• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.5
• /
• pp.645-653
• /
• 2014

We examined seasonal variation in fish species composition in coastal waters near Wolseong Nuclear Power Plant in the East Sea of Korea. A total of 72 species, 39 families, 14 orders, 46,214 individuals, and 4,639,667 g were collected. Glyptocephalus stelleri was the most dominant species by number of individuals (35%), followed by Clupea pallasii (26%). Liparis tanakai and Lophius litulon were the dominant species by biomass, accounting for 46% and 28%, respectively. We showed that bottom salinity and temperature are the most important environmental factors influencing fish species composition. Although bottom salinity did not differ statistically among seasons or stations, we detected some variation among stations. Additionally, bottom temperature differed among seasons and stations (P<0.05), affecting numbers of individuals and biomass. Thus, seasonal variation in fish assemblages can be classified into two groups: spring/summer and autumn/winter.

• Korean Journal of Ichthyology
• /
• v.23 no.3
• /
• pp.206-216
• /
• 2011

To investigate seasonal and yearly variation of fishes composition in Yeoja Bay of Korea, fisheries survey were carried out using beam trawl from 2006 to 2009. A total of 44 fish species were collected. The major dominant species were Pennahia argentatus, Thryssa adelae, Thryssa kammalensis and Cynoglossus joyneri, which were occupied over 63% total individuals, and 50% of wet weight. The diversity index (H') was about 1.62 (1.46~1.77) by seasons, and seasons of similarity by fishes were divided into two groups, which were March with December and June with September. ANOVA test showed that there were not significant difference between individuals and catch weight (kg) per unit area (km$^2$) by year and season, except for catch weight per unit area by season.

• Spatial Information Research
• /
• v.6 no.1
• /
• pp.25-33
• /
• 1998

The study region encompasses about 5,900$km^2$ including the topographic maps of Kimhae, Pusan, Miryang, Yangsan, Panguhjin, Tonggok, Uhnyang, Ulsan, Youngchon, Kyongju, Pulguksa, and Kampo, all at a scale of 1:50,000. The paper discusses how to have prepared the four thematic maps, landslide and unstable slope distribution map, slope classification amp, soil classification map, and lineament density map. Using all the above maps and GIS, the relative slope-stability map for the study regiun was produced at a scale of 1:100,000 ; the map can be utilized for the regional land-use planning in the study region.

• Korean Journal of Ichthyology
• /
• v.10 no.2
• /
• pp.176-183
• /
• 1998

Spawning ecology and feeding habits of Maurolicus muelleri in the Korean waters were studied. M. muelleri spawned continuously throughout the year showing a peak in August. Major spawning ground of this species was the southeastern sea of Korea. The fecundity observed from the ovaries of M. muelleri showed a range of 5,072 to 32,117, and the average number of eggs per one spawning time was approximately 250. M. muelleri was a zooplanktivore which fed mainly on copepods. Its diets also included various crustaceans such as amphipods, euphausiids, shrimps and mysids.

• The Korean Journal of Quaternary Research
• /
• v.4 no.1
• /
• pp.27-40
• /
• 1990

$^{14}C$ age dating by AMS (accelerator mass spectrometry) technique was performed on twenty five small sized fossil shells and one peat taken from the sixteen piston cores in the southern and southeastern Korean Sea. AMS technique is available to date only a few milligram of amorphous carbons compare than conventional dating technique. It is described in detail of sample pre-treatment and experimental, and applied to the reconstruction of the sea level changes since the late Pleistocene in the Korean Sea. Dated age ranges from 520$\pm$100 to older than 33,500 years. Sedimentary facies in the study area represents a different environmental set which is affected by sea level fluctuation since the late Pleistocene.

• Korean Journal of Veterinary Research
• /
• v.2 no.1
• /
• pp.15-26
• /
• 1962

Decoctions of two Korean indigenous crude drugs. Radix Jingyu(the dried root of Aconitum pseudo-laeve Nakai var. erectum Nakai form. Genuinum Nakai) and Fructus ponciri (the transversely sliced and dried unripe fruit of Poncirus trifoliata Rafinesque), are being utilized by the inhabitants in certain parts of southeastern district of Korea with an empirical belief that these serve as effective insecticides for cattle ticks. Of the two species of cattle ticks so far identified in Korea, Boophilus microplus and Haemaphysalis bispinosum, the former was employed in this experiment as the species occupies nearly 99 percent of the tick population. The results of the experiments herein reported seen to indicate that although the killing power of aqueous extracts of the drugs is minimal, the repellent effect against the ticks, especially of Radix Jingyu, is excellent. It may be of interest to note that the aqueous extract of Radix Jingyu has not proved to be inferior to any of the most effective cattle repellents commercially available. Further studies on these Korean indigenous crude drugs as cattle tick repellents are indicated to find whether active ingredients can be extracted in a hope to materialize an extensive application of these drugs in the field.

• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.487-492
• /
• 1995

The chemical compositions and pyrolysis characteristics of oil shales and source rocks distributed in the southwestern and southeastern parts of the Korean peninsular have been investigated. In order to compare the results of Korean samples with those of shales giving high oil yields, two Colorado oil shale samples and one Paris source rock samples were also investigated. Chemical compositions of the samples were analysed by means of gravimetry, CHN analysis, X-ray diffraction method, inductively coupled plasma atomic emission spectrometry and atomic absorption spectrometry. A custom made pyrolyser and a Rock-Eval system were used for the pyrolysis studies. Pyrolyses of the samples were carried out by means of a temperature controlling device to $600^{\circ}C$ at a heating rate of $5^{\circ}C/min$ with a helium flow rate of $1200m{\ell}/min$. The results of pyrolysis study indicated that Colorado shale samples belong to type I and all the other samples belong to type II.

• Economic and Environmental Geology
• /
• v.29 no.3
• /
• pp.357-367
• /
• 1996

A total of 113 samples (basalts, tuffs, and siltstones from coal-bearing sediments) was collected from 14 sites of the Tertiary Changgi basin in southeastern Korea, and studied palaeomagnetically. Site-mean declination of the ChRM from 5 sites was found to be deflected clockwise about $30^{\circ}$. Other 5 sites showed no vertical-axis deflection of ChRM direction. In consideration of previous palaeomagnetic data from other Tertiary basins in the vicinity, it is interpreted that the deflection of ChRM directions has been caused by NNW-SSE simple shear associated with the opening of the East Sea, and the time of rotation should be about 16 Ma. Other 2 sites showed counterclockwise deflection of site-mean ChRM. These sites might be located among lager tectonic blocks which were rotating clockwise. AMS (anisotropy of magnetic susceptibility) study revealed $NE{\rightarrow}SW$ directed magnetic lineation at two tuffaceous sites. This might indicate flow direction of tuffs during the time of deposition. Most of the other sites showed load-foliation lying subparallel to the bedding plane. This must have been caused by gravitational loading acted vertically to the strata.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.5
• /
• pp.571-578
• /
• 2018

Seasonal variability in algal community structure of the subtidal zone was examined at four study sites on the southeastern coast of Korea from February to November 2016. A total of 81 species of algae (8 green, 12 brown, and 61 red) were indentified. During the study period, the greatest number of species was observed at Sinamri (57 species) followed by Daesongri (50 species), Dongbaekri (47 species) and Gangyangri (42 species). Of the six functional seaweed forms, the coarsely-branched form was the most dominant, accounting for about 43% of the total species at Daesongri. The annual average biomass in wet weight varied from $700.59g/m^2$ at Sinamri to $1,712.45g/m^2$ at Daesongri. The parameters of seaweed community structures were as follows: dominance index (DI), 0.30-0.54; richness index (R), 4.92-7.05; evenness index (J'), 0.54-0.72; and diversity index (H'), 2.05-2.91.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.6
• /
• pp.625-631
• /
• 2003

The aim of the present study was to investigate the ecological relationship between female body size (=shell length) and fecundity in a Korean population of protandric hermaphrodite, Crepidula onyx Sowerby, using 6 reproductive variables (the number of capsules per brood, capsule size, the number of embryos per capsule, total number of embryos per brood, egg size, and larval size). The investigation was based on 32 females, 107 egg capsules, 263 eggs, and 250 veliger larvae sampled in January 2000, from Yangpo, the southeastern coast of Korea. All foregoing reproductive variables, except larval size, were significantly correlated with the female body size (p<0.001$\~0.01$). There was a significant increase both in the number of capsules per brood and the number of embryos per capsule with female body size (p<0.001). Consequently, the fecundity of the female C. onyx increased with female body size to over 14.65 mm (the minimum size of egg brooding in the present study). This investigation, therefore, provides additional evidence that female fecundity of protandric hermaphrodites is positively correlated with female body size.