2011 Bass Angler Information Team - Alabama Department of ...

Standardized Electrofishing Results
Abundance
Another important population variable is the abundance of catchable
sized fish in the population. Actual abundance is determined by a wide
range of things, which may include survival during critical phases of life,
habitat suitability, water quality, fertility, water productivity, competition with
other fish, predation, or disease. However, it is also important to
remember that a biologist’s assessment of overall abundance is
determined from electrofishing samples that are a snapshot in time and
may be influenced by temporary environmental conditions during the
sample period. Muddy water can prevent a biologist from seeing fish
beneath the surface while electrofishing, cold fronts may cause fish to
move away from the shoreline, aquatic weeds can hinder their ability to
see or capture fish that would ordinarily be collected, fish may be deeper
than the reach of the electrical field in extremely clear water, etc. All of
these things have the potential to bias estimates of abundance.
The number of 8-12 inch fish collected per hour of electrofishing is a
general indicator of overall population abundance. In Alabama, the
majority of samples, statewide, fall within the 11 – 26 fish per hour range.
The chart below illustrates these values for samples conducted on public
reservoirs during Spring 2011 survey efforts.
Number of 8 - 12 Inch Largemouth Bass Caught by Electrofishing
LOW
DENSITY
MODERATE
DENSITY
HIGH
DENSITY
Demopolis
Eufaula
Guntersville
Inland
Lay
Logan Martin
Martin
Miller's Ferry
Mitchell
Mobile Delta
Point A
Wheeler
0 10 20 30 40 70 80
Catch Per Hour of Electrofishing
11