Summary of 2013 Northern Pike Suppression Results on Box Canyon Reservoir, Pend Oreille River, WA.

The second year of mechanical suppression of northern pike (NP) in Box Canyon Reservoir resulted in the removal of 6,452 northern pike (Table 1). Kalispel Natural Resources Department and Washington Department of Fish and Wildlife sampled 410 northern pike in the 2013 Spring Pike Index Netting (SPIN) Survey. This resulted in a catch per unit effort (CPUE) of 1.21 NP/ net-night (95% CI: 0.87-1.56), in sloughs and mainstem river between Riverbend and Pioneer Park campground, which met the target of ≤ 1.73 NP/net-night for these sections of the reservoir. The CPUE north of Riverbend was higher than the target of ≤ 0.50 NP/net-night (1.44 NP/ net-night) which triggered Phase 2 of the mechanical suppression effort.

In the initial year (2012) of mechanical removal of northern pike crews deployed 1,031 nets and removed 5,808 northern pike between March 19 and June 13. 4,552 northern pike were removed during Phase 1 (March 19 to April 22) for an overall CPUE of 9.30 NP/net-night; Phase 2 (April 27 to June 13) resulted in the removal of 1,256 northern pike with an overall CPUE of 2.48 NP/net-night. The 2012 SPIN survey took place between April 23 and April 26 with 60 nets deployed and 131 northern pike sampled. This resulted in a CPUE of 2.30 NP/net-night for all sloughs and the mainstem river south of Riverbend and CPUE of 0.80 NP/net-night for the mainstem river north of Riverbend.