Effects of Artificial Reefs on the Macrobenthic Community Structure Through Functional Trait Analysis

Abstract

Artificial reefs enhance marine biodiversity by increasing habitat complexity and heterogeneity, which in turn provide living space for various marine species. Macrobenthos, an important component of aquatic ecosystems, with limited mobility and sensitivity to environmental changes, commonly serve as indicators of aquatic ecosystem health. This study, conducted in the summer and autumn of 2022 in Sishili Bay (SB) and the Changdao Archipelago (CA), Yantai, China, aimed to evaluate the effects of artificial reefs on macrobenthic community structure using functional trait analysis. The nonmetric multidimensional scaling (nMDS) analysis based on species abundance and occurrence frequency did not reveal any clear separation between areas inside and outside the artificial reefs. However, the construction of artificial reefs increased the species number of macrobenthos, especially the Mollusca species. Feeding type, a key functional trait, distinguished areas inside and outside artificial reefs, with significant spatial and temporal variations. The key species driving differences between reef and nonreef areas include the carnivorous Lumbrineris longifolia and Glycinde bonhourei and the omnivorous Eriopisella sechellensis and Sigambra bassi, which were pivotal in the observed variations in relative abundance. Functional richness (FRic) and species richness (S) showed consistent patterns of variation, both contributing to improving the community stability in summer. However, in autumn, community stability was reduced by the extraordinary dominance of a single species. Multiple environmental factors rather than a single one significantly influenced species distribution and diversity, reflecting the complex interplay of reefs and seasonal dynamics. This study used functional trait analysis to assess the impact of artificial reefs on macrobenthic community structure, offering a more effective measure than species-level assessments.