]108 , U. S. BUREAU OF FISHERIES 



had been reared in the station ponds. One lot of 2-year-old bass 

 oontainintr 10 females and 5 males produced an average of over 

 1,200 frv to each female. 



Experiment ivith smaUin(/uth black bass. — As in 1928. one pond 

 was stocked with 19 smallmouth bass and with adult shiners for 

 fora^re. The fry were allowed to remain in the pond with the brood 

 fish throuijhout'the summer. When drained on October 1 the pond 

 yielded 6.010 3-inch finaerlings, which was at the rate of approxi- 

 mately 7.000 to the acre. The success attained with smallmouth bass 

 during two successive seasons has been somewhat surprising inas- 

 much as conditions in the ponds are quite different from those 

 usually considered essential for smallmouth bass. 



Propagation of bluegill sun-fish and crappie. — Two small ponds 

 devoted to the propagation of bluegill sunfish gave a surprisingly 

 large production so far as numbers are concerned. The production 

 in one pond was at the rate of 136,280 tingerlings per acre. In the 

 second pond the yield was at the rate of 298.280 hngerlings to the 

 acre, but the fish were considerably smaller than in the first pond. 



The results with crappie during the season of 1929 were very un- 

 satisfactory, probably largely due to the poor condition of the 

 brood stock. 



Fertilizing ponds. — During the past three years the ponds, with 

 few exceptions, have been fertilized with a mixture of superphos- 

 phate and dry sheep manure. This fertilizer has given uniformly 

 good results, but during the past year comparative tests with this 

 mixture and sovbean meal indicate the superiority of the latter as a 

 fertilizer for fish ponds. Final judgment should be reserved, how- 

 ever, until further tests are made. 



INVESTIGATIONS IN THE UPPER MISSISSIPPI WILD LIFE AND 



FISH REFUGE 



The investigations in the Upper Mississippi Wild Life and Fish 

 Refuge, supervised bv Dr. H. S. Davis, were continued under the 

 immediate direction of Eugene W. Surber. A number of sloughs 

 in the vicinity of Trempealeau, Wis., were selected for intensive 

 work and most of the activities of the past season centered around 

 these sloughs. They are connected with the river only during periods 

 of extrenie high water and appear to afford suitable conditions 

 for the propagation of bass and other game fishes. 



Preparation of sloughs for bass culttire.— The sloughs selected for 

 experimental work were cleared of brush and coarse vegetation 

 early in the season after which they were seined so as to remove 

 predacious fish, such as pickerel and gar-pike, which might inter- 

 fere with the propagation of more desirable species. Unfortunately, 

 l)lans to i)ropagate black bass in the sloughs were not realized owing 

 to the imi)ossibilitv of obtaining a stock of brood fish. Nevertheless, 

 Avork on cleaning up the sloughs was continued and several are now 

 ready for stocking early in the spring of 1930. A supply of adult 

 largemouth bass has been ol)tained for brood stock, and these fish are 

 being wintered in a spring- fed ]iond at Trempealeau. 



Limnological observations.— KMhow^h it was found impossible to 

 rear fish in any numbers during the summer of 1929, extended lim- 

 nokxrical observations were made at regular intervals. These obser- 



