• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.591-595
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• 2003

Settlement of larvae, growth, and survival of juvenile abalone (Haliotis discus hannai) were examined after feding of 5 species of benthic diatoms (Cocconeis suctellum, Navicula sp Nitzschia longissima Bacillavia paxillifera, Licmophora flabellata). All of the benthic diatoms were isolated from natural populations on plastic plates for the abalone. The settlement of larvae, shell growth, and survival rate of juvenile abalone varied by diatoms species. The highest settlement rate of larvae was $43.1\%$ with the Cocconeis suctellum diet. Daliy growth rate reached a maximum at 64.1 ${\mu}m/day$ with the Navicula sp. diet and a minimum at 22.4 ${\mu}m/day$ with the Licmophora flabellata diet. Survival rate of the juvenile abalone was highest at $62.0\%$ with the Navicula sp., Cocconeis suctellum , and Nitzschia longissima diets. Survival rate of the Juvenile abalone was significantly higher than the control group with mixed diatom population diets (P<0.05). Therefore, diatom . species composition in diets can be a controling factor for the settlement, growth, and survival rates of Juvenile abalone.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.290-300
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• 2023

This study aimed to identify the actual catch situation of offshore dredge gear which is newly regulated in the legislation. It's also conducted to identify the species composition, weight of the catch including the target species and incidental catches, and to provide the basic information necessary for the resource management of aquatic organisms caught by offshore dredge. During the investigation period (from September 2022 to May 2023), a total of 61 species appeared in the test operation sea of Boryeong, Chungcheongnam-do and Gunsan, Jeollabuk-do, with 31 species of fishes, 11 species of malacostraca, six species of gastropoda, five species of bivalvia, three species of cephalopoda, three species of asteroidea, one species each of asteroidea and holothuroidea appeared. According to the results of the test operation conducted in September and November 2022, the non-catch season of Atrina (Servatrina) pectinata, 1,203 shellfishes were caught out of 2,979 caught in number, showing a bycatch rate of 59.6%, and by weight, 157.9 kg of shellfish was caught out of the total catch of 448.4 kg, showing a bycatch rate of 64.8%. On the other hand, in February and May 2023, the catch season for Atrina (Servatrina) pectinata, 3,692 fishsells were caught out of the 4,232 catches in total, showing a bycatch rate of 12.8%, and by weight, 1,185.0 kg of shellfish was caught out of the total catch of 1,293.2 kg, showing an 8.3% bycatch rate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.469-477
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• 2004

This study examined distributional patterns of Asterias amurensis in Tongyeong, the central South Sea of Korea. The density of the sea star was estimated at 10 chosen sites in the inner and the outer parts of the Tongyeong coast from December 2000. The mean density of the species in this area was $2.4ind./m^{2}$. The seasonal surveys conducted at 3 arbitrary chosen sites (i.e., sea cage, reef and soft sediment) also showed that the abundance of the species at the sea cage site $(density:\;3.6\;ind./m^{2};\;biomass:\;250.7\;gwwt/m^{2})$ was significantly higher than at the reef site $(density:\;1.7\;ind./m^{2};\;biomass:\;63.5\;gwwt/m^{2})$ and the soft sediment site $(density:\;0.4\;ind./m^{2};\;biomass:\;18.9\;gwwt/m^{2})$. Densities were higher at sea cages areas than at reefs and soft bottom sites. At sea cage site, A. amurensis population exhibited a strong aggregated distributional pattern. In contrast, at reef and soft bottom sites, A. amurensis population showed a random distributional pattern. The spatial difference in prey species and its abundance was the primary factor determining the spatial heterogeneity of the sea star in its behavior characteristics. Experiments on the feeding preference indicated that A. amurensis had a strong selectivity on its prey, but this selectivity varied between populations living in different sites. In particular, A. amurensis populations at the reef site showed a strong selectivity on various sessile and mobile animals living in reef areas, suggesting that these animal groups may play a role as "windows for the survival of A. amurensis". These results suggest that the distribution of A. amurensis in Tongyeong is closely associated with abundance of prey species and the bottom composition.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.1
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• pp.10-24
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• 2021

A seasonal characteristic of fish assemblages in the coastal waters of Gapa-do was determined using samples collected by a trammel net from 2015 to 2019. Annual mean temperature and salinity were 18.9℃, 33.6 psu (2015), 19.5℃, 33.6 psu (2016), 18.9℃, 33.8 psu (2017), 18.8℃, 34.5 psu (2018) and 19.5℃, 33.7 psu (2019), which show a stable water mass. During the survey period, a total of 50 species (30 families and 8 orders) of fishes were identified, including Scorpaeniformes (3 families and 9 species) and Perciformes (18 families and 29 species) that accounted for 68% of the total number. The number of species was higher in summer than in winter, showing the peak in the summer by 35 species and the low in the winter by 20 species. The number of individuals and the biomass peaked in the summer by 690 individuals and 151.4 kg, and were the lowest in the autumn by 336 individuals and 76.6 kg. The annual diversity index, evenness index and richness index were appeared to be 2.54-2.75, 0.68-0.76 and 5.32-6.65 at each stations. The dominance index was appeared to be the highest in 2018 and the lowest in 2015. Marbled rockfish (Sebastiscus marmoratus), rock fish (Sebastes inermis), filefish (Stephanolepis cirrhifer), rabbit fish (Siganus fuscescens), porcupine fish (Diodon holocanthus) and smallscale blackfish (Girella melanichthys) were dominant species, which occurred abundantly during the entire survey period. Subtropical fishes were identified as a total of 24 species (48.0%) and the number of species was higher in 2019 by 20 (60.6%) species and lower in 2015 by 13 (44.8%) species. The dominant species of the subtropical fishes were appeared to be rabbit fish, porcupine fish, smallscale blackfish, flag fish (Goniistius zonatus), stripey (Microcanthus strigatus), grunter (Parapristipoma trilineatum), and bluestriped angelfish (Chaetodontoplus septentrionalis) at the study sites.

• Ocean and Polar Research
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• v.23 no.3
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• pp.255-264
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• 2001

Development process of benthic community on experimental substrata attached on a newly installed artificial reef complex in Jeju Island was observed for 27 months from 1992 to 1994. Among 34 species of algae and 64 species of zoobenthos obtained from the study, Ecklonia cava dominated with a maximum biomass of about $10kg/m^2$. It was able to smother the other animals, however it provided a new substrate for the new settlers. Opportunistic bryzoans such as Likenopora radiata and Dexiospira spirillum occurred during the early stage were substituted by poriferans, banacles and other bryzoans. Young barnacles were smothered by bryozoans, on the contrary, bryozoans were bulldozed by adult barnacles. No apparent differences have been observed between vertically and horizontally installed substrates in terms of species composition and biomass during the early stage of succession. Thereafter owing to the rapid growth of E. cava, the horizontal substrata carried on a higher biomass while the vertical showed a higher coverage. The benthic process on the experimental substrata can be classified into three stages: initial stage, build up stage and regulatory stage. Important mechanisms involved were canopying of E. cava, suffocation by bryozoans and poriferans, and bulldozing of adult barnacles.

• Journal of Aquaculture
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• v.21 no.1
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• pp.19-25
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• 2008

We investigated the proper dietary protein and lipid levels for growth and body composition of juvenile sea cucumber Stichopus japonicus. Three replicate groups of the sea cucumber(average weight of 1.1 g) were fed the experimental diets containing different levels of protein(10, 20, 30 and 40%) and lipid(3, 7 and 11%) for 10 weeks. At the end of the feeding trial, survival of each group was over 87%, and there was no significant difference among the groups. Weight gain and specific growth rate(SGR) of sea cucumber were significantly affected by dietary protein(P<0.005) and lipid levels(P<0.001). The highest weight gain and SGR were observed when sea cucumber fed the diet containing 30% protein with 3% lipid(P<0.05). Weight gain and SGR of the sea cucumber fed the diet containing 3% lipid were higher than the other groups at the same protein level except for 40% protein group(P<0.05). Protein content of the sea cucumber fed the diet containing 30% protein with 3% lipid was significantly (P<0.05) higher than those fed 20% protein diets with 7% or 11% lipids and 10% protein diet with 7% lipid. Moisture, lipid and ash contents of the whole body were not significantly different among the groups. Fatty acid compositions such as linoleic acid, EPA(20:5n-3) and DHA(22:6n-3) of the whole body were affected by those of dietary lipid sources. The results of this study indicate that the diet containing 30% protein and 3% lipid is optimal for growth of juvenile sea cucumber.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.497-503
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• 2002

Fluctuation of the yield of anchovy, Engraulis japonicus and species composition of by-catch were examined to clarify the effect of sea water temperature using samples by bag net off Wando, west southern of Korea from 1999 to 2001. In 1999 and 2001, sea water temperature were higher than 20$^{\circ}C$ from July to October, However that of 2000 was higher than 20$^{\circ}C$ from August to September owing to the strong tidal front formed in south western area of Korea from late spring to summer. Fish captured by bag net off Wando was composed of approximately 73 species which belonging to the juveniles and young stages. Among them, Gymnapogon urospilotus, Lagocephalus sp., Omobranchus elegans, Platycephalus indicus and Konosirus punctatus did not appeared in 2000 when tidal front were developed stronger than in 1999 and 2001. Yield of anchovy landed at fishery of Wando were 1,000 M/T in 1999, 620 M/T in 2000, 1,056 M/T in 2001 respectively and have a tendency to increase from July to August and reach to maximum from August to October.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.4
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• pp.211-222
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• 2009

The fisheries resources by a set net in the coastal waters off Neungpo, Goeje Island from 2003 to 2004 were studied to determine species composition and catch variation. The main fishing period by a set net were from April to December in 2003 and from May to December in 2004. A total weight of 48 species caught through the survey period was 540,688.0kg. Most of them were 44 species of fishes and a few were 4 species of cephalopods. Dominant species was Trachurus japonicus accounting to 57.5% in total catch. Sub-dominant species were Trichiurus lepturus(12.9%), Engraulis japonicus(10.6%), Scomber japonicus(6.9%), Clupea pallasii(4.5%), Todarodes pacificus(2.8%) and Parapristipoma trilineaturm(1.3%). The remnant species showed a low catch, indicating the catch had less than 1% in total, respectively. T. japonicus and T. lepturus were caught throughout the survey period, but C. pallasii, Gadus macrocephalus, Oncorhynchus keta in low temperature season and Thunnus obesus in high temperature season. The fishing ground temperature was 11.7-24.0${^{\circ}C}$ in range and the catch by a set net was higher in autumn than in spring and in summer with the variation of fishing ground temperature. The annual catch by a set net was much higher in 2004 than in 2003 due to high temperature(>17${^{\circ}C}$) and the recruitment of T. japonicus from offshore seas. Therefore we concluded that the catch of Neungpo fishing ground by a set net was highly related to the variation of T. japonicus catch with fishing ground temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.118-123
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• 2021

This study was conducted to evaluate plant proteins as a replacement for a fishmeal diet in the rearing of coho salmon Oncorhynchus kisutch. Twelve groups of 20 fish averaging 34.0±0.62 g were randomly distributed into 12 rectangular tanks (250 L). Four experimental diets included a control diet containing 60% fishmeal (Control), and three other diets that replaced 20% of fishmeal with soy protein concentrate (SPC), fermented soybean protein concentrate (F-SPC), and enzyme-processed soy protein concentrate (E-SPC). At the end of the feeding trial, fish that were fed Control, SPC and E-SPC diets showed significantly higher weight gain, specific growth rate, feed efficiency, and protein efficiency ratio than those that were fed F-SPC diet. However, there were no significant differences among the fish that were fed Control, SPC, and E-SPC diets. No significant differences were observed in crude protein, crude lipid, and ash of whole body among the fish that were fed all the diets. Therefore, these results indicated that 20% of fishmeal could be replaced by E-SPC or SPC without any adverse effects on the growth performance of coho salmon.

• 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.