Distribution Patterns of Macrobenthic Invertebrates in the Rocky Intertidal Zone of the Byeonsan Peninsula

This study investigated the community structure and distribution patterns of macrobenthic invertebrates in the rocky intertidal zone of the Byeonsan Peninsula from March 2023 to January 2024. A total of 78 species were recorded during the survey period, with mean abundance and biomass estimated at approximately 171.4 ind./m² and 258.5 gWWt/m², respectively. Mollusks were the most dominant taxonomic group in terms of species richness, accounting for 36 species (46.2%), followed by arthropods with 18 species (23.1%), annelids with 12 species (15.4%), and echinoderms with 4 species (5.1%). The five most dominant species based on density were Mytilisepta virgata, Reishia clavigera, Chthamalus challengeri, Lunella correensis, and Magallana gigas, whereas the dominant species based on biomass were Reishia clavigera, Magallana gigas, Lunella correensis, Tegula turbinata, and Mytilus galloprovincialis. Community analysis revealed that the five sampling sites were classified into two distinct groups, with Sites 1, 2, and 5 forming Group A and Sites 3 and 4 forming Group B, indicating spatial differences in macrobenthic community composition. These differences are likely associated with environmental gradients in the intertidal zone, such as wave exposure and substrate characteristics.