Genomic changes revealed by repeated sampling of kelp exposed to an extreme marine heatwave
Abstract
Extreme climatic events are increasingly recognised as potent evolutionary forces, imposing sudden pressures on natural populations. Among these, marine heatwaves (MHWs) are major drivers of ecological change, causing mass mortality, range shifts, and community reorganisation, particularly in habitat-forming kelps. While their ecological impacts are well documented, the genomic consequences remain less clear. Specifically, MHWs can not only induce demographic bottlenecks but also potentially drive selection on loci associated with thermal tolerance, shifting allele frequencies in affected populations. Here, we leveraged historical samples to investigate temporal genetic changes in the kelp Ecklonia radiata (order Laminariales) at three locations in Western Australia over 16 years, spanning the severe 2011 MHW. Overall genetic diversity and composition remained largely stable before (2006, 2008) and after (2012, 2018, 2022) the event, likely reflecting population resilience. However, a subset of loci, including known temperature-associated loci, showed shifts in allele frequencies following the event. Moreover, the strongest and most numerous changes occurred at warmer, lower-latitude sites where ecological impacts of the MHW were greatest, potentially consistent with MHW-driven natural selection. These results demonstrate that MHWs, while not dramatically altering genome-wide diversity, may alter allele frequences at specific loci linked to thermal response, highlighting their role as episodic yet powerful drivers of evolutionary change in marine foundation species.
Related
- Evaluating nursing performance during heatwave simulations: Protocol for a repeated measures cross-over study
- Probiotic and postbiotic treatment improves coral health and promotes specific metabolic and microbiome changes in situ during a heatwave
- Tracking demographic changes in individual coral colonies through repeated photogrammetric surveys
- Genomic signatures of selection in Dazu Black goat (Capra hircus) revealed by whole-genome resequencing
- A distributed genomic architecture of repeated thermal adaptation in a low-dispersal marine invader
BibTeX
@article{edgeloe2026genomic,
title = {{Genomic changes revealed by repeated sampling of kelp exposed to an extreme marine heatwave}},
author = {Jane M. Edgeloe and Thomas Wernberg and Samuel Starko and Georgina V. Wood and Antoine J. P. Minne and Sofie Vranken and David Wheeler and Jacqueline Batley and Melinda A. Coleman},
journal = {Scientific Reports},
year = {2026},
month = oct,
doi = {10.1038/s41598-026-62722-w},
url = {https://www.nature.com/articles/s41598-026-62722-w},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Genomic changes revealed by repeated sampling of kelp exposed to an extreme marine heatwave
AU - Jane M. Edgeloe
AU - Thomas Wernberg
AU - Samuel Starko
AU - Georgina V. Wood
AU - Antoine J. P. Minne
AU - Sofie Vranken
AU - David Wheeler
AU - Jacqueline Batley
AU - Melinda A. Coleman
PY - 2026
DA - 2026/10/27
JO - Scientific Reports
DO - 10.1038/s41598-026-62722-w
UR - https://www.nature.com/articles/s41598-026-62722-w
AB - Extreme climatic events are increasingly recognised as potent evolutionary forces, imposing sudden pressures on natural populations. Among these, marine heatwaves (MHWs) are major drivers of ecological change, causing mass mortality, range shifts, and community reorganisation, particularly in habitat-forming kelps. While their ecological impacts are well documented, the genomic consequences remain less clear. Specifically, MHWs can not only induce demographic bottlenecks but also potentially drive selection on loci associated with thermal tolerance, shifting allele frequencies in affected populations. Here, we leveraged historical samples to investigate temporal genetic changes in the kelp Ecklonia radiata (order Laminariales) at three locations in Western Australia over 16 years, spanning the severe 2011 MHW. Overall genetic diversity and composition remained largely stable before (2006, 2008) and after (2012, 2018, 2022) the event, likely reflecting population resilience. However, a subset of loci, including known temperature-associated loci, showed shifts in allele frequencies following the event. Moreover, the strongest and most numerous changes occurred at warmer, lower-latitude sites where ecological impacts of the MHW were greatest, potentially consistent with MHW-driven natural selection. These results demonstrate that MHWs, while not dramatically altering genome-wide diversity, may alter allele frequences at specific loci linked to thermal response, highlighting their role as episodic yet powerful drivers of evolutionary change in marine foundation species.
SN - 2045-2322
ER -