• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.2
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• pp.144-150
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• 2016

In southwestern East Sea, we investigated the spatio-temporal distribution characteristics of particulate organic carbon (POC) and nitrogen (PON) in September 2011 (summer), January (winter) and May 2012 (spring). Although cold waters known as the origin upwelling in the surface layer of September were not observed, this periods showed high primary productivity because of high concentrations of chlorophyll, low percentage of non-autotrophic particulate fraction among POC calculated by POC/Chl-a ratio (27%) and low POC/PON ratio (6.2), which means active amino acid and protein synthesis, However, May, 2012 showed low primary productivity because of high percentage of non-autotrophic particulate fractions among POC (66%) and high POC/PON ratio (8.1), Although spring bloom and high primary productivity has been reported in the East Sea, high percentage of non-autotrophic particulate fractions in POC, observed in the East sea during the post 2012 spring, is suggested to be due to the increase of phaeo-pigment during post spring bloom. Thus, composition of particulate organic matter may have sensitively changed by marine environmental factors in spite of same season.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.86-96
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• 2002

The distributions of suspended particulate matter (SPM), chlorophyll a, particulate organic carbon (POC) and nitrogen (PON) and particulate biogenic silica (PBSi) along the salinity gradient were investigated in the Seomjin River estuary from March 1999 to April 2001. Sampling sites were set based on the surface salinity during each cruise rather than geographic locations. Concentrations of SPM were less than 20 mg/L, suggesting relatively low input of terrestrial SPM despite large freshwater discharge through Seomiin River, Chlorophyll a peaks occurred at 5$\~$ 15 psu salinity zone (10$\~$20 km from Nan Cho Island) in November 1999, at 15$\~$25 psu (10$\~$20 km) salinity zone in April 2000 and at 1$\~$15 psu salinity zone (15$\~$20 km) in October 2000 (ca. 8$\~$58%\mu$g/L). Concentrations of POC, PON and PBSi were also high at the same zone. Relatively low ratios of POC to chlorophyll a in mid-salinity zone where POM peak occurred suggests high contribution of living phytoplankton to the total POC. On the other hand, relatively high ratios of POC to chlorophyll $\alpha$ in very low salinity zone and the mouth of estuary indicated relatively high portions of detrital POC. Consequently, the low concentrations of SPM in this estuary and the high concentrations of chlorophyll $\alpha$ and the low ratios of POC to chlorophyll $\alpha$ in the mid-salinity zone suggest that production of living phytoplankton is primary factor in controlling distribution of POM along the salinity gradients in the Seomjin River estuary.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.488-488
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• 2018

본 연구는 보 구간에서 조류와 조류 발생원인 물질의 거동해석 및 조류예측모델의 입력 자료로 활용하기 위하여 부유물질의 침강량과 침강속도를 조사하였다. 낙동강 수계 4개보(달성보, 강정고령보, 합천창녕보, 창녕함안보)를 대상으로 2017년 6월, 7월, 11월, 12월에 조사하였으며, Sediment trap을 이용하여 포집한 침강물질에 대해 seston, POC, PON, POP, Chl-a, Pheo-a의 침강량, 침강속도 및 물질의 함량비를 분석하였다. 조사기간 동안 낙동강수계 4개보 지점에서 seston, POC, PON, POP, Chl-a, Pheo-a 의 침강량은 각각 $322.7{\sim}58,011.5mg/m^2/day$, $33.8{\sim}1,127.2mg/m^2/day$, $4.2{\sim}150.6mg/m^2/day$, $0.667{\sim}10.634mg/m^2/day$, $0.3{\sim}18.7mg/m^2/day$, $0.3{\sim}14.7mg/m^2/day$의 범위로 나타났으며, seston, POC, PN, PP, Chl-a의 침강속도는 각각 0.02~1.46m/day, 0.02~1.36m/day, 0.03~3.18m/day, 0.01~1.18m/day, 0.02~0.60 m/day의 범위로 나타났다. 조사기간 동안 4개보 지점의 평균 침강속도는 seston 0.94m/day, POC 0.44m/day, PON 0.52m/day, POP 0.21m/day, Chl-a 0.22m/day로 보 건설 전인 2004년도 낙동강 본류 지점에서의 침강속도(seston 14.54 m/day, POC 18.32m/day, PON 1.64m/day, POP 5.96m/day, Chl-a 0.29m/day)에 비해 적은 것으로 나타났다. 한편 활성을 잃은 식물플랑크톤을 나타내는 Pheo-a의 농도와 살아있는 식물플랑크톤의 현존량의 지표 Chl-a의 농도 비교결과 죽거나 활성을 잃은 식물플랑크톤의 양이 평균 1.5배 많은 것으로 나타났다. 조사기간 동안 4개 보 지점의 Sediment trap 포집된 침강물 내 C:N비는 2.0~7.4 범위로, N;P비는 14.2~52.5 범위로, C/Chl-a비는 14.4~253.3의 범위로 나타났다. 일반적으로 조류의 C/Chl-a 비가 40으로 볼 때 본 연구에서 조사된 보 지점에서의 침강물은 외부로부터 유입된 유기물이 많은 것으로 판단된다. 본 연구에서는 조류의 침강속도는 조류의 종을 구분하지 않은 총 조류에 대한 것으로, 향후 보 구간에서 종 조성을 고려한 조류예측 모델을 향상시키기 위해서는 조류 종별에 대한 침강속도에 대한 연구할 필요가 있다.

• Journal of Environmental Science International
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• v.29 no.5
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• pp.531-539
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• 2020

To understand the composition, quantity, and quality of Suspended Particulate Organic Matter (SPOM) in the Gangneung Namdae Stream, Korea, we examined spatiotemporal variations in water temperature, salinity, chlorophlly a (Chl a), Particulate Organic Carbon (POC) and nitrogen (PON), and carbon stable isotope (δ¹³C) of SPOM at six stations in June (pre-monsoon), July (monsoon), and September (post-monsoon) 2017. With increasing precipitation, the average POC and C/N values increased significantly in July than in June. In September, the values decreased with decreasing precipitation. The δ¹³C values showed irregular spatiotemporal fluctuations among the stations and periods, thereby suggesting a greater contribution of autochthonous organic matter to the pool of SPOM than that of allochthonous organic matter derived from upstream. In addition, the large and irregular changes in POC, C/N ratio, C:Chl a, and δ¹³C compared to that of PON were observed for all periods among the stations, indicating a serial discontinuity of the stream. Our results suggest that the Gangneung Namdae Stream is significantly influenced by the increase in freshwater discharge caused by heavy rainfalls during the summer monsoon and post-monsoon periods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.442-450
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• 1997

The chemical properties of water masses were investigated at 33 stations of the southeastern last Sea in February, 1995 on board R/V Tam-Yang. The water masses were not clearly distinguished due to the vortical mixing in winter. However, on the basis of the T-S and $T-O_2$ diagrams, water masses in the study area were divided into five groups (Type I, Type II, Type III, Type IV, Type V). (1) $>9.0^{\circ}C,\;>34.35\;psu,\;5.08\~5.60m\ell/\ell$ at Type I, (2) $6.0\~9.0^{\circ}C,\;34.15\~34.35\;psu,\;5.60\~5.90\;m\ell/\ell$ at Type II, (3) $4.0\~6.0^{\circ}C,\;34.00\~34.15\;psu,\;>5.90m\ell/\ell$ at Type III, (4) $1.5\~4.0^{\circ}C,\;34.00\~34.05\;psu,\;5.40\~5.90\;m\ell/\ell$ at Type IV, (5) $<1.5^{\circ}C,\;34.05\~34.07\;psu,\;4.80\~5.40\;m\ell/\ell$ at Type V. In the vertical profiles of nutrients, the concentrations were very low in the surface layer and increased rapidly with depth. The highest concentrations occurred in Type IV, while the concentrations in Type I were the lowest. The N/P ratios were less than Redfield ratio, indicating that nitrogenous nutrients were the limiting factor tor phytoplankton growth. The concentrations of POC and PON were in the range of $0.49\~20.03\;{\mu}g-at/\ell\;and\;0.09\~5.34\;{\mu}g-at/\ell$, respectively. The relatively high concentration occured in the surface layer of inner shore, showing that the concentration at each water mass followed the order Type I > Type II > Type III > Type IV > Type V, respectively. The C:N ratio in particulate organic matter was lower than the values reported in other region due to relatively high concentrations of PON in the study area. Relatively high ratios of POC to chlorophyll $\alpha$ during the study periods indicate that non-living detritus comparised most of the POC in the study area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.1
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• pp.57-69
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• 2001

The chemical, elemental and biochemical components of the suspended particulate matter (SPM) were investigated in order to quantify particulate organic matter (POM) and assess diet quality for suspension feeders in the southern coastal bay systems of Korea where the marine farming of the suspension feeders are most active, The intense field observation program was carried out seasonally in the three coastal bay systems of Chinhae, Gosung and Kangjin bays, The SPM was characterized as collective properties of organic carbon (POC), nitrogen (PON), phosphorus (PP) and more refined collective properties of protein (PPr), carbohydrate (PCHO) and chlorophyll a (Chl a) compound. Although the three coastal bays are regarded as phytoplankton based ecosystem, the SPM is not composed entirely with phytoplankton cells. Due to the shallow water depth, resuspension of bottom sediment contributes significantly to some of the regions. Therefore, concentration of SPM in the surface water did not co-vary with Chl a or PPr, PCHO. In general, temporal variation of POC, PON and Chl a contents in seawater were closely associated with phytoplankton biomass in the three coastal bays, However, PPr and PCHO contents in seawater were higher in Chinhae bay than in Gosung and Kangjin bays and Chl a PPr-N ratio was higher in Chinhae bay than in Kosung and Kangjin bays, since Chinhae bay is more eutrophicated than other bays. Average C : N ratios from regressions of POC and PON of SPM were 6.6, 6.6 and 5.0 in Chinhae, Gosung and Kangjin bays, respectively. SPM in Chinhae and Gosung bays appears to be made of largely phytoplankton cells and SPM in Kangjin bay appears to be contributed from the bacterial biomass due to the shallow water depth. N : P ratios from regressions of PON and PP of SPM were 10.8 and 14.7 in spring, and 18.2 and 24.6 in Chinhae and Gosung bays, respectively. With respect to the hypothetical Redfield molecule, phytoplankton appears to be limited by the lack of N and f in spring and summer, respectively, in the two bays, In Kangjin bay, N : P ratios from regressions of PON and PP of SPM were varied from 6.3 to 12.8 throughout the year. The low N : P ratio with resepct to the hypothetical Redfield molecule, phytoplankton growth appears to be limited by the lack of N-nutrients.

• 한국해양학회지
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• v.29 no.2
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• pp.107-118
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• 1994

An investigation of the annual change and C:N:P ratio in particulate organic matter (POM) in Chinhae Bay, a semi-enclosed bay of the southern coast of Korean Peninsula, was carried out for a period of 12 months between January and December, 1993. The concentrations of POM have a broad range: 198∼4,416 ugC/l, 24∼792 ugN/l and 4.5∼69.0 ugP/l, Marked seasonal changes of POM, particularly particulate organic carbon (POC) and nitrogen (PON), were observed in the surface water. Generally, the concentration of POM peaks in summer. The C:N:P composition ratio of particulate organic matter, which is high in summer, also shows a seasonal change. The C:N assimilation ratio is constant at 6.53, which is consistent with the Redfield ratio. The significant linear relationship between POM and chlorophyll-a in the surface water during the survey period (except for January and February) and the C:N ratio suggest that the concentration of POM is controlled by phytoplankton biomass. POM peaks in summer, a period characterized by high freshwater input and the strong stratification, as a result of the intense proliferation of phytoplankton by a large amount of nutrient loading from the tributaries. On the other hand, the high C:P and N:P ratios in summer indicate that P is limited for phytoplankton growth owing to N-enrichment from a high input of freshwater with a high dissolved inorganic N:P ratio.

• Korean Journal of Ecology and Environment
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• v.35 no.1 s.97
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• pp.1-9
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• 2002

In order to understand the relationship between succession of phytoplankton community structure and inorganic nutrients and particulate organic matters, a one station in Kyungan stream in Korea during the dry season was chosen. Water samplings were carried out once a week from 18 August to 13 November 1993. The DIN concentration distributed always abundantly, however, phosphate and silicate gradually reduced during the period. Phytoplankton community had a peak chlorophyll a concentration of $90.6\;{\mu}g/l$ in late summer (21 August 1993) and a second peak of $29.7\;{\mu}g/l$ in autumn (2 October 1993). After then late autumn was characterined by relatively low chlorophyll a concentration of $15{\sim}16\;{\mu}g/l$. Seasonal fluctuation of chlorophyll a concentrations were correlated with measured POC and PON concentrations: phytoplankton blooming may be a major factor controlling POC and PON concentrations in this ecosystem. Phosphate plays an most important role as a limiting factor of phytoplankton growth. However, when Si/P ratio low, silicate may be a more critical limiting factor than phosphate. Shifts of P-limitation to Si- limitation the succession of dominant phytoplankton can in duce: diatom to cyanobacteria such as Anabaena, Microcystis and Oscillatoria.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.203-215
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• 2006

Field observations on the spatio-temporal distribution of organic matter of the surface sediment were carried out at 15 stations in the central parts of the South Sea of Korea from April 2002 to January 2003. The range of water temperature and salinity in bottom waters, mud content and water content of surface sediment were $8.06{\sim}23.35^{\circ}C,\;29.20{\sim}34.51\;psu,\;71.2{\sim}99.9%$ and $38.7{\sim}68.9%$, respectively. Measured parameters on the surface sediments of ignition loss (IL), chemical oxygen demand (CODs), phaeopigment, particulate organic carbon (POC) and particulate organic nitrogen (PON) also ranged in $3.9{\sim}l2.5%,\;9.60{\sim}44.05\;mgO_2/g-dry,\;1.58{\sim}29.51\;{\mu}g/g-dry,\;3.12{\sim}13.01\;mgC/g-dry$ and $0.49{\sim}2.00\;mgN/g-dry$, respectively. The spatio-temporal distribution of organic matter demonstrated higher concentrations offshore than at lesions near the coastal line. Higher concentrations occurred in the summer and spring. The results indicated that the origin of organic matter in surface sediments in the central part of the South Sea was autochthonous rather than allocthonous because the organic matter had an average C/N ratio of 6.44 (${\pm}0.51$). However, the composition of autochthonous organic matter was mainly derived from detritus rather than living phytoplankton, which was Indicated by the results of the POC/phaeopigment ratio. A principal component analysis (PCA) indicated that 73.2% of the variability in the data was described by two factors: 1) an 'environmental factor concerning the accumulation of materials (57.3%)' and 2) 'origin of organic matter and the composition by primary production (15.9%)'. The sedimentary environment in the central part of the South Sea was divided into four regions from the factor score of the PCA by the concentrations of organic matter and the composition ratio of organic matters from phytoplankton in surface sediments.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.1
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• pp.1-13
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• 2006

A field survey on the spatio-temporal distribution characteristics and origins of organic matter in surface sediments was carried out monthly at six stations in Gamak Bay, South Korea from April 2000 to March 2002. The range of ignition loss(IL) was $4.6{\sim}11.6%(7.1{\pm}1.6%)$, while chemical oxygen demand(CODs) ranged from $12.25{\sim}99.26mgO_2/g-dry(30.98{\pm}19.09mgO_2/g-dry)$, acid volatile sulfide(AVS) went from no detection(ND)${\sim}10.29mgS/g-dry(1.02{\pm}0.58mgS/g-dry)$, and phaeopigment was $6.84{\sim}116.18{\mu}g/g-dry(23.72{\pm}21.16{\mu}g/g-dry)$. The ranges of particulate organic carbon(POC) and particulate organic nitrogen(PON) were $5.45{\sim}23.24 mgC/g-dty(10.34{\pm}4.40C\;mgC/g-dry)$ and $0.71{\sim}2.99mgN/g-dry(1.37{\pm}0.58mgN/g-dry)$, respectively. Water content was in the range of $43.1{\sim}77.6%(55.8{\pm}5.6%)$, and mud content(silt+clay) was higher than 95% at all stations. The spatial distribution of organic matter in surface sediments was greatly divided between the northwestern, central and eastern areas, southern entrance area from the distribution characteristic of their organic matters. The concentrations of almost all items were greater at the northwestern and southern entrance area than at the other areas in Gamak Bay. In particular, sedimentary pollution was very serious at the northwestern area, because the area had an excessive supply of organic matter due to aquaculture activity and the inflow of sewage from the land. These materials stayed longer because of the topographical characteristics of such as basin and the anoxic conditions in the bottom seawater environment caused by thermocline in the summer. The tendency of temporal change was most prominently in the period of high-water temperatures than low-water ones at the northwestern and southern entrance areas. On the other hand, the central and eastern areas did not show a regular trend for changing the concentrations of each item but mainly showed a higher tendency during the low-water temperatures. This was observed for all but AVS concentrations which were higher during the period of high-water temperature at all stations. Especially, the central and eastern areas showed a large temporal increase of AVS concentration during those periods of high-water temperature where the concentration of CODs was in excess of $20mgO_2/g-dry$. The results show that the organic matters in surface sediments in Gamak Bay actually originated from autochthonous organic matters with eight or less in average C/N ratio including the organic matters generated by the use of ocean, rather than terrigenous organic matters. However, the formation of autochthonous organic matter was mainly derived from detritus than living phytoplankton, indicated the results of the POC/phaeopigment ratio. In addition, the CODs/IL ratio results demonstrate that the detritus was the product of artificial activities such as dregs feeding and fecal pellets of farm organisms caused by aquaculture activities rather than the dynamic of natural ocean activities.