

BULLETIN OF THE UNITED STATES FISH COMMISSION. 417 



Vol. Ill, No. 27. Washington, D. C\ ©ec. 7, 1883. 



7S EXPERIMENTS IIV THE POND C'UETURE OF TROUT, SUCKERS, 



AND CATFISH. 



By A. P. GARDNER. 



[From letter to Prof. S. F. Baird.] 



The first requisite in fish culture in ponds is an absolutely tight dam 

 wherever a dam is needed. My first effort in that respect was perfect 

 as to holding water, but in a few years the muskrats gave me much 

 trouble. I was obliged to take up the plank spiles, dig the trenches 

 deeper, put in sheer-bottom broken glass, and redrive the spiling, be- 

 sides building a rat-proof stone wall to support the spiling and prevent 

 them from entering under the dam from below ; after wlUch, when well 

 graveled, I have had no trouble from muskrats or leakage. In fact, 

 my dam, though rough and cheap, is as impervious to either water or 

 the rats as an iron kettle. I will further say on the subject of dams 

 that a large waste weir and fine screen upon it are indispensable to re- 

 taining small as well as large fish in small ponds. 



My pond covers an area of about one and a half acres, and the water 

 at first stood upon the natural ground — grass, sod, stumps, marsh 

 land, and all — as it was after partial clearing and improvement for 

 agricultural purposes; the lower portion consisting of stony, gravelly 

 bottom, and the upper half consisting of muck and clay, which soon 

 produced a great quantity of flags in the water, and a great variety of 

 weeds as well as cranberry vines around the shores. After my third 

 failure in raising fish, viz, first with trout, next with catfish or bull- 

 heads, and finally with suckers, as described below, I made the improve- 

 ment in the dam above referred to. At the same time I removed the 

 soil and muck, stumps, &c, from the lower half of the pond, and deep- 

 ened and cleaned the margins of this part to a depth of about 2 feet 

 along the shores. I then built two stone walls, 2 ieet high, equidistant 

 from the shore and each other, extending from near the dam up stream 

 CO feet, with a depth of (3 feet of water between them ; thence I continued 

 two other walls up stream, about 3 feet apart, in the center of the pond, 

 and covered them with flagstones. This structure is about 18 inches 

 high, with an average depth of 4 feet of water, and extends to where 

 the muck and flags still remain as feeding grounds and shelter. Leav- 

 ing the pond at this point, and running around it, is a canal or conduit, 

 18 inches deep and 3 feet wide, branching at the head of the pond. 

 Each branch originates in a principal spring, always affording fresh 

 running water. These conduits are lined on either side with flagstones, 

 lying horizontally, about 4 to 6 inches from the bottom, as shelter. The 

 banks of these canals are also partially lined already with shrubbery as 

 shelter for the fishes, and are intended to be fully so. 

 Bull. U. S. F. 0. 83 27 



