Lemhi River Juvenile Chinook Salmon Telemetry Study

Within the Lemhi River, over-winter habitat capacity is a critical limiting factor for spring/summer Chinook salmon (SPCH) and steelhead (STHD) productivity. The Lemhi River Juvenile Chinook Salmon Telemetry Study will build on this body of work by determining the use of both engineered and natural side-channels during the critical over-winter period. Furthermore, this study will provide data that informs restoration managers by determining the relationship between habitat restoration and salmonid productivity and habitat use in the Lemhi River Intensively Monitored Watershed. This research will monitor restoration effectiveness and provide restoration validation monitoring that is essential in allowing for the greatest possible uplift in habitat capacity and juvenile survival.

1. evaluate the proportion of spring/summer Chinook salmon (SPCH; Oncorhynchus tshawytscha) and steelhead (O. mykiss) that use engineered and natural side channels; and

2. determine if juvenile Chinook salmon and steelhead use the entire side channel or just the head and mouths of the side channels; and

3. determine what the residence time within side channels are for juvenile Chinook salmon and steelhead.

To meet these goals, Biomark will monitor juvenile SPCH collected, and PIT tagged at existing rotary screw traps (RSTs), or with electrofishing if needed. Biomark will conduct annual SPCH redd surveys and carcass counts, continue operation of two RSTs, and the operation and maintenance of 3 existing and 18 new temporary In-stream PIT Tag Detection Systems (IPTDS).

This project will improve habitat restoration action implementation by:



1. identifying specific attributes (e.g., size, length, depth, structural complexity, etc.) within habitat classes (e.g., pools, side-channels, etc.) that are preferred by SPCH during the over-winter period;

2. determining whether the sequence and relative size of habitat units increases the probability of juvenile selection; and

3. directly linking habitat types to the probability of juvenile over-winter survival.



In short, the outcomes of this study will refine habitat restoration actions to maximize capacity uplift and juvenile over-winter survival.