• Korean journal of applied entomology
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• v.52 no.3
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• pp.185-191
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• 2013

The damage of citrus by Scirtothrips dorsalis Hood appears to have increased since 2007 in Jeju, although the characteristics of seasonal abundance are not clear. This study was conducted to investigate the relationship between host plants and the seasonal abundance of S. dorsalis, observing plants distributed around citrus orchards. The host plants of S. dorsalis surrounding citrus orchards were determined to include 32 families, 54 species: 39 woody plant species and 15 herbaceous plant species. The host plants which related to the occurrence of 1st generation of S. dorsalis were Lonicera japonica, Clematis apiifolia, Hedera rhombea, and Viburnum awabuki. The occurrence of 1st generation S. dorsalis was estimated to be due to overwintered female adults having laid eggs into those plants from late March to early April, and the new adults having emerged from late April to late May. The host plants which were associated with fruit damage of citrus were Mallotus japonicus, and Camellia japonica, as well as creeping plants such as Clematis apiifolia, Paederia scandens and Cayratia japonica. The adult phase density of S. dorsalis caught on yellow-color sticky traps placed on the citrus trees on the edge of the citrus orchard. S. dorsalis were predominantly 3rd generation from late of June to early of July, and 6th generation from late of August to early of September, and their numbers were directly related to the degree of damage caused to the citrus fruit. The density of S. dorsalis depended on the number of new growing shoots of host plants, which indicated that the immigration of adults of S. dorsalis to the citrus was based in the suitability of host plants surrounding the orchards.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.52-61
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• 1999

Seasonal variation in species composition of fish with depth was determined by analysis of bimonthly samples collected by a beach seine at the shallow water (St. 1 < 1.5m) and by beam trawl at the two stations (St. 2, 5~7m and St. 3 > 15 m) from October 1997 to August 1998 off Ippa-do in Asan Bay. Of forty species identified, 13 species at St. 1,28 species at the St. 2 and 30 species at the St. 3 were collected. The fish density was also increased with depth. Favonigobius gymnauchen occupied 55.7% at St. 1 and 38.9% of the number of individuals at St. 2. Almost of fish collected at these two stations were juveniles, and they were principally collected in August and in November. At St. 3, relatively large fishes were collected. Among them Pholis fangi and Chaeturichthys stigmatias predominated in the number of individuals. Abundance was low, but a large number of species were collected in winter. Principal component analysis revealed that the species composition at the shallower stations was different from that at the deeper station. The number of species and abundance of fish in Asan Bay was lower than in the other western coastal waters of Korea. Species composition in the study area of sandy bottom was different from that in the inner Asan Bay of mud bottom.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.3
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• pp.175-184
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• 2012

Changes of fish assemblage inhabiting around Dae Island in Gwangyang Bay, Korea were investigated using a small beam trawl monthly from March 2009 to February 2010. These data were compared with those obtained in previous studies(1990~1991 and 1995~1996) at our study sites. A total of 8,133 fish belonging to 74 species in 38 families were collected. Leiognathus nuchalis, Argyrosomus argentatus, Acentrogobius pellidebilis, Sillago japonica, Apogon lineatus, Thryssa hamiltoni, Repomucenus richardsonii, Pholis nebulosa, Pleuronichthys cornutus, Hexagrammos otakii, and Limanda yokohamae dominated, and these were responsible for 89.5% and 58.9% in the number of individuals and in biomass, respectively. These were primarily small species or early juveniles of larger species. Seasonal variation in both species composition and abundance was large: the peak number of fish species occurred in May and October 2009, whilst both number of individuals and biomass were the highest in May 2009. Fish numbers as well as biomass was lowest in January and February 2010. Seasonal changes in the abundance of fishes corresponded with temperature. Compared with the previous studies, the total number of individuals and biomass per unit area($m^2$) were higher, and the predominance of L. nuchalis occurred while abundances of Liparis tanakai were significant decreased. These results seemed to be change of species composition in fish assemblage which was due to variation of annual environmental characteristics in Gwangyang Bay.

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.119-128
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• 2006

Fish assemblages associated with eelgrass beds and unvegetated area were compared based on specimens collected every month in Jindong Bay. The common fish species were Hexagrammos otakii, Acanthopagrus schlegeli, Lateolabrax japonicus, Pholis nebulosa, P. fangi, Leiognathus nuchalis, Repomucenus valenciennei, and Acanthogobius flavimanus. H. otakii, A. schlegeli, P. nebulosa and L. japonicus were higher abundance in an eelgrass bed than unvegetated area, whereas P. fangi, R. valenciennei and A. flavimanus were higher in unvegetated area. Sillago japonicus, Hippocampus japonica, Takifugu niphobles, Pseudoblennius percoides, Sebastes inermis, Syngnathus schlegeli, Sebastes schlegeli were found in an eelgrass bed, but not in unvegetated area. Most of fish species were primarily small fish species or juveniles of fish species in an eelgrass bed, while larger fish species were found in unvegetated area. The eelgrass bed in Jindong Bay seem to play a nursery role for fishes. Seasonal variations in both species composition and abundance were large in two habitats; higher number of species and individuals occurred May 2002, and April 2002 to July 2002, while biomass was the highest in April 2002 and July 2002. Fish numbers as well as biomass were lowest in January 2002. Species richness, number of individuals and biomass of fishes in an eelgrass bed were significantly higher than those of in unvegetated area. These result suggest that differences in fish species richness and abundances are primarily related to habitat structure. Different habitat preferences were evidenced for the juveniles and adult of several fish species.

• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.25-36
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• 2001

Precent study has been carried out to clarify the ecological characteristics of Tintinnina community, during the period from March,1998 to January, 1999 at twelve stations in lower Seomjin river system. During the surveyed period, a total of 56 species were identified. Seasonal variation of number of species occurred was varied: 43 species during spring season, 21 species during summer season, 27 species during autumn season, 20 species during winter season. Total abundance of Tintinnina ranged from 0 to 170,134 indiv./㎥. The abundance was high in March and low in September. Among 22 dominant species, 18 species (81.8%) were Tintinnopsis genus. The relationships between environmental factors and Tintinnina community were as follows; 11 species (Tintinnopsis rara, T. angulata, T. sp. 1, T. sp. 4, T. sp. 5, T. sp. 8, T. sp. 9, Stenosemella pacifica, S. steini, Codonellopsis nipponica, Favella taraikaensis) occurred from 10 to 15$^{\circ}C$ and 2 species (Codonella amphorella, Leprotintinnus neriticus) occurred from 5 to 3$0^{\circ}C$. Many species occurred from 10.1 to 25.0$\textperthousand$ of salinity. Four species (Tintinnopsis acuminata, T. angulata, T. sp. 10, T. sp. 11) occurred in freshwater only, while four species (Tintinnopsis rapa, T. baltica, T lata, Codonella sp.) occurred from 0.1 to 31.2$\textperthousand$ of salinity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.163-180
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• 1983

Fish larvae were collected from Changson channel, Namhae over the period from June 1982 to May 1983. A total of 44 species (33 families and 41 genera) were identified and described with morphological feature. The larvae of Cyclopsis tentacularis is newly reported in the Korean waters. Abundance of the species in numbers was as follows : Engraulis japonica $86.56\%$, Acanthogobius flavimanus $5.91\%$, Enedrias sp. $1.71\%$, Sebastes inermis $1.18\%$, Leucopsarion petersi $0.78\%$, Hexagrammos otakii $0.68\%$. According to variation of seasonal abundance the larvae were grouped into three seasonal groups as follows : Spring type: Engraulis japonica, Astroconger sp., Enedrias sp., Leucopsarion petersi, Sebastes inermis, Hexagrammos otakii Summer type : Engraulis japonica, Leiognathus nuchalis, Acanthogobius flavimanus, Omobranchus elegans, Syngnathus schlegeri. Winter type: Enedrias sp.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.2
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• pp.78-86
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• 2002

Abundance, carbon biomass and chlorophyll a concentration of each size-fractionated plankton on the basis of trophical level were investigated in terms of spacial and temporal distribution, and interactions between each biological parameter and environmental factors in Jungmun coastal waters of Jeju Island from July 1999 to June 2000. Heterotrophic picoplankton (HPP) abundance averaged 1.4${\times}$$10^{6}$ cells ${\cdot}$ $ml^{-1}$ at of offshore and 8.3${\times}$$10^{5}$ cells ${\cdot}$ $ml^{-1}$ at inshore, while autotrophic picoplankton (APP) abundance 9.9${\times}$$10^{4}$ cells ${\cdot}$ $ml^{-1}$ at of offshore and 7.1${\times}$$10^{4}$ cells ${\cdot}$ $ml^{-1}$ at inshore. They were more abundant at of offshore than at inshore, and also more abundant than the other areas of Korean waters. On the other hand, heterotrophic and autotrophic nanoplankton (HNP, ANP) were more abundant at inshore than at of offshore. Microplankton (AMP) abundance was affected by diatom (r=0.962, P${\le}$0.001) at inshore and by dinoflagellate (r=0.868, P${\le}$0.001) at of offshore. However correlations between each plankton group in terms of size and trophic level were not significant. Carbon biomass showed as same as the distribution pattern of abundance, but composition percentage of each biomass of plankton group were quite different from that of abundance, representing the highest percentage in ANP. Seasonal fluctuation of chlorophyll a were different according to size class, showing the highest with 0.42 ${\mu}g$CHl-${\alpha}$${\cdot}$$1^{-1}$(57.9%) of APP in March 2000, 1.42 ${\mu}g$CHl-${\alpha}$${\cdot}$$1^{-1}$(74.7%) of ANP in May 2000, and 1.51 ${\mu}g$CHl-${\alpha}$${\cdot}$$1^{-1}$(81.8%) of AMP in July 1999. Correlation between biological parameters and environmental factors by principle component analysis revealed that the first factor as main explanation is the increasing of phosphorus and silica and the increasing of the at both of offshore and inshore. The N:P ratio were 36.4 at inshore and 32.6 at of offshore, showing the lack of phosphorus. Thus we suggest that phosphorus might be a main limiting factor to affect phytoplankton community in the study area.

• 한국해양학회지
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• v.18 no.2
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• pp.169-179
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• 1983

Distribution of soft-bottom macrobenthos en Masan Bay was studied in terms of seasonal changes in species composition, abundance, and diversity from August, 1980 to May, 1981. Of the 65 species ot benthic macrofauna observed, polychaete was the most dominant taxonomic group with 34 species, which accounted for 72% of the total number of benthic animals. Species richness and numerical abundance seemed to decrease from the outer Bay stations to the innermost bay station, where certain zoological groups such as crustaceans and echinoderms were eliminated. Based on the ecological indices calculated, the inner basins of the Masan Bay apparently receive high input levels of organic material derived from land drainage, domestic wastes, and industrial complex installed in Masan city and nearby urban area. Particularly, at two inner bay stations of the Masan Bay, these levels seemed to approach the limit of the degradative capacity of the muddy bottom ecosystem, and have significantly affected the characteristics and distfibution of the benthic macrofauna.

• 한국해양학회지
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• v.29 no.1
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• pp.5-16
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• 1994

Particulate biogenic silica (PBSi), diatom abundance and dissolved silicate were measured in the Nakdong River estuary from March, 1991 to April, 1992. The PBSi concentrations were in the range of 0.40∼11.45 ug-at/l with being relatively high in spring and fall. The concentrations were higher in inner Bay than in outer Bay. In vertical profiles, the concentrations showed maximum in the surface layer, decreasing with depth, and then increased slightly in the bottom layer. the PBPi concentrations were related with diatom abundances, but the relatively high ratios of PBSi concentrations were related with diatom abundances, but the relatively high ratios of PBPi to diatom abundance (ca.500 pgSi$.$cell/SUP -1/) suggest that there be much detrital PBSi. The source of dissolved silicate was the Nakdong River discharge and the dissolved silicate does not seem to be a limiting factor of diatom growth due to relatively high concentration during the study period. the silicate concentrations in the bottom layer seem to be related with the PBSi concentrations existed just before the sampling time in addition to river discharge. Relatively low ratios of PBSi to POC (average 0.2 gSi$.$gC/SUP -1/) and relatively high ratios of POC to chlorophyll a (ca. 900) suggest that much detrital POC comprise the total POC.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.346-356
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• 2000

This study was carried out to investigate the distribution pattern of macrobenthos in the subtidal sandy bottoms of the east coast of Korea, and seasonal samplings were performed from April 1993 to February 1994. The species number of macrobenthos was in the range from 70 in winter to 109 in spring season. Polychaete worms were the most dominant faunal group in species richness and abundance, but mollusks showed the highest biomass. The mean density of macrobenthos fluctuated from 631 individuals/m$^2$ in autumn to 1,995 individuals/m$^2$ in summer. The major macrofauna in abundance were polychaetes, Spiophanes bombyx which occurred all seasons with top rank and Prionospio sp. and a mollusk, Alvenius ojianus, and crustaceans, Wecomedon sp. and Urothoidae spp. were also numerically dominant macrobenthic fauna. The macrobenthos in the study area were classified into two assemblages by water depth. However, they showed a different community structure near small rivers in autumn and winter seasons.