Return Timing For Adult Winter Steelhead Based on Age Hal Michael Washington Department of Fish and Wildlife

QUESTIONS FOR DISCUSSION If a steelhead run is best described as “temporally mixed” how do you model this? If a steelhead run is best described as “temporally mixed” how do you manage this?

STREAMS EVALUATED Hoh River commercial fishery, Nov-March , n=454 Snow Creek upstream trap , n=1014 Buckley Trap, White River , n=1236

AGES OBSERVED FOR FIRST RETURN SW Age FW Age 1 XXX 2 XXX 3 XXXX 4 XX

REPEAT SPAWNING OBSERVED.?+S+.?+S+S+.?+S+S+S+ ? Represents years in saltwater before first return

FRESHWATER AGE Hoh days age 1age 2age 3 Snow Creek days age 1age 2age 3 White River days age 2age 1age 3

FIRST RETURN FROM SALTWATER Hoh 02 days7 days 3 years1 year2 years Snow Creek 07 days11 days 1 year2 years3 years White River 014 days36 days 1 year2 years3 years

FIRST TIME vs. REPEAT SPAWNERS Hoh (n=376, 78) first timers 6 days earlier Snow (n=203, 21) first timers same day White (n=1205, 22) first timers 4 days later

IMPLICATIONS OF VARIABLE RETURN TIME Runsize = 1000 Total mortality= 10% all fish arriving after closure survive to spawn close last day March Escapement900 esc post close734 Actual mortality rate38%