FOREST, FISH AND GAME COMMISSIONER. 179 



and before its nature was discovered it caused heavy losses among the 

 two-year old brook trout as well as fish of greater age. 



The only means of checking this parasite, available at most of our 

 stations, is the introduction of a surface-feeding fish which will consume 

 the swimming larvae of this crustacean. For this purpose it is believed 

 that the fresh-water killv will be most suitable for trout waters, as it is a 

 lover of cold, pure streams such as trout inhabit. Doubtless there are 

 other native fishes which may become available, but this one is suggested 

 because its distribution in the State is rather extended, its size is small, 

 and it would not, therefore, interfere with the natural or artificial repro- 

 duction of trout. Furthermore, it would furnish suitable live food for 

 the large fish. It is a prolific species and when once established at a sta- 

 tion it is reasonable to expect that its introduction would prove wholly 

 beneficial. 



Fungus is another fish pest much dreaded by fish culturists every- 

 where. This can be controlled at the stations, and has been controlled 

 at the Adirondack Hatchery, by means of salt freely used in the troughs 

 and races. High summer temperatures and scant flow of water have 

 caused difficulty at this station and elsewhere. The only remedy for this 

 situation appears to be the pumping of spring water suggested above. 

 This natural drawback to trout propagation is a very serious matter often 

 resulting in the loss of tens of thousands of fry and fingerling fish. One 

 of the essentials of a successful trout station is the presence of a bountiful 

 supply of pure spring water obtainable bv gravity, if possible. 



Pleasant Valley Hatchery. 



The Pleasant Valley station has suffered many serious vicissitudes 

 during the past, and its work has been hampered to a greater extent than 

 one would consider possible. The stream flowing through the hatchery 

 grounds is so thoroughly impregnated with injurious bacilli, originating 

 chiefly through sewage pollution, that it is no longer suitable either for 

 hatcher\- purposes or for rearing ponds, and I earnestly recommend that 

 it be employed no more except as a sewer to carry off the waste from the 

 ponds and the hatchery. 



During the year the spring formerly owned by Mrs. Church, and used 



