• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.254-264
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• 1990

Using the meteorological data, surface weather map, and oceanographic data for 5 years(1984-1988). I investigated the characteristics of the fog occurrence and the role of the inshore in Pusan about the fog occurrence. And the meteorological data and sea surface temperature(SST), which were observed in July, 1989 in Suyoung Bay, were compared with those in Pusan. The fogs in Pusan concentrate in May, June and July. And at fog occurrence time the principal wind directions are Southwest(SW) winds, which easily supply with water vapor, and a series of Northeast(NE) wind. At the fog days pressure patterns are pattern 7 in spring time (March, April, and May) and pattern 10 and pattern 13 in summer time (June, July, and August). Also the advection fog(sea fog) is closely related with the relationship between warm and cold advection in 850~700mb and cold and warm SST rather than the increase of the instability of atmosphere in 850~500mb. The fogs in Taegu, which is the inland region, mainly occur at dawn in fall time due to the strong night radiation fog. On the other hand in Pusan the coastal region, the fogs occur from late spring time to summer time (May, June, and July). Because there is the abundant supply of the water vapor from the ocean owing to a series of South(S) wind at this time. Then the atmosphere, which has high relative humidity, reaches easily the supersaturation by the radiation cooling. In Suyoung Bay and Pusan the meteorological observation data, SST and fog days are almost similar. And I think that the mechanism of the fog occurrence nearly accords with both regions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.83-90
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• 1984

The secular fluctuations of catches and fishing grounds of mackerals and the oceanographic conditions for the fishing grounds are examined by using the data of catches of mackerals by middle and large class purse-seiner during 1951 to 1981 and those of oceanographic observation carried out by Japan Meteorological Agency. The results are as follows; The fishing grounds of mackerals are respectively distributed at northeastern and southwestern areas from the central part of the East China Sea through every season of the studied years: 1968, 1974 and 1980. The narrow belt type of fishing grounds were formed inside of the Kuroshio in spring and winter of the three years. In summer mackeral species move northward and the fishing grounds are formed in the southern sea of Korea. In winter, however, mackeral species move southward and the fishing grounds are appeared in the Tsushima Current region. The dispersion of fishing grounds is generally larger in summer and smaller in spring, and especially it is the largest in summer in 1980. It seems that the concentration and dispersion of fishing grounds are related to the depth of thermocline and the position of horizontal temperature gradient in this area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.265-274
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• 1990

The temperature inversions were studied on the basis of Digital Memory Bathythermography(DBT) data collected by training ship, Pusan 402, of the National Fisheries University of Pusan in August 23~25, 1986 and Fisheries Reserach and Development Agency of Korea in August, 1986, The results were as follows; Among the 67 stations of studied area, occurrence frequency of temperature inversion was 58.20%, And the frequency of onefold occurrence of temperature inversion at its profile of each station was 13.42%. of twofold occurrence was 20.80%, and of threefold occurrence was 23.88%. In the studied area, the temperature inversion usually occurred below the 40m depth and its layers also located below the thermocline. The temperature range of its inversion was from 14$^{\circ}C$ to 16$^{\circ}C$. The temperature inversion in the study area was oaused by the interaction between Tsushima Warm Current and Korea Coastal Waters.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.348-354
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• 2015

Experiments for catch and cluster analysis on the catch by gillnet for the Pacific herring were conducted using traditional nylon net (PA) and developing biodegradable net (PBS) with different monofilaments of #2 (=0.23 mm) and #3 (=0.28 mm) in diameter between 2011 and 2012, and of #2, #2.5 and #3 in 2013 in the eastern coastal waters of Samcheok, Korea. The total catch during the experiments was 3,337kg in weight and 16,757 individuals in number. Though the catch ratio of the Pacific herring in 2011 and 2012 was 97.4% and 98.7%, respectively, that of the Pacific herring in 2013 was 73.6% as the biggest and followed by goldeye rockfish (8.6%), black edged sculpin (8.4%), atka mackerel (7.2%) and Alaska cod (1.0%). The ANOVA analysis on the total catch in relation to net material showed that there was not statistically significant difference at the 5% level between nylon net (PA) and biodegradable net (PBS) (p=0.91). With the cluster analysis on the catch in relation to net material (PA, PBS) and twine thick (#2, #3), it showed the influence of net material on the catch was greater than that of twine diameter in this experiment. From the test of homogeneity on the catch by the gillnet with PA and PBS in which several species were caught in 2013, there was not statistically significant homogeneity in relation to net material (p<0.005). That meant the traditional gillnet of nylon (PA) was more efficient than the biodegradable (PBS) gillnet to catch several kinds of fish, however the PBS gillnet was better than the PA gillnet to catch the target Pacific herring.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.63-68
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• 2001

The skeletal development of the larvae and juvenile of red marbled rockfish, Sebasticus tertius (Barsukov et Chen) was studied based on individuals that were discharged and reared in the laboratory from April to May 1997. In 8 days after bearing, the postlarvae attained 4.42 mm in total length (TL), and its parasphenoid, premaxillary, maxillary, and clavicle were ossified for the first time at this stage. In 15 days after bearing, the postlarvae attained 5.23 mm in TL, and its pterotic, basioccipital, exoccipital, opercle, and preopercle were ossified, with one spine on the each cranium and preopercle. In 27 days after bearing, the postlarvae attained 8.81 mm in TL, its vertebra were posteriorly ossified to the 15th centrum, and five spines were formed on the preopercle. In 39 days after bearing, the juveniles attained 14.21 mm in TL, and the all bones were almost completed at this stage.

• Korean Journal of Ichthyology
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• v.4 no.2
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• pp.31-43
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• 1992

The blenniid fish, Entomacrodus stellifer light(Herre) is distributed in the coastal waters of southern Japan and south-eastern Korea. Matured adults of blenniid fish were collected from the rocky shore of Namchun-dong, Nam-gu, Pusan, Korea in July, 1991. The observations were made on the morphology and skeletal development of the reared larvae and juveniles. The lavae reached 5.80mm in mean total length(MTL) in 10 days after hatching. A this time the larvae have absorbed the yolk completely and became postlarvae. Melanophores are distributed on the fin membrane of the lower part of pectoral fin and ventral margins of tail. The larvae averaged 6.20mm in TL and the caudal notochord flex at $45^{\circ}$ in 13 days after hatching. The part of the fin-fold of the future dorsal and anal fins became high. The lavae reached juvenile stage in 31 days after hatching and attained 15.80mm in MTL, and all fin-rays was formed. Ossification of the cranium took place at 6.20mm of MTL(11 days after hatching) in parasphenoid. Vertebrae began to develop from the anterior end to ossify posteriorly. Ossification of all bones nearly completed when the larvae reached to 15.80mm in MTL (31 days after hatching).

• Korean Journal of Ichthyology
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• v.19 no.2
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• pp.101-106
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• 2007

We investigated the maturity and spawning of black edged sculpin, Gymnocanthus herzensteini caught by gillnet in the East Sea from March 2003 to February, 2004. We analyzed monthly changes in maturity stages, gonadosomatic index (GSI), gonad weight (GW), egg diameter, fecundity, total length at 50% group maturity and sex ratio. The spawning period was December to February. The fecundity ranged form 8,814 eggs at 14.7 cm (TL) to 25,560 eggs at 24.4 cm (TL). The relationship between total length (TL) and fecundity (F) was $F=285.11TL^{1.4092}$ ($R^2$ =0.571) and fecundity increased with total length. The total length at 50% group maturity was estimated to be 15.25 cm. The sex ratio was 60 for female and 40 for male, where the female population was seen to be slightly predominant. For sex ratio by length class, male was a little predominant in small size, but female was 90% more than 24 cm.

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.116-120
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• 2016

A specimen of Cocotropus masudai (41.2 mm in standard length), belonging to the family Aploactinidae, was firstly collected from the eastern coastal waters of Jejudo Island, Korea by using a fish trap in July 2011. This species is characterized by having the following morphological traits: XII, 9 dorsal fin rays; I, 8 anal fin rays; 12 pectoral fin rays; I, 3 pelvic fin rays; five preopecular spines; five sensory pores present on lower jaw and isthmus tip beyond fifth sensory pore. This species is similar to C. izuensis except for the number of preopercular spines (five in C. izuensis vs. four in C. masudai) and the anterior position of the isthmus (well beyond the fifth lower jaw sensory pore vs. the tip mostly reaching to the pore). In Korea, C. masudai can be easily distinguished from the Erisphex pottii in having the dorsal fin with nine soft rays (vs. 10~14 for Erisphex pottii), anal fin with seven soft rays (vs. 10~13) and pelvic fin with three soft rays (vs. two). We propose new Korean names, "Dot-chi-sok" and "Dot-chi" for the genus and species, respectively.

• Journal of the Korean earth science society
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• v.26 no.5
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• pp.443-458
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• 2005

Late Quaternary deposits of the core in the western area of the Nakdong River delta consist of four sedimentary units: Unit I, II, III and IV, in ascending order, controlled by the sea-level change since the last interglacial period. Unit I unconformable overlying Cretaceous basement rocks is composed of sandy gravel and sand deposited in a fluvial channel before the first marine transgression. Unit II composed of stiff massive mud is interpreted as a shallow marine deposits formed during the last interglacial period (probably MIS 5). The development of the fissures coated with oxidized materials in the upper part of Unit II is a feature of subaerial exposure, which indicates erosional contact with the upper Unit III. Unit III is made up of soft massive mud and soft shelly massive mud deposited in a tidal flat and a inner shelf, respectively, since the Holocene transgression (about 9,000 yr BP). Unit Ⅳ consisted of soft shell bedded mud and yellowish sandy mud was deposited in the delta environments during the regression (after about 5,000 yr BP). The lower shell bedded mud was deposited in a tidal flat and the upper sandy mud was deposited in the floodplain corresponding to present site of the Nakdong River delta.

• Journal of the Korean earth science society
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• v.26 no.3
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• pp.268-275
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• 2005

One of the nonlinear statistical modelling, neural network method was applied to predict the Sea Surface Temperature Anomalies (SSTA) in the Nino regions, which represent El Nino indices. The data used as inputs in the training step of neural network model were the first seven empirical orthogonal functions in the tropical Pacific $(120^{\circ}\;E,\;20^{\circ}\;S-20^{\circ}\;N)$ obtained from the NCEP/NCAR reanalysis data. The period of 1951 to 1993 was adopted for the training of neural network model, and the period 1994 to 2003 for the forecasting validation. Forecasting results suggested that neural network models were resonable for SSTA forecasting until 9-month lead time. They also predicted greatly the development and decay of strong E1 Nino occurred in 1997-1998 years. Especially, Nino3 region appeared to be the best forecast region, while the forecast skills rapidly decreased since 9-month lead time. However, in the Nino1+2 region where they are relatively low by the influence of local effects, they did not decrease even after 9-month lead time.