Walleye Predation on Smolts?

[FISHFINDER]

I have often pondered just what effect the walleye that were introduced to the Columbia have on the salmon/steelhead smolts. Anyone have any thoughts or facts?

FF

[sturgn]

I pulled hte following information out of a report on the ODFW site, heres the link:
http://www.dfw.state.or.us/ODFWhtml/publicreview.pdf

Biological Issues: Predation
1. Walleye
All native species produced in the Columbia and Snake rivers and their tributaries could be subject
to predation during juvenile out-migration. The introduced species of primary concern are
smallmouth bass, walleye and channel catfish. All are present in the lower Columbia River and
upstream impoundments.
The relationship of introduced fishes to salmonids in the mainstem Columbia reservoirs was
studied extensively in the mid-1980s, during a state-federal research study. Salmonids comprised
about 4% of smallmouth bass diet, 14% of walleye diet and 33% of channel catfish diet by weight
over all months, years and locations. By contrast, the diet of northern pikeminnows (*********) ¡Ý
300-mm in length consisted of 83% salmonids. More recent research conducted throughout the
lower Columbia and Snake Rivers confirmed this diet information (Zimmerman, 1997). In these
studies, salmonids comprised about 6% of smallmouth bass diet, 11% of walleye diet, and 41 %
of northern pikeminnow diet. When adjusted for predator abundance, the most important
predators were pikeminnows, walleye, channel catfish and smallmouth bass, in that order.