FISHING INDUSTKY OF THE GREAT LAKES 555 



They have a combined area of over 95,000 square miles, and all of 

 them, excepting Lake Erie, have depths of 600 feet or more. A 

 depth of over 1,000 feet is known to exist in Lake Superior. From a 

 limnological point of view the lakes are very primitive; that is, they 

 have little except algal vegetation, although, of course, larger plants 

 grow in the bays and river mouths, in which semipond conditions 

 obtain. The lakes are very cold, also, and in most of them the 

 bottom waters beyond a depth of 350 feet are never warmer than 4° C. 

 (39.2° F.).^ The wind stirs up the water sufficiently so that oxygen 

 is distributed throughout, and some sort of life occurs even at the 

 maximum depths. 



The conditions present in the lakes are favorable to the develop- 

 ment of fish life, and before their commercial exploitation fish were 

 extremely abundant in them. Records of the abundance of fish are 

 found in the relations of the Jesuit Fathers as early as the beginning 

 of the seventeenth century, and these accounts do not fail to mention 

 the excellent quality of these fish. Even within the memory of the 

 present generation the fish supply exceeded any limits now known 

 to us. For the last 50 years the annual production has averaged over 

 100,000,000 pounds, and the output in 1922 totaled over 140,000,000 

 pounds, valued at more than $9,000,000. The capital invested in 

 fishing runs into millions of dollars, and over 12,000 persons are 

 directly engaged in the industry. 



FISHING INDUSTRY 



HISTORICAL 



The original fisheries were prosecuted by means of seines, which 

 were drawn along the shores during the spring and fall when the fish 

 came into shallow water. At first enough fish were taken by this 

 method to supply the limited demands, but as the fish became 

 fewer (as a result of intensive and wasteful methods) and the demand 

 increased, pound nets and gill nets were employed. All netting was 

 originally made by hand, and there are fishermen still plying their 

 trade who once spent their winter evenings weaving the webbing for 

 their summer's use. The first pound nets were not radically dif- 

 ferent from those now in use, but the gill nets were much more crude. 

 Instead of lead weights, stones, fastened by strings, sunk the nets and 

 hand-whittled cedar splinters 6 to 10 inches long, split at one end 

 and pinched onto the float line after the manner of a clothespin, 

 served as floats. Both weights and floats were removed every time 

 the nets were brought ashore, a procedure so laborious that only a 

 few thousand feet of netting comd be used. This equipment was 

 carried by rowboats or sailboats to its place in the lake, which was 

 always within sight of shore. 



BOATS 



The fishing industry has long outgrown such methods. Rowboats 

 are no longer used except in conjunction with mechanically propelled 

 craft, and sailboats have been abandoned since the early part of the 

 present century. They were last in general use on the Canadian 



» Lake Superior lies 2 to 3 degrees of latitude farther north, aod the temperature readings, so far known, 

 indicate that this temperature probably is seldom exceeded below 200 feet. 



