OTHER RESOURCES OF MICHIGAN 123 



Michigan is estimated to have 16,000 miles of 

 rivers and small streams and it has innumerable 

 inland lakes — the home of many varieties of edible 

 fish, such as pike and pickerel, perch, bullheads, 

 bass and trout, the aggregate output of which se- 

 cured by commercial fishermen and sportsmen, while 

 not statistically ascertained, is undoubtedly very 

 large. The Great Lakes encompassing the State yield 

 the great supply of marketable fish, amounting in 

 1917 to 29,737,335 pounds. In that year 3,183 per- 

 sons were engaged in this occupation in the State, 

 and the total product was valued at $1,668,529.^ 

 Of the Great Lakes in the IMichigan area. Lake Huron 

 contributed the largest fraction of the total supply — 

 13,363,207 pounds. Lake Michigan was second in 

 rank, with some two million pounds less product 

 than Lake Huron ; while Lake Superior, with an 

 output of 2,891,131 pounds, was a very poor third in 

 rank. It seems to be a fact, not generally under- 

 stood, that the growth of fish in Lake Superior is 

 much less rapid than in the lakes of a more southerly 

 latitude. This is attributable to the lower tempera- 

 ture prevailing in this greatest fresh-water sea and 

 to the diminished supply of vegetable matter con- 

 sumed by fish as food. John Lowe of the Northern 

 State Normal School, Marquette, has estimated that 

 during the first year of life, a fish in Lake Superior 

 increases some three ounces in weight, while in 

 Lake Michigan the growth is about thrice as rapid. 



^"Fisliery Industries of the U. S. Bur. Fisheries," 1919, 

 123, 124. 



