Journal article
Cross‐Depth Genetic Connectivity Supports the Role of Deep Kelp Forests as Refuge From Climate Change
Diversity & distributions, Vol.32(5), pp.1-19
05/2026
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Abstract
Aim: Ocean warming and marine heatwaves are threatening the persistence of kelp forests, but cooler, deeper reefs might act as refuges from which shallow populations can recover. This study aimed to assess the genetic connectivity, diversity, and adaptive structure of deep kelp reefs to evaluate their potential as climate refuges.
Location: Three regions in Western Australia were studied: the Abrolhos Islands, Albany, and Esperance.
Methods: We used ddRAD sequencing to compare neutral and adaptive genetic diversity and determine the genetic connectivity between deep (30–50 m) and shallow (10–15 m) populations of the kelp Ecklonia radiata. We also compared allele frequencies of loci putatively under selection across depths and between the warm range edge and cooler populations to better understand adaptation across contrasting environmental conditions.
Results: There was no significant difference in genetic diversity and weak neutral genetic differentiation between depths at each location, supported by high bi-directional gene flow. The SNP outliers revealed broad-scale adaptive divergence across the sampled range, marked by numerous fixed alleles under selection. Depth-specific selection was only detected at the warm edge population (Abrolhos Islands), with elevated levels of loci under selection and greater adaptive differentiation between depths. These outlier loci were associated with genes involved in thermotolerance, light sensing, immune response, and general environmental stress responses.
Main Conclusion: At high latitude, the extensive gene flow across depths and the lack of adaptive differentiation suggest high potential for deep kelps to facilitate the recovery of shallow reefs following climate-mediated loss. In contrast, at the warmer range edge, depth-specific adaptation could lead to maladaptation if shallow reefs are reseeded from deep reefs following loss. Hence, the role of deep reefs as refuge from which shallow reefs can recover following climate-mediated loss is spatially dependent on local selective regimes.
Details
- Title
- Cross‐Depth Genetic Connectivity Supports the Role of Deep Kelp Forests as Refuge From Climate Change
- Creators
- Antoine J. P. Minne - The University of Western AustraliaThomas Wernberg - The University of Western AustraliaDave Wheeler - Department of Primary Industries and Regional DevelopmentJacqueline Batley - The University of Western AustraliaMelinda A. Coleman - The University of Western Australia
- Publication Details
- Diversity & distributions, Vol.32(5), pp.1-19
- Publisher
- Wiley
- Number of pages
- 19
- Grant note
- Australian Research Council (DP240100230)
- Identifiers
- 991013380342602368
- Copyright
- © 2026 The Author(s). Diversity and Distributions published by John Wiley & Sons Ltd.
- Academic Unit
- Faculty of Science and Engineering; Science
- Language
- English
- Resource Type
- Journal article