thumbnail

Consumption estimates of walleye stocked as fry to suppress fathead minnow populations in west-central Minnesota wetlands

Ecology of Freshwater Fish

By:
, , , , , , and
DOI: 10.1111/j.1600-0633.2007.00257.x

Links

Abstract

Fisheries managers throughout the Prairie Pothole Region of Minnesota often use semi-permanent and permanent wetland basins to extensively culture walleye Sander vitreus fry. Waterfowl managers have expressed concern over this practice because of the potential influence that fish have on food resources used by waterfowl during development and migration. It is well known that native fathead minnows Pimephales promelas can have detrimental effects on macroinvertebrates, zooplankton, water clarity, epiphyton, and macrophytes in wetlands. Because walleye commonly become piscivorous as soon as mouth gape allows, walleye fry may suppress fathead minnow populations and improve wetland conditions for waterfowl. In this study, we quantify consumption estimates, specifically predation on fathead minnows, by age-0 and age-1 walleye reared in natural wetland basins. Six wetlands were stocked in mid-May 2001 and 2002 at a rate of 12,000 walleye fry ha-1. Age-0 walleye were sampled bi-weekly from mid-June through mid-September 2001. Age-0 and age-1 walleye were sampled monthly from mid-May through mid-September 2002. A generalised diet shift from zooplankton to fish to macroinvertebrates was observed in 2001, whereas diets of juvenile walleye contained primarily macroinvertebrates in 2002. Stocked walleye quickly reduced fathead minnow populations in 2001 and suppression was maintained throughout 2002. Although walleye consumed primarily macroinvertebrates once prey fish populations became suppressed, consumption estimates of invertebrates by walleye were substantially less than those documented for fathead minnow populations. Thus, stocking age-0 walleye was an effective biomanipulation tool that substantially reduced fathead minnow densities and influenced lower trophic levels in these aquatic communities. ?? 2007 Blackwell Munksgaard.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Consumption estimates of walleye stocked as fry to suppress fathead minnow populations in west-central Minnesota wetlands
Series title:
Ecology of Freshwater Fish
DOI:
10.1111/j.1600-0633.2007.00257.x
Volume
17
Issue:
1
Year Published:
2008
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Ecology of Freshwater Fish
First page:
59
Last page:
70