Holland-Bartels, L. E., and Duval, M. C., 1988, Variations in abundance of
young-of-the-year channel catfish in a navigation pool of the upper Mississippi
River: Transactions of the American Fisheries Society, v. 117, no. 2, p. 202-208.

Abstract:

Spatial and temporal variations in the abundance of young-of-the-year channel
catfish Ictalurus punctatus   were determined over 3 years based on 154 trawls taken
from Navigation Pool 7 of the upper Mississippi River.  No significant spatial
patterns in abundance or length of fish in the catch were found in seven poolwide
surveys  of the main channel. However, high variation among replicates existed.
Temporal patterns in abundance and  length-frequency distributions varied among
the study years. Seasonal catch curves were similar in 1984 and  1986, although
offset due to earlier spawning in 1986. Spawning appeared to have been protracted
in both years,  based on analyses of back-calculated dates of spawn and
length-frequency patterns of young. Sixty to seventy  percent more young were
produced in 1985, when spawning occurred over a shorter period of time and a
more  uniformly sized year class was produced.

Keywords:

population-dynamics, river-fisheries, stock-assessment, abundance,
Ictalurus-punctatus, annual- variations, USA, Mississippi-R.,
Navigation-Pool-Seven, age-groups; juveniles