Figure 19. Size distribution of juvenile chinook observed in Kusal Slough in 1997.
The smaller-size cohort in on 2/5/97 can be tentatively assigned to the fall race by applying the rule of a slightly larger cut-off size for tributaries.
The group of much larger fish on that date are probably not fall-run, but there is no certainty that they are winter-run. On 3/22/97, the smaller-size cohort falls clearly into the spring-run size, but these are probably the same fish assigned to the fall-run on 2/5/97. The 4/26/97 distribution adds more confusion. If the fish continued growing faster than the river rate, the mode should have moved closer to the right edge of the spring distribution, but instead, it has become very diffuse and, if anything, closer to the left edge of the spring distribution. The probable explanation is that most of the larger members of the cohort smolted and left.