• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.211-220
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• 2016

Species composition of aquatic organism in the marine ranching area of Gunsan, Korea were investigated using shrimp beam trawl from May to December in 2010. A total of 91 species, $98,127ind./km^2$ and $877.6kg/km^2$ of aquatic organism were collected. Among them, species were included 60 species in Pisces, 21 in Crustacea and 10 in Mollusca. The individual dominant species, occupying over 10% of total individuals, were Latreutes anoplonyx($47,327ind/km^2$, 48.23%), Crangon hakodatei($11,578ind./km^2$, 11.80%) and Trachysalambria curvirostris($10,237ind./km^2$, 10.40%). And the biomass dominant species, occupying over 9% of total biomass, were Paralichthys olivaceus($135kg/km^2$, 15.4%), Okamejei kenojei($98.2kg/km^2$, 11.2%) and Portunus tribuberculatus($84.8kg/km^2$, 9.6%). From the cluster and MDS analysis based on Bray-Curtis similarity matrix of fourth root transformed data of number of species and individuals per unit area collected more than two times during this survey by each month and station was divided into three different groups. Group A showed seasonal similarity of characteristic of distribution in August and November, Group B in December and Group C in May.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.52-56
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• 2016

A single specimen (700 mm in disc length) of Plesiobatis daviesi, belonging to the family Plesiobatididae, was firstly collected in the north-eastern coastal waters of Jejudo Island, Korea by using a bottom trawl on 24 October 2010. This species was characterized by having five pairs of gill openings, tail with one to three large spines, long snout length, long caudal fin, and pleated margin of nasal curtain. It is morphologically similar to Urolophus aurantiacus, but the former is distinguished from the latter by having longer caudal fin and snout length. We add P. daviesi to the Korean fish fauna and suggest the new Korean names, "Gin-kko-ri-huin-ga-o-ri-gwa", "Gin-kko-ri-huin-ga-o-ri-sok" and "Gin-kko-ri-huin-ga-o-ri" for the family, genus and species, respectively.

• Ocean and Polar Research
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• v.25 no.4
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• pp.653-662
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• 2003

Changes in the area of geo-ecosystem $(62^{\circ}09'S,\;58^{\circ}31'w)$ reflect climatic changes in the South Shetland Islands. Air temperature and deglaciation will increase. The ice-free space area at the SSSS 8- (ASPA 121) site has enlarged threefold during the last 21 years, thus creating conditions for inhabitation and succession. Wind, water and snow play important roles in transportation of geochemical components. They distribute nutrients, mineral substances, seeds, fragments of plants and animals, etc. Plant and animal colonization is patchy and it happens at random in an 'island' - like manner. The colonization pattern is dependant, to a high degree on physical factors. The newly uncovered ice-free areas are at first inhabited by a vascular plant known as the Deschampsia antarctica. The border of the land-oasis with Admiralty Bay is the place where the processes related to animal feeding at the sea and reproduction on the land take place. Bird colonies and pinniped lairs form centers of fertilization surrounded by high chemical gradients dependent on the direction of the flow of nutrients $(e.g.\;NH_4)$. During the last 25 years, the numbers of penguins in this region have decreased, and thus the amount of materials excreted on land has diminished. The numbers of fur seals change in multi-annual cycles, and their migration into this area is related to the E1 $Ni\~{n}o$ phenomenon. The numbers of elephant seals in the area did not change. Organic matter deposited by the sea onto the shore are a source of nutrients and deficient chemical elements on land. Mineral matter is washed out into the waters of Admiralty Bay. These processes change seasonally, and multi annually. Negative effects on the environment at Arctowski Station induced by man are slight, but noticeable nevertheless. Physical processes have the largest influence on the living conditions and distribution of plants and animals, and as a consequence, on the functioning of the geo-ecosystem in the coastal-shore zone of the Maritime Antarctic.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.1-8
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• 2012

The geographical distribution of the toxic blue-lined octopus (commonly known as the blue-ringed octopus), Hapalochlaena spp., around the East/Japan Sea was investigated. Observation records of the octopus were gathered using commercial search engines on the Internet. A questionnaire to complement and enhance the base data was conducted that targeted fishermen from areas where the octopus was most likely to occur, i.e., the southeast coast and islands of Korea in the East/Japan Sea. Overall, 32 observational records of the blue-lined octopus were found from Korea and Japan. In Korea, only one record, from 2003, was found on a website; none of the 240 fishermen who participated in the questionnaire reported seeing blue-lined octopus. However, a total of 31 observations of the blue-lined octopus from 2004 to July 2010 were found from 17 different regions in the East/Japan Sea and neighboring waters in Japan. Twenty-two cases were from coastal Honshu Island, and nine were from the west coast of Kyushu Island, Japan. The northern distributional boundary of the blue-lined octopus on the Japanese coast was off Fukui Prefecture around latitude $36^{\circ}$10' N. Our results indicate that the blue-lined octopus is distributed extensively along the Japanese coast, at a low frequency, in the East/Japan Sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.5
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• pp.315-322
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• 2007

Kjellmaniella crassifalia Miyabe is one of the valuable seaweed crops cultured in the Korean coastal waters of the East Sea. Unfortunately recent environmental changes have adversely influenced its growth, prompting the need to develop techniques for species restoration. To obtatin biological information, the growth of the species was monitored for one year. The maximum blade length, $110{\pm}45cm$, was attained in July, and zoospores were released in November. The optimum culture conditions allowing juvenile sporophytes to grow to young blades consisted of $20{\mu}mol/m^2s\;at\;10^{\circ}C$ under which the blade length grew to $1,732.5{\pm}143.3{\mu}m$ in 42 days. Sporangial sori started to form in September, reaching 85% maturity in November and 89% maturity in December. Examining the growth of the species according to depth, the individuals growing at 5 meters grew the most, reaching a blade length of $75.9{\pm}18.9cm$ in August.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.345-348
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• 2014

Six specimens (151.4~171.2 mm in standard length) of the poacher Aspidophoroides monopterygius were collected by Danish seine net in the coastal waters off Samcheok and Gangneung, the East Sea, Korea. This species is characterized by a slender body, one dorsal fin, terminal mouth, no barbel on the head, and a pair of nasal spines on the snout. It differs from Anoplagonus occidentalis Lindberg in having a nasal spine. We describe it as the first record within the Korean fish fauna, and propose the new Korean name "Ak-eo-jul-go-gi" for this species.

• Korean Journal of Ichthyology
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• v.30 no.2
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• pp.114-118
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• 2018

A single specimen (1,058 mm TL) of Pteroplatytrygon violacea, belonging to the family Dasyatidae, was firstly collected by using drift gill net in the north-western coastal waters of Jejudo Island, Korea on 6 July, 2017. This species was characterized by having a broadly rounded snout, five pairs of gill openings, tail with a large spine, ventral tail fold not reaching to the tip of tail, no dorsal fold, and ventral surface of disc dark purple. Based on such morphological characters, the specimen was identified as P. violacea and confirmed with the nucleotide sequence of the mitochondrial cytochrome c oxidase subunit I gene. We added P. violacea to the Korean fish fauna and propose the new Korean names, "Bo-ra-saek-ga-o-ri-sok" and "Bo-ra-saek-ga-o-ri" for the genus and species, respectively.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.177-184
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• 2010

The structure of the ovary, ultrastructure of oocytes and morphological characteristics of vitellogenesis during oogenesis in female Gomphina veneriformis were investigated in clams collected from coastal waters of Samchok, Gangwon-do, Kore. In the previtellogenic oocytes, the Golgi complex was involved in the formation of a number of vacuoles. In the early vitellogenic oocytes, lipid droplets appeared among the Golgi complex, endoplasmic reticulum, and mitochondria in the cytoplasm of the oocyte were involved in the formation of lipid droplets. Coated vesicles, resulting from endocytosis appeared at the basal region of the early vitellogenic oocyte. The uptake of nutritive materials in the coated vesicles formed by receptor-mediated endocytosis appeared through the formation of coated endocytotic pits on the oolemma. In the late vitellogenic oocytes, large yolk granules were formed by a combination of small yolk granules. In the mature oocyte, a mature yolk granule in composed of three components: crystaline core, electron lucent cortex, and a limiting membrane. According to cytological and histological observations, vitellogenesis occurred by way of endogenous autosynthesis and exogenous heterosynthesis. Autosynthesis involved the conbined activities of the Golgi complex, mitochondria, rough endoplasmic reticulum, whereas heterosynthesis involved endocytotic incorporation of extraovarian precursors at the basal region of the early vitellogenic oocyte. The follicle cells which was attached to oocytes, were involved in the development of the previtellogenic and early vitellogenic oocytes as a kind of nutritive cells containing a number of glycogen particles and lipid droplets in the cytoplasm.

• Journal of Ocean Engineering and Technology
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• v.18 no.6 s.61
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• pp.8-15
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• 2004

Wave power distribution is investigated to determine the optimal sites for wave power generation at Jeju sea which has the highest wave energy density in the Korean coastal waters. The spatial and seasonal variation of wave power per unit length is calculated in the Jeju sea area based on the monthly mean wave data from 1979 to 2002 which is produced by the SWAN wave model simulation in prior research. The selected favorable locations for wave power generation are compared in terms of magnitude of wave energy density and distribution characteristics of wave parameters. The results suggest that Chagui-Do is the most optimal site for wave power generation in the Jeju sea. The seasonal distribution of wave energy density reveals that the highest wave energy density occurs in the northwest sea in the winter and it is dominated by wind waves, while the second highest one happens at south sea in the summer and it is dominated by a swell sea. The annual average of wave energy density shows that it gradually increases from east to west of the Jeju sea. At Chagui-Do, the energy density of the sea swell sea is relatively uniform while the energy density of the wind waves is variable and strong in the winter.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.378-383
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• 2023

A re-examination of Luciogobius guttatus was conducted using 84 samples, which lives on all coastal waters of Korea. As a result, 41 specimens (31.3~54.4 mm SL) collected from the west and south coasts were classified as L. martellii. The morphological features of L. martellii as follows: number of abdominal vertebrae 16; total number of vertebrae 35~37; dorsal fin base length longer than upper caudal peduncle length or equal; one free ray on its upper pectoral fin; and edge of tail fin white. Among these, the most prominent morphological difference in L. guttatus is comparing the dorsal fin base length and upper caudal peduncle length, which is also well observed in syntypes of L. martellii. We proposed a new Korean name, "Geom-jeong-mi-kken-mang-duk" referring to their color.