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Dryad

Data from: Remnant salmon life history diversity rediscovered in a highly compressed habitat

Data files

May 10, 2024 version files 19.79 KB

Abstract

Chinook salmon (Oncorhynchus tshawytscha) display remarkable life history diversity underpinning their ability to adapt to environmental change. Maintaining life history diversity is vital to the resilience and stability of Chinook salmon metapopulations, particularly under rapidly changing climates. However, the conditions that promote life history diversity are rapidly disappearing, as anthropogenic forces promote homogenization of habitats and genetic lineages. In this study, we use the highly modified Yuba River in California to understand if distinct genetic lineages and life history still exist, despite reductions in spawning habitat and hatchery practices that have promoted introgression. There currently is a concerted effort to protect federally listed spring run populations, given that few wild populations still exist. Despite this, we lack a comprehensive understanding of the genetic and life history diversity of Chinook salmon present in the Yuba River system. To understand this diversity, we collected migration timing data and GREB1L genotypes from hook-and-line, acoustic tagging, and carcass surveys of Chinook salmon in the Yuba River between 2009-2011. Variation in the GREB1L region of the genome is tightly linked with run timing in Chinook salmon throughout the range, but the relationship between this variation and entry on spawning grounds is little explored in the Central Valley. We found that the date Chinook salmon crossed the lowest barrier to Yuba River spawning habitat (Daguerre Point Dam) was tightly correlated with their GREB1L genotype. Importantly, our study confirms that ESA-listed spring run Chinook salmon are spawning in the Yuba River, promoting a portfolio of life history and genetic diversity, despite spawning in a compressed habitat. This work highlights the need to identify and protect this life history diversity in heavily impacted systems to maintain healthy Chinook salmon metapopulations in those systems. Without this, we run the risk of losing the last vestiges of important variation.