Arthuk. — On the Brown Trout introduced into Otago. 477 



loamy soil, in some parts marshy, and has a fall of only 4 feet to the mile. 

 The river-bed consists of clay, overhanging banks, and a gravelly bottom, 

 and in its course is extremely tortuous. It has also plenty of fine weed- 

 beds, as nurseries for fish-food. The water is deep and has very little 

 current and no stream, consequently there is an extraordinary range of 

 water. It is discoloured sometimes by gold-mining works slightly. This is 

 the Upper Taieri, where most of the great trout are, and it has an altitude 

 of 1,800 feet above sea-level. The food-supply is not as yet well ascer- 

 tained. It certainly does not include our smelts and whitebait (Retropinna 

 richardsonii and Galaxias attenuatus), which are anadromous, and only 

 found within a certain distance from the ocean ; but I believe I am correct 

 in saying that it consists of crayfish, fresh-water molluscs (LimncEa), flies 

 with their larvse, beetles, grasshoppers, and of fish, bullies and minnows 

 (Eleotris gobioides and Galaxias fasciatus). So far as my own knowledge 

 goes, I am satisfied there is not by any means a great number of these two 

 latter fishes in the Upper Taieri, and bottom feed generally is not super- 

 abundant. The great weight attained by the trout must evidently then be 

 the consequence of a fair supply of food, both surface and bottom food, but 

 more particularly the unusual range of water and the excellent shelter 

 afforded by the river's banks. The Shag Kiver, in its upper waters, flows 

 over slate formation, being a good deal affected by silt from gold-mining 

 operations ; and in its lower waters over shingle, gravel, and sand, with 

 good pools and plenty of range ; while the whole course of the Water of 

 Leith is over trap boulders, and it has few pools, with little shelter except 

 from bush, and no range of water. The food in both is generally similar to 

 that in the Upper Taieri ; but besides that they have the great advantage of 

 an endless supply of the migratory fish, the smelts and whitebait. The 

 Shag Eiver fish, living within the limits of migration, therefore, of these 

 little visitors, are fat and well-formed and still fairly plentiful, the largest 

 trout being near the tidal way, and small trout numerous above. The 

 larger trout, however, are not now found in the Leith except during the 

 spawning-time. Fishing has fallen off very much during summer ; and this 

 winter, for example, although Mr. Deans searched the Leith several times 

 carefully, he found no large fish till a big flood had come down. This proof 

 is of course negative, yet when the smallness of the stream, and want of 

 water and shelter are considered, it seems reasonable to believe that as large 

 trout are not now seen in the Leith except during winter, they must live in 

 the brackish water at its mouth or in the bay itself, for nine months out of 

 the twelve. And this is further borne out by the fact oi many large fish 

 being netted by fishermen in the bay, with the characters more or less of 

 the brown trout, 



