EXPERIENCE IN ABATING DISEASE AMONG BROOK TROUT. 



By ALBERT ROSENBERG, 



Proprietor Spring Brook Trout Hatchery, Kalamazoo, Mich. 



Mr. President: I shall ask your kind indulgence at the beginning of this 

 paper to give you a brief history of my own fish-cultural operations, as this is 

 essential to the subject. 



I established the Spring Brook Trout Hatchery in 1895 without having had 

 any practical experience. The site on which operations were commenced was a 

 basin of about 4^^ acres surrounded by high hills. The water supply originates 

 at the north end of the basin at the foot of the hills, where is a number of what are 

 called in this part of the country (Michigan) spring holes. The land was cov- 

 ered with tamarack, elm, ash, etc. These were all cut off and a dam 209 feet 

 long was built across the site, flooding about three-fourths of an acre. Eight 

 ponds were excavated by hand labor, as the soil was muck, and ditches were dug 

 to carry the water from springs that were uncovered. I took about 20,000 eggs 

 in the fall of 1895 from wild fish and hatched a good percentage; also bought 

 25,000 fry in the spring of 1896. 



It soon appeared that conditions were not right for extensive fish-cultural 

 operations, as I had started too near the head of the supply and the water became 

 too warm and stagnant. Some of the ponds contained a number of bottom 

 springs which supported a limited number of fish. By 1897 the reservoir had 

 grown up to a dense mass of moss, which, although it was raked out by the boat 

 load, could not be suppressed. 



In February, 1S99, there were three weeks of intensely cold weather, which 

 heaved all the raceways and put the ponds out of commission. Early in the 

 spring the remainder of the farm was purchased and a large reservoir constructed 

 at the head of the valley. Here was a water supply of 453 gallons a minute. 

 The reservoir was 277 feet long, had an average width of 58 feet, and an average 

 depth of 3K feet, and was full of small bottom springs. 



In 1900 the pond built in 1895 went out during a severe storm. Meanwhile 

 fry of 1899 had grown to good size and 1,500,000 eggs were taken that fall. 

 Losses during the spawning season were normal. 



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