Tagart 1984: Fines and Coho Egg to Fry Surv.

Excerpt from Lestelle et al., 2024:

"We employed the empirical relationship reported by Tagart (1984) for the effects of percent
fine sediment (<0.85 mm) on survival to emergence for coho (Figure 5). We assumed the
same relationship is applicable to chinook salmon and steelhead trout. Using a benchmark
survival to emergence of 60% (assumed average survival under optimal conditions for
chinook and coho), we can convert Tagart's survivals into sensitivity (as 1 minus survival
divided by the benchmark) and plot the values against the appropriate Level 2 rating values
on the x-axis (Figure 6). The resulting relationship forms the rule for sediment effects on the
incubation life stage, except when the hydrologic regime is mainly characterized as
groundwater fed.7 In that case, upwelling associated with groundwater sources appears to
largely protect embryos from deleterious effects of high fines (Bjornn and Reiser 1991,
Waters 1995). This explains why salmonids can have high rates of reproduction in some
streams despite excessive deposits of fine sediment (e.g., chum and sockeye salmon are
known to spawn heavily in groundwater fed streams, even in areas of excessive fines). We
therefore created a Rule Category for this hydrologic regime that maintained high survivals
even at high levels of fine sediment"

Consider important interaction with temperature

Function: Y = 934.2X-1.1963

Keywords: Fine, fines, sediment, sedimentation, erosion. substrate.