Buck. — Controlling the Movements of Fish 143 



DISCUSSION 



Prof. L. L. Dyche, Pratt, Kan. : Mr. Buck referred to the manner 

 is which we control water through certain pipes at the Kansas state 

 fish hatcher}-. The method in the old hatchery is not satisfactory, and 

 the new hatchery which we are planning will be under a different 

 method altogether. The water will be allowed to flow from one pond 

 to another through pipes and cement gateways which latter will be 

 two feet nine inches wide; these gateways will have at either end 

 places for putting in flash-boards, and other places for putting in wire 

 screens. The screens will be made of three-inch mesh, half-inch mesh 

 or quarter-inch mesh, and very fine screen mesh, as fine as is necessary, 

 to control the fish or keep them from passing through the screens. This 

 will admit of free passage of the water through these passage-ways 

 from one pond to another, and it will be under control. 



In this new hatchery we plan to have all the ponds connected, as 

 indicated above. We like large ponds, but not too large. We like a 

 pond that can be drained easily, and these ponds will be so arranged 

 that each one can be drained independently without any interference 

 with any other pond. Many of them are arranged in pairs, so that 

 when we put breeders in a pond, it will be possible for the younger 

 fish to pass through the gates into the next pond. We plan to have 

 V-shaped screens that will allow the young fish to pass •hrough be- 

 tween the fine wire screens, through a narrow slit , then they can swim 

 about and feed in pond number two and not be able to get back where 

 the old ones are. Experiments have shown that the young fish will 

 hunt a very small outlet. At the Kansas hatchery we discovered that 

 many young fish had passed from a breeding pond to a retaining pond 

 where we did not want them. On examination we found a pipe cov- 

 ered with wire screen. The meshes of the screen were a little coarse, 

 and were large enough to allow the small fish to run through, and thou- 

 sands of them came through there, though the pipe through which they 

 passed was only three inches in diameter. 



The above experience suggested a number of things to us in regard 

 to the moving of fish from a breeding pond into a pond where they 

 could be cared for and handled by themselves without disturbing the 

 old fish and without disturbing the young fish, and it undoubtedly had 

 something to do with the ideas that guided us in the planning of a new 

 hatchery. It furnished an idea of how fish might be handled through 

 the entire system of ponds in the new hatchery, which will embrace 

 more than a hundred in number when completed, and will be so ar- 

 ranged that fish can be moved from one pond to another without 

 handling them. One acre has been adopted as the standard size for 

 ponds, but as a matter of fact the size will vary from one-half to 

 one and a half acres in area. In the system we are trying to develop, 

 any one of these ponds can be drained independently of any other 

 pond, and can be drained, if necessary, in 24 to 36 hours, and can be 

 filled in 24 hours. Any pond can be shut off and the water can be made 



