Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 2002-2003 Annual Report.

Prior to 1992, decisions on dam operations and use of stored water relied on recoveries of branded hatchery fish, index counts at traps and dams, and flow patterns at the dams. The advent of PIT-tag technology provided the opportunity to precisely track the smolt migrations of many wild stocks as they pass through the hydroelectric complex and other monitoring sites on their way to the ocean. With the availability of the PIT tag, a more complete approach to these decisions was undertaken starting in 1992 with the addition of PIT-tag detections of several wild spring and summer chinook salmon stocks at Lower Granite Dam. Using data from these detections, we initiated development of a database on wild fish, addressing several goals of the Columbia River Basin Fish and Wildlife Program of the Pacific Northwest Electric Power Planning Council and Conservation Act (NPPC 1980). Section 304(d) of the program states, ''The monitoring program will provide information on the migrational characteristics of the various stocks of salmon and steelhead within the Columbia Basin.'' Further, Section 201(b) urges conservation of genetic diversity, which will be possible only if wild stocks are preserved. Section 5.9A.1 of the 1994 Fish and Wildlife Program states thatmore » field monitoring of smolt movement will be used to determine the best timing for water storage releases and Section 5.8A.8 states that continued research is needed on survival of juvenile wild fish before they reach the first dam with special attention to water quantity, quality, and several other factors. The goals of this ongoing study are as follows (1) Characterize the migration timing and estimate parr-to-smolt survival of different stocks of wild Snake River spring/summer chinook salmon smolts at Lower Granite Dam. (2) Determine whether consistent migration patterns are apparent. (3) Determine what environmental factors influence these patterns. (4) Characterize the migrational behavior and estimate survival of different wild juvenile fish stocks as they emigrate from their natal rearing areas. This study provides critical information for recovery planning, and ultimately recovery for these ESA-listed wild fish stocks. This report provides information on PIT tagging of wild chinook salmon parr in 2002 and the subsequent monitoring of these fish. Fish were monitored as they migrated through two in-stream PIT-tag monitoring systems in lower Valley Creek and at juvenile migrant traps in 2002 and 2003 as well as through interrogation systems at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams during 2003. Fish were also monitored by the PIT-tag trawl in the mouth of the Columbia River in 2003. In 2002-2003, we also continued to collect environmental data for the Baseline Environmental Monitoring Program, which was developed from 1993 to 1997. The project was designed to collect data for use in conjunction with data on parr and smolt movements to discern patterns or characteristic relationships between these movements and environmental factors. Water quality data collected consist of water temperature, dissolved oxygen, specific conductance, turbidity, water depth, and pH measured at five monitoring stations in the Salmon River Basin, Idaho.« less