Spatial decoupling of α and β diversity suggest different management needs for coral reef fish along an extensive mid-oceanic ridge

Karkarey, Rucha, Arthur, Rohan, Nash, Kirsty L., Pratchett, Morgan S., Sankaran, Mahesh, and Graham, Nicholas A.J. (2022) Spatial decoupling of α and β diversity suggest different management needs for coral reef fish along an extensive mid-oceanic ridge. Global Ecology and Conservation, 36. e02110.

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Understanding the underlying drivers of biodiversity is essential for conservation planning of large, connected seascapes. We tested how patterns in α and β components of species and functional diversity of coral reef fish (214, species, 23 families) varied along the extensive Chagos-Lakshadweep oceanic ridge (the largest chain of mid-oceanic atolls in the Indian Ocean) and evaluated geomorphological, environmental, and anthropogenic predictors of diversity patterns. α and β diversity (species and functional) showed contrasting patterns along the ridge; richness and α diversity decreased towards the north and were influenced by anthropogenic pressures, while β diversity increased towards the north, along environmental gradients and with geographic distance. Species β diversity was dominated by turnover (> 80%), while functional β diversity was dominated by nestedness (> 60%). Geographically distant reefs (> 2000 km apart) with high structural complexity were functionally similar, illustrating a ridge-wide capacity for reefs to maintain ecological structure and function despite significant differences in biodiversity. Low spatial congruence in different facets of biodiversity suggest differentiated management needs for reef fish communities along the Chagos-Lakshadweep ridge. Specifically, while a single large marine reserve may be effective for biodiversity conservation in the Chagos archipelago in the south, a network of several smaller conservation areas may be needed to confer resilience to densely populated and biologically differentiated reefs further north.

Item ID: 74469
Item Type: Article (Research - C1)
ISSN: 2351-9894
Keywords: Coral reef fish, Taxonomic and functional diversity, Turnover and nestedness, α diversity, β diversity
Copyright Information: © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (
Funders: Australian Research Council (ARC)
Projects and Grants: ARC DE210100606
Date Deposited: 19 Oct 2022 01:36
FoR Codes: 31 BIOLOGICAL SCIENCES > 3103 Ecology > 310305 Marine and estuarine ecology (incl. marine ichthyology) @ 100%
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