• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.479-480
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• 2001

Harpacticoid copepods are one of the most important components in the benthic meiofaunal community. In spite of their numerical significance the study of harpacticoids in Korea, as distinct from meiofauna in general (Kim et al., 1998, 2000a, b), has been limited. During the course of investigation on ecological significance of harpacticoids in the intertidal sandy shore, a new species of the genus Rhizothrix was determined and described here. (omitted)

• 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.8 no.1
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• pp.1-13
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• 2003

To investigate the community structure and meiofaunal density in seagrass/bare non-seagrass beds, a survey was conducted at three seagrass bed locations in Doomoojin of Baegryongdo, inner harbor of Eocheongdo in May 1999, and Yulim of Dolsando for every month from February to July 1999. Meiobenthic samples were collected from sediments within seagrass beds (SB) and non-seagrass bed (or adjacent to barren sand area, NSB). Nematodes were the most dominant group among representative 13 meiofaunal groups. The sub-dominant groups were benthic for-aminiferans, benthic harpacticoids, and annelids. The highest density of meiofauna was recorded at a seagrass bed of Yulim (7,244 ind/10 $\textrm{cm}^2$ in June), and lowest density was recorded at a non-seauass bed of Baegryoungdo (438 ind/ 10 $\textrm{cm}^2$ in May). For vertical distribution, the highest density of meiofauna was recorded at 0-2 cm depth, and the density abruptly decreased with depth in all stations. The density of meiofauna in size between 0.125 m and 0.25 mm was maximum. Sediment types for the study areas ranged from sandy to sandy mud by the Folk's classification. The density of total meiofauna, the number of taxa, and the density of the dominant groups (nematodes, benthic for-aminiferans, benthic harpacticoids, annelids) between SB and NSB were significantly different. The results clearly showed the importance of seagrass bed as suitable habitat for meiofauna.

• Ocean and Polar Research
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• v.36 no.3
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• pp.209-223
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• 2014

The community structure of benthic meiofauna was investigated from seasonal surveys at seventeen stations off the Saemangeum area, in 2007. Ten meiofaunal taxa were identified. Nematodes were the dominant faunal group in all seasons and harpacticoids were dominant only at a few stations. The mean density of meiofauna was 383 indiv. $10cm^{-2}$, highest in May and November (434 indiv. $10cm^{-2}$), lowest in February (284 indiv. $10cm^{-2}$). Meiofaunal mean biomass was $80.49{\mu}gC{\cdot}10cm^{-2}$, highest in November ($99.54{\mu}gC{\cdot}10cm^{-2}$), lowest in February ($51.56{\mu}gC{\cdot}10cm^{-2}$). Cluster analysis revealed that the study area was composed of three benthic meiofaunal communities. There were significant correlations between major meiofaunal groups and sediment composition and the concentrations of heavy metals. The abundance of harpacticoids are positively correlated with silt (0.559, p < 0.01) and clay (0.340, p < 0.01), and negatively correlated with sand (-0.548, p < 0.01). Harpacticoids also showed positive correlations with heavy metals. The community structure of meiofauna in the study area varied seasonally in response to the change of sediment composition.

• Ocean and Polar Research
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• v.22 no.1
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• pp.15-23
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• 2000

The community structure of meiobenthos was studied in tidal flats of Kanghwado in November, 1997. Nematodes were the most dominant group among 18 total meiofaunal groups at most stations except for at lower tidal flats where the most abundant groups were harpacticoid copepods. Meiobenthos were the most abundant in the upper 1cm and their density decreased depending on the depth from the surface. The highest density of the meiobenthos was 6,094 inds. $10cm^{-2}$ at the upper tidal flat, while the lowest was 1,524 ind. $10cm^{-2}$ at the lower tidal flat. The density was higher in general at the upper tidal flats, but decreased at the stations toward lower tidal flat at all transect lines. At all transect lines, nematodes decreased as stations were along toward lower tidal flat whereas harpacticoids increased. The values of N/C(nematodes/benthic harpacticoids) ratio were higher at the upper tidal flats than the lower tidal flats at all transect lines.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.590-603
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• 2021

Benthic harpacticoids were collected from the East Sea of Korea. Specimen were identified as members of the genus Robertgurneya Apostolov & Marinov, 1988 based on the following characteristics: the fourth segment of antennule with aesthetasc, antenna with three-segmented exopod, shape of mandible, and P1-P4 armature formula. Robertgurneya donghaensis sp. nov. is morphologically most closely related to R. simulans (Norman & Scott T., 1905) and R. similis similis (Scott A., 1896). However, R. donghaensis is characterized by the rostrum with a pointed tip, caudal rami about as board as the length of its inner edge, the first segment of the P1 endopod much longer than entire exopod, and the P5 exopod with five setae in male. The genus Robertgurneya is reported from Korean waters for the first time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.223-230
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• 2006

We investigated the spring and summer community structure of meiobenthos in a tidal-falt near Iwon, Korea, in 2002 and 2003. In total, 12 meiofaunal groups were found in the study area among which nematodes were the most dominant. Benthic foraminiferans, harpacticoid copepods, polychaetes, and crustacean nauplli were also dominant groups at all sites. The total density of meiobenthos at each station was be 246-2,177 ind./$10cm^2$. As the depth of sediment increased, the density of meiobenthos at each station gradually decreased. Changes in the vertical distribution of meiobenthos in the study area occurred mainly near the sediment surface (0-1 cm). Generally, between spring and summer the density of nematodes increased, and the density of other dominant meiofaunal groups (benthic harpacticoids, crustacean nauplii, benthic foraminiferans) decreased near the sediment trap the control site of sediment traps compared to that at the control site. The results of cluster and multidimensional scaling plots indicate that the meiofaunal community changed following construction of a low artificial wood groin structure.

• Ocean and Polar Research
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• v.27 no.3
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• pp.299-309
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• 2005

The community structure of meiobenthos was studied in the sediment of Kongfjorden, Spitsbergen of Svalbard Island in the Arctic Sea. Samples of meiobenthos were collected in August, 2003. Meiobenthic organisms were collected by SCUBA and van veen grab or acryl sub-corers 34mm in internal diameter, and were taken from upper sediment to a depth of 3cm at each station. A total of 26 meiofaunal groups were found in the sediment of Spitsbergen in Svalbard Island. Nematodes were the most dominant faunal group. Sarcomastigophorans, benthic harpacticoids, and nauplius larvae of crustaceans, were also important components of the meiobenthic community of Kongsfjorden. All of these low faunal groups were comprised of more than 90% of total meiobenthos at every station. The total density of meiobenthos at each station was highest at station MeG 6 $(3,583{\pm}1,137inds./10cm^2)$, and lowest at station $MeG9(28{\pm}1inds./10cm^2)$. Meiobenthos in general showed the highest density in the upper 1cm layer. This may be associated with food and oxygen supply to subsurface. Harpacticoids showed extreme preference at the surface and little presence in layers deeper than 2cm. These animals may be less resistant to oxygen deficiency, and nauplius also showed the same trend. However, in St. MeG 8 and 9, meiobenthos were dense at depths of more than 0-1cm, at especially at depths of 2-3m because of relatively easy penetration of oxygen. Based on the results of cluster analysis, three meiobenthos assemblages were distinguished: one was in the outer and two were in the inner fjord. Station SCU 5 was grouped with the meiobenthos assemblage located in the outer fjord. The outer ford community was characterised by : 1) a relatively low mean number of meiobenthos taxa, 2) a relatively high density of harpacticods and nauplius. One of the inner ford communities (a group of four nation: MeG 2, 3, 8, 9) was in the proximity of the glaciers. Specifically, it was characterised by : 1) a low mean number of meiobenthos taxa, 2) a low density. The other inner ford community was characterised by both a high density and great mean number of meiofaunal taxa.

• Ocean and Polar Research
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• v.33 no.3
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• pp.265-280
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• 2011

The temporal dynamics of the meiofauna community in Marian Cove, King George Island, Antarctica were observed from March 7 to December 21 2007. Nine meiofauna taxa were found, with nematodes the most dominant group, making up 92.97% of the total meiofauna density, followed by harpacticoid copepods (3.18%). Meiofauna abundance ranged from 123 to 874 individuals per 10 $cm^2$ (mean 464 inds.10 $cm^{-2}$), which is lower than that found in some polar and temperate regions. The lowest meiofauna abundance was found in the 26th April sample (III) and the highest meiofauna abundance was found in the March 23rd sample (II). There was no correlation between meiofauna abundance and season. The seasonal changes were likely caused by meltwater runoff, and there were the physical disturbances on the bottom sediment by huge iceberg. Biomass of meiofauna varied between 20.36 and 101.02 ${\mu}gC{\cdot}10\;cm^{-2}$, and overall mean biomass was 54.17 ${\mu}gC{\cdot}10\;cm^{-2}$ during the study periods. More than 80% of meiofauna was concentrated in the upper 2 cm of the sediment, and density decreased with depth. The mean diversity index was 0.37, and the ratio between the abundance of nematodes: and harpacticoids (N/C) ratio ranged from 7.31 to 95.04 (mean 26.39). NMDS analysis divided the community into three groups: A (III, IV, V, VII, VIII), B (II, IX, XI, XII) and C (I, V, X). The results of ANOSIM and SIMPER analysis revealed significant differences in community structure among three groups and major contributed meiofauna taxon in grouping were nematodes and copepods. No significant correlations were observed between major meiofauna taxon and environmental factors. Thirteen species in 12 genera representing nine families of harpacicoids were recorded. Ancorabolidae was the most diverse family, and Heteropsyllidae was the most abundant. The correlation analysis between benthic harpacticoid copepods and environmental factors showed that some species were affected by water temperature, sediment temperature, salinity, chlorophyll a concentration, grain size of the sediments and heavy metal contents of the sediments. These data describe the usefulness of benthic harpacticoid copepods as biological indicator species in Antarctic regions.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.3
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• pp.400-421
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• 2019

This study was conducted to find out the seasonal distribution characteristics of meiobenthic communities to understand the benthic ecosystem of Gwangyang Bay, one of the representative bays in the southern coast of Korea. The faunal sampling was conducted eight times seasonally at 20 stations from 2010 to 2011. Among the meiobenthic fauna that appeared during the study period, the nematodes and harpacticoids were the most dominant. In the summer of 2011, the lowest density ($13ind.10m^{-2}$) was seen at station 10 on the inner part of the bay. In the winter of 2011, the highest density ($3,109ind.10m^{-2}$) was seen at station 4 on the inner part of the bay. Although the trend of seasonal changes in density was not clear, the meiobenthic community was seen to be affected more by the environmental factors in each season. Particularly, while the density of the harpacticoids, a dominant faunal group, showed negative correlations with the organic content and average particle size in the summer sediments (p<0.05, p<0.01), the density of the nematodes showed no significant correlation with the environmental factors except with the winter average particle size and the bottom layer's water temperature. The density change of meiobenthos showed irregular changes in Gwangyang Bay, instead of a general trend showing a low density in winter due to low water temperature but an increased density in spring and summer when the water temperature rises and a decreased one again in fall. Considering such a seasonal trend, it seems that the benthic ecosystem of Gwangyang Bay is affected more by artificial environmental factors than by natural environmental ones.