| Introduction | Creek Description | Rotenone Treatment | Species | Results | Discussion |


We chose three study sites within the treated area (Map), near the upper end, near the middle, and just upstream of the detox site. The sites are chemically and physically similar, being within a tributary-free 16 km reach of stream. However, in terms of fish recolonization, they were quite different.

The upper (PW) site, about 100 m below the Ponderosa Way bridge, has ready access to recolonization from upstream populations of rainbow and brown trout and was heavily planted with fry of steelhead rainbow trout and chinook salmon from the Feather River Hatchery. Up to 500 thousand chinook and 100 thousand steelhead were planted each spring from 1987 to 1991. In addition, a local landowner added unspecified numbers of eggs and fry purchased from a commercial hatchery.

The middle (UB) site, about 100 m upstream of the end of the gravel road in Upper Bidwell Park (UBP), is well removed from downstream colonization by resident trout. Colonization from downstream untreated reaches or the Sacramento River is restricted by the Iron Canyon barrier. No fish were stocked near the UBP site during the course of this study.

The lower (Detox) site has free access from the untreated downstream reach and the Sacramento River.

In 1984, DFG electrofished the PW and UBP sites and a site about 0.2 km downstream of the detox site. During the 1986 treatment, the CSUC limnology class led by Professor Paul Maslin collected rotenone-killed fish at all three sites. Each fall from 1987-1996, limnology classes have electrofished the three sites, using blocknets and making two passes with three shockers fished in coordination from downstream to upstream. All fish collected were identified, measured and weighed.