Summary of 2017 Northern Pike Suppression and SPIN Results on Boundary Reservoir, Pend Oreille River, WA

Category: Aquatic Invasive Species

Published: 2018

Pages: 4

Author(s): WDFW and Kalispel Natural Resources

Introduction

This was the second year of mechanical suppression of Northern Pike (NP) in Boundary Reservoir. In total, 146 nets were deployed with 307 Northern Pike captured (303 NP removed; 4 tagged NP were released) between March 13 and April 20, with a final catch-per-unit-effort (CPUE) of 2.09 NP/net-night (including released fish). The Kalispel Natural Resources Department collected 28 Northern Pike during the 2017 Spring Pike Index Netting (SPIN) Survey conducted May 8 through May 10. The resulting CPUE of 0.70 NP/ net-night (95% CI: ± 0.42), in sloughs and mainstem river between Box Canyon Dam and Metaline Falls. While not meeting the abundance target of ≤ 0.50 NP/net-night for these sections of the reservoir, it does fall within the confidence interval range.

In total, 414 NP were removed in 181 overnight gillnet sets during the two years of suppression in Boundary Reservoir (111 NP in 2016 and 303 NP in 2017), with 4 additional tagged NP released (Seattle City Light study).