Genomic and oceanographic evidence of reef connectivity across the western and central Indian Ocean
- 1Institute of Zoology, zoological society of London
Abstract
Connectivity among coral populations, via larval dispersal, is one of the key mechanisms supporting reef recovery after climate-driven bleaching events. This study examines reef connectivity of remote atolls of the understudied central and western Indian Ocean seascape, focusing on a key reef-building species, Acropora aff. tenuis. Using genomic data from ultra-conserved elements alongside particle-tracking simulations, we investigate patterns of population structure and gene flow, and the influence of ocean currents. Results show asymmetrical connectivity: strong gene flow occurs within the Chagos Archipelago and between Chagos and the Inner Seychelles, highlighting their importance as regional larval sources. In contrast, the Outer Seychelles mainly functions as a larval sink, and IIes Glorieuses appears to be the least connected. Whilst population structure suggests a partially permeable dispersal barrier between the Inner and Outer Seychelles. Differences between genetic patterns and simulated ocean-driven dispersal suggest that ocean currents are not the only important driver of connectivity patterns. Additional factors, such as stepping-stone dispersal among atolls, fine-scale oceanographic processes, and species biology likely play important roles. Overall, we find widespread genomic connectivity across this seascape, which has positive implications for reef resilience, though future resilience will depend on frequency and severity of future bleaching events.
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BibTeX
@misc{head2026genomic,
title = {{Genomic and oceanographic evidence of reef connectivity across the western and central Indian Ocean}},
author = {C. E. I. Head and L. Colin and P. Hosegood and M. L. Taylor and M. B. Arias-Mella and A. J. Burt and A. Koester and M. Steyaert and T. Bridge and C. Yesson},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.22.761076},
url = {https://www.biorxiv.org/content/10.64898/2026.10.22.761076v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Genomic and oceanographic evidence of reef connectivity across the western and central Indian Ocean
AU - C. E. I. Head
AU - L. Colin
AU - P. Hosegood
AU - M. L. Taylor
AU - M. B. Arias-Mella
AU - A. J. Burt
AU - A. Koester
AU - M. Steyaert
AU - T. Bridge
AU - C. Yesson
PY - 2026
DA - 2026/10/22
PB - bioRxiv
DO - 10.64898/2026.10.22.761076
UR - https://www.biorxiv.org/content/10.64898/2026.10.22.761076v1
AB - Connectivity among coral populations, via larval dispersal, is one of the key mechanisms supporting reef recovery after climate-driven bleaching events. This study examines reef connectivity of remote atolls of the understudied central and western Indian Ocean seascape, focusing on a key reef-building species, Acropora aff. tenuis. Using genomic data from ultra-conserved elements alongside particle-tracking simulations, we investigate patterns of population structure and gene flow, and the influence of ocean currents. Results show asymmetrical connectivity: strong gene flow occurs within the Chagos Archipelago and between Chagos and the Inner Seychelles, highlighting their importance as regional larval sources. In contrast, the Outer Seychelles mainly functions as a larval sink, and IIes Glorieuses appears to be the least connected. Whilst population structure suggests a partially permeable dispersal barrier between the Inner and Outer Seychelles. Differences between genetic patterns and simulated ocean-driven dispersal suggest that ocean currents are not the only important driver of connectivity patterns. Additional factors, such as stepping-stone dispersal among atolls, fine-scale oceanographic processes, and species biology likely play important roles. Overall, we find widespread genomic connectivity across this seascape, which has positive implications for reef resilience, though future resilience will depend on frequency and severity of future bleaching events.
ER -