishiiig over a mile from the shore and in thirty feet or more of water. They rose splendid to the fly, he said. ,At this time the fish inshore (that were hanging about the mouth of the rivers on the chance of getting. frogs or worms) were in poor condition, whilst those , caught in the deep water were fast fattening into well-conditioned fish; it is these fish that will be ready to go up in April for spawning in May, and from which Taupo lake should be stocked from year to year, instead of 'being stocked mostly from the fish which are not worth the natives’ catching. The question is, what do the fish feed on in deep water ? Most probably koura and small trout from yearlings upwards. If they do not feed on small trout, why do they take the spoon or minnow so greedily ? Why are the small fish in the deep water? Probably because they also feed on enunga and the ova of koura, which abound in the lake. I was sitting last month on a rock on tho edge of Lake Taupo, with deep water (twenty to thirty feet) under me, and watching three trout, say, six to nine pounds weight respectively. Every now and then they would shoot out from under a ledge, and then return. After a _ while I ascertained they were feeding on small trout fly, of which several hundred could bo seen every now and again when they came near the surface of the water. Later on one of the fish' came to the surface for_ a fly, and he got it, but it was artificial. The trout scaled 71b, but I could find no trace of small trout in it, the fish having no doubt disgorged the moment it was hooked. If the lake is kept full of well-bred, perfect-conditioned fish they are so active and can eat such an enormous quantity of food that weak

or diseased fry yearlings, or even large fish, would not have a chance, and so the survival of the fittest would go on; and if nature is helped by man m the right direction wonderful results would be obtained, and fish of enormous size, I feel sure, would be caught on the flyIt would be a good thing to erect a koura (crayfish) hatchery at Tokaanu and 'i'aupo so that large quantities of these crustaceans could be hatched and piaced m tho rivers every year. Inis would encourage the fish to go up the rivers early for food, as well as to spawn, frogs could also be reared for the same purpose, and it should not be a difficult matter to rear a few million enuuga every year. I am satisfied nature supplies all that the trout requires at Taupe to produce fish, not only fifteen or twenty pounds, but forty to fifty pounds, if properly looked after; but, as you say, the lake has been left to take care of itself, and if this policy is continued there can be only one result: that is, the Rotorua experience over again. A ranger should be employed, especially during May, June, July, August, September, and October (close season), with a launch at his disposal to look after tho lake and rivers. He could also look after the game which should abound in this district hut for illicit shooting. During the open season he could see that all fishermen carried a license, and do other necessary ranger’s work w'hich is now neglected. I am pleased to see the shag idea is dying a natural death. It is about time, after years of trial at Rotorua, with not the slightest improvement to tho trout. There are few shags on Taupo lake, as they have been shot out, but on tho Waikato river, below Atiamuri, there are large shaggeries and thousands of these birds, and yet I have not heard of any fish in the Waikato having disease or worm. Some years ago a big flood brought down the Waikato quantities of pumice, which got into the gills of the trout and killed large numbers, but since they have recovered from the effects of the flood, good fly-fish-ing can be obtained, both above and below Atiamuri. It is a great waste of money to pay 2s 6d per head for shags in Rotorua district, for, if the fish are well-bred they will not take disease. The native question should not be a difficult one. They did not put the fish in the lake, neither did they put the.game on the land; they respect the game laws when there are rangers to see the law is not brokeh, and I am satisfied they would also respect the law in regard to not taking the fish during the close season. Indeed, I have discussed the question with several of the leading natives, and they agreed it would spoil the fishing it taking fish out of season was not stopped.