November, 1954 
most other centrarchids with which it may 
be associated in a pond, and the young 
bass may be just enough larger than the 
fry of the other pond fishes to feed heavily 
upon them. Further, as the quantity of 
young bass produced is inversely related 
to the amount of interference with the 
nesting bass and to actual predation on 
the eggs and fry, all that is necessary to 
increase the numerical size of the bass 
population is to reduce the numbers of 
fish of the other species inhabiting the 
water with the bass. The resulting in- 
crease in the production and survival of 
young bass may vary from a few indi- 
viduals to a brood or year-class so large 
that it dominates the fish population of 
the pond. When the individuals of a 
dominant brood of bass grow to a weight 
of 0.5 or 0.75 pound each, they may 
furnish excellent fishing. 
There is some possibility that a fish- 
thinning operation may allow, under some 
situations, the survival of too large a 
population of young bass, so that not only 
is a dominant brood produced, but the 
individuals may be so numerous that their 
food requirements exceed their food supply 
and they become stunted. Such a popu- 
lation of bass was produced in Ridge Lake 
in 1941. The 1941 year-class, which be- 
came stunted in 1942 at an average total 
length of 7.6 inches, could have been re- 
duced to a numerical level that had food 
needs approximately commensurate with 
its food supply had fishermen in 1942 
been freed from the state’s legal restric- 
tions of a 10-inch minimum length and 
a creel limit of 10 bass. Overabundant 
year-classes of bass did not develop in 
Ridge Lake after 1941 because enough 
bass of larger sizes were present in the 
lake to thin out the larger broods before 
the individuals reached  postfingerling 
sizes. An overpopulation almost certainly 
would have resulted from the very large 
brood of bass that appeared in 1945 had 
not predation on this brood been high 
when it was in the fingerling stage. 
In the 1945 and 1947 draining censuses 
at Ridge Lake, all bass below 10 inches 
in length were culled out and all larger 
bass were returned to the water. In the 
1949 census, the minimum length of bass 
returned to the water was reduced to 9 
inches and in the 1951 census to 8 inches. 
BENNETT: LARGEMOUTH Bass IN RipGE LAKE 271 
There was no evidence that the reduction 
in minimum lengths of bass returned to 
the water after the 1949 and 1951 censuses 
had a significant effect upon the survival 
of bass spawn. 
In studying the population dynamics of 
bass and bluegills at Ridge Lake, it is 
obvious that this combination of fishes in 
this impoundment would not produce a 
continuous high yield of bass over a period 
of years without considerable population 
adjustment at regular intervals. Bluegill 
spawning and survival in any 2-year period 
between draining censuses was excessively 
high; the bass showed no great ability to 
control the number of small bluegills. Ap- 
parent failure of the bass to keep the 
bluegill population at a low level probably 
was related to the presence of a large 
crayfish population in the lake; the bass 
seemed to prefer crayfish to bluegills as 
food. Murphy (1949:162) found that 
bluegill fry were not an important item 
in the diet of the young bass of Clear 
Lake, Lake County, California, although 
small bluegills were relatively abundant 
in the lake at the time his study was made. 
The preference of bass for foods other 
than bluegills may be rather general and 
may have a great deal to do with the 
variable results that have been obtained 
trom the bass-bluegill combination in some 
Illinois lakes. 
The catch records at Ridge Lake show 
that bass rapidly lose their vulnerability to 
angling, so that, within a few days of 
the beginning of intensive fishing, the 
catch rate becomes discouraging to a large 
percentage of the fishermen, and most of 
the fish caught are taken by anglers who 
might rate as experts. There is no question 
that skill is important in catching bass. 
Records prove that certain fishermen are 
much more proficient than others. Superior 
ability to catch bass appears to be asso- 
ciated with the methods of “working” the 
lures. 
The wariness of the largemouth bass is 
both encouraging and discouraging: en- 
couraging to the aquatic biologist in that 
he can be certain that this bass will survive 
in numbers in spite of very heavy angling 
pressure (Bennett 1945:385); discour- 
aging to the angler in that, unless he is an 
expert, his chances of making a good catch 
of bass in a public lake are rather poor. 
