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Main Authors: Buzzoni, Daisy, Lachs, Liam, Beauchamp, Elizabeth, Bukurou, Leah, Bythell, John, Edwards, Alasdair J, Golbuu, Yimnang, Humanes, Adriana, Martinez, Helios M, Mereb, Geory, Baum, Julia K, Guest, James R
Format: Artículo científico
Language:en
Published: Molecular ecology 2026
Subjects:
Online Access:https://pubmed.ncbi.nlm.nih.gov/41546521/
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author Buzzoni, Daisy
Lachs, Liam
Beauchamp, Elizabeth
Bukurou, Leah
Bythell, John
Edwards, Alasdair J
Golbuu, Yimnang
Humanes, Adriana
Martinez, Helios M
Mereb, Geory
Baum, Julia K
Guest, James R
author_facet Buzzoni, Daisy
Lachs, Liam
Beauchamp, Elizabeth
Bukurou, Leah
Bythell, John
Edwards, Alasdair J
Golbuu, Yimnang
Humanes, Adriana
Martinez, Helios M
Mereb, Geory
Baum, Julia K
Guest, James R
Buzzoni, Daisy
Lachs, Liam
Beauchamp, Elizabeth
Bukurou, Leah
Bythell, John
Edwards, Alasdair J
Golbuu, Yimnang
Humanes, Adriana
Martinez, Helios M
Mereb, Geory
Baum, Julia K
Guest, James R
collection PubMed - marine biology
contents Algal Symbionts Indicate Heatwave Vulnerability in Corals From Hotspots but Not From Thermal Refugia. Buzzoni, Daisy Lachs, Liam Beauchamp, Elizabeth Bukurou, Leah Bythell, John Edwards, Alasdair J Golbuu, Yimnang Humanes, Adriana Martinez, Helios M Mereb, Geory Baum, Julia K Guest, James R Animals Symbiosis Anthozoa Climate Change Hot Temperature Coral Reefs Dinoflagellida Refugium Thermotolerance Palau DNA Barcoding, Taxonomic Reef-building corals face continued declines due to climate change-amplified marine heatwaves. In addition to affecting coral heat tolerance, corals' algal endosymbionts (family Symbiodiniaceae) can reflect their prior heatwave exposure, although understanding is often limited to heatwave-induced shifts between symbiont genera. Here, we used ITS2 metabarcoding to characterise Symbiodiniaceae assemblages in 293 individuals of the common Indo-Pacific coral Acropora aff. digitifera in Palau (Western Pacific), between two outer-reef regions with contrasting heatwave histories. During the strongest recorded heatwaves, southwestern 'hotspot' reefs have typically accrued an additional 2°C-weeks of heat stress compared to thermal 'refugia' located 60 km north. In contrast to previous studies that observed declines in symbiont richness following heat stress, we found a greater diversity of symbiont taxa and low-abundance sequence variants in 'hotspot' corals, predominantly within the C40 lineage in genus Cladocopium. Combining these data with experimental heatwave performance from 168 of these corals revealed that approximately 10% of heat tolerance variability at hotspot reefs was associated with hosting different symbiont taxa. Compared to other hotspot corals, those hosting symbionts with the C15h sequence variant suffered bleaching mortality at 0.8°C-weeks lower heat stress. Despite higher variability in heat tolerance among corals from thermal refugia compared to hotspot reefs, we found no association between heat tolerance and the symbionts hosted by refugium corals. As the world's coral reefs are exposed to intensifying marine heatwaves under accelerating climate change, the low-abundance variants that characterise symbionts within genera or lineages may become increasingly important indicators of poor heatwave tolerance.
format Artículo científico
id pubmed_41546521
institution PubMed
language en
publishDate 2026
publisher Molecular ecology
record_format pubmed
spellingShingle Algal Symbionts Indicate Heatwave Vulnerability in Corals From Hotspots but Not From Thermal Refugia.
Buzzoni, Daisy
Lachs, Liam
Beauchamp, Elizabeth
Bukurou, Leah
Bythell, John
Edwards, Alasdair J
Golbuu, Yimnang
Humanes, Adriana
Martinez, Helios M
Mereb, Geory
Baum, Julia K
Guest, James R
Animals
Symbiosis
Anthozoa
Climate Change
Hot Temperature
Coral Reefs
Dinoflagellida
Refugium
Thermotolerance
Palau
DNA Barcoding, Taxonomic
Algal Symbionts Indicate Heatwave Vulnerability in Corals From Hotspots but Not From Thermal Refugia. Buzzoni, Daisy Lachs, Liam Beauchamp, Elizabeth Bukurou, Leah Bythell, John Edwards, Alasdair J Golbuu, Yimnang Humanes, Adriana Martinez, Helios M Mereb, Geory Baum, Julia K Guest, James R Animals Symbiosis Anthozoa Climate Change Hot Temperature Coral Reefs Dinoflagellida Refugium Thermotolerance Palau DNA Barcoding, Taxonomic Reef-building corals face continued declines due to climate change-amplified marine heatwaves. In addition to affecting coral heat tolerance, corals' algal endosymbionts (family Symbiodiniaceae) can reflect their prior heatwave exposure, although understanding is often limited to heatwave-induced shifts between symbiont genera. Here, we used ITS2 metabarcoding to characterise Symbiodiniaceae assemblages in 293 individuals of the common Indo-Pacific coral Acropora aff. digitifera in Palau (Western Pacific), between two outer-reef regions with contrasting heatwave histories. During the strongest recorded heatwaves, southwestern 'hotspot' reefs have typically accrued an additional 2°C-weeks of heat stress compared to thermal 'refugia' located 60 km north. In contrast to previous studies that observed declines in symbiont richness following heat stress, we found a greater diversity of symbiont taxa and low-abundance sequence variants in 'hotspot' corals, predominantly within the C40 lineage in genus Cladocopium. Combining these data with experimental heatwave performance from 168 of these corals revealed that approximately 10% of heat tolerance variability at hotspot reefs was associated with hosting different symbiont taxa. Compared to other hotspot corals, those hosting symbionts with the C15h sequence variant suffered bleaching mortality at 0.8°C-weeks lower heat stress. Despite higher variability in heat tolerance among corals from thermal refugia compared to hotspot reefs, we found no association between heat tolerance and the symbionts hosted by refugium corals. As the world's coral reefs are exposed to intensifying marine heatwaves under accelerating climate change, the low-abundance variants that characterise symbionts within genera or lineages may become increasingly important indicators of poor heatwave tolerance.
title Algal Symbionts Indicate Heatwave Vulnerability in Corals From Hotspots but Not From Thermal Refugia.
topic Animals
Symbiosis
Anthozoa
Climate Change
Hot Temperature
Coral Reefs
Dinoflagellida
Refugium
Thermotolerance
Palau
DNA Barcoding, Taxonomic
url https://pubmed.ncbi.nlm.nih.gov/41546521/