Disentangling evolution and plasticity in adult sockeye migration date: a new method provides evidence of evolutionary change Lisa Crozier Mark Scheuerell Rich Zabel NWFSC, NOAA-Fisheries

Many populations have shifted the timing of life-history events in recent decades mean shift towards earlier spring timing of 2.3 days per decade 423 / 484 spp (87%) Parmesan & Yohe 2003 Nature 83.8% of 25,532 species earlier, avg 3.9 days per decade Thackeray 2010 GCB

British Columbia Oregon Washington Idaho Columbia R. Bonneville Dam Lower Granite Dam Snake R. Salmon R. Okanogan R. Columbia R. Salmon R. Basin Montana Grande Ronde R. Redfish L. L. Wenatchee ESU Okanogan ESU Osoyoos Lake Okanogan River Bonneville Dam Redfish Lake

Median migration date July 4 June 29 July 9 June 24 Sockeye migrate ~10.3 days earlier than in the 1940s

Summer and fall Chinook also changing Crozier et al Evolutionary applications 1:

The Columbia River has warmed dramatically over the 20 th century July temp ( o C)

High temperature blocks migration 10 year avg Chinook counts and daily mean temperature at Lower Granite Dam Number of Chinook Temperature ( o C)

This blockout period is lengthening 10 year avg Chinook counts and daily mean temperature at Lower Granite Dam Number of Chinook Temperature ( o C)

Disentangling plastic and genetic change is important for predictive modeling and to avoid negative anthropogenic impacts Evolution: adaptive genetic change in response to natural selection Plasticity: non-genetic response to environmental variation

1 st approach: simple linear regression shows flow-timing relationship

But the relationship differs in the early and late time periods

2 nd approach 1)Quantify historical selection pressure 2)Combine selection and plastic response in predictive model of annual migration date 3)Compare predicted and observed timing through model selection (AIC) (evolution, plasticity, or both)

Survival ~ temperature Daily mean temperature at Bonneville Dam ( o C) Survival to spawning grounds Crozier et al American Naturalist avail. online October

^ S = β = Annual selection differential (Median migration day of initial population – survivors) Crozier et al American Naturalist avail. online October

State-space model Median offspring cohort migration date ~ 1)Median parental cohort migration date 2)The response to selection on parents (~h 2 S) 3)Environmental effects on parents 4)Environmental effects on offspring Crozier et al American Naturalist avail. online October

Potential triggers of plasticity Ocean conditions –Upwelling strength –PDO –NPGO –NPI River conditions –Flow –Temperature Population interactions/ proportions

Results: Model Comparison Model-Average Results

Model prediction r 2 = 0.80 h 2 = 0.49 β = haldanes Crozier et al American Naturalist avail. online October

Drivers of overall trend 33-66% of trend (3-6 days) ~ Selection remainder ~ Flow Change in migration date

Summary  We found strong support for a role for selection, indicating that sockeye have likely been adapting to recent climate change  Both plastic and evolutionary responses appear important  These results are highly robust to uncertainty in selection function Crozier et al American Naturalist avail. online October

Caveats  Costs to earlier migration: energetic costs of holding pre-spawn mortality loss of feeding opportunity  Fishery-induced evolution also likely  Multiple populations make h 2 estimate rough

Conclusions  Evolution is contributing to phenotypic responses to environmental change in salmon  Hydrosystem management will likely affect both the strength of selection and the effectiveness of plastic cues for migration timing  Life-history trends reflect both heritable and non- heritable traits. Constraints on phenotypic evolution are not well understood, and might limit future responses to climate change

Thank you! George Naughton, Matt Keefer, Jeffery Fryer and collaborators for amazing tracking of sockeye through the Columbia Basin All the fish counters at dams Northwest Fisheries Science Center, and NOAA- Fisheries for data sharing infrastructure and financial support