• 한국해양학회지
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• v.23 no.4
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• pp.184-193
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• 1989

To study the pelagic fish egg community in the mid-east coastal waters of the Yellow Sea, pelagic eggs were sampled with Bongo net at 13 stations from Chonsu Bay to Keum Estuary from July, 1985 to June, 1986. Nineteen taxa of pelagic eggs were collected. Among them, 7 taxa were identified to the species level, and 2 taxa to the family level. Engraulis japonica was the most abundant species with 89.5% of the total eggs; Sillago japonica was 2.5%; Clupanodon punctatus, 2.4%; Herklotsichthys zunasi, 1.7%; Callionymidae spp., 1.6%. These 5 taxa occupied 97.7% of the total eggs. Pelagic eggs occurred from April to October. In June and July, their abundances were high, but the species diversities were low as E. japonica eggs were predominant. The range of spawning temperature for each taxa were estimated from the occurence pattern of the pelagic eggs.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.676-682
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• 2007

The bacterial number, extracellular enzyme activities and structure of bacterial community which are major constituent of aquatic ecosystem within the artificial vegetation island (AVI) were compared to those of the nearby pelagic lake waters in order to evaluate the possibility of the AVI as a eco-technological measure for water quality improvement and restoration of littoral zone in man-made reservoirs. There was not a significant difference in the total number of bacteria, but the number of active (viable) bacteria within the AVI was about 0.7 to 4.1 times higher than nearby pelagic lake water. The ratio of the number of active bacteria versus the total number of bacteria was also higher in the AVI than nearby pelagic lake water. The activities of ${\beta}$-glucosidase and phosphatase were 1.0 to 13.1 and 0.8 to 7.3 times higher respectively in the AVI than nearby pelagic lake water, showing that microorganisms were more active within the AVI. The bacterial communities of the two waters, examined by FISH method, did not indicate a clear difference in the springtime when the growth of macrophytes was immature, but during summer and fall it showed a clear difference indicating the formation of distinct bacterial community within the AVI compared to nearby lake water. From the results of this study, we conclude that AVI can contribute to make up the littoral ecosystem which show rapid cycling of matters through active detritus food chain in the dam reservoirs which have unstable aquatic ecosystem due to short hydraulic residence time and to strengthen the self-purification capacity of the lake.

• Ocean and Polar Research
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• v.30 no.3
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• pp.303-312
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• 2008

Despite the impacts of the climate changes on the pelagic ecosystem, few studies have examined the pelagic-benthic coupling in the adjacent East China Sea and Korea Strait. Therefore, the species composition and abundance of the macrobenthic community, as well as the potential food sources of benthic fauna were investigated in the present study using stable isotope analysis (${\delta}^{13}C\;and\;{\delta}^{15}N$) for suspended particulate organic matter (SPOM), sedimentary organic matter (SOM), phytoplankton, and zooplankton. A total of 157 macrobenthic fauna were collected, and the density of the macrobenthic fauna ranged from 4 to 434 ind./0.25 $m^2$, with an average density of 149 ind./0.25 $m^2$. The density of the benthic fauna increased moving from offshore shelf sites to coastal sites adjacent to the Korea Strait. Cluster analysis showed that the macrobenthic communities consisted of three distinct groups: group A in the Korea Strait, group B in the East China Sea, and group C near Ieodo. The dominant species in group A were the amphipods Photis japonica and Ampelisca miharaensis, followed by the polychaete Scolotoma longifolia. Environmental variables, such as the temperature of the seawater and sediment, and oxygen, and chlorophyll a levels, appeared to affect the structure of the community, suggesting the importance of coupling with the pelagic system. The ${\delta}^{13}C$ values of SPOM and zooplankton ranged from -22.97 to -23.5% and -19.92 to -21.86%, respectively, showing a relatively narrow range(<1%) between the two components. The difference between the ${\delta}^{13}C$ values of SOM and pelagic organic matter was also within 1%, suggesting that the SOM originated from the pelagic system, which is an important factor controlling the macrobenthic community.

• 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.28 no.4
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• pp.188-195
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• 2010

The Abundance of zooplankton was studied in the pelagic and the littoral zone in four shallow reservoirs along with the Nakdong river basin of S. Korea. In the pelagic zone, there was a higher zooplankton density ($477.5{\pm}312.4$ ind. $L^{-1}$) than in the littoral zone during our study period (t=2.337, p<0.05). Overall, Rotifers were the most abundant group in the studied reservoirs. However, there are no significant correlations between the pelagic and the littoral zone in physical and chemical parameters. In the pelagic and the littoral zone, zooplankton density usually increased with increasing density of aquatic plants in the littoral zone. However, this study showed different trends. Although macrophyte abundance was higher in the littoral zone than in the pelagic zone, zooplankton abundance was higher in pelagic zone. Moreover, when macrophytes (Trapa japonica and Spirodela plyrhiza) covered the complete water surface of the reservoir, zooplankton abundance was higher. It appears that comparisons between the pelagic and the littoral zone give important cues on the selection of habitats by zooplankton. It is assumed that a higher density of aquatic plants does not always imply a higher density of zooplankton in the littoral zone. Furthermore, when the water surface was covered with aquatic plants, the zooplankton communities showed the highest density in the pelagic zone. These results imply that habitat selection of the zooplankton community (Rotifers) is influenced by aquatic plant density with an associated decrease in predation pressure during summer.

• 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 Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.219-226
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• 1995

A study was made of the concentration of the naturally occurring radionuclide $^{210}Po$ in seawater, plankton and fishes collected from Yongil Bay, Korea, in summer 1993. The mean value of the $^{210}Po$ concentration in sea water was determined to be about 1.9 mBq/l, with the proportion of the dissolved forms being about $46\%$. The mean $^{210}Po$ concentration factor in the centric diatom Skeletonema costatum, comprises > $95\%$ of the total phytoplankton cell number, was $7.6\times10^4$. Of five species of zooplankton examined, four species (two copepods and two mysids) had $^{210}Po$ concentrations in the range of $^{210}Po$ mBq/g dry weight. A copepod Labidocera bipinnata, however, was exceptional with a particularly high $^{210}Po$ level of 2,070 mBq/g. This indicates that L. bipinnata is primarily a raptorial feeder. The concentration of $^{210}Po$ in the pyloric caecum of pelagic fishes was 2,979-3,811 mBq/g, with the concentration factors of $3.4-4.3\times10^6$. The food chain concentration of $^{210}Po$ occurred as follows: phytoplankton < filter feeding copepods < omnivorous mysids < raptorial copepod < pelagic fishes.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.240-247
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• 2015

This study was carried out to provide the preliminary data for study of zooplankton community structures and coastal pelagic ecosystem by understanding the seasonal change of zooplankton community depending on environmental factors at Dangdong bay in Tongyeong city. In this study, the environmental factors and the change of zooplankton community were analyzed for 2008 to 2011. In the results, a total of 80 species of zooplankton was sampled with a mean density of $1,599inds.m^{-3}$. The dominant species changed seasonally, and the most dominant species was Acartia steueri in winter and spring, Penilia avirostris in summer, and Evadne nordmanni in autumn. The Canonical Correspondence Analysis was conducted between the major dominant species and environmental factors. And for the environmental factors that effect the zooplankton community, the high correlation was observed with the water temperature, COD, DO and T-N, though there was slight difference among species. Therefore, more various research and environmental study are necessary to understand of planktonic ecosystem because the zooplankton community is affected by the interaction of both physical and biological factors.

• Ocean and Polar Research
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• v.41 no.4
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• pp.251-263
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• 2019

We investigated the mesozooplankton community structure during autumn in the southern Yellow Sea. Mesozooplankton density generally ranged from 352 to 2,954 ind. m^-3 and varied according to different sampling stations. The copepod Paracalanus parvus s.l. and its copepodites dominated in the communities, corresponding to 57.3% in density of the total. Surface and water-column averaged salinity were positively correlated with density of total mesozooplankton, copepods and a few dominant species, and the tunicate Thalia rhomboides was negatively related to chlorophyll-a concentration. The mesozooplankton community of the study area was divided into three groups according to the cluster analysis using species composition and density: one in the northern coastal region, another in the northern offshore region, and the other in the south. The most significant indicator species for each of the groups were Labidocera euchaeta in the northern coastal region, T. rhomboides in the northern offshore region, and Themisto sp. juveniles in the south. This study provides recent data on the characteristics of the mesozooplankton community in the southern Yellow Sea, which may be valuable for gaining a better understanding of changes in the pelagic ecosystem of the Yellow Sea.

• Ocean and Polar Research
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• v.23 no.2
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• pp.63-75
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• 2001

Species composition and community structure of the fouling found on the hulls of 28 ships traveling through 6 main shipping routes (SR)in the Far East Sea Basin were analyzed using statistical methods. Samples obtained during 1976-1990 expeditions of the Institute of Marine Biology were used for the analyses. These samples were taken from the ships anchored in the harbor by SCUBA diving and in dry-docks of the Vladivostok ship-repairing yard. Similar composition of the fouling communities occurred on the ships travelling the same SR. In five cases, fouling was dominated by different Cirripedia communities. And, in one case, a community of the mussel Mytilus trossulus was found. In most cases the results of the factor analyses showed extremely low level of the relationships among different animals and algal species in fouling communities. Each ocean-going ship had an original structure of the fouling. Spatially disconnected animal associations of tropical and boreal origin may simultaneously coexist at the same ship. This paper testified to the originality of the zone of anthropogenic substrata as a benthos concentrator in the pelagic regions of the world ocean. The fouling from different zones showed that each zone possesses peculiar features and regularities of the composition and relationships between organisms dwelling here.