PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1931 661 



takes the water again at the end of March, all fish on hand at the substation 

 must be Hberated prior to that time. 



The hatchery foundation and floor were temporarily patched and miscellaneous 

 repairs were made to other station buildings. Eight hundred pounds of salmon 

 were salted for fish food. 



FISHES OF THE GREAT LAKES 



As usual, vaiying weather conditions affected greatly the collection 

 of the eggs of lake fishes. Taken in general, very little difference is 

 noticeable between the collections of 1931 and 1930. There was no 

 successful egg take of cisco eggs at Duluth nor of pike perch eggs at 

 Northville, and large increases were evident in the collection of lake 

 trout and whitefish eggs at Charlevoix where the capacity of the 

 hatchery was reached. The Put-in-Bay station realized large gains 

 in collecting pike perch and whitefish eggs, as did the Cape Vincent 

 station with cisco and whitefish spawn. In pond fish work the Cape 

 Vincent station is credited with the laj'gest production of smallmouth 

 black bass of any station in the Northeast. 



DTJLUTH (MINN.) STATION 

 [Ward A. Cook, Superintendent] 



Operating under more favorable weather conditions than were experienced 

 during the spawning season last year, the personnel of the Duluth station collected 

 20,500,000 lake trout eggs. Of these, 740,000 were shipped in the eyed stage to 

 applicants in Maine, New York, Wyoming, Colorado, and Utah. The remainder 

 were incubated and most of the resulting fry and fingerling fish were planted on 

 the spawning grounds of the species in the Michigan waters of Lake Superior. 

 The few otherwise utilized were given to applicants for the stocking of inland 

 waters, among them being the Minnesota Fish and Game Department, which 

 desired the fish for the planting of inland lakes in northern Minnesota. Lake 

 trout egg collections began October 1, approximately two weeks later than the 

 corresponding date last year. The first field occupied was the Portage Lake 

 Ship Canal; but by October 13 the run of spawning trout had reached a point 

 where it was deemed desirable to start fishing at Manitou Island, Huron Island, 

 and Portage Entry, Mich., and by October 21 all available field stations were 

 engaged in the work. 



Through the efforts of commercial fishermen around the Isle Royale (Mich.) 

 field 9,300,000 whitefish eggs were secured and incubated, and the 6,450,000 

 resulting fry were returned ifor liberation in the waters from which the eggs were 

 derived. The high mortality experienced in the development of the eggs is 

 believed to have been due to the adverse conditions under which they were col- 

 lected and shipped. Through an exchange of eggs between the bureau and other 

 parties, 237,000 eyed brook trout eggs were secured. The losses sustained in the 

 hatchery were slight and the 214,000 fingerlings produced from the consignment 

 were distributed by messengers to applicants in Michigan and Minnesota. In 

 the spring cooperative pike perch egg collections were conducted in the vicinity 

 of Bemidji, Minn., by the bureau and the Minnesota Game and Fish Depart- 

 ment. Unfavorable weather retarded the run of fish and curtailed the supply of 

 eggs. As a result of the work the Duluth station secured 8,000,000 eggs. From 

 this stock 7,500,000 fry were developed and distributed to applicants in Minne- 

 sota, Wisconsin, and Michigan. 



NORTHVILLE (MICH.) STATION AND SUBSTATIONS 



[Frank L. Snipes, Superintendent] 



No brood stock of trout is maintained at the Northville station. Eggs of 

 brook trout, rainbow trout, and landlocked salmon were received and hatched 

 during the year, and the resulting fry were reared to the fingerling size before 

 being liberated. A few brook and rainbow trout on hand at the opening of the 

 year were distributed and a number of fingerlings of these species remained on 



