Intertidal Zonation of the Macroinfauna in Five Sandy Beaches on the East Coast of Korea

초록

Five sandy beaches on the east coast of Korea were surveyed from October 19 to October 21, 2010 during spring low tides. A transect line was laid out from above the high water mark to the low tide swash zone and 11 stations were demarcated along this line at similar slope intervals. Sampling was conducted using a corer with a 15cm diameter, and five replicates were collected from each location. The samples were then sieved in situ through a 1mm mesh, after which the collected organisms were stored in 5% formalin and identified to the species level in the laboratory. A total of 11 species were identified. Crustaceans were the most diverse group in terms of both numbers of species and numbers of individuals. Specifically, Trinorchestia longiramus, Excirolana chiltoni, Tylos granuliferus, Archaeomysis grebnitzkii, and Grandifoxus sp. were dominant, although some other species such as a glycerid polychaete, Hemipodus yenourensis, a venerid bivalve, Macridiscus melanaegis, and the polygordid annelid were observed in some stations. Analysis of similarities (ANOSIM) indicated that the species distribution did not differ between beaches. Cluster analysis and ordination of samples by Multi-Dimensional Scaling (MDS) clearly showed that some zonation occurred with T. granuliferus and T. longiramus in the supralittoral zone, E. chiltoni, Grandifoxus sp., and H. yenourensis in the littoral zone, and A. grebnitzkii and M. melanaegis in the surf zone. Moreover, the study area was divided into three regional and zonal groupings based on analyses of tidal level and granulometry of the sediments.