Time to Evolve? Potential Evolutionary Responses of Fraser River Sockeye Salmon to Climate Change and Effects on Persistence
Authored by Daniel E Schindler, Thomas E Reed, Merran J Hague, David A Patterson, Eli Meir, Robin S Waples, Scott G Hinch
Date Published: 2011
DOI: 10.1371/journal.pone.0020380
Sponsors:
No sponsors listed
Platforms:
SimBiotic
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Evolutionary adaptation affects demographic resilience to climate change
but few studies have attempted to project changes in selective pressures
or quantify impacts of trait responses on population dynamics and
extinction risk. We used a novel individual-based model to explore
potential evolutionary changes in migration timing and the consequences
for population persistence in sockeye salmon Oncorhynchus nerka in the
Fraser River, Canada, under scenarios of future climate warming. Adult
sockeye salmon are highly sensitive to increases in water temperature
during their arduous upriver migration, raising concerns about the fate
of these ecologically, culturally, and commercially important fish in a
warmer future. Our results suggest that evolution of upriver migration
timing could allow these salmon to avoid increasingly frequent stressful
temperatures, with the odds of population persistence increasing in
proportion to the trait heritability and phenotypic variance. With a
simulated 2 degrees C increase in average summer river temperatures by
2100, adult migration timing from the ocean to the river advanced by
similar to 10 days when the heritability was 0.5, while the risk of
quasi-extinction was only 17\% of that faced by populations with zero
evolutionary potential (i.e., heritability fixed at zero). The rates of
evolution required to maintain persistence under simulated scenarios of
moderate to rapid warming are plausible based on estimated
heritabilities and rates of microevolution of timing traits in salmon
and related species, although further empirical work is required to
assess potential genetic and ecophysiological constraints on
phenological adaptation. These results highlight the benefits to salmon
management of maintaining evolutionary potential within populations, in
addition to conserving key habitats and minimizing additional stressors
where possible, as a means to build resilience to ongoing climate
change. More generally, they demonstrate the importance and feasibility
of considering evolutionary processes, in addition to ecology and
demography, when projecting population responses to environmental
change.
Tags
Life-history
Extinction risk
Fresh-water
Conservation biology
Oncorhynchus-nerka
British-columbia
Pacific salmon
Spawning migration
Contemporary evolution
Migration mortality