560 REPORT OF THE COMMISSIONER OF FISHERIES. 



REACTION OF CARP IN PONDS TO INFLOWING FRESH WATER. 



This reaction, which is very curious and marked, I am uncertain 

 whether to consider a reaction to the current caused by the inflowing 

 water or a response to the volume of fresh water being- added to that 

 which has been standing in the pond. Hessel (18S1, p. 879) says: 



The inflow of water into the pond should never he allowed to he direct; as, for 

 instance, a hrook falling into it. This often causes the water to rise at an inoppor- 

 tune time, carrying into the pond other fishes, especially the rapacious pike. Tlie 

 carp alsohas the disposition to swim toward the inflowing water, by which menus it is drawn 

 away from its proper feeding-places. a 



This matter was first brought to my attention in a practical way by 

 Mr. Thomas Hurrell, who owns a carp pond near Port Clinton, Ohio. 

 This pond covers an area of some 20 acres, or more, of marsh land 

 beside the Portage River. A deep cut was made along the riverside 

 and embankments thrown up on three sides so that it is possible to 

 keep the water level two or three feet above that of the river, the 

 fourth side of the pond being formed by the natural slope of the land. 

 The water is maintained at a nearly constant level by pumping in fresh 

 water, as necessary, from a dredge-cut just outside the embankment 

 which leads from the river. The water is really elevated by means of 

 an endless-chain elevator. This is shown in figure 2, plate in, while 

 figure 1, plate in, shows the chute which empties into the pond. At this 

 place the water in the pond is some 8 to 10 feet deep, and directly 

 from it leads the deep ditch along the riverside, while shallower ditches 

 lead off into other parts of the pond. (See figure, p. G28.) Mr. Hur- 

 rell said that scarcely has he started the elevator when the fish begin 

 to come from all parts of the pond and to congregate in the deep area 

 where the fresh water pours in. His account of their quick response 

 seemed almost incredible, and I expressed a desire to see the thing 

 myself ; at which Mr. Hurrell kindly started the gasoline engine oper- 

 ating the elevator, and at once a good stream of fresh water began to 

 be poured into the pond. I was subsequently fortunate enough to 

 witness the phenomena I am about to describe on several different 

 occasions. The following account is taken with little change from my 

 notes of one time: 



At the time of which I am speaking, a number of carp could be seen 

 swimming about in the vicinity of the pumping house with their backs 

 out of water. Mr. Hurrell attributed this to the fact that he had 

 recently been pumping, and that the fish had not all dispersed as yet. 

 He now started the engine again, and within five minutes the carp began 

 to congregate in numbers in that vicinity, and they could be seen com- 

 ing far down the large ditch, as many of them swam with their dorsal 

 fins above the surface. The water near the inflow was soon full of 

 them — it seemed as if there must be a number of tons of fish right 



a The italics are mine. 



