Modelling the linkages between flow management and salmon recruitment in rivers

Changing streamflow on Columbia basin tribal lands—climate change and salmon

“…The HF is defined as the largest daily streamflow that occurs during one autumn month. October, November, and December were chosen, given the seasonal increase in Pacific Coast storms and high flow timing shifts across the western U.S. (Hamlet and Lettenmaier 2007), the vulnerable time for salmon egg nests (ISAB 2007), and the linkage between egg mortality and high flow scour events (Jager et al 1997). A frequency analysis was plotted for each basin.…”

“…The LF is defined as the 7Q10 flow (i.e., lowest streamflow over seven consecutive days having a 10-year recurrence interval) during August 1 to November 15, when most anadromous fish are likely to spawn and need critical habitat, e.g., flows of adequate quantity and quality with cool temperatures. Jager et al (1997) state that salmon egg mortality risk is caused by extreme temperatures, loss of habitat due to extreme high and low flow events, and superimposition of eggs. A frequency analysis was plotted for each basin.…”

Quantifying Temperature Effects on Fall Chinook Salmon

“…Typically fall Chinook begin the smoltification process after reaching a certain size, and thus it is reasonable to assume that development is predicted by growth. Examples of bioenergetics models for Chinook salmon are common (e.g., Jager et al 1997), but the supporting data are rare. The underlying parameter values derive from the same handful of studies, in some cases from related species in very different habitats (e.g., Chinook salmon in the Great Lakes, sockeye salmon in British Columbia, rainbow trout, brown trout) suggesting that more research to obtain species-specific bioenergetics data may be needed.…”

“…In an individual-based and spatially explicit model for fall Chinook salmon (ORCM), we simply compared accumulated degree days against threshold values, discounting low temperatures by half (Jager et al 1997). Literature values for degree-days are summarized for fall Chinook salmon in Table 2.…”

Bi-Annual Report 2010-2011: Shaping pulse flows to meet environmental and energy objectives

“…The spatial distribution of initial redds was represented as a triangular distribution over the upper portion of the river to Lsegsp = 40.5 rkm as described in Jager et al 1997). The 5 th , 25 th , 50 th , 75 th , and 95 th quantiles were used to characterize the distribution of redds in time and space.…”