Human mining activity across the ages determines the genetic structure of modern brown trout (Salmo trutta L.) populations

Abstract

Humans have exploited the earth's metal resources for thousands of years leaving behind a legacy of toxic metal contamination and poor water quality. The southwest of England provides a well-defined example, with a rich history of metal mining dating to the Bronze Age. Mine water washout continues to negatively impact water quality across the region where brown trout (Salmo trutta L.) populations exist in both metal-impacted and relatively clean rivers. We used microsatellites to assess the genetic impact of mining practices on trout populations in this region. Our analyses demonstrated that metal-impacted trout populations have low genetic diversity and have experienced severe population declines. Metal-river trout populations are genetically distinct from clean-river populations, and also from one another, despite being geographically proximate. Using approximate Bayesian computation (ABC), we dated the origins of these genetic patterns to periods of intensive mining activity. The historical split of contemporary metal-impacted populations from clean-river fish dated to the Medieval period. Moreover, we observed two distinct genetic populations of trout within a single catchment and dated their divergence to the Industrial Revolution. Our investigation thus provides an evaluation of contemporary population genetics in showing how human-altered landscapes can change the genetic makeup of a species.

Lost in parameter space: a road map for stacks

“…The TRT dataset showed a moderate number of fixed SNPs, and the highest number of polymorphic r80 loci was recovered for n = M −1. This is in accordance with high levels of differentiation between geographically proximate populations of the species, occupying metal‐contaminated and clean rivers (Paris, King & Stevens ). In king penguins, studies have shown low levels of genetic divergence both within (Cristofari et al .…”

“…We used three empirical RAD‐seq datasets for analysis, representing a phylogenetically diverse group of organisms (Table ). The first dataset ( TRT ) consists of data from brown trout ( Salmo trutta L.) samples occupying two different environmental niches (Paris, King & Stevens ): clean (8 individuals) and metal‐impacted (8 individuals) sites. The second dataset ( PGN ) is from the king penguin ( Aptenodytes patagonicus), from two different colonies on different archipelagos (Cristofari et al .…”

Investigating patterns of straying and mixed stock exploitation of sea trout, Salmo trutta, in rivers sharing an estuary in south‐west England

“…; Paris et al . ), although markedly greater than values detected between Atlantic salmon populations in the Tamar catchment (Ellis et al . ).…”

Recent genetic changes in enhanced populations of sea trout (Salmo truttam.trutta) in the southern Baltic rivers revealed with SNP analysis

“…Jager et al 2001;Morita and Yamamoto 2002). All of them have genetic consequences, for example reduction in effective population size, shift in migration-selection-drift equilibrium and in local adaptations (Meldgaard et al 2003;Faulks et al 2011;Paris et al 2015). A divergence of brown trout populations isolated by dams established as early as middle ages has been found ).…”