• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.509-517
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• 1986

Abundances of small fishes that utilized eelgrass meadows of Hansilpo, Chungmu, were analyzed to determine fish species composition and monthly changes of this temperate seagrass fish community during 1983-1986. A total of 4,646 fishes that comprised 35 species in 19 families was collected during the period of investigation. Pholis taczanowskii, Pseudoblennius cottoides, Tridentiger trigonocephalus, and Sryngnathus schlegeli predominated in ichthyofauna that occupied the eelgrass meadows most of the year. These four most abundant fish species accounted for approximately $64\%$ of the number of fish collected. Juveniles of economically valuable fish species such as Sebastes inermis, Platycephalus indicus and Limanda yokohamae were also collected in the study area. Seasonal changes in both species composition and abundances of fish populations were major characteristics in these eelgrass meadows. A peak abundance of total fishes occurred during spring, with a secondary peak during fall. The lowest abundance of total fishes occurred in winter. Each abundant fish species showed its own seasonal abundance pattern, and a peak abundance 1-3 months separated from other species with some overlap of the increased larval recruitment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.129-135
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• 2003

Species composition and seasonal variations in abundance of fishes in the Nakdong River estuary were investigated using an otter trawl seasonally from September 2001 to July 2002. These data were compared with those obtained before the construction of the estuary barrage in 1987. A total of 3,648 fishes that comprised 30 species in 21 families were collected. Acanthogobius flavimanus and Leiognathus nuchalis predominated, and they were responsible for $71.2\%\;and\;67.8\%$ in the number of individuals and biomass, respectively. The next abundant fish species were Platycephalus indicus and Liparis tanakai. Compared with data obtained before the construction of the estuary barrage in 1987, abundances of Acanthogobius flavimanus, Platycephajus indicus, Liparis tanakai, Tridentiger trigonocephalus and Lateolabrax japonicus increased, while those of Pholis fangi, Repomucenus valenciennei, Sardineila zunasi and Scomber japonicus decreased. These results seems to be related to change of sediment environment caused by irregular discharge of freshwater with variation of sea water movement in the Nakdong River estuary.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.1
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• pp.1-13
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• 2009

Experimental fishing operation by the shrimp beam trawl was carried out to investigate the bycatch in order to develop the selective fishing gear of the shrimp beam trawl fishery. The experimental trawling was performed by the prototype fishing gear in coast sea of Boryeong, Buan, Kangjin, Tongyeong and Geoje from 30 April to 13 November 2005. Bycatches of the experimental trawling were analyzed species composition, total length composition. The results obtained can be summarized as follows; Target fishes caught by the shrimp beam trawl were Palaemon gravieri, Crangon Hakodatei, Trachysalambria curvirostris, Parapenaeopsis tenellus, Rhynchocinetes uritai and Matapenaeus joyneri. And their fishing rate and total length range were 50.0%, 46.0%, 2.6%, 0.4%, 0.3%, 0.3% and 40-80mm, 40-80mm, 120-150mm, 60-80mm, 60-80mm, 60-120mm respectively. Bycatches caught by the shrimp beam trawl consisted of fishes of 30 kinds, 6 kinds of mollusk, 5 kinds of shellfishes and 3 kinds of crabs. The main fish was Engraulis japonicus, Platycephalus indicus, Paralichthys olivaceus, Leiognathus nuchalis and Conger myriaster, their occupied rate were 47.0%, 16.6%, 13.6%, 5.5%, 2.7% respectively, and their total length range were 60-150mm, 80-410mm, 80-600mm, 30-80mm and 150-460mm respectively. A number bycatch rates of shrimp beam trawl fishery were 99.7% in Buan, 60.0% in Kangjin, 14.6% in Boryeong, 10.6% in Tongyeong and 2.7% in Geoje, The weight bycatch rate were 99.9% in Buan, 75.1% in Kangjin, 57.1% in Tongyeong, 47.4% in Boryeong and 15.4% in Geoje.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.264-273
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• 2014

To investigate species composition and seasonal variation of demersal organisms in the coastal waters off the Taean peninsula, otter trawl surveys were conducted from April 2010 to January 2011. A total of 75 species were collected, including 44 species of Pisces, 19 species of Crustacea, 6 species of Cephalopoda, 4 species of Gastropoda, and 1 species each of Bivalvia and Echinoidea. The dominant species in each season were Palaemon gravieri in spring, Charybdis bimaculata in summer, Loligo japonica in autumn, and Crangon hakodatei in winter. The number of species, individuals and biomass were highest in autumn and lowest in winter. The diversity index was highest in summer and lowest in winter. The dominance index was highest in winter and lowest in summer. The richness index was highest in autumn and lowest in winter. The evenness index was highest in summer and lowest in autumn. A cluster analysis showed that demersal organisms were divided into two groups; spring and winter organisms (Group 1) and summer and autumn organisms (Group 2). We detected a significant difference (P<0.05) between these groups, mainly owing to Platycephalus indicus, Repomucenus koreanus, and Paralichthys olivaceus within Pisces: Trachysalambria curvirostris, Metapenaeopsis dalei, P. gravieri, and C. hakodatei within Crustacea: and L. japonica within Cephalopoda.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.335-345
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• 2010

Species composition and seasonal variation of fish assemblage in Sacheon marine ranching, Korea were examined. Sampling was seasonally made by a shrimp trawl from February 2009 to November 2009. A total of 55 species were collected. Of these, five species was dominant species comprising 51.1% of the total number of individuals. Nine species represented 57.3% of the total biomass. While total abundance (number of individuals) was high in spring, total biomass and species richness (number of species) and diversity were high in autumn. Cluster analysis, based on seasonally abundance data of the 21 most common species, showed that the species were separated into 4 different groups. Group A composed of Pholis nebulosa, Pleuronectes yokohamae, Hypodytes rubripinnis, Hexagrammos otakii, Tridentiger trigonocephalus and Paracercis sexfasciata, which were year round residents, group B Congr myriaster, Leiognathus nuchalis, and Platycephalus indicus, which were abundant in autumn, group C Sillago japonica, Pseudaesopia japonica, Zoarces gilli, Pholis fangi, and Pleuronichthys cornutus which were abundant in spring, and group D Sillago sihama, Cociella sp., Johnius grypotus, Cynoglossus joyneri, Cynoglossus robustus, and Pennahia argentata, which were abundant in summer. Principal component analysis revealed that seasonal variation in the fish assemblage was attributed to the abundance of temporal species such as conger and sand smelt fishes, which were abundant in summer, due to seasonal variation of water temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.320-324
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• 2000

Fish were collected by an otter trawl from December 1995 to July 1997 in Suyoung Bay, Korea. The temperature ranged from $12.0 to 27.7^{\circ}C$ and salinity ranged from $31.2 to 34.45{\%}_{\circ}$, The number of species, number of individuals and biomass of fish collected were 52 species, 2,006 individuals and 63,580 grams, respectively. The demersal fish predominated in the number of individuals ($90.4{\%}$) and biomass ($81.4{\%}$). The diversity index (H') was $1.5{\~}2.6$, The dominant species were Platycephalus indicus, Limanda yokohamae, Siliago sihama and Hexagrammos otakii.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.686-694
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• 2003

Monthly fish samples were collected using bottom gill nets and analyzed to study species composition and seasonal variation of fish assemblages in the coastal waters off Gadeok-do, Korea in 1998. During the study period, a total of 49 fish species representing 30 families were collected. The fish assemblages predominantly consisted of Limanda yokohamae, which accounted for $53.3\%$ of the number of individuals and $42.2\%$ in the biomass. The fish species, which had over 100 individuals, included Cynoglossus abbreviatus, Ditrema temmincki, Hexagrammos otakii, and Stephanolepis cirrhifer. These four species accounted for $24.1\%$ of the number of individuals and $24.3\%$ of the biomass. More fish species were collected in May and June than in any other months. The number of individuals and the amount of biomass peaked in April and May and reached a low in August. While the predominance of L. yokohamae caused the lowest species diversity by number of individuals in April, the predominance of Platycephalus indicus caused the lowest species diversity by biomass in July. Although gill nets show a strong selectivity for the target species or for size, gill nets can be used as an alternative fishing gear to collect fish in waters with rough bottoms, like rocky reefs, where other kinds of fishing gear such as trawls can not be used.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.2
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• pp.105-120
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• 2019

The species composition and abundance variations of fishery resources in the adjacent marine ranching area, Tongyeong, Korea, were investigated by shrimp trawl, gill net, and longline during the period of July, September, and October in 2016. During the study period, the total catch were 8,522.9 kg with 34 species from the shrimp trawl, 32 species from the gill net, and nine species from the longline. The dominant species were different by gear, which were Hypodytes rubripinnis and Parapercis sexfasciata in the shrimp trawl, Platycephalus indicus and Raja kenojei in the gill net, and Conger myriaster and Scomber Japonicus in the longline. In terms of spatial distribution, Yongchodo showed the highest total catch in number as well as of in weight while Jukdo showed the lowest total catch in number and Bijindo showed the lowest total catch in weight. The amount of demersal fish resources in the survey area estimated as 301 ha, was 99,396 individuals which was converted to be 8,552.9 kg. The amount of demersal fish resources by gear were of trawling area, which area is 127 ha, were 76,251 and 3,489.5 kg, 74 ha in the gill net and longline survey area was 16,213 and 3,457.3 kg, and the other 100 ha area was 6,932 and 1,606.1 kg. In this study, the minimum resources for demersal fish is 61,687 and 4,265.2 kg, and the maximum is 149,439 and 14,197.9 kg.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.461-477
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• 2022

We investigated the community structure and performed detailed characterization of fish larvae assemblages collected from the southern coast of Korea in the spring and summer of 2021. The total abundance of fish larvae varied from 193.6 to 1,915.6 ind. 10 m^-3. The species were distributed across 10 orders with 23 families, and 41 taxa. The dominant taxa were Gobiidae spp., Engraulis japonicus, Nibea albiflora, Sebastiscus spp., Callionymus valenciennei, Pennahia argentata, Sebastes thompsoni, Parablennius yatabei, and Platycephalus indicus. Engraulis japonicus individuals were collected from April to August and their presence contributed greatly to the total abundance of fish larvae. The total number and abundance of species peaked in early summer and the Shannon-Weaver index was in the range 0.11-1.49. Redundancy analyses revealed that the major environmental factors affecting the fish larvae assemblage differed according to the dominant taxa. Water temperature, zooplankton density, and Paracalanus parvus s. l. density were the key factors affecting the spatial and temporal distribution of fish larvae in the southern coast of Korea in spring and summer.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.223-233
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• 2006

The annual and spatial changes in the species composition of catch off Yeosu were analyzed using the daily sales slip catch data by a set net in the inshore waters off Dolsan Islands in Yeosu from April to October 2001, off Yeon Islands of Yeosu from April to October 2002 and in the offshore waters off Dolsan Islands of Yeosu from April to December 2003, respectively. Scomberomorus niphonius, Seriola spp., Trichiurus lepturus, Engraulis japonicus, Sarda orientalis, Todarodes pacificus, Pampus echinogaster, Sardinella zunasi, Scomber japonicus, Lophius litulon and Loligo beka were dominant species in abundance, indicating that pelagic fish were mainly caught by a set net off Yeosu. S. zunasi, P. echinogaster, Platycephalus indicus and L. beka inhabited mainly in the inshore waters, and S. niphonius, Seriola spp., T. lepturus, P. echinogaster, T. pacificus, Takifugu porphyreus and Pagrus major resided mainly in the offshore waters as the pelagic resident species. E. japonicus was a representative dominant species moving between the inshore and the offshore waters seasonally. S. zunasi and E. japonicus occurred in the inshore waters, and E. japonicus, L. litulon and Seriola spp. begain to be caught in the deep offshore waters in spring. Total catch was high during the summer season by migration of the open sea species such as T. lepturus, S. niphonius, S. japonicus, Seriola spp., S. orientalis, P. echinogaster and T. pacificus. In fall, S. niphonius, E. japonicus, Sphyraena pinguis, Siganus fuscescens and Leiognathus nuchalis were dominant in the inshore waters, and S. niphonius, P. echinogaster, Hyporhamphus sajori, S. japonicus and T. lepturus continued to occur from summer in the offshore waters but total catch decreased, indicating the typical seasonal variation pattern of the temperate region. Most of catchable fishes by a set net were the pelagic species showing a significant temporal variation. Collection and analysis of daily catch data by large set nets can be used to determine seasonal variation in species composition of pelagic fish in a study area.