• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.339-347
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• 2007

Zooplankton community dynamics were studied after establishment of an artificial vegetation island (AVI) in Lake Paldang, from April 2005 to November 2006. There were distinct seasonal and inter-annual changes of total zooplankton abundance at the survey site. Total zooplankton abundance rapidly increased in spring and fall, while it remained low throughout winter. During summer, the dynamics of zooplankton community seemed to be largely affected by hydrological parameters such as, precipitation and inflow. Total zooplankton abundance and biomass below AVI was much higher than that of pelagic zone (L1) in Lake Paldang. Copepoda and cladocera represented the main bulk of the zooplankton community from summer to fall at the both sites. Copepods were more dominant at AVI area, while cladocera were more dominant at pelagic zone (L1). Water quality, prey and habitat condition, species competition between zooplankton seemed to play important roles in dominance of the copepoda and cladocera in zooplankton community at AVI area. Our results conclude that artificial vegetation island provide the stable habitat and besides phytoplankton, diverse food to zooplankton, and consequently influence the diversity and richness of zooplankton community.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.490-498
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• 2012

This study demonstrates the investigation of zooplankton communities (e.g. rotifers, cladocerans and copepods) and environmentally related driving factors (e.g. elevation, area size, water depth, types of dike construction, and bottom substrates). We hypothesized that zooplankton community structure and composition would be influenced by ambient driving forces in different scales of the irrigation ponds (Dumbeong). A total of 66 zooplankton species/groups (56 rotifers, 9 cladocerans, 1 copepods) were found and identified at 45 Dumbeong of Goseong region (i.e. Goseong-gun) in 2011. The rotifers occupied 84.9% of the total zooplankton abundance. We could categorize a clear separation of zooplankton communities into 4 different patterns based on cluster analysis. Zooplankton diversities in Dumbeongs were lower than those in natural ponds or wetlands. In addition, community structure of zooplankton was also simpler and had a broken stick distribution based on SHE analysis. Species composition in each Dumbeong was not significantly discriminated each other. The result of canonical correspondence analysis (CCA) pinpointed that significant influential variables upon zooplankton community were dissolved oxygen percent saturation, pH, and Dumbeong's material. This study indicated that morphological type of the Dumbeong and its water quality could determine the community structure of zooplankton. Furthermore, the connectivity between ambient habitats and materials could be necessary to be rigorously considered in respect to producing the Dumbeongs to subsidize alternative habitats for wetland ecosystem in freshwater landscape.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.869-877
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• 2017

The monthly variations of zooplankton community were investigated at 12 stations near Tongyeong and Namhaedo in the South Sea of Korea from April to July, 2012. Zooplankton samples were collected by a plankton net (RN80) from near the bottom to the surface. Zooplankton community consisted of 97 taxa, and the mean abundance ranged from $213inds.m^{-3}$ in July to $426inds.m^{-3}$ in April. Copepods constituted 38.98% of zooplankton abundance, and included 39 species. Calanus sinicus, Corycaeus affinis, Paracalanus parvus s.l., copepodids, Evadne nordmonni, Podon leuckarti, cirriped nauplii, Muggiacea sp., Diphyes sp., and Zonosagitta bedoti were dominant species. Of these, Calanus sinicus was the most abundant throughout the study period, being constituted 18.6% of total zooplankton abundance. The density variations of dominant species between stations and months were correlated with the environmental factors. Zooplankton community varied with by sampling months, being influenced by monthly oceanographic variations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.445-455
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• 2021

We aimed to study the structure of the zooplankton community in the Southern Sea of the Republic of Korea. Zooplankton samples were collected in February (winter), May (spring), August (summer), and November (autumn) of 2020. The zooplankton collected belonged to a total of 166 taxa and 12 phyla, including some unidentified individuals and those from upper taxa. The number of taxa collected were the highest in winter at 117, and the lowest in May at 93. The dominant taxa were Oikopleura spp. in the winter, Gastropoda larvae in the spring, and Paracalanus parvus s.l. in the summer and autumn. The community structure of the zooplankton was clearly distinguishable between the seasons. The mean density of zooplankton was the highest in autumn and the lowest in summer (576,039 and 313,000 individuals/1,000 m³, respectively). Based on the analysis of relationships between the density of the six major taxa and environmental factors, a significant correlation (P<0.05) between the four taxa and environmental factors was found. Therefore, in order to understand changes in the zooplankton community, quantitative and qualitative investigations of biological factors as well as physical factors should be conducted.

• Ocean and Polar Research
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• v.31 no.4
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• pp.327-338
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• 2009

Zooplankton community structure was investigated in the Saemangeum region in March, May, July and October of 2007 and 2008 in order to understand the potential effect of post construction of Saemangeum dyke on their temporal and spatial distribution. Mean abundance of zooplankton in the inner and outer area of the dyke, except for dinoflagellate Noctiluca scintillans, ranged from 173 to 15,830 ind.m$^{-3}$, showing higher variability in the inner area compared to the outer area. Zooplankton abundance was higher in the outer area than the inner area in 2007, and vice versa in 2008. In the inner area of the dyke, zooplankton abundance was the highest in May 2007 and March 2008. In the outer area of the dyke, abundance was the highest in October 2007 and July 2008. Brackish species such as Tortanus derjugini and Pseudodiaptomus inopinus were dominant prior to construction of the dyke, and appeared less frequently in the inner area. Marine zooplankton taxa such as juvenile hydromedusa, and calanoid copepods Acartiahongi and Paracalanus parvus s.l. dominated both areas of the dyke. In CCA analysis, zooplankton community structure in the inner and outer area was similar in March and May, but different in July and October. Temperature, salinity and COD were important environmental factors affecting zooplankton community structure. These results suggest that zooplankton community structure in the inner and outer area of Saemangeum dyke are significantly affected by whether the sluice gates are closed or open.

• Korean Journal of Environmental Biology
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• v.30 no.1
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• pp.64-70
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• 2012

This study compares the abundance and community structure of zooplankton organisms from the littoral and pelagic regions, and considers particularly trophic levels vs. zooplankton abundances. Zooplankton samples, collected every 3 months over a year from 2010 to 2011 at 29 temperate lakes and reservoirs, which belong to two different river basins (Youngsan and Seomjin River). The spatial pattern of rotifers was similar to that of total zooplankton abundance. This reflected the fact that rotifers strongly dominated the zooplankton community. There were considerable spatial variations in total zooplankton abundance (ANOVA, p<0.01), while there were no significant differences both in littoral and pelagic regions in abundance of zooplankton (ANOVA, p=0.205). The mean abundance of zooplankton in eutrophic systems was much higher than that of mesotrophic systems, while significant difference in number of species and diversity index were not shown in both trophic systems.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.231-247
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• 2020

The seasonal variation in the zooplankton community and hydrographic conditions were examined in three regions (inner, central, and outer regions) of Gamak Bay, Korea. Zooplankton samples were collected over a period of 12 months from January to December 2006. The hydrographical parameters of temperature, salinity, chlorophyll-a concentrations, dissolved oxygen, and chemical oxygen demand were measured. The total zooplankton density varied from 411 to 58,485 ind. m^-3, with peaks in early summer. A total of 65 taxa accounted for approximately 86.9% of the annual mean zooplankton density: Noctiluca scintillans (30.9%) Paracalanus parvus s. l.(24.3%), Acartia omorii(11.9 %), Eurytemora pacifica (5.7%), cladocerans (4.1%), cirriped larvae (3.8%), Oithona similis (3.7%), and Pseudevedne tergestina(2.5%). Copepods dominated numerically throughout the year and comprised 54.3% of the total zooplankton. Most of the dominant copepods showed a well-defined seasonal pattern. The density and diversity of zooplankton in Gamak Bay were influenced by the hydrographic environment that was subject to significant spatial and temporal variations. Multivariate statistics showed that seasonal temperature was the most significant predictor of zooplankton taxa, density, and diversity, as well as the density of dominant taxa. Our results suggest that fluctuations in the zooplankton populations, particularly copepods, followed progressive increments in the temperature and COD concentrations.

• Journal of Korean Society on Water Environment
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• v.39 no.3
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• pp.215-222
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• 2023

Zooplankton are primary consumers in the food web connecting primary producers and predators such as small fish, playing an important role in energy transfer in aquatic ecosystems. Therefore, it is essential to understand the zooplankton community structure in material cycle and energy flow in aquatic ecosystems. Zooplankton in large rivers with a low flow rate would distribute vertically as in lakes. In this study, we collected zooplankton by surface water filtration and vertical haul method with 64 ㎛-mesh plankton net at three stations (ND-1, ND-2, ND-3) in Nakdong River fortnightly from June 2018 to December 2019. Species composition and individual densities were analyzed. All three stations showed differences in relative abundance of zooplankton groups between surface water and vertical integrated water, with the largest difference shown in the deepest station, ND-2. In vertically integrated water at ND-2, the relative abundance of rotifera was low by a maximum of 25% and that of cladocera was high by a maximum of 22% compared to surface water samples. These results indicate that surface water filtration method is not enough to represent the community structure of zooplankton compared to the vertical haul method in large rivers.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.850-859
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• 2010

Structure and succession of zooplankton community studied by hydraulic and ecological characteristics targeting the five lakes in the Han river system from March to December 2008. Results separated by river-type lake and lake-type lake depending on the type of hydraulic, Paldang lake and Cheongpyeong lake were river-type lake, while Chungju lake, Hoengseong lake and Doam lake was lake-type lake. The Paldang lake was a eutrophic lake, zooplankton community density and species number were the most among the five lakes. Relative dominance of the rotifera was the largest and the yearly first dominant species was a small cladocera Bosmina longirostris. The Cheongpyeong lake was a mesotrophic-eutrophic lake, hydraulic characteristics and zooplankton community changes were similar the Paldang lake. Relative dominance of the cladocera was the largest and the yearly first dominant species was a small cladocera Bosmina longirostris. The Chungju lake was a oligotrophic-mesotrophic lake, zooplankton community density was the least among the five lakes. Relative dominance of the copepoda was the largest and the yearly first dominant species was a large cladocera Daphnia galeata. The Hoengseong lake was a oligotrophic-mesotrophic lake, relative dominance of the rotifera was the largest and the yearly first dominant species was a small cladocera Bosmina longirostris. The Doam lake was a mesotrophic-eutrophic lake, zooplankton community density showed dramatic difference at the investigation time. Relative dominance of the rotifera was the largest and the yearly first dominant species was the copepoda Nauplius.

• Journal of the korean society of oceanography
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• v.38 no.3
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• pp.111-121
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• 2003

The seasonal succession of zooplankton communities in the coastal area off Incheon, Kyeonggi Bay, was investigated with the samples collected at intervals of 10 to 15 days from January 1999 to December 2000. Total abundance of zooplankton communities showed remarkable seasonal variations, ranged from 1,100 to $120,400{\;}indiv./\textrm{m}^3$, and annual mean abundance was $22,000{\;}indiv./\textrm{m}^3$. There were several times of the total abundance during a year, and the timing ofhigh abundances were about the same in 1999 and 2000. During the study period except summer, the abundance of dinoflagellate Noctiluca scintillans and copepod Acartia hongi contributed to the most part of total zooplankton. Whereas, during summer, smaller copepod Oithona davisae and Paracalanus crassirostris were dominant species. Zooplankton communities in the coastal waters off Incheon showed typical characteristics of coastal-estuarine communities, which were dominated by a few species, and abrupt seasonal variations in abundance. We suggest that the seasonal succession and abundance variations of zooplankton communities were caused by the seasonal variations in water temperature and by the seasonally varying phytoplankton biomass in the study area.