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Explore the biological characteristics and habitat requirements crucial for the survival of wild winter steelhead in Western Washington. Learn about spawning behavior, smolt ages, repeat spawners, habitat characteristics, and fishery management considerations.
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Life History of Western Washington Winter Steelhead, a 30 Year Perspective Hal Michael Washington Department of Fish and Wildlife michahhm@dfw.wa.gov 360-902-2659
STEELHEAD ARE NOT SALMON • Salmon “overwhelm” the environment. • Salmon populations generally return and spawn over relatively short periods of time. • Salmon populations zero in on “one” solution to the ecosystem they live in.
Winter steelhead life history and population dynamics are what they are because they are necessary for the long term survival of the population. Survival of a population is dependant on retaining all aspects of a population, not just the most convenient.
BIOLOGICAL CHARACTERISTICS OF A HEALTHY POPULATION OF WILD WINTER STEELHEAD IN WESTERN WASHINGTON
RETURN TO FRESHWATER • Timing different for different ages
SPAWNING LOCATION • Prefer upper portions of tributaries • Mainstems not the preferred habitat for rearing, particularly lower mainstems
SPAWN TIMING • As with return timing, is lengthy. Generally February-May. • May be lots of wild spawning before March 15
SURVIVAL TO EMERGENCE • Varies within season. • May vary between seasons.
SMOLT AGES • Puyallup 2004-1:2:3, only 16 fish • 44:50:6 with age 1 fish averaging the longest • Snow/Salmon 1978-2001 • 10.3:82.4:7.3
STRAY RATES • Because they don ‘t die after spawning it is difficult to evaluate. • BC experience • Snow Creek first returns • Snow Creek repeat spawners.
REPEAT SPAWNERS • Apparently critical to long-term survival of run. • Waddell Creek NEVER (5 complete broods) had first returning spawners replace parent brood. • Keogh River has seen similar problem.
RESIDENT/ANADROMOUS • Resident “rainbow” an important part of population • Recognized as part of population in Waddell Creek. • Anadromy/residency optional depending on fish age, size, watershed conditions
HABITAT CHARACTERISTICS SUPPORTING A HEALTHY POPULATION OF WILD WINTER STEELHEAD IN WESTERN WASHINGTON
SALMON CREEK INCREASE IN LENGTHMANY CHUM SPAWN IN LOWER REACHES
Steelhead Parr per metre in Treatment and Control Habitats Greatest effect came from combined treatment of structures and nutrient enrichment. It is essentially additive.
WINTER HABITAT AVAILABILITY AND QUALITY DETERMINE SMOLT OUTPUT
FISHERY MANAGEMENT CHARACTERISTICS SUPPORTING A HEALTHY POPULATION OF WILD WINTER STEELHEAD IN WESTERN WASHINGTON
BASIC HARVEST MANAGEMENT CONSIDERATIONS • Harvest needs to come proportionally from all segments of the run. • Early returning segments need to be restored. • Repeat spawners need to be restored.
CATCH AND RELEASE • Very successful with resident trout. • Offers a conceptually satisfying fishery; high opportunity and low mortality. • Mortality measured at around 5%.
CATCH AND RELEASE CONCERNS • Successful C&R applied to post-spawning stocks. • Some evidence in sturgeon that C&R too close to spawning leads to resorption of eggs. • For SH, how does C&R “too close” to spawning affect spawning location, fry production, and survival to repeat spawn?
CHARACTERISTICS OF A HEALTHY WINTER STEELHEAD POPULATION I Return from ocean at least November to May Spawn at least January-May Repeat spawners make up a significant portion of escapement Spawn primarily in upper reaches of tributaries Smolt ages primarily 1 and 2 in south to 3 and 4 in north Freshwater habitat complex Streamflows controlled by natural forces and patterns
CHARACTERISTICS OF A HEALTHY WINTER STEELHEAD POPULATION II Resident and anadromous spawners present Large escapements of salmon in areas where steelhead spawn and rear. Spawner biomass of 1-2 kg per square metre
ONLY WHEN THE LAST TREE HAS DIED AND THE LAST RIVER HAS BEEN POISONED AND THE LAST FISH HAS BEEN CAUGHT WILL WE REALIZE THAT WE CAN NOT EAT MONEYmichahhm@dfw.wa.gov