• Korean Journal of Ichthyology
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• v.36 no.1
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• pp.58-67
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• 2024

The purpose of this study was to find out the fish species that appeared monthly through the fish stock survey of Minyang eelgrass beds in Tongyeong and compare them with the results of previous studies in the same area. This survey confirmed the species compositional characteristics of fish using surf net from March 2021 to February 2022. During the survey period, a total of 24 species, 8,679 individuals, and 3,714.42 g of the total fish were collected. The dominant species were Gymnogobius castaneus, G. heptacanthus, Chaenogobius gulosus, Pholis nebulosa, Rudarius ercodes which accounted for 95.9% of a total number of individuals collected. Similar to previous studies, most of the fish species that appeared were gobiidae, and in this study. Leiognathus nuchalis, which was selected as pollution indicator species, appeared for the first time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.351-361
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• 2010

Among common estuarine submerged plants, seagrasses are the most extensively studied due to their ecological importance in estuarine ecosystems. Seagrass meadows are important biological habitats for a wide variety of marine animals and plants. They are a source of organic carbon for commercially important animals. Furthermore, seagrasses act as nutrient filters in estuarine and coastal marine ecosystems. As such, mapping the distribution of seagrass beds is important for management and conservation strategies. In order to survey the seagrass distribution within the Seomjin Estuary, We directly observed seagrass beds in Kwangyang and Hadong using SCUBA. The distribution area, species composition, morphology, density, biomass and productivity of seagrass meadows were examined. Seagrass meadows were distributed in the intertidal and subtidal zones of the Galsa tidal flats, and in the subtidal zone of the neighboring POSCO area. Patches of Zostera japonica was found at patches at the Galsa tidal flats intermediate point. The total estimated seagrass distribution area of the Seomjin Estuary was $1.84\;km^2$. Of the total, $1.83\;km^2$ was Zostera marina (eelgrass) and $0.01\;km^2$ was Zostera japonica (dwarf eelgrass). Zostera japonica was found in intertidal zones. Zostera marina was found from the intertidal to subtidal zones at a 2 m mean sea level (MSL) depth. The leaf productivity of Zostera marina was $4.47g\;DW\;m^{-2}\;day^{-1}$. The annual production of eelgrass was $1,632\;g\;DW\;m^{-2}\;yr^{-1}$, which corresponds to $731g\;C\;m^{-2}\;yr^{-1}$. The total production of eelgrass was $3,002\;tons\;DW\;yr^{-1}$, which corresponds to $1,343\;tons\;C\;yr^{-1}$.

• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.179-185
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• 2010

This is a study of the fish assemblages in eelgrass beds of Geoje Bay on Geoje Island, Korea. Samples were collected by surf net monthly from June 2006 to May 2007. A total 26 species, 1,825 individuals, and 4,483.1 g of fishes were collected. The dominant species were Acentrogobius pflaumii, Aulichthys japonicus, Gymnogobius heptacanthus, Rudarius ercodes, Chaenogobius annularis, Gymnogobius urotaenia, Syngnathus schlegeli, Pterogobius elapoides, Zoarchias glaber, Takifugu niphobles, Zoarchia suchidai. These species accounted for 90.6% of the total number of individuals and 76.2% of the biomass of the fishes collected. The fish assemblages in the eelgrass beds showed clear seasonal changes; the number of fish species and individuals increased in March and were highest in September, whereas the biomass attained its highest level in May and subsequently decreased. Meanwhile the species diversity indices showed their highest value in December.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.278-285
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• 2018

Monthly variation in species composition of fishes in the eelgrass bed of Jangpyeong in Tongyeong, Korea was determined using monthly samples from a seine net from May 2016 to April 2017. A total of 32 species, 2,042 individuals and 3,991.1 g of fishes were collected during the study period. The dominant species were Takifugu niphobles, Rudarius ercodes, Gymnogobius heptacanthus, Zoarchias glaber, Pholis nebulosi and Leucopsarion petersii. These species accounted for 79.5% of the total number of individuals. The fish assemblages in the eelgrass bed showed clear seasonal changes: the number of fish species increased in March and was highest in October, while the number of individuals increased in December and was highest in July.

• ALGAE
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• v.25 no.1
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• pp.17-26
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• 2010

The effects of salinity on various ecophysiological parameters of Ulva pertusa such as growth, nutrient uptake, photosynthetic performance and internal nutrient composition were tested. U. pertusa was collected from an eelgrass bed in a semi-protected embayment on the southwest coast of Korea. Under salinity regimes from 5 to 40 psu, the specific growth rates $(\mu)$ of U. pertusa ranged from 0.019 to $0.032\;d^{-1}$. Maximum growth rate was observed at 20 psu, and minimum at 40 psu. This species showed various uptake rates for nitrate and phosphate. Nutrient uptake was noticeably higher at intermediate salinity levels, and lower at both extremes. Salinity significantly influenced chlorophyll-$\alpha$ content and effective quantum yield. Tissue nitrogen content ranged from 1.5 to 2.9% N (dry weight), whereas tissue phosphorus ranged from 0.1 to 0.14% P (dry weight). The N : P ratio in the tissue of U. pertusa was considerably higher, ranging from 30 to 50. Increased growth at lower salinity suggests that the initial growth rate of U. pertusa is greater during the rainy season (i.e., late spring and early summer) than any other season during the year. The appearance of an Ulva bloom in eelgrass beds may be triggered by salinity more than by other environmental factors such as light and temperature.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.66-72
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• 2002

The intraspecific variability, habitats, and morphological characteristics of eelgrass (Zostera marina L.) along the eastern coast of Korea were examined during June to August 1998. Morphological characteristics including shoot height, leaf length, leaf width, number of leaf veins, and shape of leaf apex were measured, and eelgrass habitats were analyzed using character correlation, principal components and cluster analyses. The morphological characteristics varied with the habitat types and water depth. Eelgrass beds distributed mostly in lagoons, ports and bays along the east coast of the Korean peninsula. The quantitative morphological features that enabled recognition of the two phonetic groups were short- narrow and long-broad leaf types. Leaf apex in particular varied with the habitat characteristics.

• Journal of the korean society of oceanography
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• v.38 no.2
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• pp.68-79
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• 2003

Although seagrasses are relatively abundant, few studies have been conducted on seagrass physiology and ecology in Korea. Zostera marina is the most abundant seagrass species, widely distributed throughout all coastal areas of the Korean peninsula. To examine seasonal dynamics and spatial variations of eelgrass, Zostera marina distributed on the coast of Korea, morphological characteristics, biomass, tissue nutrient constituents, leaf productivity and environmental factors were monitored monthly from the eelgrass beds in Kabae Bay and Kosung Bay on the south coast of the Korean peninsula from June 2001 to June 2002. Eelgrass density, biomass, morphological characteristics, leaf productivities, and tissue nutrient constituents exhibited clear seasonal variations, and these seasonal trends reflected seasonal changes in water temperature. Eelgrass shoot density and biomass at Kabae Bay site showed more obvious seasonal trends than Kosung Bay. No strong seasonality in Kosung Bay site appeared to be caused by high water temperature ($>30{\circ}C$) during summer months at this site. Despite differences in nutrient availabilities between two study sites, eelgrass biomass and leaf productivities were not significantly different between study sites, and this lack of spatial variations implies that the ambient nutrient availabilities at the present study sites are in excess of seagrass nutrient demand. Eelgrass tissue N content and sediment pore water DIN concentrations exhibited reverse relationship at the present study. This reverse relationship suggests in situ nutrient concentrations are not good indicator of nutrient availabilities, and regeneration and turnover rates of sediment nutrients are also important factors to determine nutrient availabilities at the site.

• ALGAE
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• v.17 no.4
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• pp.249-257
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• 2002

• 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 Ichthyology
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• v.29 no.2
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• pp.130-138
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• 2017

Fish species composition in eelgrass bed of Bongam on Hansando island, Korea was determined using monthly samples collected by a surf net from August 2009 to July 2010. A total of 30 species, 3,237 individuals and 6,850.1g of fish were collected. The dominant species were Gymnogobius heptacanthus, Rudarius ercodes, Takifugu niphobles, Chaenogobius annularis, Pterogobius elapoides and Syngnathus schlegeli which accounted for 86.7% of total number of individuals of fish collected. Eelgrass started growing from May ($DW61.9g/m^2$) showing a peak biomass in August ($DW81.6g/m^2$), and low values in November ($DW57.23g/m^2$) to February ($DW15.41g/m^2$). The fish assemblages in the eelgrass beds showed clear seasonal changes; the number of fish species and individuals were low from September to December 2009, and high from December 2009 to July 2010. Seasonal variation in species composition and abundance was related to the water temperature and standing crops of eelgrass.