198 Transactions.— Zoology. 
Art. XXI.—On Diseased Trout in Lake Wakatipu. By W. Anruvr, C.E. 
(Read before the Otago Institute, 15th August, 1882.] 
Plate XXIII 
For several years back the large trout in Queenstown Bay, Lake Wakatipu, 
have been a subject of notoriety and interest to visitors and others. These 
trout, in weight from 21bs. up to 15 lbs. or more, and in shoals of several 
hundreds, frequent the east margin of the bay near the mouth of the Town 
Creek, the reef at the end of the Peninsula, and the shore near the One- 
mile Creek on the west side. They appear quiet and lazy in habit, except 
when, as often occurs, they throw themselves with great vigour into the air. 
It is also to be remarked that they are to be seen at these places both in 
summer and winter, caudal and dorsal fins on the surface, and an occa- 
sional one may also be observed in the middle of the bay or at the steam- 
boat jetty. The water is very deep throughout this bay, but has a shallow 
margin a few yards in width running round parallel to the beach. The 
great body of the lake itself is abysmal, the only sounding got as yet being 
at a depth of 1,300 feet. Along the east side of the Queenstown Bay there 
is a belt of weeds growing on the bottom on the outer edge of the aforesaid 
shoal-water, the bottom itself consisting of shingle, gravel, and sand. The 
water of the lake is remarkable for clearness and purity, and is snow-fed 
through the Dart, Rees, Greenstone, and such rivers, which drain the sur- 
rounding mountains of the Southern Alps. Dr. Black, of our University, 
remarks, on his analysis of this water, that he never examined any water so 
destitute of common salt—a fact of great importance as regards the health 
of trout. His analysis I may repeat is,— 
Organic Matter in Solution. Table Salt. Degree of Hardness, 
Wakatipu—0'5 grains per gallon. Scarcely a trace. 3-1 degrees, very soft. 
In summer storms are frequent on the Wakatipu, but in winter its surface 
is generally calm or nearly so. The trout S. fario, ansonii, Günther, were 
put into the feeders of the lake about the year 1874. 
Besides the abnormal habit of great trout herding together in shoals, 
these Wakatipu fish almost without exception have refused the baits of 
anglers who have fished for them. The exception I refer to is that of a 
beautiful but small trout of 13 Ibs. weight, taken by Mr. J. P. Maitland with 
minnow, while fishing from the beach of Queenstown Bay in January, 
1880. This fish was remarkable by its bright silvery scales, the absence of 
all spots excepting on one gill-cover, and the absence of teeth on head of 
vomer. The condition generally of these trout is suggestive of good living, 
as they are fat and sometimes very much so, and are said to possess excel- 
lent edible qualities. But for some years I have heard of the presence of 
