Biological Survey — Erie-Niagara Watershed 215 



This report conii)ares closely with that of last year based on carp 

 living' in Oneida lake and it adds confirmation to the statement 

 that carp feed primarily on the lower forms of animal life. At 

 the same time it must not be overlooked that carp show selective 

 preference for some plant materials such as corn or potatoes, both 

 of which were used successfully as bait. 



The intestinal contents of eight 3'oung carp taken in the Oswego 

 canal consisted principally of insect larvae, midge larvae, wath 

 smaller amounts of Ostracods, Copepods, Cladocera and vegetable 

 debris. 



In spite of the vast body of water comprising the canal system, 

 there are very few feeding grounds comparable with those to be 

 found in Oneida lake. Such a situation accounts for the important 

 movement of canal carp during the night as they patrol the shore 

 in search of food. Under the glare of the boat's spot light, carp 

 singly and in small groups w^re seen to work along the narrow 

 fringe of shallow water bordering the channel, methodically rout- 

 ing the mud bottom or sucking about the foliage of scattered 

 aquatic plants. That this is a nocturnal movement is shown by our 

 trap net records which show that not a single carp w^as caught dur- 

 ing the day between 7 a.m. and 5 p.m. 



Associated Fish Fauna. — The number of fish, exclusive of 

 carp, taken in five hauls made between Oneida lake and Lock 20 

 consisted of 2 small-mouthed bass and 1 bullhead. From twenty 

 hauls made at fourteen different carp habitats along the Seneca 

 and Oswego divisions of the canal the following were caught : 

 23 pike-perch, 44 calico bass, 28 large-mouthed bass, 9 small- 

 mouthed bass, 3 rock bass, 43 common suckers, 96 red-fin suckers, 

 14 pickerel, 242 bullheads, 6 catfish, 27 sunfish, 1 eel, 3 garpike 

 and 18 lawyers (Amia calva). Lamprey scars w^re detected on 

 carp taken at New London, at the mouth of Fish creek, in Oneida 

 lake and in the canal near the Cayuga division. 



The relatively large number of game fish taken on grounds 

 frequented by carp, their fat condition and the fact that these 

 game fish ignore the bait of fishermen, indicate that there is an 

 abundance of food. As long as the available natural food exceeds 

 the demand fishermen wall have difficulty in attracting game fish 

 to the baited hook, irrespective of carp or other supposedly 

 detrimental fish. 



The degree and manner in which carp are detrimental to game 

 fish are poorly understood. It is popularly believed that carp eat 

 the young of game fish, but such an idea is not supported by our 

 studies. Its sucker mouth is not adapted to predacious habits and 

 the food material found in the digestive tract includes no fish 

 remains. A second accusation against the carp is that it destroys 

 the spawn of game fish. No evidence was obtained to support this 

 belief. The most important charge against the carp is the usurping 

 of shallow waters frequented by game fish. Omitting the question 

 of food, this large fish with aggressive movements keeps the smaller 

 more timid game fish and minnows from enjoying the unmolested 



