42 U. S. BUREAU OF FISHEEIES. 



the work could not be found to cover all fields and at some points 

 local help had to be employed to perform this important duty. 

 Under such circumstances it was impossible to secure a uniformly 

 good grade of eggs, and while the season's collections — amounting to 

 55,640,000 — were considerably in excess of the total of any year in 

 the recent past, their quality was far below the desired standard. 

 The collecting season extended from October 31 to December 22, and 

 the incubation of the eggs was completed at the expiration of 140 

 days in a mean water temperature of 38.5°. 



The salt-solution process was employed almost throughout the 

 season for separating poor eggs from the good ones, thereby effect- 

 ing a large saving in the employment of temporary help. In con- 

 nection with the work it was discovered that good eggs were being- 

 carried out^of the troughs with the discarded ones, and a method 

 was at once devised and put in operation by the assistant in charge 

 of fish culture, which conserA^ed practically all good eggs. 



Collections of whitefish spawn were made at various points in 

 Lake Michigan between November 16 and December 30. the .season's 

 total aggregating 16,660,000. This stock was augmented in Decem- 

 ber by the receipt of the partially incubated eggs from the Alpena 

 hatchery, though most of the transferred eggs were returned to that 

 point just prior to the hatching stage. The incubation of the eggs 

 was completed at the end of 180 days in a mean water temperature 

 of 39°. In order to effect any considerable improvement in white- 

 fish propagation in this region it will be necessary to provide penning 

 facilities at suitably located points for the holding of the partially 

 ripened fish until their eggs are fully matured. Some investigations 

 are now being made with the view of establishing several of such 

 stations as soon as funds are available for the purpose. 



Early in .April 15,827 eyed eggs of the landlocked salmon were 

 received from the bureau's Craig Brook (Me.) station. They were 

 hatched with not more than normal losses and carried in good con- 

 dition until about the time when the sac was absorbed, at which pe- 

 riod the water supply became polluted from the exhaust of the city 

 water- works engine and one-third of the stock was lost. The re- 

 mainder was delivered to an applicant for that species. 



ALPKNA (MICH.) SUBSTATION. 



While whitefish and lake-trout eggs are collected annually in the 

 Alpena field, for several years past no attempt was made to incubate 

 them in the Alpena hatchery, as the city water supply, upon which 

 the substation is dependent^, was so heavily charged with chlorine 

 as to be very injurious to eggs or fry held in it. Having received 

 information" that the conditions in tliis respect had improved some- 

 what, the hatchery was stocked by the bureau during the fall of 

 1922 with whitefish and lake-trout eggs secured in the immediate 

 region. It quickly developed, however, thaf the water supply was 

 still detrimental, and all stock on hand had to be transferred, being 

 divided between the hatcheries at Charlevoix and Northville. Act- 

 ing on advice from the city authorities that the contemplated opera- 

 tion of a filtration plant in course of construction would obviate the 

 necessity of chlorinating the water after March 1, 1923, the eggs 

 sent to other points earlier in the season were returned to Alpena; 



