Kootenai River White Sturgeon Investigations; White Sturgeon Spawning and Recruitment Evaluation, 1996 Annual Report.

• Main Author: Paragamian, Vaughn L.
• Other Authors: United States. Bonneville Power Administration.
• Format: Report
• Language: English
• Published: Idaho. Department of Fish and Game. 1997
• Subjects: Fishery Management - Idaho; Hydroelectric Power Plants; Numerical Data; Burbot - Kootenai River; Dams; Environmental Impacts; Progress Report; Columbia River Basin; Migration; Fishes; 13 Hydro Energy; White Sturgeons - Kootenai River; Fisheries White Sturgeons - Kootenai River; Burbot
• Online Access: https://doi.org/10.2172/663506; https://digital.library.unt.edu/ark:/67531/metadc709215/

Test flows for Kootenai River white sturgeon Acipenser transmontanus spawning, scheduled for June 1996, were postponed until July. However, an estimated 126% snow pack and unusually heavy precipitation created conditions for sturgeon spawning that were similar to those occurring before construction of Libby Dam. Discharge in the Kootenai River at Bonners Ferry rose to nearly 1,204 m{sup 3}/s (42,500 cfs) during May and water temperature ranged from 5.8 C to 8.4 C (42 F to 47 F). Migration of adult white sturgeon into spawning areas occurred in late May during a rising hydrograph. Discharge and water temperature were rising and had reached approximately 1,077 m{sup 3}/s (38,000 cfs) and 8 C (46 F). Discharge at Bonners Ferry peaked at about 1,397 m{sup 3}/s (49,300 cfs) on June 5. A total of 348 eggs (and one egg shell) were collected with 106,787 h of mat effort during the flow events. The first white sturgeon eggs were collected on June 8 and continued through June 30. Staging of eggs and back-calculating to spawning dates indicated there were at least 18 spawning episodes between June 6 and June 25. Discharge on June 6 was 1,196 m{sup 3}/s (42,200 cfs) and decreased steadily to 850 m{sup 3}/s (30,000 cfs) by June 26. Although sturgeon spawned in the same reach of river that they had during 1994 and 1995, the majority of eggs were found significantly (P = 0.0001) farther upstream than 1994 and 1995 and this in turn may be related to elevation of Kootenay Lake.