EBEL: TRANSPORTATION OF CHINOOK SALMON AND STEELHEAD SMOLTS 



km of the migratory route would be eliminated, 

 and the fish would be intercepted during their 

 juvenile migratory life stage about 2-3 wk earlier 

 than they were at Ice Harbor Dam. The results 

 achieved at this site could be quite different from 

 those obtained at Ice Harbor Dam. To facilitate the 

 collection offish, an orifice bypass system, juvenile 

 fish diversion screens, and raceways for collection 

 of juvenile fish were built into Little Goose Dam 

 during its construction. This system provided sub- 

 stantial numbers of fish for the experiment, but 

 there was the possibility that these fish might be 

 injured or stressed during the diversion and collec- 

 tion process. 



Table l. — Number of transported and nontransported (control) 

 juvenile chinook salmon and steelhead that were marked and 

 released from Little Goose Dam, 1971-73. 



'Transported fish were released in the Columbia River at two sites down- 

 stream from Bonneville Dam: 2 km downstream on the Washington (side re- 

 ferred to in the table as Bonneville Dam) and 1 7 km downstream on the Oregon 

 side at Dalton Point. 



^Release totals adjusted for initial tag loss. 



METHODS 



Experimental Design 



During the downstream migrations in 1971, 

 1972, and 1973 juvenile chinook salmon and 

 steelhead were randomly selected from the race- 

 ways at Little Goose Dam and divided into three 

 groups — one control and two transported groups. 

 The adipose fin was removed from all experimen- 

 tal fish and each group was selectively marked 

 with a thermal brand and magnetized wire tags. 

 Thermal brands were changed every 5 d among all 

 treatment groups except for the first 10-d marking 

 period. During this period, marking continued for 

 10 d before a change was made. Codes for mag- 

 netized wire tags were changed yearly for each 

 treatment group. The control group was released 

 at Central Ferry, about 10 km upstream from Lit- 

 tle Goose Dam; the transported groups were 

 hauled in tank trucks to two locations downstream 

 from Bonneville Dam (Figure 1). One release site 

 was at Dalton Point, 17 km downstream from 

 Bonneville on the Oregon side of the river; the 

 other was at the Washington State boat launching 

 site, about 2 km downstream from Bonneville 

 Dam. Each year the goal was to mark at least 

 50,000 chinook salmon and 25,000 steelhead for 

 each group. This goal was exceeded every year 

 (Table 1) except for all groups ofchinook salmon in 

 1971 and the control group ofchinook salmon in 

 1972. 



Collection and Marking of Fish and 

 Fish Hauling Procedures 



Juvenile chinook salmon and steelhead were 

 collected at Little Goose Dam, using a fingerling 



collection and bypass system (Smith and Farr 

 1974). The system consisted of: 1) screens in the 

 turbine intakes which diverted fish into the 

 gatewells of each turbine intake; 2) a gatewell 

 orifice and piping system which transported fish 

 from the gatewells to a grader and counter; and 3) 

 a fish grader and counter which sorted fish by size 

 and electronically counted fish entering five race- 

 ways. When desired, fish could be diverted directly 

 to the river — thus bypassing the grader, counter, 

 and raceways. 



Fingerling chinook salmon and steelhead were 

 pumped with a 5 -in Paco model fish pump into the 

 marking building where they were anesthetized 

 and sorted. Previously marked fish were returned 

 to the river in the tailrace of the turbine discharge. 

 Samples of at least 100 chinook salmon and 

 steelhead were examined each day for percentage 

 descaling to provide an index offish condition. Any 

 fish with >10'^ of the scales missing was consid- 

 ered descaled. Each of the remaining fish was 

 cold-branded with liquid nitrogen (Park and Ebel 

 1974), had the adipose fin excised, and had a 

 magnetic wire tag ( Jefferts et al. 1963) inserted in 

 the snout. Before passing into a transport truck, 

 the fish went through a magnetic field and detec- 

 tion coil; an untagged fish was automatically re- 

 jected and returned to the marker for retagging. 

 Initial tag loss was measured by examining sam- 

 ples of juveniles 48-72 h after tagging; subsequent 

 tag loss was determined by examining returns of 

 adult control and test fish at Rapid River Hatchery 

 near Riggins, Idaho, and Dworshak National Fish 

 Hatchery at Ahsahka, Idaho. A branded fish with 

 an adipose fin clip that did not also have a coded 



^Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



493 



