• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.154-170
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• 2022

The zooplankton composition, abundance, community structure, and species diversity in the major commercial fishery species spawning grounds in the southern coast of Korea were investigated in this study. A total of 80 taxa were sampled, with the mean abundance range of 5,612-11,720 ind. m^-3 and the mean biomass range of 41.6-1,086.8 mg m^-3. The dominant species were Paracalanus copepodites, Paracalanus parvus s. l., Oithona copepodites, Paracalanus nauplii, Noctiluca scintillans, Oithona similis, and Ditrichocorycaeus affinis. The species diversity indices were highest in August, suggesting that diversity is influenced by neritic and oceanic warm-water species. A cluster analysis with non-metric multidimensional scaling (nMDS) revealed three groups of zooplankton communities. The April and May samples clustered into Group A, having the highest mean total zooplankton abundance and lowest species diversity, consisting mainly of temperate species located in the middle region of the southern coast of Korea. Cluster Group B was from the early summer season (June) and contained the highest species diversity with some oceanic and neritic zooplankton species. Cluster Group C from the summer season (July and August) mainly comprised P. parvus s. l. and O. similis. The redundancy analysis (RDA) indicated that abundance is positively correlated with salinity, and chlorophyll-a concentrations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.243-249
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• 2000

Seasonal variation in species composition and abundance of shallow water fish off Yongwon, Jinhae in the southern coast of Korea was determined by the analysis of monthly samples collected by a beach seine from January to December, 1998. Among 54 species identified, the resident species such as Favonigobius gymnauchen, Chaenogobius laevis, Pholis nebulosa and juvenile Hyporhamphus intermedius were predominated in abundance. The temporal species such as Sardinella zunasi, Leiognathus nuchalis and Takifugu niphobles were collected between April and September. Mean abundance (322 individuals/1000 $m^2$ or 806 g/1000 $m^2$) was higher than that in the shallow sand surf zone of Teachon, but lower than that in the shallow mud area of Chonsu Bay in the western coast of Korea. A large number of H. intermedius were collected in cold months between November and January. The dominant resident species began to be collected from february, and the number of species and biomass were increased until July. A small number of temporal species were collected and subsequently the abundance was low from August to October when high abundance was expected as in the other shallow waters by recruitment of a large number of juveniles of temporal species. The low abundance in these warm months seemed to be related to the water quality by weak water circulation in this shallow mud area.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.295-305
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• 2011

Many studies have suggested the positive effects of grazing by large herbivorous mammals on seed dispersal, but little is known about how herbivores could affect the fate of ingested seeds. This study examined the effects of seed ingestion by sika deer (Cervus nippon) on seed fate in a temperate grassland established in an urban park long resided by high densities of sika deer. I compared species composition and seasonal traits of seed abundance and maturity in the grassland community with those in deer fecal pellets. In total, 27 herbaceous species were observed, including the predominant Zoysia japonica. Seed phenology and production differed among the three dominant species (Z. japonica, Digitaria violascens, and Hydrocotyle maritima). Pellets contained at least 26 species of herbaceous seeds, and their abundance differed among species. Of the 26 species, 15 were observed in the vegetation at the study site. The peak of seed abundance in pellets for the dominant species appeared 1 month after the peak of inflorescence production (but most of the inflorescences were immature and susceptible to digestion) and consequently corresponded to the peak of mature inflorescence. Because sika deer are likely to ingest seeds at any maturity stage in the grassland and immature seeds are less hardened, ingested immature seeds can suffer great losses. The results suggested that the survival of germable seeds with great losses of immature seeds may be a factor determining which plant species can be successfully dispersed by herbivores.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.503-509
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• 2010

The seasonal and interannual variation in the species composition and abundance of the decapod assemblage (shrimps, crabs, and hermit crabs) collected using pots in the coastal waters off Gori were studied between 2005 and 2008. During the study period, 49 decapod species belonging to 19 families were collected. The dominant species were Crangon hakodatei, Pandalus gracilis, Carcinoplax longimana, Charybdis bimaculata, Carcinoplax vestita, Diogenes edwardsii, and Dardanus arrosor. These seven species accounted for 95.46% of the total number of individuals collected. The number of species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number and biomass of individuals occurred in July 2006. The number and biomass of individuals were higher in summer and lower in winter, and the diversity indices were lower in summer than in the other seasons. The abundance of dominant species showed some seasonal and interannual change; in particular, those of C. hakodatei and P. gracilis corresponded with the bottom water temperature.

• Journal of Forest and Environmental Science
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• v.37 no.3
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• pp.217-225
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• 2021

This study evaluated the species composition, diversity and phorophyte preference of epiphytes at the University of Port Harcourt located in southern part of Nigeria. Purposive sampling technique was used to select sites representing major avenues in the three campuses (Abuja, Choba and Delta) of the University. Data were collected on species name of phorophytes, number of individuals, diameter at breast height (dbh) and height, and species/number of epiphytes present on them. The points/sections of attachment of epiphytes on phorophytes were also recorded. A total of eight species of epiphyte belonging to six families were recorded in the study. Species diversity was higher in Abuja campus (Simpson 1-D=0.81; Shannon H=1.79), followed by Choba campus (Simpson 1-D=0.73; Shannon H=1.09) and Delta campus (Simpson 1-D=0.56; Shannon H=0.93). Species richness was highest in Abuja campus (n=8) followed by Delta campus (n=4) and Choba campus (n=3). Similarity in epiphyte species composition was highest between Choba and Delta campuses (85.71%), followed by Delta and Abuja campuses (66.67%) and lowest between Choba and Abuja campuses (54.55%). The family-Polypodiaceae, had the highest number of species (n=3). Microgramma owariensis had the highest relative abundance (27%) followed by Platycerium bifurcatum (26%) while Tillandsia utriculata and Peperomia pellucida had the least relative abundance (3%). Epiphyte abundance was weakly correlated with both the dbh and height of phorophytes. However, epiphytes were more abundant on phorophytes with rough/scaly/corky/flaky barks than on those with smooth barks. The planting of avenue tree species with rough barks is recommended to enhance the diversity of epiphytes in the study area.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.83-93
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• 2023

This study compares the abundance and community structure of zooplankton organisms from pelagic regions, and considers particularly the trophic levels vs. zooplankton abundances and biomass. Zooplankton samples were collected three times from May to November 2022, at 30 temperate lakes and reservoirs, which belong to four different river basins. The total zooplankton abundance, biomass and species index were showed considerable spatial variation. The spatial pattern of rotifer abundance was similar to that of total zooplankton abundance, while there were not showed similar patterns of zooplankton biomass (㎍ L^-1) in lentic ecosystems. The rotifer strongly dominated the zooplankton assemblage in smaller lentic system than that of larger. A total of 130 species of zooplankton were identified (83 rotifers, 34 cladocerans and 13 copepods). The total average of zooplankton abundance and biomass were 213.7±342.3 Ind. L^-1 (n=129) and 1382.8±1850.4 ㎍ L^-1, respectively. Total and average of zooplankton abundance were usually dominated by the rotifers (>56.9%), while those of zooplankton biomass were dominated by the cladocerans and copepods (>73.6%) in lentic ecosystems. Considering the Trophic State Index (TSI), the factors of zooplankton abundance and biomass were included in between meso- and eutrophic states(27 lakes, 90% of all). The mean abundance and biomass of zooplankton in eutrophic systems were higher than that of meso- and hypertrophic systems. From this result, we suggest that management strategy for the lentic ecosystem water environment has to be focused more on small-sized lakes and reservoirs, in terms of zooplankton assemblages.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.14-28
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• 2003

The macrobenthic faunal community of Gwangyang Bay comprised 154 species and showed the overall mean density of 1,286 individuals/$m^2$. Polychaetes were the most important component of the macrofaunal community in species richness, abundance and biomass. The dominant species in abundance were poly-chaetes like Tharyx sp.(44.8%), Lumbrineris longifolia(14.0%), Heteromastus filiformis(3.6%), a mussel Mytilus edulis, and an amphipod crustacean Corophium sinense. The abundance and biomass in the western part of the bay were lower than in the channel regions and mouth of the bay. The community indices showed the same trend in the spatial distribution with the abundance and species richness. The study area can be divided into seven station groups； five station groups in the eastern part, two groups in the channel and open mouth part of the bay.

• ALGAE
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• v.37 no.4
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• pp.281-291
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• 2022

Quantifying the abundance of Chattonella species is necessary to effectively manage the threats from ichthyotoxic raphidophytes, which can cause large-scale mortality of aquacultured fish in temperate waters. The identification and cell counting of Chattonella species have been conducted primarily on living cells without fixation by light microscopy because routine fixatives do not retain their morphological features. Species belonging to the Chattonella marina complex, including C. marina and C. marina var. ovata, had high genetic similarities and the lack of clear morphological delimitations between the species. To estimate the abundance of C. marina complex in marine plankton samples, we developed a protocol based on the droplet digital polymerase chain reaction (ddPCR) assay, with C. marina complex-specific primers targeting the internal transcribed spacer (ITS) region of the rDNA. Cell abundance of the C. marina complex can be determined using the ITS copy number per cell, ranging from 25 ± 1 for C. marina to 112 ± 7 for C. marina var. ovata. There were no significant differences in ITS copies estimated by the ddPCR assay between environmental DNA samples from various localities spiked with the same number of cells of culture strains. This approach can be employed to improve the monitoring efficiency of various marine protists and to support the implementation of management for harmful algal blooms, which are difficult to analyze using microscopy alone.

• Korean Journal of Ichthyology
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• v.17 no.1
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• pp.8-18
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• 2005

A total of 33 fish species were collected by a small beam trawl from an eelgrass bed in Myoungjuri of Jindong Bay, Korea. The dominant fish species were Hexagrammos otakii, Pholis fangi, Repomucenus valenciennei, Pseudoblennus cottoides, Pholis nebulosa, Rudarius ercodes, Syngnathus schlegeli, and Sebastes schlegeli. These 8 fish species accounted for 79.5% of the total number of individuals collected. The fishes collected in the study area were primarily small fish species or juveniles of large fish species. Seasonal variations in both species composition and abundance were large; higher numbers of fish occurred from April to June 2002, while biomass was the highest in September 2001 and 2002. Seasonal changes in fish abundance corresponded with eelgrass biomass and abundance of food organisms.

• 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.