Mark and recapture studies and angling impacts on largemouth bass

Raibley, P. T., T. M. O'Hara, K. S. Irons, K. D. Blodgett, and R. E. Sparks. 1996. Mark
and recapture studies and angling impacts on largemouth bass in La Grange and Peoria
reaches of the Illinois River. Center for Aquatic Ecology, Illinois Natural History Survey,
Alton, Illinois. Aquatic Ecology Technical Report 96/1. Reprinted by U.S. Geological
Survey, Environmental Management Technical Center, Onalaska, Wisconsin, May 1998.
LTRMP 98-R008. 23 pp. + Appendixes A B (NTIS #PB98-153786)


ABSTRACT

Largemouth bass (Micropterus salmoides) are an important component of the recreational
and tournament fisheries in the Illinois River.  From 1992 through 1994, we tagged and
released 4,507 largemouth bass.  Through 1995, 652 different anglers caught and reported
1,162 (24.9%) tagged largemouth bass. Including those we recaptured, of 1,473 largemouth
bass for which we had the location of recapture, 985 (66.9%) were recaptured within 1 mile
(1.6 km) of their release location, indicating tagged largemouth bass usually stayed in the
area they were released.  Fish released along the main channel were more likely to move
than those released in backwaters or sloughs, and largemouth bass translocated by
tournament anglers and released by us were more likely to move than those released in their
home areas after electrofishing sampling.

During a 5-day intensive sampling, we calculated a population estimate of 1,684
largemouth bass in a 2.5-mile (4-km) stretch of a backwater slough; largemouth bass
densities were comparable to those documented on Mississippi River backwaters in the late
1980s when fishing there was considered high quality. 

We documented 106 tournaments on the La Grange and Peoria Reaches from 1992 to
1995, where anglers brought in 6,793 largemouth bass weighing 11,544 pounds (5,247 kg)
with an average weight of 1.7 pounds (0.8 kg). 

Perhaps the most effective strategy for managing Illinois River largemouth bass populations
is to preserve and enhance spawning, nursery, and wintering habitats.


KEYWORDS

Harvest, Illinois River, largemouth bass, mark and recapture, movements, population
estimate, recreational fishery, tagging, tournament