Nature Bulletin No. 241-A   October 22, 1966
Forest Preserve District of Cook County
Seymour Simon, President
Roland F. Eisenbeis, Supt. of Conservation

****:FISH, WEATHER AND PEOPLE

Fishing can be one of the cheapest and most satisfying forms of 
recreation for people of all ages and both sexes. The proudest moment 
for many a boy is when he comes home with a big catfish or a string of 
bluegills caught with a can of worms for bait, and a cane pole or a 
willow cut from a thicket. Fishing can also be an expensive sport when 
the fisherman, laden with gadgets and high-priced tackle, journeys long 
distances to northern waters.

The time of year, the sign of the moon, the barometric pressure, the 
direction and velocity of wind, rainfall, the amount of fishing and other 
conditions are some of the reasons given by credulous fisherman to 
bolster up their alibis. None of them can be proved. We do know that, 
in general, in the streams, ponds and inland lakes of Illinois, the 
principal fish caught in early spring are bullheads and, after them, the 
crappies. In summer the catches are mostly bluegills and largemouth 
black bass. In autumn, often, we again get good strings of crappies. But 
beyond that, as far as we know, in only one body of water has there 
been kept sufficient records over a long term of years, and a scientific 
study of such records, to throw any light upon the theories about why 
and when fish bite or don't bite.

Rinaker Lake, a 14-acre impoundment near Carlinville, Illinois -- about 
midway between Springfield and St. Louis -- has been used for almost 
50 years by a club of local people to furnish some of the best year-
round fishing in the state. From 1932 to 1943, a careful day-to-day 
record was kept of each angler's catch, to serve as a guide for the 
management of the lake. During this 12-year period, a total of over 
15,000 pounds of hook-and-line fish was taken. This amounted to 3-1/4 
pounds per fisherman per trip -- over twice as good as the average 
success in other waters of Illinois. The catch was made up almost 
exclusively of four kinds -- largemouth black bass, white crappies, 
bluegills and black bullheads. Although each of these kinds, in certain 
years, made up a much more important part of the total catch than in 
other years, the total average catch per fisherman' s trip was about the 
same from year to year.

These records and the records of the local weather station were used to 
test some of the beliefs that weather has a lot to do with the best time to 
fish. One of the oldest ideas is that fish bite better during and following 
rains. There was a moderate increase in the average catch on the 244 
days when over a half inch of rain fell but there was little effect during 
the days that followed except that bass bit almost twice as well when 
the water cleared up, two or three weeks later. Whether it was sunshiny 
or cloudy made little difference. Neither did wind direction, possibly 
because the lake was so small that there could be little wave action.

Some fishermen claim that fish bite better on days with a high 
barometric pressure, and others that a rising barometer is best. This was 
tested in detail, using US Weather Bureau records, but there was no 
evidence of any effect. Incidentally, fish rising or sinking through a few 
inches of water undergo greater pressure changes than the most extreme 
changes shown by the barometer during the course of a year. Both 
bluegills and crappies seemed to bite a little better in the light of the 
moon than in the dark of the moon but the average difference was only 
a few percent. Further, confirmed anglers fishing one or more times 
each week had no better luck than persons who fished only a few times 
a year. During the entire twelve years, men averaged 3.25 pounds per 
day, while the women averaged 3.22 pounds.

Of course, the men say they hooked a lot of big ones that got away.