Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
권호 표지
DOI QR코드

DOI QR Code

The Variability of CDOM Along the Salinity Gradients of the Seomjin River Estuary During Dry and Wet Seasons

우기와 건기 중 섬진강 하구역에서 염분경사에 따른 유색용존유기물의 변동성

  • Lee, Jae Hwan (Institute of Coastal Management & Technology) ;
  • Park, Mi Ok (Department of Oceanography, Pukyong National University)
  • Received : 2016.05.16
  • Accepted : 2016.06.27
  • Published : 2016.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

The distribution patterns of Chromophoric Dissolved Organic Matter (CDOM) and the chemical characteristics of CDOM in the Seomjin river estuary were investigated in March, June and July 2012 in order to determine the spatial and temporal variability of CDOM along the salinity gradient considering the effects of mixing, nutrients and Chl a. The average CDOM values were $1.0{\pm}0.3m^{-1}$, $1.3{\pm}0.4m^{-1}$, and $1.4{\pm}0.3m^{-1}$ in March, June and July, respectively. A high concentration of CDOM (greater than $1.5m^{-1}$) was found at the head of the river which decreased towards the river mouth to as low as less than $0.5m^{-1}$. The average concentrations of CDOM increased from the dry season (March and June) to the wet season (July), and the average slope values ($S_{300-500}$), which were used as indicators of CDOM characteristics and sources, were in the range of $0.013-0.018m^{-1}$. The CDOM and $S_{300-50}$ values showed that not only the concentration of CDOM but also the chemical properties of DOM clearly changed between upstream and downstream in the Seomjin river. CDOM and FDOM showed a negative correlation with salinity ($R^2$ > 0.8), and CDOM was positively correlated with FDOM. Furthermore, the mixing pattern of CDOM was confirmed as conservative for all seasons. The main environmental factors influencing the concentration of CDOM was confirmed as conservative for all seasons. The main environmental factors influencing the concentration of CDOM were salinity (mixing) and water temperature, which meant the dilution of low CDOM seawater, was the controlling factor for the spatial distribution of CDOM. Increases in water temperature seemed to induce the production of CDOM during summer (June and July) through the biological degradation of DOM either by microbial activity or photo-degradation.

섬진강 하구역에서 염분경사에 따른 유색용존유기물(CDOM)의 농도와 특성을 시공간적으로 이해하기 위해 2012년 건기(3월과 6월)와 우기(7월)에 분포특성을 조사하고, 환경요인(수온, 염분)과 영양염, 엽록소와의 상관관계를 고찰하였다. 유색용존유기물의 평균농도는 각각 $1.0{\pm}0.3m^{-1}$(3월), $1.3{\pm}0.4m^{-1}$(6월), $1.4{\pm}0.3m^{-1}$(7월)로 측정되었다. 섬진강 상류의 높은 유색용존유기물 농도(> $1.5m^{-1}$)는 하류로 갈수록 감소(< $0.5m^{-1}$)하였고, 우기에 건기의 평균값에 비해 증가하였다. 또한 유색용존유기물의 화학적 특성과 공급원에 대한 지시자로 사용되는 평균값 $S_{300-500}$은 $0.013{\sim}0.018nm^{-1}$로, 건기에 비해 우기에 높은 값을 나타내었다. 유색용존유기물과 염분은 역상관계를 보였고($R^2$ > 0.8), 우기와 건기 모두 보존성 혼합의 양상을 보였다. 유색용존유기물은 강 하류로 갈수록 해수와 혼합되는 과정에 의해 희석되고, 그 특성 또한 뚜렷한 변화를 보이는 것을 확인하였다. 환경 조건 중 유색용존유기물의 변동에 영향을 주는 주요한 요인은 염분 (혼합)과 온도로 확인되었으며, 전자는 낮은 유색용존유기물 농도의 해수와의 혼합에 의한 희석으로 주로 공간적인 변동을 조절하는 것으로 보였고, 온도의 증가는 유색용존유기물의 생산에 영향을 주는 미생물학적 활동과 광분해에 통한 작용으로 유추된다.

Keywords

References

  1. Blough, N. V. and S. A. Green(1995), Spectroscopic characterization and remote sensing of non-living organic matter, In "The role of Non-living Organic Matter in the Earth's Carbon Cycle" (R. G. Zepp and C. Sonntag, Eds.), Wiley, Chichester, pp. 23-45.
  2. Blough, N. V., O. C. Zafiriou and J. Bonilla(1993), Optical absorption spectra of waters from the Orinoco River outflow: Terrestrial input of colored organic matter to the Caribbean, J. Geophys. Res., Vol. 98, C2, pp. 2271-2278. https://doi.org/10.1029/92JC02763
  3. Carder, K. L., R. G. Steward, G. R. Harvey and P. B. Ortner(1989), Marine humic and fulvic acids: Their effects on remote sensing of ocean chlorophyll. Limnol. Oceanogr., Vol. 3, pp. 68-81.
  4. Coble, P. G.(1996), Characterization of marine terrestrial DOM in seawater using excitation-emission matrix spectroscopy, Marine Chemistry, Vol. 51, No. 4, pp. 325-346. https://doi.org/10.1016/0304-4203(95)00062-3
  5. Granskog, M. A., A. K. Pavlov, S. Sagan, P. Kowalczuk, A. Raczkowska and C. A. Stedmon(2015), Effect of sea-ice melt on inherent optical properties and vertical distribution of solar radiant heating in Arctic surface waters, Journal of Geophysical Research: Oceans, Vol. 120, pp. 7028-7039. https://doi.org/10.1002/2015JC011087
  6. Green, S. A. and N. V. Blough(1994), Optical absorption and fluorescence properties of chromophoric dissolved organic matter in natural waters, Limnology and Oceanography, Vol. 39, pp. 1903-1916. https://doi.org/10.4319/lo.1994.39.8.1903
  7. Ha, S. Y., S. W. Kang, M. O. Park, Y. N. Kim, S. H. Kang and K. H. Shin(2010), Photoinduction of UV-absorbing Compounds and Photo-protective Pigment in Phaeocystis pouchetii and Porosira glacialis by UV Exposure, Ocean Polar Research, Vol. 32, No. 4, pp. 397-409. https://doi.org/10.4217/OPR.2010.32.4.397
  8. Hansell, D. A. and C. A. Carlson(2002), Marine Dissolved Organic Matter, Elsevier Science, pp. 516-543.
  9. Hill, V. J.(2008), Impact of chromatographic dissolved organic material on surface ocean heating in the Chuck Sea, J. Geophys. Res. Oceans, Vol. 113, No. C07024.
  10. Hojerslev, N. K., N. Holt and T. Aarup(1996), Optical measurements in the North Sea-Baltic Sea transition zone. I. On the origin of the deep water in the Kattegat, Cont. Shelf. Res., Vol. 16, No. 10, pp. 1329-1342. https://doi.org/10.1016/0278-4343(95)00075-5
  11. Kowalczuk, P.(1999), Seasonal variability of yellow substance absorption in the surafce layer of the Baltic Sea, J. Geophys. Res. Ocean, Vol. 104, No. C12, pp. 169-217.
  12. Kwon, K. Y., C. H. Moon and H. S. Yang(2001), Behavior of Nutrients along the Salinity Gradients in the Seomjin River Estuary, J. Korean Fish. Soc, Vol. 34, No. 3, pp. 199-206.
  13. McKnight, D. M. and G. R. Aiken(1998), Sources and age of aquatic humus, In: Hessen, Tranvik (Eds.), Ecological Studies: Aquatic Humic Substances, Springer-Verlag, Heidelberg, Vol. 133, pp. 9-39.
  14. McCallister, S. L., J. E. Bauer, H. W. Ducklow and E. A. Canuel(2006), Source of estuarine dissolved and particulate organic matter: A multi tracer approach, Org. Geochem, Vol. 37, pp. 454-468. https://doi.org/10.1016/j.orggeochem.2005.12.005
  15. Moran, M. A., W. M. Sheldon and R. G. Zepp(2000), Carbon loss and optical property changes during long-term photochemical and biological degradation of estuarine dissolved organic matter, Limnol. Oceanogr, Vol. 45, pp. 1254-1264. https://doi.org/10.4319/lo.2000.45.6.1254
  16. Nelson, J. R. and S. Guarda(1995) Particulate and dissolved spectral absorption on the continental shelf of the southeastern United States, J. Geophys. Res., Vol. 100, pp. 8715-8732. https://doi.org/10.1029/95JC00222
  17. Nieke, B., R. Reuter, R. Heuermann, H. Wang, M. Babin and J. C. Therriault(1997), Light absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) in the St. Lawrence estuary (Case 2 waters), Continental Shelf Research, Vol. 17, pp. 235-252. https://doi.org/10.1016/S0278-4343(96)00034-9
  18. Pavlov, A. K., C. A. Stedmon, A. V. Semushin, T. Martma, B. V. Ivanov, P. Kowalczuk and M. A. Granskog(2016), Linkages between the circulation and distribution of dissolved organic matter in the White Sea, Arctic Ocean. Continental Shelf Research, Vol. 119, p. 13.
  19. Rochelle-Newall, E. J. and T. R. Fisher(2002), Production of chromophoric dissolved organic matter fluorescence in marine and estuarine environments: an investigation into the role of phytoplankton, Mar. Chem, Vol. 77, pp. 7-21. https://doi.org/10.1016/S0304-4203(01)00072-X
  20. Stedmon, C. A., R. M. W. Amon, A. J. Rinehart and S. A. Walker(2011), The supply and characteristics of colored dissolved organic matter (CDOM) in the Arctic Ocean: Pan Arctic trends and differences Marine Chemistry, Vol. 124, No. 1, pp. 108-118. https://doi.org/10.1016/j.marchem.2010.12.007