• Title/Summary/Keyword: Dominant Species

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Effect of Environmental Variables on Changes in Macrobenthic Communities in the Coastal Area of Inchon, Korea (인천연안 대형저서동물 군집 변동에 미치는 환경요인의 영향)

  • YU Ok Hwan;KOH Byoung-Seol;LEE Hyung-Gon;LEE Jae-Hac
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.5
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    • pp.423-432
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    • 2004
  • In coastal area of Inchon, dredging and the disposal of dredged material for sea-wall construction and reclamation have increased in recent years. These activities may impact the benthic environment and result in changes in benthic communities, but little information is available on the extent and direction of these changes. We investigated whether there have been changes in the dominant macrobenthic species and benthic community over the last decade, and explored the relationship between environmental variables and spatial patterns of macrobenthic community structure. We sampled macrobenthos and recorded environmental variables in the coastal habitats of Inchon in March and June 2004. In total, 212 macrobenthic species were recorded during this study, predominately crustaceans $(34{\%})$, mollusks $(32{\%})$ and polychaetes $(21{\%})$. The mean density of macrobenthos was $1,393\;ind./m^{2}$.The most abundant species was Amphioplus japonicus $(20.5{\%})$, followed by Heteromastus filiformis $(14.4{\%})$, Theora fragilis $(8.2{\%})$ and Ampharete sp. $(4.0{\%})$. Over the past decade the dominant macrobenthic species in this area shifted. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among three regions: the middle part of the sampling area (B), site 8 (C) and other sites (A). Mean density varied significantly among the three regions, but no differences in the number of species and diversity (H') were observed. The distribution of the macrobenthic community was affected by environmental variables such as percentage sand content and sediment kurtosis. Species that were important in different areas included A. japonicus in region A, Raeta puchella in region B and T. fragilis in region C. The important species in regions B and C were filter-feeding bivalves, and the abundance of these species may be related to the increase in percentage sand content. We suggest that the sediment composition (percentage sand content) may be an important factor in determining the dominant species and structure of the macrobenthic communities in coastal Inchon. Long-term monitoring programs are necessary to understand ongoing changes in the benthic communities of this area.

Spatio-temporal Distribution of Phytoplankton Community in the Jangsu Bay and Adjoining Sea of South Sea, Korea (장수만 식물플랑크톤 군집의 시.공간적 분포 특성)

  • Yoon, Yang Ho
    • Korean Journal of Environmental Biology
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    • v.32 no.1
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    • pp.75-87
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    • 2014
  • This study describes about the spatio-temporal distributions in phytoplankton community such as species composition, standing crop and dominant species from May 2006 to February 2007 in the Jangsu bay and the northwestern parts of Gamak bay. Based on the principal component analysis (PCA) of the environmental factors as well as biological parameters, the bio-oceanographical characteristics were analysed. A total of 83 species of phytoplankton belonging to 47 genera were identified. Whereas diatoms and dinoflagellates occupied more than 65% and 30% of total species, respectively. The annual dominant species were Chaetoceros affinis, Paralia sulcata and Bacillaria paxillifera in spring, Chaetoceros didymus, Ch. affinis and Octactis octonaria in summer, Skeletonema costatum-like species and B. paxillifera in autumn. Moreover phytoplankton cell density was ranged between 3.1 $cells{\cdot}mL^{-1}$ in spring and 521.0 $cells{\cdot}mL^{-1}$ in winter. It fluctuated with an annual mean of 76.0 $cells{\cdot}mL^{-1}$ between the lowest value of 7.6 $cells{\cdot}mL^{-1}$ in spring and the highest value of 220.2 $cells{\cdot}mL^{-1}$ by Skeletonema costatum-like species in winter. Briefly, the phytoplankton cell density in the mixing seasons was higher in comparison with the other seasons. According to the PCA, the biological oceanographic characteristics of the Jangsu bay was affected by the introduction of outside seawater particularly in temperature increasing seasons, and the other seasons, it may be described the light intensity, and mix between inner and outer bay sea waters.

Practical application of DNA markers for high-throughput authentication of Panax ginseng and Panax quinquefolius from commercial ginseng products

  • Jung, Juyeon;Kim, Kyung Hee;Yang, Kiwoung;Bang, Kyong-Hwan;Yang, Tae-Jin
    • Journal of Ginseng Research
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    • v.38 no.2
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    • pp.123-129
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    • 2014
  • Korean ginseng (Panax ginseng) and American ginseng (Panax quinquefolius) are widely used medicinal plants with similar morphology but different medicinal efficacy. Roots, flowers, and processed products of Korean and American ginseng can be difficult to differentiate from each other, leading to illegal trade in which one species is sold as the other. This study was carried out to develop convenient and reliable chloroplast genome-derived DNA markers for authentication of Korean and American ginseng in commercial processed products. One codominant marker could reproducibly identify both species and intentional mixtures of the two species. We further developed a set of species-unique dominant DNA markers. Each species-specific dominant marker could detect 1% cross contamination with other species by low resolution agarose gel electrophoresis or quantitative polymerase chain reaction. Both markers were successfully applied to evaluate the original species from various processed ginseng products purchased from markets in Korea and China. We believe that high-throughput application of this marker system will eradicate illegal trade and promote confident marketing for both species to increase the value of Korean as well as American ginseng in Korea and worldwide.

Freshwater Fish Fauna in the Seomjin River, Gokseong-gun, Korea (섬진강 수계의 곡성군 어류상)

  • 김성호;윤창호;주현수
    • Korean Journal of Environmental Biology
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    • v.20 no.2
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    • pp.152-157
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    • 2002
  • The fauna of freshwater fish and the structure of fish community were investigated from March to October in 2001 at six stations in the middle reach of the Seomjin River, Gokseong-gun. The collected fishes (1,786 individuals) were identified into 30 species of 22 genera belonging to S families. Of them, cyprinid fish occupied 26 species, only one species (Rhinogobius brunneus) was secondary freshwater fish. Dominant species was Zacco platypus (dominance index: 24.2%) and subdominant species was Pungtungia herzi (10.7%). The endemic species of Korea were 11 species including Rhodeus uyekii (36.7%) about the ichthyofauna. In estimation of water quality by diversity indices, the general conditions of water quality of all survey times and all stations were relatively fine $(\beta$-mesosaprobic, diversity index: 2.70). But four survey sites except St. 2 and St. 3 showed severe water pollution with one or move times in total survey periods.

Seasonal Bycatch Variations in the Shrimp Beam Trawl Fishery of Coastal Wan-do, Korea (완도 해역의 새우조망어업에서 발생한 부수어획물의 계절적 변동)

  • Oh, Chul-Woong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.1
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    • pp.69-77
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    • 2010
  • We examined shrimp and bycatch species composition in the shrimp beam trawl fishery off Wan-do, Korea(in the major or fishing ground)from December 2004 to November 2005. We observed a total of 103, 072 individuals in 96 taxa. By densities of individuals, 96.97% were shrimps, 1.20% decapods, 1.10% fish, 0.30% cephalopods and 0.43% other species. By catch weight, 57.29% were shrimps, 26.33% fish, 6.82% decapods, 4.64% cephalopods and 4.92% other species. In spring, the dominant bycatch species by biomass were Okamejei kenojei, Lophiomus setigerus, and Charybdis bimaculata. In summer, the dominant species were Charybdis bimaculata, Muraenesox cinereus, and Paralichlhys olivaceus. In autumn, dominants were Okamejei kenojei, Conger myriasler, and Sefipinna tenuifilis, and in winter they were Okamjei kenojei, Chaeturichthys stigmatias, and Sillago japonica. Bycatch species composition and individual species abundances differed significantly among seasons, probably indicating that variations were related to the life history characteristics of bycatch species. The diversity index was highest in October (2.797) and lowest in July (1.012). The July dominance index (0.569) was much higher than in other months; evenness was highest in September (0.856) and lowest in July (0.374). During the study period, the bycatch-to-shrimp ratio of this fishery varied from 0.063 in February 2005 to 11.031 in May 2005, with a mean of 3.363 These temporal variations may be linked 10 variations in reproductive behaviors and migration patterns of the marine animals sampled.

Changes in Marine Algal Flora settled on the Artificial Seaweed Reefs Before and After Rocky Cleaning and the Early Succession of the Seaweeds attached to the Test Panels (갯닦기 전후의 해중림초의 해조상과 시험 부착판에서의 해조류 초기 천이)

  • Gim, Tae-Yeon;Kwak, Cheol-Woo;Chung, Ee-Yung;Kim, Young-Sik
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.6
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    • pp.1336-1347
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    • 2013
  • The marine algal flora assemblages settled on the artificial seaweed reefs in Jeju-do before and after rocky cleaning were investigated during summer and the early succession of seaweeds attached to the test panels on the structures of the artificial reef after rocky cleaning were observed by visual observations and under the dissecting microscope in order to evaluate the effects of this rocky cleaning operation. Species composition and algal biomass on the Bboolsamgak-typed seaweed artificial reefs before and after rocky cleaning were measured and compared before and after rocky cleaning. Before rocky cleaning in July 2012, only nine algal species had existed on the Bboolsamgak-typed seaweed artificial reefs, however, twenty algal species occurred on the seaweed artificial reefs after rocky cleaning in July 2013. Particularly, 15 species among them in July 2013 were not found in July 2012 and they seemed to occur newly on the artificial reefs. A large quantity of algal biomass increased in July 2013 after rocky cleaning. Based on the importance value, there was a drastic change in the dominant species between July 2012 and July 2013 after rocky cleaning. By dissecting micrographs, an epiphytic diatom, Licmophora sp. and flagellates, were observed on the 9th day. A chlorophyte, Ulothrix flacca was observed after 14 days, Ulva pertusa, Bryopsis pulmosa, crustose coralline algae, and Cladophora spp. were after one month. After two months, a significant species succession was observed from three previous chlorophyte species to crustose coralline algae existed as a dominant species on the panels. In this study, however, any brown algae were not found until three months in the early seaweed succession. All above results indicates that the rocky cleaning is a very efficient method for the establishment of macroalgal assemblages on the artificial reefs.

Spatial Species Diversity of Macrobenthos in the Intertidal Zone of Hwasoon, Jeju Islands (화순 조간대 저서 대형무척추동물의 공간적 종다양성에 관한 연구)

  • 이정재;강경철;김종철
    • The Korean Journal of Malacology
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    • v.17 no.1
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    • pp.63-70
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    • 2001
  • The distribution and seasonal changes of the intertidal macrobenthos community was performed on five intertidal rocky stations of Hwasoon at Jeju Islands September 1999 to August 2000. The macrobenthos was composed of six phyla, 13 classes, 24 orders, 49 families, and 97 species. The dominant species of the upper zones were Nodilittorina exigua, Notoacmea schrenckii, Liolophura japonica and Patelloida saccharina. Those of the middle zones were Monodonta labio, Chthamalus challengeri, Siphonalia japonica and Liolophura japonica. Those of the lower zones were Siphonalia sirius, Patelloida saccharina, Chthamalus challengeri, and Liolophura japonica. The community dominance indices of the upper zones were much higher than those of the middle and lower zones. Species diversity and evenness in all investigated zones were highest in station 1 and lowest in staton 3. But, species richness was highest in station 1 and lowest in station 4.

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On the Flies Collected from Suseungdae Area, Geochang-gun, Gyeongnam, Korea and Their Seasonal Prevalence (경남 거창군 수승대 일대의 파리류와 계절적인 발생 소장)

  • Jo, Tae-Ho;Jung, Youn-Yong
    • Journal of Environmental Science International
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    • v.17 no.7
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    • pp.719-732
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    • 2008
  • The total number of flies collected was 4,864 with sex ratio of 32.8% from Suseungdae area, Geochang-gun, Gyeongnam, Korea. The fauna of fly was 35 species consisting of 13 Calliphoridae, 12 Muscidae, 8 Sarcophagidae, 1 Dryomyzidae and 1 Anthomyiidae. The number of genus and species of Calliphoridae and Muscidae of Suseungdae area were similarly found in the mountain and residential areas, however, those of Sarcophagidae was similar with that of residential area. Calliphoridae was the most dominant family at the survey sites with 60.4% of the total collected flies, and followed Muscidae 33.3% and Sarcophagidae 6.2%. The dominant species were constituted of 83.6% of the total flies and the order of collected flies was Chrysomyia pinguis (42.2%), Limnophora sp. (10.8%), Muscina angustifrons (8.6%), Calliphora lata (8.1%), Fannia scalaris (5.5%), Lucilia caesar (3.9%), and Boettcherisca peregrina (4.2%). The seasonal prevalence of flies was from the middle of March to the end of November, and the peak time of appearance was the middle of June, middle of September and middle of October. The highest peak of prevalence was the middle of October. The similarity index of the flies was above 80%, compared to Mt. Geonheung and landfill in Geochang-gun. The number of fly species was more affected by the mean air temperature. In the comparison of the seasonal prevalence and relative abundance of 7 predominant species among 35 species, each species was found to exhibit its specific characteristics and showed the pattern of species.

Ichthyofauna collected from reservoirs in Pohang-si, Gyeongsangbuk-do (경상북도 포항시 저수지에서 채집된 어류상)

  • Yoo, Dong-Jae;Han, Kyeong-Ho;Lee, Sung-Hoon;Yim, Hu-Soon;Hwang, Jae-Ho;Lee, Jin-Hee;Kang, Kyeong-Wan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.5
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    • pp.363-370
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    • 2008
  • The ichthyofauna of certain reservoirs in Pohang-si, Gyeongsangbuk-do, were studied during the period from October 7-19, 2005. During the study period, 9,480 individuals (ind.) belonging to 22 species, 17 genera, 8 families and 4 orders were collected. Of these, 11 species were cyprinidae fishes, and the dominant species was Pseudorasbora parva (relative abundance 47.14%). There were six Korean endemic species (289 ind., relative abundance 3.04%), including Squalidus chankaensis tsuchigae, Squalidus mulimaculatus, Hemiculter eigenmanni, Iksookimia yongdokensis and Coreoperca herzi, and the dominant Korean endemic species was Pseudobagrus brevicorpus (relative abundance 3.04%) collected in Hoehakji, Cheonggyeji, Ahnsimji and Mabukji. There were five introduced species. Three species, including Hemiculter eigenmanni, Pseudobagrus fulvidraco and Hypomesus nipponensis, were introduced from other native stream systems, and two species, including Carassius cuvieri and Lepomis macrochirus, originated in foreign countries. Of these, Lepomis macrochirus (l,521 ind., relative abundance 16.05%) was collected at the all reservoirs except at Gidongji. These results suggest that the exotic fishes in question have been widely dispersed within the reservoirs in Pohang-si.

Temporal Variation in Species Composition and Abundance of Fish Assemblages in Masan Bay (마산만 해역에서 서식하는 어류군집의 종조성 및 출현량 변동)

  • Kwak, Seok Nam;Huh, Sung-Hoi
    • Korean Journal of Ichthyology
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    • v.19 no.2
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    • pp.132-141
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    • 2007
  • A total of 27 fish species were collected by a gill net in Masan Bay. The dominant fish species were Konosirus punctatus, Mugil cephalus, Engraulis japonicus, Psenopsis anomala, Lateolabrax japonicus, Leiognathus nuchalis, Chelon affinis, Trachurus japonicus, and these accounted for 87.6% of the total numbers. The numerically dominant fish species made up 95.4% of biomass. These were primarily juvenile species or early larger species. Temporal variation in both species composition and abundance was large: the peak number of fishes occurred in March 2005 and July 2005, whilst biomass of fishes was the highest in September 2005 and November 2005. Fish numbers as well as biomass was lowest in November 2005. Temporal changes in the abundance of fishes corresponded with temperature. A gill net can be used as an alternative fishing gear to collect pelagic fishes commercially, although a gill net has a strong selectivity for the target fish species or for size.