• Korean Journal of Environmental Biology
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• v.22 no.2
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• pp.308-320
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• 2004

The Community structure of meiobenthos was studied seasonally at 5 stations of Bangameori tidal flat and 3 stations of subtidal area in Daebudo near the Shiwha dike in the west coast of Korea, from May 2000 to February 2001. Mean grain size of intertidal stations ranged from $3.16\;\varphi\;to\;3.73\varphi$ (sand), subtidal stations were $5.81~6.67\;\varphi$ (mud). Nematodes were the most dominant group among the representative 19 meiofaunal groups at all stations in both tidal flat and sub-tidal area. The subdominant groups were benthic harpacticoid copepods and Sarcomastigophorans. The density of meiobenthos ranged from 145 inds. $10cm^{-2}$ to 2,057 inds. $10cm^{-2}$ (0~1 cm) in the sediment of intertidal stations, and from 391 to 3,787 inds. $10cm^{-2}$ (0~5 cm) in the subtidal stations. The lowest meiofaunal density was recorded in winter, whereas the highest density was shown in spring. Comparing with another previous work at the same area, data from this study does not statistically shown differences with results before discharge of shiwha lake water.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.159-171
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• 2001

Community structure, horizontal distribution, density, and ratio between nematodes and benthic harpacticoid copepods of the meiobenthos within the sediments of inner Sihwa Lake were investigated in May 1999 and May 2000. A total of 11 and 8 classes of meiobenthic animals were identified in 1999 and 2000, respectively, which were much lower than other coastal areas. The dominant animals during both sampling periods was the nematodes, followed by sarco-mastigophorans, nauplius of crustaceans, benthic harpacticoid copepods and polychaetes. These five classes of animals comprised more than 90% of total abundance of neiobenthos presented in the samples. In 2000, a lot of polychaete larvae were identified. The most abundant animal were the size that fits in 0.063 mm sieve size. Lower density was observed upper inner part of the Sihwa Lake during both sampling periods, and higher density was observed around the Sihwa floodgates. The average density between those two numbers were observed in the samples collected in the middle of the lake. Lower nematodes to betnhic harpacticoides (N/C) ratio, a relative indicator of environmental pollution, was observed to be lower around the floodgate but higher ratios were observed in the upper inner Sihwa Lake. The present study indicated that inner upper part of the lake becomes unsuitable for the meiobenthos, and the most inner upper lake was considered to be polluted.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.217-225
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• 1998

This study was performed to compare the effects of a fish cage on the structure of meiobenthic communities at two locations during May, 1996. The number of meiofaunal taxa at the existing cage site and control site was 15 and 26, respectively. Nematoda was the most dominant group of meiobenthos. Nematoda and Sarcomastigophora comprised more than $90\%$ of total meiofauna at both sites. The total density of control site was 7,702 inds./$10\;cm^{2}$ which is 10 times more than that of fish cage site. The density was highest in the upper 1 cm and decreased with sediment depth. The nematodes/harpacticoid copepods ratio as an index of pollution monitoring for benthic ecosystem at fish cage site was two times higher than at control site. Kinorhyncha known to be sensitive to pollution stress was not found at fish cage site.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.125-137
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• 2022

To assess the characteristics of meiofaunal community fluctuations related to environmental factors, seasonal surveys were conducted in the subtidal zone of Hallyeohaesang National Park. The average depth of the study area was about 20 m, and the average water temperature at the bottom was low in winter(11.33℃) and high in summer(17.95℃). The sedimentary particles mainly comprised silt and clay at most stations. The abundance of meiofauna ranged from 81.7 to 1,296.5 Inds. 10 cm^-2, and the average abundance was 589.3 Inds. 10 cm^-2. The average abundance of meiofauna in each season was the lowest at 416.5 Inds. 10cm^-2 in winter and the highest at 704.5Inds.10 cm^-2 in spring. The dominant taxa were nematodes (about 92%) and harpacticoids (about 5%). In the cluster analysis of meiofaunal communities, they were divided into four significant groups. The largest group mainly contained spring and summer samples, and contained stations with a high nematode density of over 500 Inds. 10 cm^-2 and harpacticoids below 50 Inds. 10 cm^-2 with a high composition ratio of nematodes. In the cluster analysis, no regional division was found between the stations, and it was thought to be divided by the seasons with high abundance according to seasonal variation and the composition ratio of nematodes and harpacticoids. In the Spearman rank correlation analysis, the density of total meiofauna and the most dominant taxa, nematodes, was not significantly related to environmental factors. However, the density of harpacticoids had a significant positive correlation with water depth and a negative correlation with sediment particle size.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.307-319
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• 2000

Community structure (seasonal fluctuation), taxon diversity, nematodes/benthic harpacticoids and nematodes/kinorhynchs ratios of meiobenthos were studied in the Gamak Bay, Korea. A series of samplings were carried out from April 1997 to May 1999. Meiobenthic organisms was collected by van Veen grab and three subcores of 34 mm in internal diameter were taken from each sediment sample. The total density of meiobenthos in each seasons was found to be the highest in May 1999, and the lowest in December 1998. Total density of meiobenthos at each station was the highest at Station 9 in May 1999 ($2,218 inds./10 cm^2$) and the lowest at Station 3 in December 1998 ($2 inds./10 cm^2$). The Gamak Bay seemed to have an individual number increased from the inner toward the outer stations. The highest number of meiobenthos was observed on 0.125 and 0.063 mm mesh size. In every season, over $80{\%}$ of the meiobenthos was composed of only four groups: nematodes, benthic harpacticoids, sarcomastigophorans and nauplius larvae of crustaceans. Seasonal fluctuation of meiobenthos was also studied. The nematodes/benthic harpacticoids(nematodes/kinorhynchs) ratios were studied as an index of pollution monitoring for benthic ecosystem at each station in each season. The value of nematodes/benthic harpacticoids ratio was the highest at the inner stations and the lowest at the outer stations in the Gamak Bay. Taxon diversity (H') was the highest at the outer stations and the lowest at the inner stations in the Gamak Bay. The value of nematodes/benthic harpacticoids ratio significantly increased from the outer toward the inner stations, whereas the taxon diversity (H') significantly increased from the inner toward the outer stations in Gamak Bay.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.245-254
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• 2000

This study was conducted to investigate the community structure and distributional pattern of meiobenthos in the deep sea bottoms of northeastern Pacific during July 1998. The faunal samples were collected using the multiple corer at ten stations; eight stations along the transects from 5$^{\circ}$N to 12$^{\circ}$N, and two stations in the Preservation Zone and Impact Zone of the KODOS (Korea Deep Ocean Study) area. The organic carbon content in sediments ranged from 0.79 to 1.76 mg cm$^{-3}$, and higher concentration appeared at stations in lower latitudes than 8$^{\circ}$N. The most abundant meiobenthos was nematodes and followed by foraminiferans; these two taxa comprised more than 70% of the total abundance at all stations. The most abundant meiobenthos occurred with mesh size of 0.063 nm. The maximum density of meiobenthos was 442 ind./10 cm$^2$ at station N5, and the density gradually decreased toward station N8 where the minimum density of 92 md./10 cm$^2$ was found. More than 60% of meiobenthos were distributed at surface sediment layer within 1.0 cm, and the peak abundance was found at 0-0.25 cm layer. The latitudinal distribution pattern of meiobenthos in the study area seemed to be related with the primary productivity of the surface water that is also connected to the water circulation pattern of the Pacific Ocean near the Equator, diverging at latitude of 8$^{\circ}$N and conversing at 5$^{\circ}$N.