210 XEUROPTKROID IN.SEC'TS OF THE HOT SPRIXGS REGION, X.Z., 



where the fauna, though seriously reihu'eil in many places, is usually found to 

 be more abundant than it is in this Region, it appears certain that the Rainbow 

 Trout has had a gi'eater share in the eating-out of the insect fauna than has the 

 slower and less greedy Brown Trout. The histt)ry of the Trout-flslieries of the 

 Region may be briefly stated as follows : — 



(i.) Before the introduction of the trout the rivers of New Zealand swarmed 

 with an aquatic insect fauna as abundant as that to be found in any 

 part of the world. The lakes carried a less abundant fauna of fewer 

 species, 

 (ii.) The great majority of these insects, having evolved to their present 

 state without the stimulus of the predatory action of any rapacious 

 fish, possessed no means of defence against the trout when they were 

 introduced. 

 (iii.) The introduced trout, and especially the Rainbow, gorged themselves at 

 leisure upon the rich food ; so tliat, in the course of a few years, trout 

 of record size were being caught, and the fisheries obtained a world- 

 wide reputation. 

 (iv.) No scientific attempts have been made to conserve or renew the food- 

 supply. On the contrary, the only idea seemed to be to put in more 

 and more fry. 

 (v ) As soon as the food supply began to fail, some of the trout became 

 weakened; "slabbiness" became noticeable; and disease in the form of 

 thread-worm and fungoid growths appeared. There is also consider- 

 able evidence of actual starvation of trout in certain streams. 

 (vi.) Rome attempts liave been made of late years to reduce the nunil)er of 

 trout by netting and trawling. These efforts may be said to have 

 tjrouglit about some slight improvement in the condition of the fish. 

 At the same time, the destruction of shags has diminished the pre- 

 valence of the thread-worm (of which the shag is said to be the inter- 

 mediate host). But the disease is by no means stamped out. and most 

 certainlv recjuires further careful study. 

 The present ]iosition of the trout-fislieries of the Hot Spring's Region is that 

 there is, throughout most of the Region, not enough food for the trout present. 

 Many of the streams, especially those in which the fish spawn legularly. are 

 almost totally "eaten-out," and the amount of food in the lakes is woefully defi- 

 cient. The only part of the Region in which the state of affairs can be described as 

 at all hopeful, so far as my investigations go, is the Tongariro River and its tri- 

 butaries, where the supply of food is still fairly abundant. 



One might sum up the position, somewliat caustically, t)y comparing it with 

 that of a gi-azier who put 10,000 head of cattle into a very rich 1000-acre paddock, 

 left the animals to feed, and, when the food supply began to fail, prepared to 

 remedy it by putting in a fresh supply of calves every year, without making any 

 attempt to improve the impoverished food supply ! 



(iii.) Recommexiwtions. 



It is clear that improvement in the Trout fisheries of the Hot Springs Re- 

 gion can be effected along two distinct lines, \nz.: — improvement of the food supply 

 and reduction in the numh^r of trout. No considerations of the attractions to to\irists 

 or anglers, from a super-ubundant supply of trout, should be allowed to cloud 

 the main issue, which is this that, unlesx a natural balance can he brought about 



