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Explore the variability in smolting and early male maturation of Yakima River spring Chinook salmon based on emergence timing. An in-depth study conducted by NOAA Fisheries and SAFS, University of Washington. Investigating life history decisions influenced by emergence timing in a thought experiment. Results analyzed show implications on male maturation and ecological factors.
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Variation in emergence timingpromotes variability in smolting andearly male maturation in YakimaRiver spring Chinook salmon Yes - this is the same title as last year,Molly used the old one since I was late in sending her a new oneThe talk will be different(I promise) Brian Beckman, Don Larsen, Paul Parkins, Deb Harstad, Dina Spangenberg and Kathy CooperNOAA Fisheries and SAFS University of Washington
That is getting more complicated miniJacks age 2 microJacks (precocious parr) age 1 18 16 14 12 10 8 May Sep May May May May May Sep Sep Sep Sep Sep Jan Jan Jan Jan Jan 0-age smolt Spring Chinook salmon life cycle: A simple story hours of daylight summer 4’s 5’s Jacks age 3 spawn Smolt age 1.5 emerge winter
Does this variation occur in Yakima River spring Chinook salmon?What is/are mechanism(s) inducing variation?Does this variation occur in the wild?(a thought experiment)
10 years of sampling, >12,000 fish = 2 precocious parr (<0.02%) Why so few microJacks?
One of the reasons CESRF is special: (there are many) Seasonal timing for ponding fry
Fry are ponded “late” - avoid silting of ponds, smaller size “normal” distribution of emergence time Compress and shift late (incubate at cold temp) 3 months CESRF 3 weeks
Experimental Question: What is the effect of emergence timing on life-history decisions? Experimental approach: Pond fry at 3 different photoperiods 1 December (early) 15 February (middle) 1 May (late)
Experimental approach II: feed fry at 3 different rates Low High Satiation (1st half of experiment only)
18 16 14 12 10 8 Experimental emergence (ponding) times spanned range from aggressive hatchery program to coldest, high elevation sites Emergence dates Hours of daylight D J F M A M J J A S O N D
240 220 200 180 160 140 120 100 80 60 40 20 Emergence and growth of fish varied Length (mm) Jan Mar May Jul Sep Nov Jan Mar May Jul Thanks to Charlie Strom and CESRF staff for eggs
smolts Monitoring Smolting #1:24 hr seawater challenge freshwater sea water parr 0% survival 100% survival
110 90 70 50 30 10 -10 Late emerge fish smolt in the spring as yearlings Gill Na+ K + ATPase activity LateEmerge 24 hr SW survival (%) Jan Mar May Jul Sep Nov Jan Mar May Jul
110 MiddleEmerge 90 70 50 30 10 -10 Middle emerge fish smolt in the spring as yearlings Gill Na+ K + ATPase activity a little something happening 24 hr SW survival (%) Jan Mar May Jul Sep Nov Jan Mar May Jul
Smolting in early emerge fish is variable Gill Na+ K + ATPase activity 24 hr SW survival (%) Jan Mar May Jul Sep Nov Jan Mar May Jul
Smolting summary: early emerging fish smolted both in the summer/ autumn (under-yearling) and spring (yearling). middle and late emerging fish smolted in the spring as yearlings.
Monitor Age-1 (precocious parr) Maturation:milt expression or simple dissection
Gender ratios were similar between treatments and were not different than 50:50 Females % of total fish feed rate early middle late emergence timing
Lo Lo Lo Hi Hi Hi The late emergence treatment produced almost no microJacks % of total males microJacks (age 1) early middle late emergence timing
50 40 early, HF early, LF early, SF 30 late, HF late, LF late, SF 20 middle, HF middle, LF middle, SF 10 0 Proportion of microJacks (age 1) varies negatively with emergence timing % of total males Dec Jan Feb Mar Apr May emergence timing
Lo Lo Lo Hi Hi Hi Proportion of miniJacks (age 2) varies with treatment % of total males emergence timing
If a parr becomes a microJack there was no opportunity for that fish to subsequently become a miniJack parr miniJack microJack smolt • So, need to redo the math: %miniJacks = # miniJacks/(#total males - #microJacks)
No difference in % miniJacks among emergence timing => Propensity to mature as a miniJack dependent on growth the previous year % of males not microJacks No significant differences between emergence times
Lo Lo Lo Hi Hi Hi 60 50 40 30 20 10 0 The overall accounting: Total mature males (micro + mini) is higher in early emerging fish % of total males early middle late
The Yakima Basin Ellensburg Roza Dam Yakima
no dam A dam The upper Yakima Basin Teanaway River Easton Cle Elum Cle Elum River
a temperature logger Not a beer Teanaway River Cle Elum River Andy Dittman
Differences in water temperature may drive differences in life history Winter temperature units measured estimated
Cle Elum calculated emergence Teanaway calculated emergence 50 40 30 20 10 0 Proportion of microJacks in the Upper Yakima Basin may differ based on differences in temperature % microJacks in experiment D J F M A M J J A S O N
The Yakima Basin Ellensburg Roza Dam Yakima What about the lower river?
Conclusions Early life history of Yakima River spring Chinook salmon may be variable Thermal regimes may vary regionally within the Yakima Basin This thermal variation may have significant affects on life history variability One of the primary mechanisms through which thermal affects may modulate life history is variation in emergence timing