Impact of White Perch on Walleye

Habitat alterations and accidental introduction of white perch into Branched Oak Lake have shifted the fish community from one dominated by littoral (near-shore) species (e.g., largemouth bass and bluegill) to one dominated by pelagic (open-water) species (e.g., white perch and gizzard shad). Along with the change in the fish community, angler trips to Branched Oak Reservoir have declined by 85% over the last two decades. Further, the white perch population has become stunted (high density of slow growing individuals that mature at a small size). Like Branched Oak Lake, Pawnee Lake historically supported an active and diverse fishery, and has experienced similar habitat alterations and accidental introduction of white perch. However, unlike Branched Oak Lake, stunting has not yet occurred for the white perch population in Pawnee Lake.

Two companion projects provided an opportunity to examine white perch interactions with other fishes in two similar Nebraska reservoirs having different white perch population stages (i.e., stunted and non-stunted). Food habits and diet overlap among white perch, crappie, walleye, white bass, and channel catfish were evaluated.

Goals

To document potential competition bottlenecks that exist between white perch and other fish species of importance in the hopes of developing a management program to eliminate the "stunted" status for the white perch population in Branched Oak Lake and to prevent stunting of the white perch population in Pawnee Lake.

Current Status

This project is complete with results compiled into a master's thesis.

Straining contents of a fish stomach
Straining contents of a fish stomach
Nate Gosch measuring fish
Nate Gosch measuring fish
Principal Investigator(s)
-Kevin Pope, NE CFWRU
Graduate Student(s)
-Nathan Gosch (MS 2008)
Funding
-U.S. Geological Survey, and the Nebraska Game and Parks Commission