Seasonal Variation of Heterotrophic Activity in the Estuary of Naktong River over Half Tidal Cycle and Salinity Effect

낙동강 하구의 조석변화에 따른 Heterotrophic Activity의 계절적 변화와 염분의 영향

  • 안태영 (단국대학교 미생물학과) ;
  • 박중찬 (서울대학교 미생물학과) ;
  • 하영칠 (서울대학교 미생물학과)
  • Published : 1991.11.01


Heterotrophic activity, total bacteria and salinity were determined seasonally in the estuary of Naktong River over half tidal cycle. Heterotrophic activity was determined by the uptake of [U- $^{14}$ C]glucose. Heterotrophic activity fluctuated with the tides and was decreased as salinity increased. Teh great activity occurred near low ebb tide at all seasons except summer. The main environmental factor affecting hetreotrophic activity was the salinity rather than water temperature in the estuary of Naktong River. In order to estimate the effect of salt, salt was added to estuarine water. Vmax for glucose of salt-added water was 17% and 77% of original estuarine water at station 1 and 2 respectively and slight increase was observed at station 3. Respiration rate and Kt+Sn for glucose of salt-added sample increased at all 3 stations. The increase of the Kt value implies the reduced affinity of bacterial population for glucose. The effects of salinity on the heterotrophic activity were more extensive in the upper region of estuary than at the mouth.


Heterotrophic activeity;half tidal cycle;salinity;estuary of Naktong River