Table 3. Candidate experimental management, monitoring, and research activities to concurrently reduce key uncertainties and recover stocks (Marmorek et al. 1999). Activities with an asterisk were evaluated quantitatively (Peters et al. 2000).

Candidate approach
Experi-
ment
Research/
monitoring
Possible survival effects
Hypothesis tested
1. Current hydrosystem operations/Measure D
 
X

none beyond current

D
 
2. Modify smolt transportation and Measure D*
X

post-BONN survival of
transported fish
D
 
3. Transportation/no transportation*
X

direct passage survival; post-BONN survival of transported fish
D
 
4. Two-reservoir drawdown
X
 
passage survival; post-BONN survival; upstream survival
hydro
 
5. Four-reservoir drawdown*
X

passage survival; post-BONN survival; upstream survival
hydro
 
6. Carcass introductions/stream fertilization*
X

egg-to-smolt survival;
other life stages
stock viability –nutrient
 
7. Manipulate hatchery production *
X

passage survival; post-BONN survival
stock viability–hatchery/disease
 
8. Predator removal
X

passage survival
hydro
 
9. Explore mechanisms for delayed mortality

X
none
D
 
10. Regime shift monitoring

X
none
regime shift

    Notes: D is the ratio of estuary/ocean survival rate of transported fish : estuary/ocean survival rate of in-river (nontransported) fish. D < 1 indicates that transported fish have a lower estuary/ocean survival rate than in-river fish, whereas D > 1 indicates that transported fish have a higher estuary/ocean survival rate than in-river fish. See Appendix 3 for details.