Contrasting Structural Changes in Two Benthic Invertebrate Communities After an Extraordinary Rainfall Event in...

Area of Science:

• Marine Biology
• Ecology
• Climate Science

Background:

• Coral reef intertidal zones are sensitive to environmental changes.
• Extreme weather events pose increasing threats to marine ecosystems.
• Understanding site-specific impacts is crucial for conservation.

Purpose of the Study:

• To compare benthic community structure changes in two distinct coral reef intertidal zones (Shanfu and Duozaiping) on Liuqiu Island.
• To analyze the impact of a prolonged precipitation event in 2021 on these communities.
• To assess extreme rainfall trends using the Standardized Precipitation Index (SPI) for coastal management.

Main Methods:

• Two-way ANOVA tests were used to determine variations in diversity indices (density, richness, dominance, diversity, evenness) between sites and years (2020-2022).
• Benthic community clustering analysis was performed to identify temporal shifts.
• Meteorological data (1997-2022) and Standardized Precipitation Index (SPI) were analyzed to understand rainfall trends.

Main Results:

• Significant differences in benthic community indices were observed between Shanfu (SF) and Duozaiping (DU) sites, with site being a more significant factor than year.
• The Duozaiping benthic community showed distinct clustering (before, after, 1-year post-rainfall), while Shanfu did not.
• Echinodermata was identified as the key taxon driving these community differences, potentially due to longer-lasting thermal and salinity stresses at the broader DU reef flat.

Conclusions:

• Coral reef benthic communities exhibit differential vulnerability to natural disturbances like extreme rainfall.
• Site characteristics, such as reef flat width, influence community resilience and recovery.
• Findings provide critical data for regional management strategies to mitigate climate change impacts on coral reefs.