Integrating otolith and genetic tools to reveal intraspecific biodiversity in a highly impacted salmon population.

Autor: Willmes M; Norwegian Institute for Nature Research, Trondheim, Norway.; Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, USA., Sturrock AM; Center for Watershed Sciences, University of California Davis, Davis, California, USA.; School of Life Sciences, University of Essex, Colchester, UK., Cordoleani F; Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, USA.; National Marine Fisheries Service, Southwest Fisheries Science Center, Santa Cruz, California, USA., Hugentobler S; Department of Integrative Biology, Michigan State University, East Lansing, Michigan, USA., Meek MH; Department of Integrative Biology, Michigan State University, East Lansing, Michigan, USA.; The Wilderness Society, Bozeman, Montana, USA., Whitman G; Center for Watershed Sciences, University of California Davis, Davis, California, USA., Evans K; Center for Watershed Sciences, University of California Davis, Davis, California, USA., Palkovacs EP; Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, USA., Stauffer-Olsen NJ; Trout Unlimited, Emeryville, California, USA., Johnson RC; Center for Watershed Sciences, University of California Davis, Davis, California, USA.; National Marine Fisheries Service, Southwest Fisheries Science Center, Santa Cruz, California, USA.
Jazyk: angličtina
Zdroj: Journal of fish biology [J Fish Biol] 2024 Aug; Vol. 105 (2), pp. 412-430. Date of Electronic Publication: 2024 Jul 09.
DOI: 10.1111/jfb.15847
Abstrakt: Intraspecific biodiversity is vital for species persistence in an increasingly volatile world. By embracing methods that integrate information at different spatiotemporal scales, we can directly monitor and reconstruct changes in intraspecific biodiversity. Here we combined genetics and otolith biochronologies to describe the genotypic and phenotypic diversity of Chinook salmon (Oncorhynchus tshawytscha) in the Yuba River, California, comparing cohorts that experienced a range of hydroclimatic conditions. Yuba River salmon have been heavily impacted by habitat loss and degradation, and large influxes of unmarked hatchery fish each year have led to concern about introgression and uncertainty around the viability of its wild populations, particularly the rarer spring-run salmon. Otolith strontium isotopes showed that Yuba River origin fish represented, on average, 42% (range 7%-73%) of spawners across six return years (2009-2011, 2018-2020), with large interannual variability. The remainder of adult Chinook salmon in the river were primarily strays from the nearby Feather River hatchery, and since 2018 from the Mokelumne River hatchery. Among the Yuba-origin spawners, on average, 30% (range 14%-50%) exhibited the spring-run genotype. The Yuba-origin fish also displayed a variety of outmigration phenotypes that differed in the timing and size at which they left the Yuba river. Early-migrating fry dominated the returns (mean 59%, range 33%-89%), and their contribution rates were negatively correlated with freshwater flows. It is unlikely that fry survival rates are elevated during droughts, suggesting that this trend reflects disproportionately low survival of larger later migrating parr, smolts, and yearlings along the migratory corridor in drier years. Otolith daily increments indicated generally faster growth rates in non-natal habitats, emphasizing the importance of continuing upstream restoration efforts to improve in-river growing conditions. Together, these findings show that, despite a long history of habitat degradation and hatchery introgression, the Yuba River maintains intraspecific biodiversity that should be taken into account in future management, restoration, and reintroduction plans. The finding that genotypic spring-run are reproducing, surviving, and returning to the Yuba River every year suggests that re-establishment of an independent population is possible, although hatchery-wild interactions would need to be carefully considered. Integrating methods is critical to monitor changes in key genetic, physiological, and behavioral traits to assess population viability and resilience.
(© 2024 The Author(s). Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)
Databáze: MEDLINE
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