FISHERIES OF THE GREAT LAKES. 385 



tlie northern part of the lake, and in some places constitutes fully half 

 the trout catch. 



About two-thirds of the trout taken in the Great Lakes are obtained 

 in Lake Michigan, the value of whose trout fishery is one-sixth that of 

 all of the other fisheries of the Great Lakes. Considering the large 

 annual production, the supply of this fish is remarkably well sustained, 

 and the catch is now larger than ever before, being fully three times 

 greater than in 18S0 and about one-third more than in 1885. 



At least five species of whitefish are of economic importance in the 

 fisheries of this lake, and there are doubtless several others of rarer 

 occurrence which in some places constitute an element of the catch, but 

 are perhaps not usually distinguished by the fishermen from closely 

 related species. Those which are generally recognized by the fisher- 

 men are the common whitefish, the lake herring, the blackfin or bluefin 

 whitefish, the long-jaw whitefish, and the Menominee whitefish. 



The common whitefish is more abundant in this lake than in any 

 other member of the chain, the catch being over a million pounds 

 larger than in Lake Superior, the lake having the next largest output. 

 The fish occurs throughout the lake, but is comparatively uncommon 

 in the southern part, and is secured in largest quantities in that part 

 of the lake north of Manistee County, Mich. The principal part of 

 the catch is taken with 2)ound nets. 



The lake herring ranks next to the trout and common whitefish in 

 importance, and is here taken in much larger quantities than in a,ll 

 the other lakes, except Erie, combined. The regions of maximum 

 abundance in Lake Michigan correspond closely with those of the regu- 

 lar whitefish. In some counties it is the principal fish taken, among 

 them being Menominee and Ottawa counties in Michigan, and Oconto 

 and Racine counties in Wisconsin. 



A species whose capture constitutes a fishery peculiar to this lake is 

 the blackfin or bluefin whitefish {Coregonus niijripinnis), which occurs 

 in great abundance in the deepest water. The fish often reaches the 

 weight of 4 or 5 pounds, but the average is under 3 pounds. About 

 November 1, the fish are reported to make their appearance in the 

 accessible localities, gradually increasing in abundance till December, 

 during which month the maximum point is attained. The fishermen 

 have found that in December and January theblackfins resort to stony 

 bottoms for the purpose of spawning, but at other seasons they seem 

 to prefer clay bottoms. This fish has up to this time been detected in 

 none of the other Great Lakes. 



Associated with the blackfin is a species similar in shape and size, bnt 

 without the black marking on the fins, generally known among the fish- 

 ermen as the longjaw. It resembles the blackfin in habits and edible 

 qualities, but is by some regarded as inferior to the latter in food value. 



In the accompanying statistics, the blackfin and the longjaw white- 

 fishes have been included with the common whitefish. This is in har- 

 mony with the practice followed in previous investigations, including 

 F C 92 25 



