The Community Structure and Grazing Rates of Meiobenthos in Chunsu Bay, West Coast of Korea

The community structure and grazing rates of meiobenthos was studied in Chunsu bay on west coast of Korea. To examine feeding habit of major meiofaunal groups, grazing rate of nematodes and harpacticoid copepods was measured using the isotope-tracer (H thymidine, ¹⁴C amino acid) method at 3 stations in subtidal area and 1 station in intertidal area of Chunsu bay. Time-serial measurement of grazing rate was made to elucidate the effects of day/night and tidal cycle on diel feeding rhythm of the animals. The number of culturable bacteria fluctuated from 1.73±0.25×10⁵ to 18.23±1.17×10⁵ CFU/cm during the study period, and was highest in October. The Concentration of Chl.a in the sediment at the study site was 18.0~168.2 mg/m in April and 36.6~111.0 mg/m in October. The most abundant meiobenthos was nematodes and followed by sarcomastigophorans, harpacticoid copepods. Density of meiobenthos were 5~1632 inds./10cm during the study period. The grazing rates of nematode varied 0.5~57.2%/h on bacteria and 0.4~53.3%/h on microalgae at the station in tidal flat. The grazing rates of harpacticoid copepods were 0.2~14.2%/h on bacteria and 0.3~12.2%/h on benthic microalgae at the station in tidal flat. In the subtidal area, the grazing rates of nematode were 33.4~82.5%/h on bacteria and 10.3~71.5%/h on microalgae and harpacticoid copepods were 0.2~14.2%/h on bacteria and 0.3~12.2%/h on benthic microalgae.