Pr.OPAGATIOX AND DISTEIBUTION OF FOOD FISHES, 1925 471 



consisting of a string of from 10 to 25 nets in a line, no part of them being visible 

 above the surface of the water. These are spread out from shore to shore, not only 

 on the river flats but in tributary streams, and as they are in operation practically 

 throughout the year, their destructive effects are only too apparent. For dis- 

 cussion of the collection of shad eggs see page 475. 



RESCUE OPERATIONS 



Homer (Minn.) Station and Substations 

 [C. F. Culler, in charge] 



With the Homer (Minn.) station as a central directing base, fish-rescue opera- 

 tions were conducted during the summer and fall on the Mississippi River bot- 

 toms lying between Prescott, Wis., on the north and Andalusia, 111., on the south. 

 Owing to unusual natural conditions the results of the work were much smaller 

 than the average returns of recent years. Activities extended from early July 

 to the close of November, which period was marked by exceptionally cold, wet 

 weather, the late spring and frequent rains maintaining the ponds and sloughs 

 in a fresh state and preventing any material shrinkage of the water area. While 

 not conducive to large collection^, this situation constituted a favorable environ- 

 ment for young fish, the unusually wide range affording them ample feeding 

 grounds, while large numbers were able to find their way into the main channel 

 of the river. All rescue areas previously occupied were thoroughly worked, but, 

 as in past years, an extensive amount of fruitful territor}^ remained uncovered 

 because of lack of funds, though several new fields might have been established 

 had it been possible to foretell what the weather would be when the season opened. 



On account of their more elevated location and the consequent lowering of the 

 water at a comparatively early period, the fields in the vicinity of the Homer 

 station and at Genoa, Wis., were the most productive, the former alone yielding 

 nearly half the total of the season's returns. Rescue work in cooperation with 

 the Wisconsin fisheries authorities having been contemplated in the vicinity of 

 Lynxville, Wis., two crews were sent by the State to cover that territory in the 

 latter part of July. However, heavy rains interfered with successful work and 

 the field was abandoned early in August. Along the upper river 62,220,565 fish 

 were rescued, this number being less than half the total of the preceding year. 

 All of the rescued fish were released in the Mississippi River and its adjacent 

 tributaries with the exception of approximately 911,000 reserved for delivery to 

 applicants. 



The season's mussel-infection work resulted in the release of 1,783,561,850 

 glochidia of the commercial fresh-water mussels on suitable host fishes, this 

 number exceeding last year's total by approximately 500,000,000. 



La Crosse (Wis.) substation. — A new 2-story hatchery building, 85 feet long 

 and 50J^ feet wide, was recently constructed at this point on land acquired from 

 the city of La Crosse. In addition to the hatching room, which is equipped 

 with a sufficient number of galvanized-iron hatching and retaining troughs to 

 handle approximately 2,500,000 eyed trout eggs, the lower floor of the building 

 contains an aquarium and an office. Part of the space on the upper floor is 

 utilized for a carpenter shop and the remainder is fitted up as sleeping quarters 

 for the station employees. 



During the winter of 1924—25, 763,400 eyed brook-trout eggs were acquired, 

 part of them from Cedar Island Lodge at Brule, Wis., and the remainder from a 

 commercial dealer in that State. The substation also handled 371,000 rainbow- 

 trout eggs transferred from other stations of the bureau, and approximately 

 96,000 eggs of the Loch Leven trout from the Madison Valley (Mont.) field. 

 All of these were successfully incubated and the resulting fry carried to the 

 fingerling stage with an aggregate loss of less than 25 per cent. 



Bellevue {Iowa) substation. — The territory included in this field extends from 

 Dubuque to Green Island in the State of Iowa. Due to high water, the output 

 of rescued fish was greatly reduced as compared with that of the preceding 

 year. 



Atchafalaya (La.) substation. — The season's work at this station began on 

 February 14, when preliminary arrangements for the propagation of buffalo 

 fish were begun. The earliest eggs v/ere obtained on March 7 and the latest on 

 March 24, the total amounting to 140,400,000. Owing to the flooded condition 

 of the Ouachita River and the consequent pollution of the local water supply, 

 the eggs could not be developed in the Atchafalaya hatchery and most of them 



