Fraser River environmental watch report August 10, 2017

Fraser River Environmental Watch Report [PDF]

Ten-day daily forecasts of lower Fraser River temperature and flow conditions as well as current conditions throughout the Fraser basin are updated bi-weekly from roughly late-June until mid-August. These short-range forecasts are generated using the Institute for Ocean Sciences River Temperature and River Flow Forecast Models (Morrison and Foreman 2005).

The latest research on Pacific salmon fresh water migration suggests there are population-specific differences in temperature and flow tolerance thresholds (Lee et al. 2003). These differences likely relate back to the variability in the average river environmental conditions experienced by salmon beginning their river migration at different times of the year and along different paths (Farrell et al. 2008). Despite these differences, there are also species-wide thresholds that will result in migration difficulties for most populations of Fraser River sockeye salmon. We provide species-level thresholds as a guide to interpreting the potential effect of current and forecasted river temperature and flow conditions on returning salmon. However, in general, fish historically returning to the Fraser River in the mid-summer will be more tolerant of higher temperatures than those fish returning in the early or late summer or early fall.

Current Temperatures
09-Aug Daily Mean Historic Mean
Fraser River @ Qualark 19.4 18.7
Fraser River @ Texas Creek 19.5 18.7
Nechako R. @ Isle Pierre NA 18.9
North Thompson @ McLure 17.1 NA
Quesnel R. @ Quesnel 16.7 17.0
South Thompson @ Chase 18.9 19.5
Stuart R. @ Ft. St. James 20.7 18.7
Thompson R. @ Ashcroft 18.2 18.2
Upper Fraser @ Shelley 18.5 15.1
Nechako @ Vanderhoof 18.4 NA
Thompson @ Spences Bridge 18.4 NA
Nautley NA NA
Stellako 15.7 NA
Fraser @ Marguerite 21.1 NA

Fraser River Discharge at Hope

Critical Levels for Fish Passage through Fraser Canyon:

Mean Daily Discharge (m3/s)

Fraser River Water Temperatures at Hope

Mean Daily Water Temparature oC