672 BULLETIN OF THE BUREAU OF FISHERIES. 
correlated with a very large and intensive plant. The catch of the third period 
exceeds that of the second more than fivefold. The number of whitefish 
appears, however, not to have increased in the period immediately followirg 
the greatest activity in planting, for while the plant of the first period was very 
great the catch of the succeeding period showed a decrease to little more than 
one-half that of the preceding period. This is possibly to be explained by the 
fact that in the nineties this area was considered to be nearly depleted of white- 
fish, and fishing for them was prosecuted with much less vigor than before. 
The number of fathoms of nets in use fell off, and it is probable that the nets set 
for whitefish fell off still more. It seems, therefore, probable that the whitefish 
may have begun to increase during the second period, but that this fact was not 
known to the fishermen until well into the third period. In other words, it is 
probable that the catch did not increase until some years after the whitefish 
themselves had increased. A glance at table 4 shows that this increase in the 
catch became noticeable in 1903. 
TABLE 15.—SHOWING THE AVERAGE CATCHES AND PLANTS OF WHITEFISH IN MICHIGAN WATERS OF 
LAKE MICHIGAN (THE NORTH SHORE AND THE SOUTHEAST SHORE) FOR THE THREE FIVE-YEAR 
PERIODS 1892 TO 1906, INCLUSIVE. 
North shore, whitzfish area 800 square miles. @ 
Catch. Plant. Nets. 
Years. 
Total Pounds per Pounds per) atore Fry per Fry per Total Fathoms 
square net- otal fry. square pound per square 
pounds. mile. fathom. mile. caught. fathoms. mile. 
| 
| | 
1892-1896 - - 791,000 988 1.99 | 7,177,000 | 8,971 9 387, 100 459 
1897-1901 -- 942,000 5 Ne ag 1. 83 5,908, 000 7,385 6 519,600 649 
1902-1906-__ I, 183,000 1,477 I.39 | 5,800,000 | 7,250 5 841,800 1,052 
| 
Southeast Michigan shore, whitefish area 300 square miles.b 
1892-1896_------- 52,000 170 Gy Bny 6,600,000 22,000 125 456,300 1, S25 
1897-1901 ------- 29,000 96 .o81 2,000,000 6,666 68 374,700 I, 249 
1902-1906. ___--- 132,000 440 ~165 ieee sane link heal eae CaaS 721,000 2,403 
@ North Gee from the Wisconsin border to the Strait of Mackinaw (excluding the Strait of Mackinaw). 
> Southeast shore, from Little Point Au Sable south to the Indiana border. 
(3) The Manistee-Frankfort area is an apparently isolated area of 90 square 
miles lying off the cities of those names. The data for this area are shown in 
table 16 (for annual data see table 5). Here we have a plant of fry which for 
the area is enormous, nearly 90,000 per square mile in the first period and nearly 
60,000 per square mile during the second period. There was no plant during 
the third period. The catch has risen during the fifteen years from 128,000 
pounds per square mile in the first period to 152,000 in the second and 211,000 
in the third. Here again we have a correlation of heavy planting with increased 
yield of fish. 
