Conceptual Spawning Habitat Model to Aid in ESA Recovery Plans for Snake River Fall Chinook Salmon, 2002-2003 Annual Report.

The goal of this project is to develop a spawning habitat model that can be used to determine the physical habitat factors that are necessary to define the production potential for fall chinook salmon that spawn in large mainstem rivers like the Columbia River's Hanford Reach and Snake River. This project addresses RPA 155 in the NMFS 2000 Biological Opinion: Action 155: BPA, working with BOR, the Corps, EPA, and USGS, shall develop a program to: (1) Identify mainstem habitat sampling reaches, survey conditions, describe cause-and-effect relationships, and identify research needs; (2) Develop improvement plans for all mainstem reaches; and (3) Initiate improvements in three mainstem reaches. During FY 2003 we continued to collect and analyze information on fall chinook salmon spawning habitat characteristics in the Hanford Reach that will be used to address RPA 155, i.e., items 1-3 above. For example, in FY 2003: (1) We continued to survey spawning habitat in the Hanford Reach and develop a 2-dimensional hydraulic and habitat model that will be capable of predicting suitability of fall chinook salmon habitat in the Hanford Reach; (2) Monitor how hydro operations altered the physical and chemical characteristics of the river and the hyporheic zone within fall chinook salmon spawning areas in the Hanford Reach; (3) Published a paper on the impacts of the Columbia River hydroelectric system on main-stem habitats of fall chinook salmon (Dauble et al. 2003). This paper was made possible with data collected on this project; (4) Continued to analyze data collected in previous years that will ultimately be used to identify cause-and-effect relationships and identify research needs that will assist managers in the improvement of fall chinook habitat quality in main-stem reaches. During FY 2004 we plan to: (1) Complete preliminary reporting and submit papers based on the results of the project through FY 2004. Although we have proposed additional analysis of data be conducted in FY 2005, we anticipate a significant number of key papers being prepared and submitted in FY 2004 which will go toward identifying the data gaps this RPA is intended to address; (2) Make available data from this project for use on Project 2003-038-00 ('Evaluate restoration potential of Snake River fall chinook salmon') which is a BPA-funded project that will start in FY 2004; and (3) Present results of our work at regional and national meetings in order to facilitate technology transfer and information sharing. The objective of this project is to define the production potential of fall chinook salmon that spawn in the Hanford Reach. We will provide fisheries and resource managers with the information they need to determine if the Hanford Reach fall chinook salmon population is indeed healthy, and whether this population will be capable of seeding other satellite populations in the future. We will accomplish this purpose by continuing our on-going research at determining the carrying capacity of the Hanford Reach for producing fall chinook salmon under current operational scenarios, and then begin an assessment of whether the Reach is functioning as a model of a normative river as is widely believed. The product of our research will be a better understanding of the key habitat features for mainstem populations of anadromous salmonids, as well as a better understanding of the measures that must be taken to ensure long-term protection of the Hanford Reach fall chinook population. Although the project was originally funded in FY 1994, it was significantly redefined in FY 2000. At that time five tasks were proposed to accomplish the project objective. The purpose of this progress report is to briefly describe the activities that have been completed on each of the five tasks from FY 2000 through FY 2003