From deployment to functioning ecosystems: assessing taxonomic richness and community composition on modular shellfish reefs using environmental DNA metabarcoding

Genus richness on modular shellfish reefs increased rapidly after deployment, reaching early gains within 9 months, while community composition continued shifting across a 9–42 month age gradient.

• Why it matters: Restoration monitoring often depends on poorly defined historical reference states and richness alone, which can miss successional community changes and the emergence of functionally important taxa.
• What they did: Using environmental DNA metabarcoding, the study modeled taxon-specific genus richness and applied multivariate community composition analyses across reef ages of 9, 21, and 42 months over four years.
• The result: Community composition was strongly age-structured, with younger reefs distinct from older ones and within-age variability declining with age, implying convergent successional assembly beyond richness metrics.