1156 U. S. BUEEAU OP FISHERIES 



DULUTH (MINN.) STATION 



[Ward A. Cook, Superintendent] 



Collecting stations in the Lake Superior field were opened shortly after 

 the middle of September for the reception of eggs from an unusually early 

 run of lake trout and approximately 500,000 wore taken before the beginning 

 of the closed season in Michigan waters. From that time on collections were 

 continued under satisfactory conditions until .shortly after the middle of 

 October. Beginning October 20 and lasting nearly a week the lake was swept 

 by gales of such intensity as to result in an immense amount of damagt; 

 to commercial fishing equipment ; and, after the winds subsided, it was found 

 that all the lake trout which had congregated on the reefs had left that portion 

 of the lake, thus ]iutting an end to the collecting season. From the 9,357,000 eggs 

 taken, 0,003,500 fry were developed and ]ilanted in the Michigan waters of 

 the lake. In addition to 2,060,000 whitetish eggs of poor quality obtained 

 in the vicinity of the Isle Royale fisheries, 3,400,000 green whitefish eggs were 

 turned over to the station by the Michigan Department of Conservation. The 

 two lots yielded approximately 2,800,000 fry, most of which were planted in 

 Isle Royale waters. Cisco eggs to the number of 18,150,000 were received 

 during November in the Bayfield (Wis.) field. A large percentage were in- 

 ferior, and only 6.200,000 fry were hatched. Practically all of them were 

 planted in the vicinity of Bayfield. Early in the winter the station received 

 by exchange 200.000 eyed brook-trout eggs. From this stock 184,000 No. 1 

 fingerling fish were produced and distributed to applicants. Egg collections 

 of jiike iierrh were made in Minnesota waters in cooperation with the fisheries 

 department of tbat State. The results were 10,000,000 eyed eggs from which 

 9.715,<HJ0 fry were hatched and distributed. 



NORTHVILLE (MICH.) STATION AND SUBSTATIONS 

 [\\. W. Tii.wER and Frank L. Sxii'ES, Superintendents] 



Fish-cultural operations in the Michigan field were on the whole very satis- 

 factory. The aggregate output of the main station and its substations exceeded 

 that of any previous year by 73,537,825. The increase consisted in the main 

 of the larger numbers of whitefish and lake trout produced at the substations. 



Xorthville (Mich.) station. — The output for the year in this field aggregated 

 1,300.800 fish, with approximately 193,000 rainbow trout and black bass on 

 hand at the close of the year. Two hundred and fort.v-six thousand brook 

 trout on hand July 1, 1929, were reared to the large fingerling size and dis- 

 tributed in the fall. In the early winter there were received from outside 

 sources 1.282,000 e.ved brook-trout eggs. Losses during the incubation and 

 fry periods totaled 521,999, leaving for distribution during the spring 746,100 

 No. 1 fingerlings. These were used for supplying applicants in the sunounding 

 region and for stocking three cooperative nurseries in Michigan. One hundred 

 and eighty thousand rainbow-trout fry, on hand when the year opened, were 

 distributed shortly afterwards. Eggs of this species numbering 302,000 were 

 received during the year. Seventy-five thousand were reshipped to oth(>r sta- 

 tions; the remainder were incubated, producing 227,000 fry of which 51,600 

 were utilized in filling applications, leaving 143,500 advanced fry on hand at 

 the end of June, 1930. The stock at that time also includv-d 4,500 No. 1 fin- 

 gerling land-locked salmon. These were the result of 10,000 eggs shipped in 

 from the Craig Brook (Me.) station. 



The .spawning of 65 smallmouth black bass in one of the station ponds, 

 furnished for distribution 36.000 advanced fry and 59.700 No. 1 fingerlings; 

 and when the vear closed there were approximately 35,000 young bass in the 

 pond. One hundred and fifteen adult smallmouth bass received from the Lake 

 Erie field were divided between two ponds, one being 0.52 of an acr(> in area 

 and the other 0.63. Soon afterwards a number of dead bass were noted in tlie.sc 

 ponds. Verv few nests were observed and neither of the ponds yielded any 

 young fish for distribution. The most important item in the line of im))rove- 

 ments during the year was the construction of a modern S-room cottage for 

 the use of the station fish-culturist. 



Charlevoix (Mich.) suhst(ition.—A total of 40,218,000 lake trout eggs were 

 handled at this hatchery, with an approximate increase of 30 per cent in 



