Emergent patterns of reef fish diversity correlate with coral assemblage shifts along the Great Barrier Reef

• Published in: Nature communications 2025-01, Vol.16 (1), p.303, Article 303
• Main Authors: González-Barrios, F. Javier, Keith, Sally A., Emslie, Michael J., Ceccarelli, Daniela M., Williams, Gareth J., Graham, Nicholas A. J.
• Format: Article
• Language: English
• Subjects: 631/158/2165; 631/158/851; 631/158/853; Animals; Anthozoa - classification; Anthozoa - physiology; Anthropocene; Anthropogenic factors; Australia; Biodiversity; Climate Change; Composition; Coral Reefs; Correlation; Decoupling; Fish; Fishes - classification; Fishes - physiology; Fluctuations; Humanities and Social Sciences; Latitude; multidisciplinary; Pattern analysis; Population decline; Reef fish; Science; Science (multidisciplinary); Species diversity; Species richness
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-55128-7

Escalating climate and anthropogenic disturbances draw into question how stable large-scale patterns in biological diversity are in the Anthropocene. Here, we analyse how patterns of reef fish diversity have changed from 1995 to 2022 by examining local diversity and species dissimilarity along a large latitudinal gradient of the Great Barrier Reef and to what extent this correlates with changes in coral cover and coral composition. We find that reef fish species richness followed the expected latitudinal diversity pattern (i.e., greater species richness toward lower latitudes), yet has undergone significant change across space and time. We find declines in species richness at lower latitudes in recent periods but high variability at higher latitudes. Reef fish turnover continuously increased over time at all latitudes and did not show evidence of a return. Altered diversity patterns are characterised by heterogeneous changes in reef fish trophic groups across the latitudinal gradient. Shifts in coral composition correlate more strongly with reef fish diversity changes than fluctuations in coral cover. Our findings provide insight into the extent to which classic macroecological patterns are maintained in the Anthropocene, ultimately questioning whether these patterns are decoupling from their original underlying drivers. Coral reefs have been severely affected by anthropogenic stress. Using long term data from the Great Barrier Reef, this study found temporal changes in the latitudinal diversity gradient, and stronger correlations between coral assemblage changes and fish diversity than with coral cover fluctuations.