Table 1.

Overview of some of the possible effects of climate change and potential plastic and evolutionary responses in Snake River spring/summer Chinook salmon.

Climate change effect	Confidence in physical effect	Effect on fish	Plastic response	Potential evolutionary response	Reference
↑ Peak summer and fall temperatures	High	↓ Parr survival	Seek cooler refugia	Heat tolerance	Bisson and Davis (1976), McCullough (1999), Crozier and Zabel (2006)*
		↑ or ↓ growth, depending on food supply and fish density		↑ Energetic efficiency at high temperatures	Brett et al. (1982), ISAB, (2007)
		↑ Predation on juveniles	Predator avoidance behavior, choosing suboptimal habitat		Petersen and Kitchell (2001)*, Marine and Cech (2004)
		↓ Adult survival due to stress from temperature or disease	Migration delays, higher stray rate	Earlier adult migration ↑ Disease resistance ↑ Energetic efficiency at high temperatures	McCullough (1999), Hyatt et al. (2003), Naughton et al. (2005), Goniea et al. (2006), Battin et al. (2007)
		↓ Reproductive success (↓ egg viability from thermal stress, or smaller eggs due to ↑ energetic cost)		Shift reproductive allocation	McCullough (1999), Kinnison et al. (2001), Rand et al. (2006)
↓ Summer and fall flows	High	↓ Parr survival	Change habitat		Crozier and Zabel (2006)*
Shorter and milder winter	High	↑ Development rates	Earlier emergence	↑ Energetic efficiency at higher temperatures	Beacham and Murray (1989), Finstad et al. (2004)
↑ Spring temperatures	High	↑ Development rates	Earlier smolt migration		Beckman et al. (1998); Achord et al. (2007)*
		↓ Smolt survival		↑ Disease resistance earlier smolt migration ↑ Heat tolerance	Smith et al. (2003)* found no effect; Zabel et al. (in press)* negative effect
Earlier spring freshet	High		Earlier smolt migration		Achord et al. (2007)*
Weaker spring freshet	High	↓ Smolt survival			Williams et al. (2005)*, Achord et al. (2007)*
		↓ Adult energetic cost (if not too hot)	Larger eggs		Kinnison et al. (2001), Rand et al. (2006)
Delay in upwelling	Low	↑ Juvenile survival if arrival time does not change			Logerwell et al. (2003), Scheuerell and Williams (2005)*, Williams et al. (2005)*, Zabel et al. (2006)*, Waples et al. (2008)*)
↑ Ocean stratification ↑ Surface temperature	High	↑ Metabolic costs in surface water	↑ Vertical migration Shift locations	↓ Metabolic rates Change migration route	Welch et al. (1998), Walker et al. (2000), Portner and Knust (2007)
Acidification	High	↓ Growth rate	Delayed maturation

References with an ^* are specific to this population.