Data from "Strong environmental and genome-wide population differentiation underpins adaptation and high genomic vulnerability in the dominant Australian kelp (Ecklonia radiata)"

AbstractOngoing and predicted range loss of kelp forests in response to climatic stressors are pressing marine managers to look into the adaptive capacity of populations to inform conservation strategies. Characterising how adaptive genetic diversity and structure relate to present and future environmental variation represents an emerging approach to quantifying kelp vulnerability to environmental change and identifying populations with genotypes that potentially confer an adaptive advantage for copying with future ocean conditions.The dominant Australian kelp, Ecklonia radiata, was genotyped from 10 locations spanning 2,000 km of coastline and a 9.5°C average temperature gradient, along the east coast of Australia, a global warming hotspot. ddRAD sequencing was used to generate 10,700 high quality single nucleotide polymorphisms (SNPs) and characterize levels of neutral and adaptive genomic diversity and structure. The adaptive dataset, reflecting portions of genome putatively under selection, was used to infer genomic vulnerability by 2050 under the RCP 8.5 scenario.There was strong neutral genetic differentiation between Australia mainland and Tasmanian populations, but only weak genetic structure among mainland populations within the main path of the East Australian Current. Genetic diversity was highest in the centre of the range, and lowest in the warm-edge population. The adaptive SNP candidates revealed similar genetic structure patterns with a spread of adaptive alleles across most warm (northern) populations. The lowest, but most unique, adaptive genetic diversity values were found in both warm and cool population edges, suggesting local adaptation but low evolutionary potential. Critically, genomic vulnerability modelling identified high levels of vulnerability to future environmental conditions in Tasmanian populations. Populations of kelp at range edges are unlikely to adapt and keep pace with predicted climate change. Ensuring the persistence of these kelp forests, by boosting resilience to climate change, may require active management strategies with assisted adaptation in warm-edge (northern) populations and assisted gene flow in cool-edge (Tasmania) populations.