Genomic repeatability and predictability of local (mal)adaptation in a reef-building coral

Climate change is a growing threat to biodiversity, and the persistence of populations largely depends on their capacity to adapt to changing environmental conditions. Although there is an urgent need to forecast population adaptive potential, it is unclear how such predictions are affected by the genomic architectures underlying local adaptation across a species range. In this study, we examine the genomic basis of local adaptation of the short-distance dispersing coral Stylophora pistillata, sampled at forty-six sites across eight reefs of the Great Barrier Reef, Australia. Our results show that thermal adaptation for this species involves hundreds of genomic loci with combinations that differ across regions. Although adaptive loci were largely region-specific, genotype-environment relationships estimated across the range provided sensible predictions of regional-level local adaptation. Additionally, predicted shifts in genotype-environment associations under increased projected warming were highly spatially variable, both between and within geographic regions. While some Great Barrier Reef S. pistillata populations might be well-adapted for near-future (2050) and moderate (SSP1-2.6 and SSP2-4.5) climate warming, up to 30% may face severe maladaptation risk by 2100 under a high-emission (SSP5-8.5) scenario. Collectively, these findings offer new insights into the spatial distribution of adaptive potential in coral populations and how it might shape their resilience in a warming ocean.