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Title: Transcriptomic resilience, symbiont shuffling, and vulnerability to recurrent bleaching in reef‐building corals

As climate change progresses and extreme temperature events increase in frequency, rates of disturbance may soon outpace the capacity of certain species of reef‐building coral to recover from bleaching. This may lead to dramatic shifts in community composition and ecosystem function. Understanding variation in rates of bleaching recovery among species and how that translates to resilience to recurrent bleaching is fundamental to predicting the impacts of increasing disturbances on coral reefs globally. We tracked the response of two heat sensitive species in the genusAcroporato repeated bleaching events during the austral summers of 2015 and 2017. Despite a similar bleaching response, the speciesAcropora gemmiferarecovered faster based on transcriptome‐wide gene expression patterns and had a more dynamic algal symbiont community thanAcropora hyacinthusgrowing on the same reef. Moreover,A. gemmiferahad higher survival to repeated heat extremes, with six‐fold lower mortality thanA. hyacinthus. These patterns suggest that speed of recovery from a first round of bleaching, based on multiple mechanisms, contributes strongly to sensitivity to a second round of bleaching. Furthermore, our data uncovered intragenus variation in a group of corals thought generally to be heat‐sensitive and therefore paint a more nuanced view of the future health of coral reef ecosystems against a backdrop of increasing thermal disturbances.

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Author(s) / Creator(s):
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Publisher / Repository:
Date Published:
Journal Name:
Molecular Ecology
Page Range / eLocation ID:
p. 3371-3382
Medium: X
Sponsoring Org:
National Science Foundation
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