Abstract
This study was measured environmental factors of flat oyster habitats and biomass of flat oyster to improve the productivity of flat oyster. Water temperature and salinity of the flat oyster habitat ranged from 5.5 to 27.4$^{\circ}C$ and from 31.2 to 33.4 , respectively. Average concentrations of DO, COD, DIN and PO$\_$4/$\^$3/ -P were 7.11 mg/l, 4.55 $\mu\textrm{g}$-at./l and 0.36 $\mu\textrm{g}$-at./l respectively. Surface sediments at the sampling area were composed of coarse sand, sandy silt and silty sand. Average level of IL, COD and AVS in the surface sediments were 2.6%, 13.70 mg/g dry and 0.33 mg/g dry respectively. In each sampling station, total standing crops of phytoplankton showed peaks twice in February and August. Dominant species of phytoplankton occurred in Haechang Bay throughout the year were Skeletonema costatum, Paralia sulcata, Eucampia zodiacus, Chaetoceros curvicetus, C. affinis, C. debilis, C. decipiens, Asterionella glacialis, Pseudonitzschia longissima, Pseudonitzschia seriata, Ceratium furca and C. fusus. Ten species of the bivalves were collected at the flat oyster habitat. Most of bivalves were the eutrophic species Ostrea denselamellosa, Crassostrea gigas, Ruditapes philippinarum, Scaphraca subcrenata, Scapharca broughtonii, Atrina pectinata, Fulvia mutica, Mytilus edulis, Protothaca jedoensis and Megacardita ferruginosa. The mean density of them was 21 inds./㎡ (479.14 g/㎡), while that of the flat oyster was at 0.25 inds./㎡ (231.25 g/㎡).
벗굴을 양식산업에 적용하여 그 생산성을 높일 수 있는 방안을 강구하기 위하여 이 종에 대한 자연서식지의 환경특성과 이매패의 자원량을 조사하였다. 벗굴 서식지 주변해역에서 수온은 5.5$^{\circ}C$-27.4$^{\circ}C$의 범위였고, 염분은 31.2-33.4 로 평균 32.3 였다. DO, COD, DIN 및 PO$_{4}$$^{3}$-P은 각각 평균 7.11 mg/L, 0.44 mg/L, 4.55 $\mu\textrm{g}$-at./L 및 0.36 $\mu\textrm{g}$-at./L이었다. 표층퇴적물의 입도조성은 사력질, 니사질, 사니질 등으로 다양하게 나타났으며, 퇴적물의 IL, COD 및 AVS는 각각 평균 2.6%, 13.70 mg/g dry 및 0.33 mg/g dry였다. 한편, 식물플랑크톤의 현존량은 90.3(9월)-1,272.0 cell/ml(2월)이었으며, 우점종은 Skeletonema costatum, Paralia sulcata, Eucampia zodiacus, Chaetoceros curvicetus, Chaetoceros affinis, Chaetoceros debilis, Chaetoceros decipiens, Asterionella glacialis, Pseudo-nitzschia longissima, Pseudonitzschia seriata, Ceratium furca, Ceratium fusus 등이었다. 벗굴 서식지에서 출현한 조개류는 벗굴(Ostrea denselamellosa), 참굴(Crassostrea gigas), 바지락(Tapes philippinarum), 새고막(Scaphaca subcrenata), 피조개(Scaphaca broughtonii), 키조개(Atrina pectinata), 새조개(Fulvia mutica), 진주담치(Mytilus edulis), 살조개(Protothaca jedoensis), 갈색이랑조개(Megacardita ferruginosa) 등 모두 10종이었다. 그리고 이매패류의 평균 자원량은 21개체/$m^2$(479.14 g/$m^2$)이었고, 벗굴은 0.25 개체/$m^2$(231.25 g/$m^2$)로 나타났다.
