We tagged 4,513 hatchery steelhead from Dworshak National Fish Hatchery (NFH), with Passive Integrated Transponder (PIT) tags to evaluate factors contributing to residualism. Steelhead from typical growth ponds (System I) averaged eight mm less and traveled two days faster to Lower Granite Dam than those in faster growth ponds (System II). The mean detection rates of steelhead by rearing system were 57.4%, 55.9%, and 57.8% for System I, System II, and System III. Steelhead released into Clear Creek, South Fork Clearwater River and directly from Dworshak NFH had detection rates of 55.0%, 59.1%, and 57.8%, respectively. Overall detection rate for all release sites, rearing systems and egg takes was 54.1%. We PIT tagged an additional 270 hatchery steelhead in the North Fork and mainstem Clearwater rivers and the adult ladder at Dworshak National Fish Hatchery between May 15 and October 29. In the four tributaries sampled, no hatchery steelhead were captured or observed. A total of 51 coded-wire tags were recovered; 3 were released at Dworshak NFH in 2001 and 47 in 2002. One fish was released at Clear Creek. Although sample sizes were small, we were able to verify that at least 33 residual steelhead tagged in 2001 persisted in the Clearwater River during winter and were detected at downstream dams in 2002. Final analysis will include influences of water flow and temperature in emigration success.
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