전자저널 > 전자저널 > Characteristics of Ocean Environmental Factors and Community Structure of Macrobenthos around Munseom, Jeju Island, Korea

Characteristics of Ocean Environmental Factors and Community Structure of Macrobenthos around Munseom, Jeju Island, Korea

Joon-Chul Ko, Jun-Ho Koo and Moon-Ho Yang

Jeju Fisheries Research Institute, National Fisheries Research and Development Institute, Jeju-do, 690-192, Korea

This study was performed to find out the community structure of macrobenthos and the environmental factorsaround Munseom coastal water in Jeju Island from June to December, 2007. Mean temperature and mean salinitywere 19.6℃ and 34.03 psu, indicating stable water masses. Concentrations of DO, COD and SS were as low asthose in the standard sea-water-quality classes I. Chlorophyll a concentrations ranged from 0.40 to 1.09 mg/L(mean, 0.69 mg/L), and higher concentration was observed in December rather than in June due to a blooming inwinter. The mean concentration (their ranges are in parentheses) of nitrate, phosphate, and silicate were 0.15mg/L (0.073-0.264 mg/L), 0.01 mg/L (0.004-0.011 mg/L) and 0.23 mg/L (0.039-0.464 mg/L), respectively. Thevalues were higher near the Munseom due to influxes from the land. Of the 112 species that were identified, 40species (36.0%) were Mollusca; 33 (28.8%) were Cnidaria; 13 (11.7%) were Porifera; 8 (7.2%) were Arthropodaand 17 species (15.3%) were others including Echinodermata. Density and biomass were estimated to be 4,340individual/m2 and 53,107.8 gwwt/m2 respectively. Anthozoa was the most dominant group in abundance (2,132ind./m2) as well as in the number of species, whereas Cnidaria was predominant in biomass (37,630.9 gwwt/m2).The dominant species were Dendronephthya gigantea, Scleronephthya gracillimum, Anthoplexaura dimorpha,Dendronephthya castanea, Thecocarpus niger, Dendronephthya spinulosa, Dendronephthya putteri, andAcabaria bicolor in the depth of 10-30 m. The seasonal variations of the number of individual and biomass ofCnidaria and Mollusca were observed. There was a slow increment in June, a decrement in October, and a drasticincreasing in December. The biodiversity, evenness and richness index in surveyed stations were 2.715-3.413 (H'),0.758-0.851(E'), and 5.202-8.720 (R) respectively. The dominance index was the highest in station M2 and thelowest in station M1.

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