Abstract

This study provides a comprehensive long-term analysis of the diversity and distribution patterns of marine mollusks inhabiting rocky shore ecosystems along the coast of Uljin, Gyeongbuk. From August 2012 to February 2024, surveys were conducted eight times at 11 stations over approximately 12 years using scientific diving and quadrat sampling methods. A total of 124 molluscan species belonging to 45 families, 18 orders, and 4 classes were identified, with Gastropoda showing the highest species richness (79 species, 63.7%). Analysis of vertical distribution revealed distinct differences in species composition between habitats, with 29 species recorded in the intertidal zone and 108 species in the subtidal zone. Dominance analysis indicated that the periwinkle Echinolittorina radiata and the mussel Modiolus kurilensis were the primary and secondary dominant species, respectively, representing key components of the rocky shore ecosystems molluscan community in Uljin. Long-term monitoring also revealed the emergence of new species such as Turbo cornutus, Chlorostoma turbinatum, Omphalius pfeifferi pfeifferi, Lacuna turrita, and Mitrella bicincta. Notably, the occurrence of the subtropical species Turbo cornutus suggests that rising seawater temperatures driven by climate change are influencing the structure and distribution of mollusks along the East Sea coast. This study provides fundamental data on molluscan diversity in the rocky shore ecosystem of Uljin and offers important scientific evidence for understanding the long-term ecological impacts of climate change on the marine ecosystems of the East Sea.