MOVEMENT OF BLUEGILLS (LEPOMIS MACROCHIRUS) AND BLACK CRAPPIES
(POMOXIS NIGROMACULATUS) IN BACKWATERS OF NAVIGATION POOL 8,
MISSISSIPPI RIVER.

Andrew D. Bartels.  
Wisconsin Department of Natural Resources, Onalaska, WI 54650.

I conducted a pilot study designed to evaluate opportunities for mark and recapture studies of
fishes within the Long Term Resource Monitoring Program (LTRMP) for the Upper Mississippi
River (UMR).  The objective was to determine if enough recapture information could be gained
during routine monitoring activities and from the angling public to characterize movement
patterns of bluegills (Lepomis macrochirus) and black crappies (Pomoxis nigromaculatus) in
Navigation Pool 8 (Pool 8) of the UMR.  Spring tagging during 1998 and 1999 yielded 5,812
bluegills and 5,476 black crappies, which were subcutaneously implanted with plastic fabric tags. 
Tagging occurred in each of three sampling sites, which differed in amount of water current
velocity, depth, and amount of aquatic vegetation.  Recapture information from 17 fish was
recorded during routine LTRMP fish monitoring.  Anglers provided 102 recapture reports, 64 of
which came during the ice-free season.  Bluegill recaptures totaled 69, or 1.18% of the total
number tagged.  Black crappie recaptures totaled 50, for a return rate of  0.91%.  Fish of both
species exhibited the greatest propensity to remain at the capture site in Lawrence Lake, which
had the greatest depth, abundant aquatic vegetation, and low current velocity.  The highest degree
of straying occurred from Shady Maples, which had the most current velocity, least aquatic
vegetation, and shallow depth.  Twenty-eight percent of bluegills and 42% of black crappies
recaptured had strayed from the original tagging site.  Maximum linear distances between the
tagging site and recapture site were 7.4 km for bluegills and 17.1 km for black crappies.   All
long-distance movements by bluegills were oriented downstream, whereas black crappies moved
large distances both upstream and downstream.  The project demonstrated that a large-scale mark
and recapture effort for these or other target species has the potential to help answer a variety of
management-related questions.  Recent interest and concern about overwintering habitat and
angling exploitation of several fish species suggests that this type of project may become
important in the near future.

Keywords: bluegill, black crappie, mark and recapture, Pool 8, Upper Mississippi River