PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1922. 57 



445,000 eggs of this species, and later on approximately 369,000 fry- 

 resulting therefrom were returned to the river. It is probable that 

 a considerably greater number of eggs might have been secured 

 had the conditions in the Pembroke River been more favorable. 

 During the entire spawning season the water stages in this stream 

 were too low to permit of the ascent of fish. The continuance of 

 this run of humpbacked salmon, transplanted from the Pacific coast 

 in Maine rivers, is an interesting fact. It occurs only in alternate 

 years, and an effort to establish an annual run would perhaps be a 

 wise undertaking. 



RESCUE OF STRANDED FOOD FISHES. 



[C. P. CuLLEK, in Charge.] 



During the fiscal year 1922 the total results of the bureau's rescue 

 operations amounted to 179,475,069 fish, all of them being of direct 

 importance to the regions in which the work was done. In the pros- 

 ecution of such work 13 crews operated on the upper Mississippi 

 River, in territory contiguous to the Homer (Minn.) station. La 

 Crosse, Wis., and Bellevue and Marquette, Iowa. One crew was 

 engaged on the Illinois River in the vicinity of Meredosia, 111., and 

 a considerable amount of rescue work on the Mississippi River was 

 directed from the Fairport Biological Laboratory, in connection 

 with the propagation of the fresh-water mussel. The operations 

 also included a comparatively small amount of rescue work in fields 

 around the San Marcos (Tex.) station. The tabular statement on 

 page 10, showing the results of the bureau's activities along this 

 line, indicates clearly the species and the number of fish salvaged 

 at each point and their final disposition. The work was done at an 

 average cost of approximately 14 cents per thousand fish rescued. 



Rescue work for the season was first undertaken on July 5, in the 

 vicinity of Homer, Minn., and was prosecuted as actively as possible 

 at all the points mentioned until the exhaustion of the available funds 

 on October 29 compelled its early closing, notwithstanding the fact 

 that a number of landlocked pools in the vicinity of Marquette, 

 Iowa, remained untouched. The work was rendered unusually diffi- 

 cult in some respects because of the unusually low stage of the 

 river and the hot, dry summer. Because of excessively high tempera- 

 tures at certain points large numbers of fish were found dead in 

 pools of an average depth of 10 inches. Even such species as carp 

 and catfish, which are particularly resistant to these conditions, 

 suffered heavy mortality. The high air and water temperatures 

 also made difficult the transfer of rescued fish to the river or the 

 holding stations, and the utmost care was required to accomplish 

 such tranfers successfully. In one respect the low water stages were 

 of direct advantage to the work. As the overflow was restricted to 

 a considerable extent by the river not reaching its usual high mark 

 during the spring rise, the ponds left by the receding waters were 

 all more conveniently located with reference to the river than is 

 the case in seasons of a wider overflow. On the Mississippi one crew 

 with houseboat operated from Prescott, Wis., to the head of Lake 

 Pepin, thence to Brownsville, Minn., and Genoa, Wis. ; one crew with 

 houseboat covered the territory from Wabasha, to Fountain City, and 



