Biological Survey — Oswego Watershed 93 



is reason to suspect that, at this time of the year, the disturbance 

 caused by carp might be destructive to the eggs of other species. 



Five days (May 8, 15, 22, 29, and June 5) were spent in study- 

 ing this question. On all but one of the days of this investiga- 

 tion, I was assisted by Mr. Myron Gordon. 



The areas under observation included parts of the old and new 

 channels of the Seneca river (near Montezuma) and the marshes 

 at the north end of Cayuga lake (especially Canoga marsh). 

 Actual spawning grounds included cat-tail marshes, flooded 

 bottom lands, and weed beds. The notes made may be summarized 

 as follows: 



(1) Spawning is influenced, to a great extent, by temperature. 

 Due to this fact, the process commences in the shallow, quickly 

 warmed water as in open cat-tail marshes. As the season advanced, 

 carp were seen spawning in deeper water, among weeds (Poiamo- 

 geton). Carp were rarely observed to spawn where the water 

 temperature was below 60 degrees F. On days of considerable 

 breeding activity (May 8, 29) water temperatures where the fish 

 were splashing were respectively, 68 and 65 degrees F. It was 

 noted that a drop to 58 degrees F. (May 15) was accompanied by 

 a virtual cessation of spawning. 



(2) Carp extended their breeding season over a considerable 

 interval. During the season of 1927 they were observed to spawn 

 from May 8 to June 27. Examinations of the reproductive organs 

 showed that not all of the eggs of a single female ripen at the 

 same time. Furthermore, individual fishes (male as well as 

 female) showed a wide difference in the period at which they 

 become ready to reproduce. Ripe males, females who had 

 spawned, and unripe females were taken on the same date (June 

 22) in the Seneca river. 



(3) Observations did not show interference of the carp with 

 the eggs of other fish. Although the carp were spawning, in 

 moderate numbers, near the nests of large-mouthed black bass 

 and common sunfish in the Canoga marsh (May 22) they did not 

 seek to molest these. The disturbances caused by their splashing, 

 in the instances noted, produced only extremely local, temporary 

 roiling of the water. The eggs of pickerel and pike (Esox) have 

 doubtless hatched before the carp spawn. Yellow perch eggs are 

 also laid earlier than those of the carp, and although perch eggs 

 were taken May 15 near the Canoga marsh, they were found in 

 much deeper water than that in which carp were then spawning. 



It should be stated that the weather conditions during the spring 

 of 1927 were such as to prevent very great concentration of spawn- 

 ing carp at any one time. This may not be the case in other 

 years. 



Fishways. — At Mud Lock, near Cayuga, New York, there is a 

 fishway which was erected for the purpose of allowing fish from 

 the Seneca river to reach Cayuga lake. Since many sportsmen 

 are of the opinion that numerous fish pass out of Cayuga lake 



