• Journal of Ecology and Environment
• /
• 제37권1호
• /
• pp.1-11
• /
• 2014

To understand the effects of fluctuations in dam discharge due to river environments and phytoplankton communities, we monitored such environments and phytoplankton communities biweekly, from February 2001 to February 2002 and from February 2004 to February 2005, in the lower Han River (LHR), South Korea. The phytoplankton abundance during the dry season was approximately two times higher than that during the rainy season. In particular, fluctuations in diatom assemblages, which constituted over 70% of the total phytoplankton abundance, were affected severely by the changes in the discharge. When a large quantity of water in a dam was discharged into the LHR, the conductivity and the concentrations of total nitrogen (TN), total phosphorus (TP), and dissolved inorganic phosphorus (DIP) decreased rapidly, whereas the concentrations of suspended solids (SS), dissolved inorganic nitrogen (DIN), and dissolved silica (DSi) increased immediately. Time-delayed relationship also revealed that the dam discharge had an immediately significant negative relationship with phytoplankton abundance. On the whole, fluctuations in phytoplankton communities in the LHR were influenced much more by hydrodynamics such as dam discharge than by the availability of nutrients. Thus, the variability in these concentrations usually parallels the strength of river flow that is associated with summer rainfall, with higher values during periods of high river discharge.

• ALGAE
• /
• 제19권3호
• /
• pp.235-245
• /
• 2004

A study on seasonal characteristics of phytoplankton dynamics and environmental factors was carried out at four stations including Mara-do and U-do located in the western and eastern coast of Jeju Island in southern Korea from April 2003 to March 2004. Out of 101 phytoplankton species identified, 84 belong to Bacillariophyceae, 9 Dinophyceae, 6 phytoflagellates and 2 coccolithophorids, and the highest value of species diversity was observed in April. Phytoplankton was more abundant at the western coast than at the eastern coast from March to September and its highest abundance was 49.24 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July. The pennate diatoms were more abundant at the western coast than at the eastern coast with the highest abundance of 38.75 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July, and during this period Nitzschia longissima contributed 68.5% of the total phytoplankton abundance. Naviculaceae was more abundant at Gosan (western coast) in November when Stauroneis membranacea represented 80.1% of the abundance. Leptocylindrus dances contributed 49.4% of the abundance at U-do in November. Dinophyceae was more abundant at U-do in August. Water temperature and pH fluctuated from 11.7${^{\circ}C}$ to 27.1${^{\circ}C}$ and from 7.31 to 8.70, respectively. Water temperature of Mara-do was about 1-2${^{\circ}C}$ higher than the other stations. Salinity varied from 30.4 to 35.0 psu with the minimum in rainy season and the maximum at the end of winter. The concentration of NH$_4$-N, NO$_3$-N, NO$_2$-N, PO$_4$-P and SiO$_2$-Si ranged 0.07-6.79, 1.0-62.0, 1.0-8.0, 1.0-7.0 and 7.0-191.0 $\mu$g-at L$^{-1}$, respectively. Chlorophyll a concentrations varied from 0.10 to 1.17 $\mu$g L$^{-1}$. NH$_4$-N concentrations were high at U-do from May to December, and at Mara-do from January to February. The high concentrations of NO$_3$-N were found at Mara-do from June to September and at U-do from January to May. The effects of various physicochemical parameters on the seasonal distribution and succession of phytoplankton population suggest that there is a classical pattern of phytoplankton dynamics in Jeju coastal waters.

• 해양환경안전학회지
• /
• 제21권5호
• /
• pp.474-483
• /
• 2015

동해 연안 식물플랑크톤의 계절별 분포 특성과 해양환경 요인과의 상호관계를 파악하기 위하여 2009년 2월, 5월, 8월 및 11월에 연안 18개 정점에 대해 조사하였다. 조사기간 중 출현한 식물플랑크톤은 규조강 37종, 와편모조강 22종, 유글레나조강 1종, 규질편모조강 3종 및 은편모조강 1종으로 나뉘었다. 현존량은 $1.2{\times}10^3-246.6{\times}10^3cells/L$(평균 $24.8{\times}10^3cells/L$)의 분포 범위를 보였으며 5월에 가장 높았다. 주요 우점종은 Leptocylindrus danicus, Chaetoceros affinis, Pseudo-nitzschia pungens 및 Thalassionema nitzschioides 등이 출현하였다. 해양환경 요인과의 상관분석 결과 식물플랑크톤 현존량은 pH, 용존산소, 클로로필-a 및 부유물질과 양의 상관관계를 보였으며, 규산규소와는 음의 상관관계를 보였다. 식물플랑크톤 우점종의 계절 변동은 등밀도선 상의 수온(T)-염분(S)도로 구분한 수괴 특성에 영향을 받는 것으로 나타났으며, 특히 5월은 수온, 8월은 염분 분포와 관계가 있었다. 현존량과 종조성을 바탕으로 다원척도 분석을 한 식물플랑크톤의 공간적인 분포는 경북 죽변과 울진을 기점으로 강원연안 그룹(Group A)과 경북연안 그룹(Group B)으로 나뉘어졌다.

• Ocean Science Journal
• /
• 제42권2호
• /
• pp.117-127
• /
• 2007

The dynamics of phytoplankton abundance with seasonal variation in physicochemical conditions were investigated monthly at 10 stations around the Chagwi-do off the west coast of Jeju Island, Korea, including inshore, middle shore, and offshore in the marine ranching are a from September 2004 to November 2005. Water temperature varied from 12.1 to $28.9^{\circ}C$ (average $18.8^{\circ}C$), and salinity from 28.9 to 34.9 psu (average 33.7 psu). The chlorophyll a concentration was $0.02-2.05\;{\mu}g\;L^{-1}$ (average $0.70\;{\mu}g\;L^{-1}$), and the maximum concentration occurred in the bottom layer in April. A total of 294 phytoplankton species belonging to 10 families was identified: 182 Bacillariophyceae, 52 Dinophyceae, 9 Chlorophyceae, 12 Cryptophyceae, 6 Chrysophyceae, 4 Dictyophyceae, 13 Euglenophyceae, 6 Prymnesiophyceae, 5 Prasinophyceae, and 5 Raphidophyceae. The standing crop was $2.21-48.69\times10^4\;cells\;L^{-1}$ (average $9.23\times10^4\;cells\;L^{-1}$), and the maximum occurred in the bottom layer in April. Diatoms were most abundant throughout the year, followed by dinoflagellates and phytoflagellates. A phytoplankton bloom occurred twice: once in spring, peaking in April, and once in autumn, peaking in November. The spring bloom was represented by four Chaetoceros species and Skeletonema costatum; each contributed 10-20% of the total phytoplankton abundance. The autumn bloom comprised dinoflagellates, diatoms, and phytoflagellates, of which dinoflagellates were predominant. Gymnodinium conicum, Prorocentrum micans, and P. triestinum each contributed over 10% of the total phytoplankton abundance.

• Ocean and Polar Research
• /
• 제26권2호
• /
• pp.113-120
• /
• 2004

The abundance, biomass and distribution of phytoplankton, bacterioplankton and heterotrophic protists in the Bering Sea were investigated from July to August 1999. Chlorophyll a concentrations in the surface waters ranged from 0.16 to $3.79{\mu}g\;l^{-1}$ Nano-phytoplankton were found to constitute from 63 to 98% of the total phytoplankton biomass, and were clearly the dominant primary producers. The biomass of bacterioplankton in the surface layers varied from 1.46 to $20.2{\mu}g\;C\;l^{-1}$ and accounted for 30% of the total phytoplankton biomass. The biomass of bacterioplankton integrated over a depth of 0 to 100m averaged 65.4% of the total phytoplankton biomass. The surface biomass of heterotrophic protists ranged from 1.2 to $27.4{\mu}g\;C\;l^{-1}$, and was within the same order of magnitude as that of bacterioplankton. Of the total biomass of heterotrophic protists in the upper 100m of the water column, 65% was attributed to protists in the nano-size class. The results of this study suggest that bacteria and nano-protists are important components of the planktonic community in the Bering Sea during the summer season. The abundance of bacterioplankton and planktonic protists decreased from the western to northeastern and eastern regions of the Bering Sea. The abundance of these organisms also decreased with depth. The available evidence suggests that variation in the abundance and distribution of these organisms may be affected by water currents and vertical temperature variation in the Bering Sea.

• Ocean and Polar Research
• /
• 제23권4호
• /
• pp.379-388
• /
• 2001

Ch1 a abundance, Ch1 a-specific productivity and phytoplankton growth rate in each size fraction (pico, $<2{\mu}m$; nano, $2-10{\mu}m$; micro, > $10{\mu}m$) in the waters around the South Shetland Islands (Ant-arctic Peninsula Area) were analysed. Although Ch1 a-specific productivity and growth rate were highest in micro-size fractions, ChI a abundance was highest in pico-size fractions. Selective removal of nano- and micro-size phytoplankton especially by krill and salp grazing, but not limitation of phytoplankton growth, seemed to be the major reason to explain this miss match between productivity and abundance of the phytoplankton community.

• 생태와환경
• /
• 제41권4호
• /
• pp.449-456
• /
• 2008

Recent studies reveal that the endocrine disrupter nonylphenol can also influence the growth of planktonic organisms. To clarify the effect of nonylphenol on the whole planktonic community, we monitored planktonic abundances after addition of nonylphenol using small-scale microcosms in a laboratory. Nonylphenol was added at final concentrations of 1.25 and $2.5{\mu}g\;L^{-1}$, close to the EC50 for the growth of the rotifer, Brachionus calyciflorus. Chlorophyll $\alpha$ concentration increased significantly between 2 to 5 days after nonylphenol treatment compared to the control. The abundance of the predominant phytoplankton, Stephanodiscus hantzschii, followed the same pattern as chlorophyll a concentration. While there was no negative effect on the abundance of ciliates and rotifers, crustacean zooplankton abundance was higher in nonylphenol treatments. Although the relationship did not reach significance, the growth rate of rotifers tended to decline with increasing nonylphenol dosing. It is likely that the decreased rotifer grazing on S. hantzschii caused significant increase in their abundance. This study emphasizes the importance of considering indirect effects of environmental pollutants when predicting the response of biological community to toxicant exposure.

• 한국해양학회지:바다
• /
• 제26권3호
• /
• pp.220-237
• /
• 2021

1880년대에 들어서서 해양 식물플랑크톤의 기능적 중요성이 처음 주창된 이래, 전통적인 형태 관찰법 및 진보된 형태 자동분석 기술을 기반으로 하여 다량의 식물플랑크톤 종별 정량자료가 생산되었다. 최근에는 해수시료 중의 색소를 직접 분석하거나 원격탐사 자료를 해석하여 색소특성에 따른 분류군별 정량자료를 생산함으로써, 자료생산 방법이 점점 다양해지고 자료 확보 대상 정점에 대한 시공간적 접근성도 크게 개선되고 있다. 장기적인 해양생태계 모니터링에서 식물플랑크톤의 종별 정량자료가 생산된 경우도 적지 않아, 각각의 해역에서 중장기적인 해양 식물플랑크톤의 구조와 기능의 변동에 대한 중요한 증거로 활용될 수 있다. 그러나 모니터링 기간 전체에 걸친 연대별 자료 생산자 간의 차이로 인해 이러한 자료의 활용성이 제한될 수 있는데, 시료 처리 및 분석법, 종의 확인 및 분류, 분석이 완료된 시료의 관리 등의 다양한 측면에서 연대별 생산자 간의 편차가 적지 않다. 해양 식물플랑크톤의 종별 정량자료 값을 정확하게 구하기 위한 심도있는 연구는 1880년대 후반 Victor Hensen이 시작한 것으로 평가된다. 정확도를 포함한 해양 식물플랑크톤 자료의 정도 관리에 관한 국제적인 논의는 ICSU의 SCOR Working Group 33을 중심으로 1969년에 시작되었다. 첫 결실로 UNESCO 해양과학기술보고서 제18편이 1974년 출판되었는데, 이는 UNESCO의 해양학 방법론의 전문연구서적 제6편인 Phytoplankton Manual 출판의 실마리였다. 1990년대 말에는 ISO 기준에 따른 해양 식물플랑크톤 종별 정량자료의 정도관리를 달성하여, 국제적인 자료의 상호비교 및 교정을 가능하게 하려는 수행기구인 IPI (International Phytoplankton Intercomparison)의 전신인 BEQUALM 사업이 유럽에서 본격 출범하였다. IPI는 지난 20여 년간의 경험과 실적을 바탕으로 정도관리 기준을 모든 나라에서 적용할 수 있도록 국제협력을 강화해 나가고 있다. 우리나라의 해양화학 분야 측정자료의 정도관리 체계와 내용이 잘 정립된 데 비하여, 해양생물의 종별 정량자료에 대한 본격적인 정도관리 체계는 아직 법제화 단계에 이르지 못하고 있다. 우선, 해양생태계의 기초 생산자인 식물플랑크톤의 종별 정량자료에 대한 정도관리 체계를 확립하고, 다양한 기능생물군으로 이를 확장해 나갈 필요가 있다.

• ALGAE
• /
• 제20권1호
• /
• pp.43-52
• /
• 2005

A study on the seasonal changes in the phytoplankton community was carried out in four aquaculture ponds of Bangladesh over a period of 16 months from August 2000 to November 2001. Out of 45 phytoplankton species identified, 30 belong to Cyanophyceae, 7 to Chlorophyceae, 5 to Bacillariophyceae and 3 to Euglenophyceae. The highest phytoplankton abundance was observed in spring followed by early autumn, summer, and the lowest was in winter. The annual succession of Cyanophyceae was characterized by spring and early autumn period dominated by Microcystis sp. Anabaena sp. and Planktolymbya sp. with Microcystis sp. as the main blue-green algae represented. Chlorophyceae was characterized by rainy season domination of Chlorella vulgaris, Pediastrum sp. and Scenedesmus denticulatus with maximum abundance of Chlorella vulgaris. Whereas Bacillariophyceae was dominant during the winter period. Navicula angusta and Cyclotella meneghiniana were the most frequently occurring species of Bacillariophyceae throughout the study period. Euglenophyceae was dominant in late autumn and Euglena sp. was the dominant species. The effect of various physicochemical water quality parameters on the seasonal distribution and succession of the above mentioned phytoplankton population as well as the interaction and eutrophication are discussed.

• 수산해양교육연구
• /
• 제28권5호
• /
• pp.1417-1434
• /
• 2016

Starting from the February 2008 till the end of November 2014, abundance of phytoplankton and their composition living in the coastal waters of Kyoungju city were investigated. Environmental and biological properties were also observed at 10 different stations on a seasonal basis. Due to the environmental variables, fluctuating pattern was appeared during the entire period of observation with different degree, as compared to those found in other costal waters in the East Sea. The concentration of phosphate was turned out to be very low which was even less than threshold level in the study area. Phytoplankton community structure was dominated by diatoms (both micro- and nanoplankton fractions) for several years and seasonal succession was also relied on the diatoms. The importance of dinoflagellates in the community was relatively low. Abundance of phytoplankton was heavily affected by physical factors in the surface water, however, affected more by chemical factors including nutrients in the deep water. For periods of this study, the phosphate concentrations was observed in an extremely low, which indicates that the main limiting factor affecting phytoplankton growth could be phosphate.