Fishery bulletin of the Fish and Wildlife Service - NOAA

WHITEFISH FISHERY OF LAKES HURON AND MICHIGAN 391
that unusual conditions in the lake which. permitted an abnormally 'high survival of
young in one or more years may restore the stock at a much higher rate than the present
depleted condition of the population would give reason to expect.
Not only did the Michigan production of Lake Huron continue its decline after
1939, but the Canadian yield showed a similar trend (table 57), although not to the
same disastrous degree. In Lake Huron proper (see p. 304 for its boundaries) the
Canadian catch fell to 92,000 pounds in 1940 and increased only 1,000 pounds in 1941.
These records are the lowest two for these waters since 1922 and comprise 42 percent
of the average catch (219,513 pounds) for the period, 1923-1939. In Georgian Bay (includes
the North Channel—see p. 304) the take decreased progressively from 1,275,-
000 pounds in 1939 to 833,000 pounds in 1941, the lowest production recorded for this
area at least since 1922. This figure represents 58 percent of the average yield (1,427,564
pounds) for the years, 1923-1939. In the Michigan waters the 1941 catch equaled only
6 percent of the average production (2,052,331 pounds) during the period, 1922-1937,
a value considerably less than the comparable'Canadian percentages of 42 and 58.
The 1939-1941 records of total catch for all waters (United States and Canadian)
represent the lowest three ever recorded for the lake.
Year
1939
1940 ... .
1941
1942
TABLE 57.—Production of whitefish in pounds in Lakes Michigan and Huron, 1939-1948
Winconsm
110.700
186,600
400,538
279,363
Lake Michigan
Michigan
839,856
754,115
896,474
1,061,056
Entire lake
950,556
854,815
1,286,354
1,340,419
Michigan
255,183
188,114
113,727
95,094
HuTon proper
115,061
92,403
93,058
Lake Huron
Ontario
WHITEFISH FISHERY OF LAKE MICHIGAN, 1940-1942
Georgian Bay
1,275,255
1,006,082
833,111
Entire lake
1,645,499
1,286,599
1,039,896
The production of whitefish in the State of Michigan waters of Lake Michigan,
which had declined irregularly from the modern peak of 4,813,000 pounds in 1930, reached
an all-time recorded low of 754,000 pounds in 1940 (table 58—for further data on
production see also table 1 of part I, tables 13, 14, 15, and 16 of part II, and
appendix B). Although this yield amounted to only 32 percent of the 1929-1939 average,
it was relatively much higher than the 1940 catch in Lake Huron (9 percent of
the 1929-1939 mean—table 52). The take of whitefish in Lake Michigan improved substantially
in 1941 (896,000 pounds; 38 percent) and 1942 (1,061,000 pounds; 46 percent).
The 1940-1942 trend of production was consistently upward in northern and
northeastern Lake Michigan (M-2, M-3, and M-4) and in the Grand Haven-Muskegon
district (M-7), but was consistently downward in Green Bay (M-l) or irregular in the
remaining districts (M-5, M-6, and M-8).
In all three years M-3 contributed considerably more than half of the total production
(63.8, 58.4, and 67.5 percent in 1940, 1941, and 1942, respectively). The Green
Bay district (M-l) ranked second each year but contributed a constantly decreasing
percentage of the total (16.3, 12.9, and 8.7 percent). Third position was held by M-5
in 1940 and 1941 (11.5 and 10.0 percent) and by M-4 in 1942 (6.7 percent). The percentage
of the total yield produced in the districts that ranked lower than third ranged
from 7.5 percent in М-á in 1941 to 0.1 percent in M-7 in 1940. It may be noted .that
the percentages of total production in the various districts in 1940-1942 resembled the
corresponding figures for 1891-1908 much more closely than they did those for 1929-
1939. The abundance percentages, records of catch per unit of effort, and figures on
fishing intensity (tables 59, 60, 61, and 62—see tables 17, 19, 20, and 21 of the main
body of this paper) show that but for a low level of fishing intensity, production would
have been much higher in 1940-1942, particularly in the last two years of the period.
The abundance of whitefish which had dropped to an extremely low level in 1940 (23