동해의 연성과 경성기질에 서식하는 대형저서동물 군집의 생태학적 특성

Abstract

This study was performed to investigate the macrobenthic community structure and spatio-temporal variations in soft and hard bottom substrate of the East Sea, Korea. Total macrobenthos was collected using a modified van Veen grab sampler in soft bottom and SCUBA diving method in hard bottom. In the soft bottom of Uljin, a total of 345 macrobenthic fauna were collected. The average macrobenthos density and biomass were 5,797 inds./ m2 and 81.39 gWWt/ m2, respectively. Dominant species in soft bottom area were Spiophanes bombyx, Magelona sp.1, Cadella semitorta and Lumbrineris longifolia. Cluster analysis and nMDS ordination analysis based on the abundance data represented two spatial groups along environmental gradients (Group A: St. 1, 4, 7, 10; Group B: St. 2, 3, 5, 6, 8, 9). Community structure in the soft bottom seemed to be related to the water depth and sediment composition. On the other hand, a total of 117 macrobenthic fauna were collected in hard bottom substrate. The average macrobenthos density and biomass were 2,230 inds./ m2 and 466.27 gWWt/ m2, respectively. Dominant species in hard bottom substrate were Amphipoda spp., Caprella spp., Mitrella bicincta and Temanella turrita. The multivariate analysis based on the abundance data represented two spatial groups and a sample affected by cold water mass (Group U: Uljin samples; Group Co: Pohang sample in July; Group P: other Pohang samples). Community structure in the hard bottom seemed to be related not only latitudinal spatial distinction but temporal cold water mass effect.