Pisapia, Chiara, Burn, Deborah, Hoey, Andrew S., Musthag, Azim, Ahmed, Basheer, Westphal, Hildegard ORCID: https://orcid.org/0000-0001-7324-6122, Afzal, Mariyam S. and Pratchett, Morgan S. (2025) Coral recovery versus reassembly following major disturbances in the Central Maldivian Archipelago. Coral Reefs . DOI https://doi.org/10.1007/s00338-025-02780-0.

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Abstract

Despite an increasing number of longer-term studies (> 5 years) that assess changes in the overall abundance (or cover) of reef-building corals following major disturbances, there is limited data on changes in population or community structure, which is necessary to assess coral resilience. This study investigates the early recovery of coral communities one year after (2017), and six years after (2022) the 2016 mass coral bleaching event focussing on key demographic processes driving coral population trajectories. We predicted that coral cover would increase significantly between 2017 and 2022, primarily driven by the regrowth of surviving Acropora colonies; coral juvenile density would increase over the same period, reflecting enhanced recruitment capacity; and community composition would not fully return to pre-disturbance (2016) assemblages within six years. Coral cover declined from 29.3% (± 6.4 SE) in 2016 to 6.93% (± 1.8 SE) in 2017, before increasing to 12.9% (± 3.8 SE) in 2022. Size frequency distributions of common coral taxa were characterized by a higher abundance of smaller colonies in 2017 (6.3–11.3 cm diameter), returning to a more even distribution among size classes in 2022, similar to pre-bleaching size structure in 2016. This suggests that the observed increase in coral cover occurred primarily through the growth of remnant colonies transitioning into larger size classes (> 63.5 cm diameter), rather than through recruitment and growth of juvenile corals. Marked shifts in coral community composition were also observed, with previously Acropora-dominated assemblages shifting to Porites and/or Pocillopora-dominated assemblages across most sites after bleaching in 2017. Sites initially dominated by Porites and Pocillopora showed minor compositional change before returning to a similar assemblage composition in 2022. Despite an increase in the relative abundance of Acropora, most communities had not yet returned to pre-disturbance community composition. Even six years after the bleaching, we found some sites showed limited signs of coral recovery, let alone reassembly. Given projected increases in the frequency and intensity of marine heatwaves combined with ongoing localized stressors, the opportunities for coral recovery in the aftermath of major disturbances will be increasingly constrained.

Document Type:	Article
Programme Area:	PA4
Research affiliation:	Biogeochemistry and Geology > Geoecology & Carbonate Sedimentology
Refereed:	Yes
Open Access Journal?:	No
DOI:	https://doi.org/10.1007/s00338-025-02780-0
ISSN:	0722-4028
Date Deposited:	18 Nov 2025 15:38
Last Modified:	18 Nov 2025 15:38
URI:	https://cris.leibniz-zmt.de/id/eprint/6010

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