They can be so pesky, insisting on empirical evidence and clear assessments of problems and accurate accounting of the results of attempts to correct problems. Measure conditions before taking an action and 2. Measure conditions after the action is taken.
Monitoring costs money.
Scientists, as a rule, like about 25 percent of a research project's cost to be committed to monitoring. Nowhere near that is budgeted for keeping tabs on salmon recovery. The scientists do caution that the results likely will not show up for a long time. With billions at stake, that's likely to make taxpayers sympathetic to scientists, who demand measurement of what they've bought with the money.