Dissecting coral recovery: bleaching reduces reproductive output in Acropora millepora

• DOI: 10.1007/s00338-024-02483-y
• Publication Date: 2024-03-20T05:09:00Z
• Authors: Nico D. Briggs; Cathie A. Page; Christine Giuliano; Cinzia Alessi; Mia Hoogenboom; Line K. Bay; Carly J. Randall
• Keywords: Acropora; Coral bleaching

Abstract Increasingly frequent and severe bleaching events driven by climate change are decreasing coral populations worldwide. Recovery of these relies on reproduction the survivors such including local upstream larval sources. Yet, corals that survive may be impaired sublethal effects suppress reproduction, reducing input to reefs, consequently impeding recovery. We investigated impact 2020 mass-bleaching event Acropora millepora inshore, turbid reefs in Woppaburra sea Country (the Keppel Islands), improve our understanding populations. A. experienced high incidence but low mortality across island group during this thus constituted an ideal population investigate potential reproductive output. Six months after heat wave, just prior spawning, we collected, decalcified, dissected samples from 94 tagged colonies with a known response, relationships between stress severity reproduction. Despite having regained their pigmentation, detected significant reduction fecundity had bleached severely. Considering sampled (i.e., mortality, colony size), coupled reductions fecundity, estimated total decrease population-level output 21%. These results suggest reduced recovery following should considered alongside traditional estimates mortality.