238 U- S. BUREAU OF FISHERIES 



pond been understocked with forage fish, as shown by the fact that 

 only three minnows were recovered. 



A much higher percentage of survival was obtained in a small 

 pond known as E-2. This pond, with an area of 0.128 acre, was 

 stocked on June 13 with 1,833 bass fry. The pond was drained 

 October 4 and yielded 1,022 fingerling bass, a survival of approxi- 

 mately 55.7 per cent. This high percentage of survival doubtless 

 was due largely to the fact that through a misunderstanding the 

 pond was overstocked with goldfish, so that an abundance of forage 

 fish was available throughout the season. An adjoining pond (E-3), 

 having the same area but understocked with forage fish, produced 

 742 bass fingerlings out of 1,833 fry, a survival of approximately 

 40.7 per cent. 



The results of two seasons' experiments at Fairport indicate that 

 when rearing ponds are properly fertilized and supplied with forage 

 fish they should be stocked wnth 20,000 to 25,000 largemouth-bass 

 fry per acre, 30 to 40 per cent of which, at least, should survive until 

 the ponds are drained in the fall. 



The bass fry were taken from the spawning pond by means of a 

 Hesen fry trap, which is designed to capture them when they rise 

 from the nest and begin to swim around the pond. The efficiency 

 of this trap is shown by the fact that over 70,000 fry were captured 

 in about four hours. It also appears that better results can be 

 obtained by using fewer brood fish than has been the practice in the 

 past. When fingerlings are to be reared in the same pond with the 

 brood fish, not more than 15 to 20 pairs of medium-sized brood fish 

 should be used per acre. If the young are to be removed as fry, a 

 larger number of brood fish may be used. One pond was stocked 

 with bass and bluegill sunfish in the hope that the bluegills would 

 make a satisfactory forage fish for the bass, but the results were 

 disappointing. The pond produced only about 1,900 No. 3 bass 

 fingerlings and 28,000 bluegill fingerlings per acre, which is a rela- 

 tively small yield. 



In 1926, and again in 1927, an attempt was made to propagate the 

 gizzard shad {Dorosoma cepediamwi) in ponds for forage purposes, 

 but without results. In each case the fish failed to spawn, and no 

 further attempts will be made to raise them at Fairport. Owing 

 to its feeding habits, this species would seem to be an ideal forage 

 fish, but the Fairport experiments indicate that it is not adapted to 

 small ponds. Other objections are the fact that it does not have an 

 extended spawning season and that it is not eaten as readily by the 

 bass as are many of the minnows. 



In 1926 a mixture of bone meal and dried sheep manure was ap- 

 ])lied to several of the ponds at the Fairport station at frequent 

 intervals during the spring and early summer in an experiment in 

 the use of fertilizers in ponds, but the results were not conclusive. 

 During the past summer (1927) superphosphate was used instead of 

 bone meal, with very encouraging results. Several applications of a 

 mixture composed of one part superphosphate to three parts dried 

 sheep manure, by weight, Avere made in the early part of the season, 

 and in every case the production in fertilized ponds was much greater 

 than in those not fertilized. The increased production of fertilized 

 ponds is evidenced best by the E series ot ponds, as the results are 



