Ryan Fitzpatrick taking a water sample Stagecoach ReservoirRyan Fitzpatrick holding a pike pulled from StagecoachThe large mouth of a pike

Northern Pike/Trout Interactions in Colorado Trout Lakes

Principal Investigator: Dana Winkelman

Graduate Student: Ryan Fitzpatrick

Funding Agency: Colorado Division of Wildlife

Start Date: August 2004

Completion Date: Ongoing Project

Introduction: Predation from nonnative fishes has caused extensive problems for Colorado trout fisheries and native fish assemblages. Controlling nonnative fishes requires a clearer understanding of recruitment and movement so that management options can be evaluated. This project will focus on the introduced northern pike (Esox lucius) in the upper Yampa River system, where pike are a documented source of predation for trout fisheries and native fishes.

Objectives: I propose to estimate the proportion of pike in the Yampa River recruited from reservoirs and other spawning areas. Once this data is collected, we can estimate the extent of pike movement between reservoirs and within the Yampa River system. This information will assist future management decisions regarding nonnative fish control.

Progress: A pilot study was conducted this fall with water samples being collected and analyzed for 7 major and 21 trace elements from 13 locations. Young-of-year pike have been collected from Stagecoach Reservoir, Lake Catamount, and Elkhead Reservoir. Preliminary results from water samples indicate significant differences between reservoirs are present. Otolith preparation will be completed by the first week of April with microchemistry results by May.

Results/Products: Fitzpatrick, R.M. February 2005. Estimation of recruitment sources and movement of northern pike (Esox lucius) using otolith microchemistry. Colorado/Wyoming meeting of the American Fisheries Society. Fort Collins, CO.Fitzpatrick, R. M. April 2005.

Estimation of recruitment sources and movement of northern pike (Esox lucius) using otolith microchemistry. Front Range Student Ecology Symposium. Fort Collins, CO.