• Journal of Marine Life Science
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• 제1권1호
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• pp.31-40
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• 2016

Macrofauna and community structure were investigated seasonally at five sites in subtidal zone of Uljin on the east coast of Korea from March 2010 to February 2013. A total of 146 species were collected and identified, including 67 molluscs, 27 arthropods, and 8,688 individuals, including 6,468 arthropods, 1,098 molluscs and 584 echinoderms. In the seasonal investigation, summer has been the highest in 96 species and 2,525 number of individuals. Site 4 was the highest species but number of individuals were the lowest (81 species with 1,377 number of individuals), whereas site 3 was the lowest species and number of individuals were the highest (45 Species with 2,213 number of individuals). These result indicate that Balanus species affected to richness and the other side a gastropod influence by diversity and evenness. And site 3 seems to be good habitate environment for Balanus as the result of 83.4% of Balanus rather than other sites.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• 제28권4호
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• pp.121-132
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• 2023

Marine heatwaves (MHWs), referring to anomalously high sea surface temperatures, have drawn significant attention from marine scientists due to their broad impacts on the surface marine ecosystem, fisheries, weather patterns, and various human activities. In this study, we examined the impact of the distribution of Changjiang diluted water (CDW), a significant factor causing oceanic property changes in the East China Sea (ECS) during the summer, on MHWs. The surface salinity distribution in the ECS indicates that from June to August, the eastern extension of the CDW influences areas as far as Jeju Island and the Korea Strait. In September, however, the CDW tends to reside in the Changjiang estuary. Through the Empirical Orthogonal Function analysis of the cumulative intensity of MHWs during the summer, we extracted the loading vector of the first mode and its principal component time series to conduct a correlation analysis with the distribution of the CDW. The results revealed a strong negative spatial correlation between areas of the CDW and regions with high cumulative intensity of MHWs, indicating that the reinforcement of stratification due to low-salinity water can increase the intensity and duration of MHWs. This study suggests that the CDW may still influence the spatial distribution of MHWs in the region, highlighting the importance of oceanic environmental factors in the occurrence of MHWs in the waters surrounding the Korean Peninsula.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제39권4호
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• pp.337-346
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• 2003

This paper describes on the system and method for automatically tracking and real-time monitoring the position of target ships relative to the own ship using a PC based radar system that displays radar images and electronic charts together on a single PC screen. This system includes a simulator for generating the GGA and VTG information of target ships and a simulator for generating the TTM and OSD outputs from a ARPA radar and then host computer accepts NMEA0183 sentences on the maneuvering information of target ships from these simulators. The results obtained are summarized as follows；1. The system developed this study can be used as a range finder for measuring the distance between two ships and as a device for providing the maneuvering information such as distance and bearing to target ships from own ship on ECS screen. 2. From the result of position tracking for a selected target ship tracked with an update rate of 5 seconds using the $\alpha$-$\beta$ tracker, we concluded that the smoothing effect by the $\alpha$-$\beta$tracker was very effective and stable except in the time interval until about one minute after the target is detected. 3. From the fact that the real-time maneuvering information of tracked ship targets via a local area network (LAN) from a host computer installed a radar target extractor was successfully transferred to various monitoring computers of ship, we concluded that this system can be used as a sub-monitoring system of ARPA radar.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.92-100
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• 1984

The seasonal variation of catch and the fishing ground formation of anchovy caught by gill net are studied by using the data for 14 years, 1969 to 1982, published by the Fisheries Research and Development Agency of Korea. The main fishing season of anchovy by gill net can be devised into two seasons: spring and autumn. The former begins early in spring, marks peak in May with the monthly mean catch of 3,000 $\frac{M}{T}$ and ends in summer. The latter begins early in autumn, marks peak in October with the monthly mean catch of 1,500$\frac{M}{T}$ and ends in winter. The fishing ground begins to be formed in the southern waters of Korea with the begining of spring fishing season, and it is extended all over the south-eastern waters from spring to summer and it is converged to the coastal areas from autumn to winter. From the calculation of correlationship between adjacent fishing sections, the fishing ground can be devided into three areas; the northern area of $37^{\circ}N$, the southern area of $35^{\circ}N$ and the area between $35^{\circ}N\;and\;37^{\circ}N$. In the northern area of $37^{\circ}N$, monthly centers of the fishing ground are located in the adjacent aea area of Sockcho-Jumunjin district in the whole year, and its annual mean variance shows about 8 miles in the latitudinal direction and 10 miles in the longitudinal direction. In the area between $35^{\circ}N\;and\;37^{\circ}N$, monthly centers are located in the adjacent sea area of Kijang-Kuryongpo district, and the variance shows about 10 miles in the longitudinal direction and 20 miles in the latitudinal direction. In the southern area of $35^{\circ}N$, monthly centers are located in the open sea in spring and summer, and are conversed to the coastal area in autumn and winter, and the variance shows 8 miles in the latitudinal direction and 35 miles in the longitudinal direction. Water temperature and salinity at the fishing ground where the anchovy gill net was effectively operated are estimated from 14 to $20^{\circ}C$ and from 33.0 to $34.0\%0$ respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제29권2호
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• pp.174-190
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• 1996

Damage assessment based on in situ surveys for oil spills in marine environment is limited by fundamental difficulties as well as tremendous expenses. Except for intertidal zones, the damage is not preserved well. Also such surveys are usually confined to adult organisms. To overcome these limitations a computer model, NRDAM/CME, was developed in the case of USA (Reed et al., 1989), where an acute toxicity data base was used to assess indirect damages through food webs and loss due to recruitment as well as adult losses. In the present study damage assessment of natural biological resources for hypothetical oil spills is attempted using a computer model for hypothetical spills of Bunker C and heavy crude oil. In the model, the logical structure of NRDAM/CME was adopted, and biomass and productivity database were compiled for the Korean waters. The results showed that the damage increased in a nonlinear fashion as the spill amount increased. The magnitude of the damage depended upon the chemical properties of oil viscosity and solubility in particular, which implies that usage of oil dispersant might increase the damage by dispersing oil. The results also indicate that long term damage due to recruitment loss could be greater than short term damage.

• Journal of Fisheries and Marine Sciences Education
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• 제8권1호
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• pp.41-47
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• 1996

The fishing experiment was carried out in order to analyses the mesh selectivity for trawl cod - end in the Southern Korean Sea and East China Sea from June,1991 through December, 1992. The mesh selectivity was examined for the five kinds with opening mesh size, of which having mesh s izes 51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.2mm. In this report, mesh selectivity were taken analyses trawl cod - end for Priacanthus macracanthus. The main results obtained were as follows : 1. The relation equations between total length(TL) and body height(BH), body girth(BG) and body weight(BW) were BH=0.256 TL+2.963, BG=0.620 TL+8.650 and $BW=7.34{\times}10^{-5}TL^{2.6956}$, respectively. 2. 50% selection length and selection factor of trial cod - end with opening mesh size having 51.2mm, 70.2mm, 77.6mm, 88.0mm were 94.8mm, 1.85 ; 159mm, 2.27 ; 204mm, 2.09 ; 217.3mm, 2.18, respectively. 3. Range of opening mesh size from 51.2mm to 88.0mm, parameters of master curve were slope 2.70, intercept - 5.7 and selection factor 2.11.

• Journal of the Korean Society of Marine Environment & Safety
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• 제27권5호
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• pp.618-629
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• 2021

The Fukushima nuclear power plant (NPP) accident caused by the East Japan Earthquake in 2011 and the recent increase in the frequency of earthquakes in Korea have caused safety concerns regarding radionuclide exposure. In addition, the Tokyo Electric Power Company (TEPCO) in Japan recently decided to release radionuclide-contaminated water from Fukushima's NPP into the Pacific Ocean, raising public concerns that the possibility of radionuclide contamination through both domestic- and foreign fishery products is increasing. Although many studies have been conducted on the input of artificial radionuclides into the Pacific after the Fukushima NPP accident, studies on the distribution and accumulation of artificial radionuclides in marine products from East Asia are lacking. Therefore, in this study, we attempted to explore recent research on the distribution of artificial radionuclides (e.g., ¹³⁷Cs, ^239+240Pu, ⁹⁰Sr, and etc.) in marine products from Korean seas after the Fukushima NPP accident. In addition, we also discuss future research directions as it is necessary to prepare for likely radiation accidents in the future around Korea associated with the new nuclear facilities planned by 2030 in China and owing to the discharge of radionuclide-contaminated water from the Fukushima NPP.

• Korean Journal of Ichthyology
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• 제35권2호
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• pp.121-128
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• 2023

Two specimens of Polymetme elongata (Phosichthyidae; Polymetme) were collected by a bottom trawl from both the southern coastal waters of Jejudo Island in October 2016 (70.65 mm SL) and Yellow Sea, Korea in August 2022 (54.04 mm SL). They are an elongated body with large mouth, 11 dorsal fin rays, 10 pectoral fin rays, 7 pelvic fin rays, 30~32 anal fin rays, 1 adipose fin, 18 gill rakers, 44 vertebrae, 1 preorbital photophore, 1~2 ventrolateral rows of photophores on body, 1 paired photophores in symphysis of lower jaw, 9 branchiostegal rays, 2 rows of 8 phorophores between pelvic fin origin and anal fin origin, and 1 row of 23 photophores thereafter. At the origin of anal fin, the second photophore is more higher than third photophore and the first photophore is most lowest. Our specimens differ from the other species of the same genus by the ratio of the head length to the standard length (1/5) and the gill rakers (18), absolutely. As this species is the first record of the family Phosichthyidae, genus Polymetme, and P. elongata in Korean waters, we suggest their new Korean names, "Gin-ael-tung-i-gwa", "Gin-ael-tung-i-sog", and "Gin-ael-tung-i", respectively.

• Journal of the Korean association of regional geographers
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• 제4권2호
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• pp.151-164
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• 1998

I analyzed the correlation between El-Nino phenomenon and our country's temperature and precipitation laying the stress on the anomaly, and the result of this analysis is as follows: (1) The extraction of the occurrences of El-Nino at the place of sea surface around Nino.3 which was known as the sea area under observation for El-Nino reveals that there are 9 years (1969, 1970, 1973, 1977, 1987, 1992, 1995, 1998) when the temperature anomaly in January is more than 1.0 during the period of research years ($1969{\sim}1998$). (2) The tendency of change of sea surface temperature around Nino.3 and that of our country are about the same, but the anomaly of Pusan and Inchon was much greater than that of Jangki in the East Coast. (3) The anomaly of sea surface temperature around Nino.3 and that of the ground temperature showed the similar changing tendency, the temperature of our country has something to do with that of sea surface as the correlation of ground temperature with the temperature of sea surface showed 0.31. Anomaly warm winter has something to do with El-Nino because the temperature of our country was high when El-Nino phenomenon appeared. (4) As for the precipitation, we can see that it has generally increased after 1989 when the phenomenon of warm climate was intense than before that year. But as we study the change of anomaly, the precipitation has less correlation in comparison with the ground temperature. The precipitation in 1973, 1983 and 1987 which were El-Nino years was correlated with El-Nino. While the change of sea surface temperature has showed a tendency of plus(+)increase since 1990, the precipitation has showed a tendency of minus (-)decrease. Therefore it seems that the temperature of sea surface has little correlation with the amount of rainfall.

• Korean Journal of Remote Sensing
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• 제39권6_2호
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• pp.1635-1650
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• 2023

Under global warming, the steadily increasing sea surface temperature (SST) severely impacts marine ecosystems,such as the productivity decrease and change in marine species distribution. Recently, the catch of Todarodes Pacificus, one of South Korea's primary marine resources, has dramatically decreased. In this study, we analyze the marine environment that affects the formation of fishing grounds of Todarodes Pacificus and develop seasonal habitat suitability index (HSI) models based on various satellite data including Geostationary Ocean Color Imager (GOCI) data to continuously manage fisheries resources over Korean exclusive economic zone. About 83% of catches are found within the range of SST of 14.11-26.16℃,sea level height of 0.56-0.82 m, chlorophyll-a concentration of 0.31-1.52 mg m^-3, and primary production of 580.96-1574.13 mg C m^-2 day^-1. The seasonal HSI models are developed using the Arithmetic Mean Model, which showed the best performance. Comparing the developed HSI value with the 2019 catch data, it is confirmed that the HSI model is valid because the fishing grounds are formed in different sea regions by season (East Sea in winter and Yellow Sea in summer) and the high HSI (> 0.6) concurrences to areas with the high catch. In addition, we identified the significant increasing trend in SST over study regions, which is highly related to the formation of fishing grounds of Todarodes Pacificus. We can expect the fishing grounds will be changed by accelerating ocean warming in the future. Continuous HSI monitoring is necessary to manage fisheries' spatial and temporal distribution.