November, 1954 
this 10-year period small bass were re- 
moved in draining censuses and, from the 
summer of 1946 on, by fishermen. 
A relatively small number of fish are re- 
quired to replace those taken by fishermen 
or lost through natural mortality and 
other causes of death. That even this 
relatively small number may not be pro- 
duced, or may not survive the period of 
BENNETT: LarGEMOUTH Bass IN RipGE LAKE Z 
Wn 
— 
census made approximately 21 months 
after the spawn appeared. The captured 
bass were fish, 6 to 12 inches in length, 
that had survived long enough to grow to 
sizes too large for “easy” predation. The 
most favorable calculated survival ratios 
of number of fry to number of bass sub- 
sequently captured were 29 to 1 for 1941 
and 30 to 1 for 1947; the 1943 and 1949 
Table 11.—Estimated number of largemouth bass fry in each of five year-classes or 
broods produced by the original stock in Ridge Lake and by adult bass returned to the lake 
following draining censuses, the number of bass of designated year-class taken by fishermen 
in the next two fishing seasons after spawning, plus those taken in the next draining census 
about 21 months after spawning, and the ratio of spawn to fish subsequently taken. Calculations 
involving acreage were based on a water area of 18 acres except where stated otherwise. 
NuMBER, PER AcRE, OF Bass OF 
DESIGNATED YEAR-CLASS TAKEN R 
+ IN THE 21 Montus SuccEEDING oS 
YeaAr-CLAss ae ett SPAWNING ; SPAWN TO 
or Broop Tea abemeapy aes SUBSEQUENT 
> nS TAKE 
By Fishermen Ue Drees Total 
(C25 Ca eae eee 8,444 28 2662 294 29 to 1 
NGAS S558 es 1,000 _ 25 aS 40 tol 
1945. 6,444 15 18 33 195 to 1 
1947. 2,056 | 17 51 68 30 to 1 
(CO aoe ee eS 2 20 45 65 34 to 1 
1 Calculations for this year based on actual water area (about 9 acres) at spawning time. 
2 Figure includes an estimated 473 bass that escaped the 1943 census. 
3 Calculations for this year based on actual water area (about 11 acres) during summer. 
high vulnerability to predation, is sug- 
gested by the spawn inventories of 1948 
and 1950, table 9, and the almost com- 
plete disappearance of the large number 
of bass fry produced in 1942. Large- 
mouth bass are capable of rapid growth. 
Thus, if small bass are available, the re- 
placement of a large loss among bass of 
desirable sizes may take place in a com- 
paratively short time. 
With estimates of the numbers of bass 
spawned and with age determinations of 
the bass taken by fishermen and in drain- 
ing censuses, it is possible to show the re- 
lationship between the number of fry in 
each brood and the subsequent catch of 
members of the brood as larger fish. In 
table 11 are shown estimates of the num- 
bers of bass fry per acre appearing in the 
years 1941, 1943, 1945, 1947, and 1949; 
for each brood or year-class, the number 
of bass taken by angling in the year of 
the spawn and the year following; and 
also the number taken in the draining 
ratios of 40 to 1 and 34 to 1, respectively, 
were only slightly less favorable. The 
poorest survival occurred in the 1945 
brood, in which the ratio was 195 fry to 
1 bass recovered. All of these survival 
ratios may have represented a higher rate 
of survival than would have occurred had 
the same numbers of schooling fry (as 
estimated in table 11) been subjected to 
predation from more nearly ‘normal”’ 
(unculled) populations of fishes. 
Growth of Bass 
At Ridge Lake the permanent removal, 
or culling out, of small fish by the Nat- 
ural History Survey staff during drain- 
ing operations in alternate years and by 
anglers during most fishing seasons re- 
duced competition for food among sur- 
viving fish in the lake and thereby allowed 
for relatively rapid growth. 
If all bass of less than 8 to 10 inches 
in length could have been permanently 
