Download presentation
Presentation is loading. Please wait.
Published byRuth Hood Modified over 9 years ago
1
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
2
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.
3
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.
5
BIOLOGICAL CHARACTERISTICS OF A HEALTHY POPULATION OF WILD WINTER STEELHEAD IN WESTERN WASHINGTON
6
RETURN TO FRESHWATER
7
Timing different for different ages
9
SPAWNING LOCATION Prefer upper portions of tributaries Mainstems not the preferred habitat for rearing, particularly lower mainstems
11
SPAWN TIMING As with return timing, is lengthy. Generally February-May. May be lots of wild spawning before March 15
13
SURVIVAL TO EMERGENCE Varies within season. May vary between seasons.
15
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
16
Effect of nutrient addition on Keogh steelhead smolt ages
18
STRAY RATES Because they don ‘t die after spawning it is difficult to evaluate. BC experience Snow Creek first returns Snow Creek repeat spawners.
19
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.
20
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
23
HABITAT CHARACTERISTICS SUPPORTING A HEALTHY POPULATION OF WILD WINTER STEELHEAD IN WESTERN WASHINGTON
24
SALMON CREEK INCREASE IN LENGTH MANY CHUM SPAWN IN LOWER REACHES
25
SNOW CREEK INCREASE IN LENGTH FEW CHUM SPAWN IN CREEK
26
SOOS CREEK STEELHEAD REMOVE LOW FLOW YEARS
27
Steelhead Parr per metre in Treatment and Control Habitats Greatest effect came from combined treatment of structures and nutrient enrichment. It is essentially additive.
28
WINTER HABITAT AVAILABILITY AND QUALITY DETERMINE SMOLT OUTPUT
29
STREAM FLOWS/HYDROGRAPH
30
FISHERY MANAGEMENT CHARACTERISTICS SUPPORTING A HEALTHY POPULATION OF WILD WINTER STEELHEAD IN WESTERN WASHINGTON
31
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.
32
CATCH AND RELEASE Very successful with resident trout. Offers a conceptually satisfying fishery; high opportunity and low mortality. Mortality measured at around 5%.
33
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?
36
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
37
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
38
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 MONEY michahhm@dfw.wa.gov
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.