• 생태와환경
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• 제44권4호
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• pp.337-346
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• 2011

We investigated nutrient loading and trophic states in a coastal estuarine system in the Asan estuary by assessing phytoplankton biomass and using the trophic index (TRIX). The monthly and yearly nutrient loading (TN, TP) from freshwater discharge from the Asan and Sapgyo reservoirs into the estuary were estimated and analyzed with related factors. Monitoring data (physio-chemical and biological variables) collected at five estuary stations were used to assess trophic states. Descriptive statistics of total phytoplankton cells, chl a concentrations and primary productivity were also used to assess seasonal trophic status. N loading from freshwater ranged $1.0{\sim}1.3{\times}10^4$ ton yearly. The yearly P loading ranged between 350 and 400 ton during 2004~2006, increasing to 570 ton in 2007. Regression results suggest that DIN and DSi were correlated with freshwater discharge at the upper region. Based on phytoplankton biomass and total cell abundance, the trophic state of the estuary was found to be eutrophic during spring due to phytoplankton bloom. Primary productivity level was remarkably high, especially in summer coinciding with high nutrient loading. Pheopigments increased during warm seasons, i.e. summer and fall. Trophic index results indicate that the trophic state varied between mesotrophic and eutrophic in the estuary water body, especially in the upper region. The results suggest that phytoplankton production was regulated by nutrient loading from freshwater whereas biomass was affected by other properties than nutrient loading in the Asan Estuary ecosystem.

• ALGAE
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• 제17권4호
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• pp.275-281
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• 2002

• 생태와환경
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• 제38권3호통권113호
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• pp.382-392
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• 2005

대청호 연중 수질 환경요인의 변화를 해석하고 영양단계를 평가하고자, 1997년부터 2002년까지 수질 환경요인과 수문학적 특성을 조사하였다. 대청호의 표층 수온은 3.2\;{\sim}\;33.1^{\circ}C$로 2월 중순에 가장 낮았다. 탁도는 $0.1\;{\sim}203.5\;NTU$이었지만, 정점 1에서만 30 NTU의 이상이었다. COD의 평균은 $3.6{\pm}1.4\;mg\;O_2\;L^{-1}$이었고, Chl a의 평균 농도는 $9.3{\pm}12.8\;{\mu}g\;L^{-1}$이었다. 총질소는 0.14 ${\sim}$ 5.09 mg N $L^{-1}$ 범위로 4월과 6월부터 8월에 다른 시기보다 높았다, 총인은 $1\;{\sim}\;247\;{\mu}g\;P\;L^{-1}$로, 11월부터 4월까지$10.6\;{\sim}\;18.1\;{\mu}g\;P\;L^{-1}$로 상대적으로 낮다가 5월부터 8월까지 평균 30.0 P $L^{-1}$ 이상으로 증가하였다. TN/TP비의평균은 $98.7{\pm}56.2$이었다. 대청호의 수질은 적용한 지수와 시기별로 영양단계평가 등급이 중영양단계 또는 부영양단계로 판정되었다.

• ALGAE
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• 제21권2호
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• pp.217-228
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• 2006

Seasonal compositions, standing crops and trophic status of phytoplankton were investigated at 13 sites of Suwon-si, Gyeonggi-do from June, 2004 to March, 2005. Total of 304 taxa were found, and classified as 4 phylums 4 classes 13 orders 36 families 93 genera 246 species 47 varieties 8 forms and 3 unidentified species by Engler’s classification system. Judged by standing crops of phytoplakton, algal blooming was observed at every sampling sites except Pajang reservoir, Hagwanggyo reservoir, Suwon-cheon and Woncheon-cheon throughtout the whole study periods. While Hagwanggyo reservoir appeared to be in mesotrophic or oligomesotrophic status, most of the remaining sampling sites in Suwon-si were in eutrophic status according to trophic status index. In this study, the most abundant taxa revealed in eutrophic status were Anabaena circinalis, Pandorina morum, Scenedesmus acuminatus, and S. quadricauda as previously reported as the most abundant taxa in eutrophic status. But Navicula cryptocephala and Cyclotella stelligera, reported as the abundant taxa of mesotrophic and oligomesotrophic status, respectively, occurred in eutrophic status in this study.

• ALGAE
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• 제19권3호
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• pp.227-234
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• 2004

A study on the dynamics of phytoplankton community and the physico-chemical environmental factors was performed biweekly from April 1998 to March 1999 in Youngchun Dam. A total 72 phytoplankton taxa was identified and dominant taxa were blue-green algae and diatoms. The highest value of phytoplankton standing crop (24,826cells·ml$^{-1}$) was observed in September 7, 1998, the blooming period of blue-green algae Phormidium sp., while the lowest (318cells·ml$^{-1}$) was measured in June 18, 1999. The phytoplankton communities were dominated by blue-green algae of Anabaena planktonica, Microcystis aeruginosa and Phormidium sp. during the summer and autumn periods and were dominated by diatoms of Synedra acus and Aulacoseira spp. during the spring and winter periods. Secchi disc transparency, chlorophyll-a, total nitrogen, total phosphorus and silicate concentration were varied in the ranges of 0.4-2.5 m, 2.4-32.2mg·m$^{-1}$, 0.845-2.352mg·l$^{-1}$, 0.005-0.093mg·l$^{-1}$, 0.2-15.7mg·l$^{-1}$, respectively. The trophic status of Youngchun Dam were estimated eutrophic according to Lake Trophic States Index (LTSI).

• 생태와환경
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• 제43권4호
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• pp.492-502
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• 2010

The study objects were to analyze long-term and seasonal variations of nutrients (N, P), suspended solids, N:P ratios, algal chlorophyll, and trophic state along with general water quality parameters in four sampling sites including two intake tower sites supplying drinking water in Daechung Reservoir. For the analysis, we used water quality long-term data sampled during 1998~2007 by the Ministry of Environment, Korea. Interannual and seasonal trends in inflow and discharge near the intake tower facilities over the ten years were directly influenced by rainfall pattern. The distinct difference between wet year (2003) and dry year (2001) produced marked differences in water temperature, pH, dissolved oxygen, organic matter contents, nutrients, and these variables influenced algal biomass and trophic state. Values of TP varied depending on the year and locations sampled, but monthly mean TP always peaked during July~August when river inflow and precipitation were maxima. In contrast, TN varied little compared to TP, indicating lower influence by seasonal flow compared to phosphorus. The number of E. coli were highest in Site 2 (Chudong intake tower) and varied largely, whereas at other sites, the numbers were low and low variations. Contents of chlorophyll-${\alpha}$ (CHL), as an estimation of primary productivity, varied largely depending on the year and season. The maximum of CHL occurred at Muneu intake tower (S4) during 2006 when the precipitation and inflow were lowest. In contrast, another CHL peak was observed in Site 2 (Chudong intake tower) in 2006 when one of the largest typoons (Ewinia) occurred and river runoff were maximum. So the CHL maxima were associated with both wet year (high flow, high nutrient supply) and dry year (low flow, nutrient supply by littoral zone). Such conditions influenced trophic states, based on Trophic State Index of nutrients and CHL. Based on all analyses, we can provide some clues for management and protection strategies of two intake tower sites.

• ALGAE
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• 제22권2호
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• pp.69-85
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• 2007

From six reservoirs in Gyeonggi-do, we have collected the distribution and standing crop of phytoplankton since Nov. 2005 through Sep. 2006. As a result, the phytoplankton appeared totally 340 taxa belong to 7 classes, 15 orders, 5 suborders, 32 families, 4 subfamilies, 84 genera, 283 species, 43 varieties, 9 forms and 5 unidentified species. The standing crop was shown as minimum was 0.3 × 106 cells and maximum was 5,950 × 106. The relation of standing crop with TN, TP and Chl-a showed as positive. Total 12 taxa including 2 taxa of blue-green algae occurred to every seasons at six lakes, and it was thought that they distributed in mesotrophic state. Also, Achnanthes minutissima, Aulacoseira granulata, Eudorina elegans, Gloeocystis ampla, Pandorina morum, Pediastrum simplex var. duodenarium, Scenedesmus ecornis were regarded as the indicators of eutrophic state. From the estimation of LTSI and TSI, it was shown that the rest of lakes except for Idong reservoir of winter were eutrophic states.

• 생태와환경
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• 제43권3호
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• pp.418-427
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• 2010

우포늪의 4개 습지를 대상으로 2005년 3월부터 2009년 12월까지 매월 영양염과 엽록소-$\alpha$ 농도를 모니터링 하였으며, 이를 토대로 수질 영양 단계를 평가하였다. 질산성질소와 암모니아성질소, 총질소 등 질소 계열 영양염은 선행 연구 결과와 비교시 감소한 것으로 나타났다. 그러나 총질소의 경우, 아직까지 수화발생 기준과 부영양 기준 농도를 상당히 초과하여 용존되어 있는 것으로 확인되었다. 인산염인과 총인 농도 또한 선행 연구와 비교 시 상당히 감소한 것으로 조사되었으나, 총인은 총질소와 마찬가지로 부영양 기준을 초과하여 용존되어 있었다. 질소 계열과 인 계열 영양염은 4개 습지 중 쪽지벌에서 가장 낮은 것으로 조사되었다. 엽록소-$\alpha$의 평균 농도는 우포에서 가장 높게 나타났으며, 목포에서 가장 낮게 나타났다. 쪽지벌과 목포에서는 하계에 높게 나타났고, 우포와 사지포에서는 비하계 기간 동안 높게 나타났다. TRIX 분석을 통해 우포늪의 수질 영양 상태를 평가한 결과 4개 습지 모두 생산성이 높고 영양 단계가 높은 수질을 의미하는 poor water quality 상태로 조사되었다.

• 생태와환경
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• 제56권1호
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• pp.83-93
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• 2023

This study compares the abundance and community structure of zooplankton organisms from pelagic regions, and considers particularly the trophic levels vs. zooplankton abundances and biomass. Zooplankton samples were collected three times from May to November 2022, at 30 temperate lakes and reservoirs, which belong to four different river basins. The total zooplankton abundance, biomass and species index were showed considerable spatial variation. The spatial pattern of rotifer abundance was similar to that of total zooplankton abundance, while there were not showed similar patterns of zooplankton biomass (㎍ L^-1) in lentic ecosystems. The rotifer strongly dominated the zooplankton assemblage in smaller lentic system than that of larger. A total of 130 species of zooplankton were identified (83 rotifers, 34 cladocerans and 13 copepods). The total average of zooplankton abundance and biomass were 213.7±342.3 Ind. L^-1 (n=129) and 1382.8±1850.4 ㎍ L^-1, respectively. Total and average of zooplankton abundance were usually dominated by the rotifers (>56.9%), while those of zooplankton biomass were dominated by the cladocerans and copepods (>73.6%) in lentic ecosystems. Considering the Trophic State Index (TSI), the factors of zooplankton abundance and biomass were included in between meso- and eutrophic states(27 lakes, 90% of all). The mean abundance and biomass of zooplankton in eutrophic systems were higher than that of meso- and hypertrophic systems. From this result, we suggest that management strategy for the lentic ecosystem water environment has to be focused more on small-sized lakes and reservoirs, in terms of zooplankton assemblages.

• 생태와환경
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• 제41권spc호
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• pp.11-20
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• 2008

본 연구에서는 농림부와 환경부의 전국수질측정망 자료를 이용하여 2002년 9월 전후에 조사된 전국 290개 농업용 저수지의 Chl-${\alpha}$ 농도를 예측하였다. 우리나라 290개 농업용 저수지의 9월 전후 영양상태를 분류한 결과, 부영양 상태 이상을 나타내는 저수지가 $TSI_{CHL}\;64.1%,\;TSI_{TP}\;75.5%$로 대부분의 저수지가 높은 부영양화 상태를 보였다. 이렇게 분류된 저수지의 영양 상태를 환경특성에 따라 판별분석을 실시하였다. 그 결과 전체 판별적중률은 약 60%를 보였다. 판별분석의 결과에 정준분석을 실시한 결과, 각 그룹은 영양상태에 따라 구분이 되었으며, COD, DO, TP등이 중요한 인자로 나타났다. 또한 MLP-PSO 모델을 이용하여 부영양화에 따른 저수지 수질을 예측한 결과 높은 예측력을 보였으며 (r=0.831, p<0.05), 민감도 분석 결과 COD와 TP가 상대적으로 가장 중요한 요인으로 작용하였으며, 고도 및 제방 높이는 음의 영향을 미치는 것으로 나타났다.