The escapement goals were set based on summer rearing numbers. As such, the represent the productivity of the systems based on in-stream productivity.

The Keogh studies rather conclusively showed that as you increase productivity you do two things to smolt production. One is to make it younger and the other is more abundant. Based on what we saw in Snow/Salmon creeks a fish that was going to smolt as an age-1 was smaller the previous fall than one that would smolt as age-2. This is because they were growing faster. Smaller fish have a higher overwinter carrying capacity than larger fish.

Monitoring in WA has shown that the significant increases in productivity (more dead salmon) the smolt age for steelhead declines. The data also showed that when the average age of the smolt run was about 1.5 the R/S was 1.0 . This also corresponded to what was seen on the Keogh.

Although the Keogh started as a fertilizer addition experiment it was converted to wild pinks earring the nutrients. It also showed that the productivity was an on-off switch. If the nutrients weren't there one year the smolt ages and numbers immediately went to older/lower numbers.