• Title/Summary/Keyword: nanophytoplankton

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Water Temperature and Community of Phytoplankton in Youngsan River, Korea (수온에 따른 영산강 식물플랑크톤군집 변동)

  • Jeong, Eun-Jeong;Na, Jeong-Eun;Kim, Gyu-Man;Shim, Sung-Sun;Lee, Hak-Young
    • Korean Journal of Environmental Biology
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    • v.28 no.2
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    • pp.56-63
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    • 2010
  • In order to clarify the ecological properties of phytoplankton community, the distribution of phytoplankton and the relation of water temperature and size-fractionation measurements were studied from November 2004 to August 2005 in Youngsan River, Korea. A total of 265 phytoplankton species was identified. It consists of 48 genera and 123 species (46%) of Chlorophyceae, 27 genera and 89 species (34%) of Bacillariophyceae, 12 genera and 25 species (9%) of Cyanophyceae, respectively. From size fractionation analysis, nanophytoplankton (2~20 ${\mu}m$) dominated from early spring to early summer, and microphytoplankton (20~200 ${\mu}m$) from summer to winter. The relationship between chl-a and nanophytoplankton showed high correlation coefficient value ($r^2$=0.93) from Najudaegyo site. The correlation coefficient values between water temperature and nanophytoplankton were low except Dongkangdaegyo site which showed high value ($r^2$=0.73).

Tidal Influence on Physical Parameters and Phytoplankton Size Structure in Youngsan River Estuary during Neap Tide (조석에 따른 영산강 하구의 물리적 환경 및 식물플랑크톤 크기구조: 소조기)

  • Park, Geon-Woo;Lee, Da-Hye;Shin, Yongsik
    • Journal of Environmental Science International
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    • v.26 no.3
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    • pp.325-334
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    • 2017
  • To understand the changes in physical parameters and phytoplankton size structure caused by tides, a fixed station in the Youngsan River estuary was monitored at 2-h intervals, on April 28, 2012 and August 12, 2012. No clear relationship was observed between the temperature and salinity changes and tidal levels in April. However, in August, temperature decreased during the ebb tide and increased during the flood tide, while salinity showed the opposite trend. In addition, there was no specific change in the phytoplankton biomass corresponding to tidal levels in April. In August, the total chlorophyll a and the biomass of net phytoplankton (>$20{\mu}m$) increased almost 20 times during the ebb tide and decreased during the flood tide. The biomass of nanophytoplankton (<$20{\mu}m$) showed a similar variation in response to tidal level changes. In April, the relationship between percent contributions of phytoplankton size structure and tidal levels was not clear. In August, the net phytoplankton was dominant in the early stage and nanophytoplankton was dominant in the later stage, while contribution of nanophytoplankton and net phytoplankton increased at high tide and low tide, respectively. Therefore, in April, other factors such as freshwater discharge were more important than the tide, whereas in August, when no freshwater discharge was recorded, the changes in semidiurnal tides influenced the physical parameters and phytoplankton dynamics. These results could contribute to the understanding of phytoplankton dynamics in the Youngsan River estuary.

Size-structure and Primary Productivity of Phytoplankton from Major Lakes in Sumjin and Yeongsan Watershed (섬진강.영산강 수계 주요 호소의 식물플랑크톤 크기구조 및 일차생산력)

  • Yi, Hyang-Hwa;Shin, Yong-Sik;Yang, Sung-Ryull;Chang, Nam-Ik;Kim, Dong-Ho
    • Korean Journal of Ecology and Environment
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    • v.40 no.3
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    • pp.419-430
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    • 2007
  • Physiochemical factors, phytoplankton biomass (Chl ${\alpha}$) and primary productivity were investigated seasonally in the three lakes of Dongbok, Juam, and Yeongsan during April 2004${\sim}$March 2006. Microphytoplankton dominated (>60%) in Dongbok lake, and phytoplankton biomass was high in the upper area, especially during April 2004, whereas they were high in the lower area during June 2004. In Juam lake, the high phytoplankton biomass in April 2004 was contributed by nanophytoplankton. In Yeongsan lake, chlorophyll a was high in August with high contribution of nanophytoplankton. Primary production was highest in Dongbok lake, and then followed by Yeongsan and Juam lakes. Regression analysis in Dongbok take showed that Chl ${\alpha}$ and primary production had close relations with secchi depth. In Juam lake, phosphate were correlated with the Chl ${\alpha}$, while temperature and TN was correlated with primary production in the lower area. In Yeongsan lake, Chl ${\alpha}$ have positively correlation with TN/TP. Primary production in the upper have high relationship with secchi depth, however, in the lower have high relationship with turbidity. Linear regression analysis showed that nutrients of nitrogen and phosphorus should be reduced for the protections in Juam and Dongbok lakes. We suggested that suspended solids and phytoplankton growth related to turbidity are needed to manage in Yeongsan lake.

Variation and Relationship between Standing Crops and Biomass of Phytoplankton Dominant Species in the Marine Ranching Ground of Tongyeong Coastal Waters from 2000 to 2007 (2002-2007년 통영바다목장해역에서 식물플랑크톤 현존량 및 생체량에 따른 우점종의 변동 및 관계)

  • Jung, Seung-Won;Kwon, Oh-Youn;Lee, Jin-Hwan
    • ALGAE
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    • v.23 no.1
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    • pp.53-61
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    • 2008
  • In order to understand variation and relationship between standing crops and biomass of phytoplankton dominant species for the long term periods, this study was seasonally investigated in the marine ranching ground of Tongyeong coastal waters from 2000 to 2007. Total 268 taxa representing 217 Bacillariophyceae, 46 Dinophyceae, 4 Dictychophyceae, 1 Euglenophyceae were observed in phytoplankton communities. Dominant species consisted of 5 species as standard in standing crops: Chaetoceros curvisetus (18.01%), Chaetoceros socialis (12.95%), Skeletonema costatum (8.39%), Chaetoceros compressus (6.87%), Asterionellopsis glacialis (5.02%). However, to determine dominant species as biomass concept, Ditylum brightwellii, Guinardia striata, Rhizosolenia spp. and Skeletonema costatum were occupied with dominant species (19.67%). As determining for cell sizes, dominant species were divided with two groups such as micro- and nanophytoplankton (standing crops) and mesophytoplankton (biomass). However, Skeletonema costatum in anophytoplankton was associated to affect fluctuation between standing crops and biomass.

Taxonomic and Ecologic Studies on Ciliate Plankton in Pal'tang Reservoir, Korea (팔당호 섬모충 플랑크톤의 분류 및 생태학적 연구)

  • Moon, Eun-Young;Kim, Young-Ok;Kim, Baik-Ho;Kong, Dong-Soo;Han, Myung-Soo
    • Korean Journal of Ecology and Environment
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    • v.37 no.2 s.107
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    • pp.149-179
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    • 2004
  • In order to understand the taxonomic and ecologic characteristics on ciliates plankton, surface water samples were collected once a weekly from March 2001 to December 2001 except once a monthly from December 2001 to January 2001 and twice a monttdy at February 2001 at Pal'tang reservoir in Korea. Totally 12 species belonging to 10 genera in 7 families of 6 order, were identified and all species new record in Korea. All of them had been recorded in eutrophic water bodies. Succession of dominant species occurred obviously according to seasonality. Large -sized Codonella cratera, Rimostrombidium lacustris, Strobilidium caudatum, Limnostrombidium viride, Pelagostrombidium fallax, Stylonychia sp., Pseudostrombidium plaktonticum and Phascolodon vorticella dominated during the period of outbreak of nanophytoplankton in winter to spring. However, small-sized Rimostrombidium hyalinum, rimostrombidium brachykinetum, Halteria gradinella and Vorticella convallaria occurred when the bacteria abundance increased in summer to autumn.

Phytoplankton Distribution in the Eastern Part of the Yellow Sea by the Formation of Tidal Front and Upwelling during Summer (황해 동부 해역에서 하계에 조석전선과 용승에 의한 식물플랑크톤군집 분포)

  • Lee, Young-Ju;Choi, Joong-Ki;Shon, Jae-Kyoung
    • Ocean and Polar Research
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    • v.34 no.2
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    • pp.111-123
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    • 2012
  • To understand the phytoplankton community in the eastern part of the Yellow Sea (EYS), in the summer, field survey was conducted at 25 stations in June 2009, and water samples were analyzed using a epifluorescence microscopy, flow cytometry and HPLC method. The EYS could be divided into four areas by a cluster analysis, using phytoplankton group abundances: coastal mixing area, Anma-do area, transition water, and the central Yellow Sea. In the coastal mixing area, water column was well mixed vertically, and phytoplankton was dominated by diatoms, chrysophytes, dinoflagellates and nanoflagellates, showing high abundance ($>10^5\;cells\;l^{-1}$). In Anma-do coastal waters characterized by high dominance of dinoflagellates, high phytoplankton abundance and biomass separated from other coastal mixing area. The southeastern upwelling area was expanded from Jin-do to Heuksan-do, by a tidal mixing and coastal upwelling in the southern area of Manjae-do, and phytoplankton was dominated by benthic diatoms, nanoflagellates and Synechococcus group in this area. Phytoplankton abundance and biomass dominated by pico- and nanophytoplankton were low values in the transition waters and the central Yellow Sea. In the surface of the central Yellow Sea, high dominance of photosynthetic pigments, 19'-hexanoyloxyfucoxanthin and zeaxanthin implies that haptophytes and cyanobacteria could be the dominant group during the summer. These results indicate that the phytoplankton communities in the EYS were significantly affected by the formation of tidal front, thermal stratification, and coastal upwelling showing the differences of physical and chemical characteristics during the summer.

Trophic Role of Heterotrophic Nano- and Microplankton in the Pelagic Microbial Food Web of Drake Passage in the Southern Ocean during Austral Summer (남극 하계 드레이크 해협의 미세생물 먹이망에서 종속영양 미소형 및 소형플랑크톤의 역할)

  • Yang, Eun-Jin;Choi, Joong-Ki;Hyun, Jung-Ho
    • Ocean and Polar Research
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    • v.33 no.4
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    • pp.457-472
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    • 2011
  • To elucidate the trophic role of heterotrophic nano- and microplankton (HNMP), we investigated their biomass, community structure, and herbivory in three different water masses, namely, south of Polar Front (SPF), Polar Front Zone (PFZ), the Sub-Antarcitc Front (SAF) in the Drake Passage in the Southern Ocean, during the austral summer in 2002. We observed a spatial difference in the relative importance of the dominant HNMP community in these water masses. Ciliates accounted for 34.7% of the total biomass on an average in the SPF where the concentration of chlorophyll-a was low with the dominance of pico- and nanophytoplankton. Moreover, the importance of ciliates declined from the SPF to the SAF. In contrast, heterotrophic dinoflagellates (HDFs) were the most dominant grazers in the PFZ where the concentration of chlorophyll-a was high with the dominance of net phytoplankton. HNMP biomass ranged from 321.9 to 751.4 $mgCm^{-2}$ and was highest in the PFZ and lowest in the SPF. This result implies that the spatial dynamic of HNMP biomass and community was significantly influenced by the composition and concentration of phytoplankton as a food source. On an average, 75.6%, 94.5%, and 78.9% of the phytoplankton production were consumed by HNMP in the SPF, PFZ, and SAF, respectively. The proportion of phytoplankton grazed by HNMP was largely determined by the composition and biomass of HNMP, as well as the composition of phytoplankton. However, the herbivory of HNMP was one of the most important loss processes affecting the biomass and composition of phytoplankton particularly in the PFZ. Our results suggest that the bulk of the photosynthetically fixed carbon was likely reprocessed by HNMP rather than contributing to the vertical flux in Drake Passage during the austral summer in 2002.

Temporal and Spatial Variations of Size-structured Phytoplankton in the Asan Bay (아산만 식물플랑크톤 크기구조의 시.공간적 변동)

  • Hyun Bong-Kil;Sin Yong-Sik;Park Chul;Yang Sung-Ryull;Lee Young-Joon
    • Korean Journal of Environmental Biology
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    • v.24 no.1 s.61
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    • pp.7-18
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    • 2006
  • Samples were collected from five stations monthly from October 2003 to September 2004 to investigate seasonal variation of size structure of phytoplankton and relationship between size-fractionated phytoplankton and environmental factors in the Asan Bay. The contribution of large cells (microphytoplankton, $>20\;{\mu}m$) to total concentrations of chlorophyll $\alpha$ was higher than small cells (nanophytoplankton, $3\sim20\;{\mu}m$; picophytoplankton, $<3\;{\mu}m$) during the sampling period. Especially, large cells contributed 80% to the total chlorophyll a from February, 2004 to April 2004 when chlorophyll $\alpha$ concentrations were high. The size structure of phytoplankton shifted from micro-size class to nano-size class and picophytoplankton rapidly increased when phytoplankton biomass decreased in May 2004. Microphytoplankton exhibited a high biomass in the upper region during winter-spring season whereas nano- and picophytoplankton showed two peaks in the middle-lower regions (Station 3,5) during spring and summer. Microphytoplankton are most likely controlled by water temperature and nutrient supply during the cold season whereas nano- and picophytoplankton may be affected by stratification, light exposure during the warm season.

Seasonal Characteristics of Phytoplankton Distribution in Asan Bay (아산만 식물플랑크톤의 계절별 군집 분포 특성)

  • Yi, Sang-Hyon;Sin, Yong-Sik;Yang, Sung-Ryull;Park, Chul
    • Ocean and Polar Research
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    • v.27 no.2
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    • pp.149-159
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    • 2005
  • Samples were collected from five stations in February, May, July, and September 2004 to investigate seasonal variations in the phytoplankton community and the relationship between dominant genera and environmental factors in Asan Bay. In February, microphytoplankton contributed 80% to the total chlorophyll a. Diatom dominated the phytoplankton community, accounting for 85.9% of the total cell number, followed by dinoflagellates (6%). Dominant species were Skeletonema costatum and Thalassiosira spp. Abundant diatom, including S. costatum and Thalassiosira spp., may be affected by water temperature and silicate at Station 1 and 2 in February 2004. In May, the nanophytoplankton contribution to total phytoplankton was higher than in other seasons. However, abundance of S. costatum and Thalassiosira spp. decreased, since the growth of S. costatum and Thalassiosira spp. might be limited by phosphates (P) resulting from low P concentration and a high DIN:DIP ratio in the outer region. In July, dominant phytoplankton groups were diatom (39%), cryptophyceae (28%), and cyanophyceae (20%). Dominant genera were Oscillatoria spp. and phytoflagellate of a monad type in the inner region (Station 1 and 2), whereas S. costatum was dominant in the outer region (Station 4 and 5). In September, dominant phytoplankton were diatom (69%) and cryptophyceae (28%). Dominant genera were phytoflagellate of the monad type, S. costatum in the inner region, while Chaetoceros spp. was dominant in the outer region.

Regeneration Processes of Nutrients in the Polar Front Area of the last Sea IV. Chlorophyll a Distribution, New Production and the Vertical Diffusion of Nitrate (동해 극전선역의 영양염류 순환과정 IV. Clorophyll a 분포, 신생산 및 질산염의 수직확산)

  • MOON Chang-Ho;YANG Sung-Ryull;YANG Han-Soeb;CHO Hyun-Jin;LEE Seung-Yong;KIM Seok-Yun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.2
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    • pp.259-266
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    • 1998
  • A study on the biological and chemical characteristics in the middle last Sea of Korea was carried out at 31 stations in October $11\~18$, 1995 on board the R/V Tam-Yang. The chlorophyll a concentration, new and regenerated production, and the vertical diffusion of nitrate from the thermocline structure were investigated. From the vertical distribution of chlorophyll a, subsurface maxima were observed near the thermorline at most stations including the frontal zone, except at the southern stations where the maximum chloropyll a concentration occurred at the surface, The nanophytoplankton was the most dominant fraction comprising $83.5\%$ of total phytoplankton cell numbers, but netphytoplankton were common at the southern stations where the dominant species were Rhizosolenia sp. Nitrogenous new production and regenerated productions were measured using the stable isotope $^{15}N$ nitrate and ammonia uptake method. The vertically integrated nitrogen production varied between 8.470 and $72.945\;mg\;N\;m^{-2}\;d^{-1}$. The f-ratio, which is the traction of new production from primary production, waried between 0.03 and 0.72, indicating that $3\%$ to $72\%$ of primary production was supported by the input of nutrients from below the euphotic zone and the rest are supported by ammonia recycled within the euphotic layer. This range of f-ratio encompasses from extremely oligotrophic to eutrophic area characteristics. The differences in productivity and f-ratio among stations were related to frontal structure and the bottom topography. The values were high near the frontal zone and low outside of it, and the station near Ulleng Island showed the highest f-ratio. Vertical diffusion coefficients were calculated from both the water column stability (Kz-1) of King and Devol's equation (1979) and new nitrogen requirement (Kz-2). The values of Kz-2 ($0.11\~0.55\;cm^2/s$) were relatively low compared to the values reported previously.

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