• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.297-305
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• 2017

This study was analysed the species composition of demersal fishes caught by a bottom trawler, KAYA, in the winter season during 4 years and the study area was the eastern fishing ground in depth of about 110m, 40 miles eastward from Jeju Island, Korea. A total of 54 species were collected, including 40 species of Pises, 9 species of Mollusks, 5 species of Crustaces. The number of individuals and biomass of unit area was $7,978ind/km^2$ and $1,800kg/km^2$, respectively. The dominant species in winter season were Dentex tumifrons, Carangoides equula, Callanthias japonicus, Thamnaconus modestus and Pagrus major. And these also were caught every year. The ranges of the diversity index(H') were 1.97 to 2.40, the richness(R) 1.91~4.59, the evenness(E) 0.54~0.83 and the dominance(D) 0.42~0.61.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.621-630
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• 2015

This study investigated the concentration of total mercury in 17 species of commonly consumed fishes and assessed the risk to human health from provisional tolerable weekly intakes PTWI% as affected by migratory characterization, such as migration and vagility. The measured mean concentrations of total mercury in these 17 species of commonly consumed fishes suggest that mean concentrations of total mercury in 10 species of migratory fishes (largehead hairtail, chub mackerel, Pacific saury, skipjack tuna, Pacific cod, anchovy, Alaska pollack, brown croaker, Japanese Spanish mackerel, yellow croaker and Pacific herring) were low compared to those in 7 species of demersal fishes (red stingray, brown sole, bastard halibut, conger eel, blackmouth angler, rockfish and filefish). Based on the mean concentrations, the PTWI% of total mercury among commonly consumed migratory fishes was 3.393%, which was higher than that of commonly consumed demersal fishes (2.710%).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.569-576
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• 2011

Proximate and fatty acid compositions in muscle tissue were studied in 14 species of coastal and offshore fishes in Korea. Lipid content ranged from 0.57 to 10.5% and was higher in migratory and reef dwelling fishes than in demersal fishes. Protein content ranged from 14.4 to 20.3% and moisture content ranged from 72.4 to 81.8% in all fish samples. There was a negative correlation between lipid and moisture content in all fish samples (r= -0.90, P<0.001). The prominent fatty acids were 16:0, 22:6n-3 (docosahexaenoic acid, DHA), 18:1n-9, 20:5n-3 (eicosapentaenoic acid, EPA), 16:1n-7, 18:0 and 18:1n-7. Most demersal fishes contained considerably higher amounts of 20:4n-6 and/or 22:5n-3 compared with migratory and reef dwelling fishes. The proportion of total polyunsaturated fatty acid (PUFA), including DHA and EPA, was higher in demersal fishes (38.6-54.0%) than in migratory and reef dwelling fishes (23.5-35.2%).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.541-555
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• 2016

This study determined the concentrations of lead and cadmium in 18 species of commonly consumed fish and assessed the risk based on provisional tolerable weekly (monthly) intakes [PTW(M)I] % as affected by behavioral characteristics, such as migration and settlement. In the 18 species, the mean concentrations of lead and cadmium were higher in the 11 species of migratory fish (llargehead hairtail Trichiurus lepturus, chub mackerel Scomber japonicus, Pacific saury Cololabis saira, skipjack tuna Katsuwonus pelamis, Pacific cod Gadus macrocephalus, anchovy Engraulis japonicus, Alaska pollack Theragra chalcogramm, brown croaker Miichthys miiuy, Japanese Spanish mackerel Scomberomorus niphonius, yellow croaker Larimichthys polyactis, and Pacific herring Clupea pallasii) than in the seven demersal species (red stingray Dasyatis akajei, brown sole Pleuronectes herzensteini, bastard halibut Paralichthys olivaceus, conger eel Conger myriaster, blackmouth angler Lophiomus setigerus, rockfish Sebastes schlegelii, and filefish Stephanolepis cirrhifer). Based on the mean concentrations, the PTWI % of lead and cadmium in commonly consumed migratory fish were 1.900 and 2.986%, respectively, which were higher than the values for lead and cadmium in the commonly consumed demersal fishes (0.257 and 0.318%, respectively). The estimation of weekly (monthly) intakes and target hazard quotients for the toxic elements lead and cadmium revealed that the commonly consumed migratory and demersal fish do not pose any health risks for consumers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.103-114
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• 1992

Diurnal and seasonal variation of demersal fishes of Asan Bay were studied using seasonal samples collected by an otter trawl from autumn 1989 to summer 1990. For each sampling period, three to five trawl hauls were completed to obtain day and night samples. Of 32 species identified, Chaturichthys stigmatias, Cynoglossus joyneri, Thrissa koreana, Repomuenus lunatus and Hexagrammos otakii accounted for $79.5\%$ of the individuals collected, and C. joyneri, T koreana, H. otakii, Raja kenojei and Kareius bicoloratus constituted $67.1\%$ of the biomass obtained. Apparently, larger number of individuals and greater biomass were collected in night hauls. However, there is no significant difference between day and night samples in community structure, mean abundance and body length of the dominant demersal species. The greatest numbers and biomass of fishes were collected in summer and the lowest in winter. The abundance of fishes in the study area were dependent upon seasonal effects such as temperature.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.7 no.1
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• pp.9-27
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• 1971

Oceanography of the Subarctic North Pacific Ocean is reviewed. The submarine topography and the current systems in the region are explained. Recent serial observation data reveals that. though the upper mixed layer of low salinity is relatively thick. the pattern of the property distribution in winter is essencially similar to that in summer. Alaskan Stream Extension Water. which influences the abundance and the location of demersal fishes. extends northward to 58${\circ}$ N Lat in the Bering Sea. A southeastward intrusion of the Bering Borcal Cold Water causes the formation of a sharp oceanic front. where the demersal fishes such as Alaska pollacks and cods arc concentrated. The Alaska pollacks seem to avoid the low salinity water of the Alaskan Coastal Water.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.7 no.1
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• pp.8-8
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• 1971

Oceanography of the Subarctic North Pacific Ocean is reviewed. The submarine topography and the current systems in the region are explained. Recent serial observation data reveals that. though the upper mixed layer of low salinity is relatively thick. the pattern of the property distribution in winter is essencially similar to that in summer. Alaskan Stream Extension Water. which influences the abundance and the location of demersal fishes. extends northward to 58${\circ}$ N Lat in the Bering Sea. A southeastward intrusion of the Bering Borcal Cold Water causes the formation of a sharp oceanic front. where the demersal fishes such as Alaska pollacks and cods arc concentrated. The Alaska pollacks seem to avoid the low salinity water of the Alaskan Coastal Water.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.10 no.1
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• pp.19-29
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• 1974

Fishing explorations for tunas and demersal fish on the sea south west from Sumatra, south sea from Java, south sea from Bali and south sea from Soemba were carried out in 1973 by MIS TaeBeak-San (310 tons, 8001P) of Fisheries Research & Development Ageney, R. O. K. The results were found to be valuable for good fishing ground for tunas and demesal fishes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.1-8
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• 1989

Demersal fish community in Cheonsu Bay was analyzed using fish samples collected by a small otter trawl from March to November, 1986. Of the 32 species identified, Nibea argentatus, Chaturichthys stigmatias Crptocentrus filifer, Cynoglossus joyneri and Jonius belengeri pre-dominated in abundance. Based upon principal component analysis of species composition data, the fishes were grouped into resident, migrant and temporal species. Resident fish wintered in the deeper part of the bay, showing a peak in biomass during cold months. In spring, warm weather seasonals, adult N. argentatus and J. belengeri, migrated o the bay for spawing. However, the biomass of the migrant was not more than that of the wintered adult residents. From July to September, juveniles of many species were collected, but the number of individuals was smaller than that of the littoral or pelagic zones. This suggests that the deeper area of the bay did not serve as a main nursery ground of the juveniles with the exception of two migrant scianid fishes. As a result, the benthic fish of the bay were more abundant in cold months than in summer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.438-445
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• 1993

Spatial and seasonal variations of community structure of demersal fishes in Asan Bay were studied using seasonal samples collected by an otter trawl from autumn 1991 to summer 1992. For each sampling station, three trawl hauls were completed to obtain a reliable sample. Of 34 species identified, Cynoglossus joyneri, Johnius belengeri, Zoraces gillii and Thrissa koreana accounted for $93\%$ of the individuals collected. The former three dominant species were more abundant on the finer sediment of the inner bay than on the sandy bottom of the outer bay. Spatial variation of community structure of demersal fishes was analysed by principal component analysis using rank correlation. The community structure did not show a spatial difference, but a clear seasonal trend. This distribution pattern seems to be related significantly to the seasonal temperature fluctuation and to the active mixing of the water by strong tidal current of the bay.