PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1923. 39 



BATTLE CREEK (CALIF.) .SUBSTATION. 



As at the Baird station, tlie season at this point was marked by 

 scarcity of rainfall, with low-water stages in all the surrounding 

 streams. The fishing racks were installed as usual, but active fishing 

 operations, conducted from October 19 to November 28, resulted 

 unsatisfactorily. Seining on the riffles in the Sacramento Eiver below 

 the mouth of Battle Creek proved equally unremunerative, and when 

 the attempt was finally abandoned there were 1,587,000 eggs in the 

 hatchery. 



As previously mentioned, the season's run of fish was unique, both 

 on account of its small size and because of the nature of the fish 

 comprising it. The few sexually matured females taken were un- 

 usually large, yielding an average of 6,000 eggs per fish. However, 

 the majority of the run was composed of immature males. 



In past years attempts have been made to procure eggs of the 

 spring run chinook salmon at various points on Battle Creek, but 

 the attempts have never met Avith success. The early run appears 

 in the stream in the spring or early summer, but the fish are not 

 in spaAvning condition until late August or early September. The 

 great ditiiculty thus far encountered in this field has been to find 

 a suitable place with a sufficiently Ioav water temperature for holding 

 the fish through the hot summer months pending the maturity of 

 their eggs. 



It has been ascertained that the Avater temperature beloAv the dam 

 of the Coleman PoAver Co. plant, some 4 miles from the Battle 

 Creek hatchery, aA'erages from 5° to 6° loAver throughout the entire 

 summer than at an}- of the other points iuA'estigated. Because of 

 this faA^orable condition it seems probable that successful Avork may 

 be accomplished beloAV the dam, and with the view of determining 

 this point racks were installed late in May for holding a limited 

 number of fish for obserA^ation. 



MILL CREEK (CALIF.) SUBSTATION. 



The total take of chinook-salmon eggs at this point amounted 

 to 791.000, being the smallest secured since fish-cultural Avork Avas 

 first inaugurated there. The rciasons ascribed for the failure of the 

 fish to appear haA^e been mentioned, but they are far from satisfac- 

 tory. The drought conditions extended to this station, but in Au- 

 gust, when the racks were installed, the creek Avas entirely dry, all 

 of the natural floAv having been diA^erted for irrigation purposes. 

 Spawn taking began October 29 and Avas continued to December 27. 

 As at Battle Creek, practically the entire run of fish appearing at 

 the racks in Mill Creek was composed of immature males. 



GREAT LAKES FISHES. 



The territory covered by the Avork in the propagation of the 

 commercial fishes coming under this head extends from Lake Su- 

 perior on the Avest to Lake Champlain on the east, and, Avith the 

 possilile exception of salmon pro])agation. it is the most important 

 branch of the bureau's fish-cultural activities. The commercially 

 A-aluable fishes of the Great Lakes are the lake trout, Avhitefish, 



