South Sea Of Korea Research Articles

Application of Light-Emitting Diode Lights to Bluefin Sea Robin (Chelidonichthys spinosus) Catch in Pot Fishery in the South Sea, Korea

The bluefin sea robin (Chelidonichthys spinosus), hereafter BSR, is one of the most important fish species in the South Sea of Korea. The production value of BSR in 2020 was USD 4,733,057. The production volume in Korea has shown an annual mean increase of 8.9% since 2010, but the efficiency of the fishing gear decreased due to excessive use. This has led to a decrease in the profitability of fishery operators, and as compensation, the use of fishing gear has further increased through competitive operations. Alternative measures for improving catch performance and reducing the use of fishing gear are needed. As one such measure, LED (Light-Emitting Diode) lights were attached to the pot, and the effects were determined. The field experiment results showed that the catch of BSR was higher for the experimental groups (n = 10–273) using fishing gear with LED lights (red, green, blue, and white) than for the control group (n = 2) (Kruskal–Wallis test, p < 0.05). Among the experimental groups, the pot with green light achieved the largest catch (n = 273). The use of LED lights was found to enhance the catch efficiency of pot fishing gear for BSR.

Description of Polaribacter batillariae sp. nov., Polaribacter cellanae sp. nov., and Polaribacter pectinis sp. nov., novel bacteria isolated from the gut of three types of South Korean shellfish.

Three aerobic, Gram-negative, and rod-shaped bacterial strains, designated strains G4M1T, SM13T, and L12M9T, were isolated from the gut of Batillaria multiformis, Cellana toreuma, and Patinopecten yessoensis collected from the Yellow Sea in South Korea. All the strains grew optimally at 25°C, in the presence of 2% (w/v) NaCl, and at pH 7. These three strains, which belonged to the genus Polaribacter in the family Flavobacteriaceae, shared < 98.8% in 16S rRNA gene sequence and < 86.68% in whole-genome sequence with each other. Compared with the type strains of Polaribacter, isolates showed the highest sequence similarity to P. haliotis KCTC 52418T (< 98.68%), followed by P. litorisediminis KCTC 52500T (< 98.13%). All the strains contained MK-6 as their predominant menaquinone and iso-C15:0 as their major fatty acid. Moreover, all the strains had phosphatidylethanolamine as their polar lipid component. In addition, strain G4M1T had two unidentified lipids and three unidentified aminolipids, strain SM13T had three unidentified lipids and three unidentified aminolipids, and strain L12M9T had three unidentified lipids and one unidentified aminolipid. The DNA G + C contents of strains G4M1T, SM13T, and L12M9T were 31.0, 30.4, and 29.7 mol%, respectively. Based on phenotypic, phylogenetic, chemotaxonomic, and genotypic findings, strains G4M1T (= KCTC 82388T = DSM 112372T), SM13T (= KCTC 82389T = DSM 112373T), and L12M9T (= KCTC 62751T = DSM 112374T) were classified into the genus Polaribacter as the type strains of novel species, for which the names Polaribacter batillariae sp. nov., Polaribacter cellanae sp. nov., and Polaribacter pectinis sp. nov., respectively, have been proposed.

A new species of sublittoral marine copepod, Normanella parvisetosa sp. nov. (Harpacticoida, Normanellidae), from the Southern Sea of South Korea

Abstract A new harpacticoid species, Normanella parvisetosa sp. nov., belonging to the family Normanellidae Lang, 1944, is described from subtidal habitats in the Southern Sea of South Korea. This new species is assigned to the minuta-lineage, based on the rostrum with a pointed apical tip, the five-segmented female antennule, the female P5 exopod without a distinct notch on the outer margin, and well-developed caudal setae IV and V each bearing an internal fracture plane. Normanella parvisetosa sp. nov. is morphologically close to N. incerta Lang, 1934, N. porosa Noodt, 1964, and N. obscura Lee &amp; Huys, 1999, whereas the new species is distinguished from females of these species in the shape of the rostrum with a pointed tip, the relative length to width ratio of the caudal rami, the second endopodal segment of the second to fourth legs, the exopod of the fifth leg, and the relative length of setae on both rami of the fifth leg. Herein, we provide a detailed description and illustrations of Normanella parvisetosa sp. nov., which is the second Normanella species identified in Korean waters.

Convolution Neural Network for the Prediction of Cochlodinium polykrikoides Bloom in the South Sea of Korea

In this study, the occurrence of Cochlodinium polykrikoides bloom was predicted based on spatial information. The South Sea of Korea (SSK), where C. polykrikoides bloom occurs every year, was divided into three concentrated areas. For each domain, the optimal model configuration was determined by designing a verification experiment with 1–3 convolutional neural network (CNN) layers and 50–300 training times. Finally, we predicted the occurrence of C. polykrikoides bloom based on 3 CNN layers and 300 training times that showed the best results. The experimental results for the three areas showed that the average pixel accuracy was 96.22%, mean accuracy was 91.55%, mean IU was 81.5%, and frequency weighted IU was 84.57%, all of which showed above 80% prediction accuracy, indicating the achievement of appropriate performance. Our results show that the occurrence of C. polykrikoides bloom can be derived from atmosphere and ocean forecast information.

남해 EEZ 골재채취단지에서 골재채취가 대형저서동물 군집에 미치는 영향

본 연구는 골재채취가 대형저서동물에 미치는 영향을 파악하기 위하여 2013년부터 2017년까지 조사가 수행된 자료를 이용하여 분석하였다. 대형저서동물의 총 출현종수는 579종, 평균 서식밀도는 1,478±845 indiv.m-2, 평균 생체량은 39.6±53.2 gWW.m<SUP>-2</SUP>이었으며, 대조구 정점이 영향해역보다 출현종수, 생체량 및 종다양도지수가 유의적으로 높은 값을 나타내었다(p<0.05). 다변량 분석결과 또한 골재채취 행위로 인하여 대조구와 영향해역으로 구분되었으며(서식밀도 : R=0.528, p<0.01), 특히 영향해역 군집의 기여종은 기회주의종인 버들갯지렁이류(Mediomastus californiensis)로 나타났다. 휴식년제 도입에 따른 채취광구 내 대형저서동물 변화 경향을 살펴본 결과, 자연회복에 대한 일관된 경향을 파악할 수 없었으나, 특정 광구에서 출현종수 및 서식밀도가 휴식년에서 채취기보다 유의적으로 높은 값을 나타내었다(p<0.05). 또한 휴식년 기간 동안 서식밀도 점유율은 기회주의종인 M. californiensis는 감소하고 단각류(Gammaropsis(Segamphopus) utinomii, Siphonoecetes spp.)의 점유율은 증가하는 경향을 나타내었다. 따라서 골재채취를 수행하는 시기에는 대형저서동물군집은 불안정한 상태를 보였지만, 골재채취가 중단되는 휴식년에는 불안정한 환경에서 벗어나는 변화를 보이고 있는 것으로 나타났다.

남해 EEZ 골재채취 해역의 부유사 발생 및 확산 특성

본 연구에서는 남해 EEZ 골재채취 해역의 부유사 발생 및 확산 특성을 파악하기 위하여 2013년부터 2016년까지 수행된 월류수 및 부유사추적 조사 결과와 2011년부터 2016년까지 촬영된 위성영상 자료(GOCI)를 수집·분석하였다. 골재 채취시 표층으로 유출되는 월류수 부유사농도는 656-36,094 g/㎥를 나타냈으며, 골재채취 작업강도가 증가할수록 부유사농도가 증가하는 양상을 나타냈다. 부유사추적 조사와 위성영상 자료(GOCI)를 통해서 분석된 부유사 확산 양상에 의하면, 연중 북동향하는 대마난류의 영향으로 대부분의 부유사 풀룸이 북동향하였으며, 월류수 부유사에 의해서 골재채취 구역 인근 표층에서 상대적으로 높은 농도를 나타내고, 채취지역으로부터 멀어질수록 표·중·저층의 농도가 유사해지는 양상을 보였다. 대마난류의 영향이 약해지는 대조기 창조시에는 부유사 풀룸이 상대적으로 좁은 범위로 서향하였으며, 표층에서 고농도의 범위가 증가하는 양상을 보였다. 위성영상 자료(GOCI)의 중첩 결과에 의하면, 골재채취 중 부유사가 북동향으로 최대 약 58 km까지 확산되는 분포를 보였다. 골재채취 부유사 발생 및 확산 특성은 골재채취선 작업 조건과 대상해역의 흐름과 바람 조건에 의해서 좌우되므로 골재채취 중 발생되는 부유사에 의한 환경영향 최소화 측면에서 골재채취 작업강도의 완화와 적절 골재채취 시기 선정에 대한 검토가 필요할 것으로 사료된다.

2021년 봄 남해 수괴 분포와 식물플랑크톤 군집의 공간분포 특성

봄 한국 남해 수괴 및 식물플랑크톤 군집의 공간분포를 파악하기 위해 2021년 4월 15개 정점의 표층과 엽록소 a 최댓 층(CML)을 대상으로 현장조사를 실시하였다. 결과, 봄 남해의 수괴는 고염수 특성인 쓰시마난류가 지배하였고, 일부에서 한국 고유연안수가 관찰되었지만, 저염 특성의 중국 대륙연안수는 관찰되지 않았다. 엽록소 a 농도는 0.20-2.53 μgL<SUP>-1</SUP> 범위에서 0.86±0.58 μgL<SUP>-1</SUP>로 변화하여, 연안수에서 1.0 μgL<SUP>-1</SUP> 이상 높았고, 쓰시마난류에서 0.5 μg L<SUP>-1</SUP> 이하로 낮았다. 식물플랑크톤 종 조성은 43속 74종으로 규조류가 68.4%, 와편모조류가 28.4%, 그리고 규질편모조류 및 유글레나조류가 각 1.6%를 보였다. 표층 현존량은 1.4-150.8 cells mL<SUP>-1</SUP> 범위에서 41.1±57.1 cells mL<SUP>-1</SUP>로, 연안부에서 100 cells mL<SUP>-1</SUP> 이상 높고, 쓰시마난류에서 5-20 cells mL<SUP>-1</SUP> 이하로 낮았다. 그리고 표층의 연안 전선 및 일부 해역에서 유기물 점액질이 높게 관찰되었다. 표층 10% 이상 우점율의 우점종은 Pseudo-nitzschia delicatissima, Leptocylindrus danicus, Chaetoceros socialis 및 Nitzschia sp./small size 등이며, CML은 L. danicus가 우점율 54.6%로 최우점종, Karenia sp. cf. mikimotoi가 우점율 12.9%로 차우점하였다. 상관분석 및 주성분 분석에서 봄 남해 식물플랑크톤 군집은 연안수에서 군집다양성이 높았지만, 쓰시마난류에서 낮은 특성으로 수괴의 영향에 따라 특성을 달리하는 것으로 나타났다.

First Concurrent Measurement of Primary Production in the Yellow Sea, the South Sea of Korea, and the East/Japan Sea, 2018

Dramatic environmental changes have been recently reported in the Yellow Sea (YS), the South Sea of Korea (SS), and the East/Japan Sea (EJS), but little information on the regional primary productions is currently available. Using the 13C-15N tracer method, we measured primary productions in the YS, the SS, and the EJS for the first time in 2018 to understand the current status of marine ecosystems in the three distinct seas. The mean daily primary productions during the observation period ranged from 25.8 to 607.5 mg C m−2 d−1 in the YS, 68.5 to 487.3 mg C m−2 d−1 in the SS, and 106.4 to 490.5 mg C m−2 d−1 in the EJS, respectively. In comparison with previous studies, significantly lower (t-test, p &lt; 0.05) spring and summer productions and consequently lower annual primary productions were observed in this study. Based on PCA analysis, we found that small-sized (pico- and nano-) phytoplankton had strongly negative effects on the primary productions. Their ecological roles should be further investigated in the YS, the SS, and the EJS under warming ocean conditions within small phytoplankton-dominated ecosystems.

First record of the caridean shrimp family Chlorotocellidae (Crustacea: Decapoda) from Korea

AbstractThe caridean shrimp family Chlorotocellidae has so far not been reported from Korean waters. One of the four genera in the family is herein reported, based on the species Anachlorocurtis commensalis. Specimens were collected from antipatharian black corals by scuba diving at depths ranging from 20–60 m from three localities: Jejudo Island (33°13′N) between the South Sea of Korea and the north-eastern East China Sea, Namhyeongjedo Islet (34°53′N) in the Korea Strait, and Dokdo Island (37°15′N) in the East Sea. The species had previously been reported in tropical to subtropical latitudes in the western Pacific, with known records from southern Taiwan (up to 21°55′N) to central Japan (down to 34°50′N). The species is thus recorded for the first time from a temperate region in the western Pacific Ocean, postulated to be influenced by a branch of the Kuroshio Warm Current.

High-Resolution Bathymetry in Shallow Waters off the Southern Coast of Korea from Satellite Altimetry and Remote Sensed Imagery

Kim, K.B. and Yun, H.S., 2021. High-resolution bathymetry in shallow waters off the southern coast of Korea from satellite altimetry and remote sensed imagery. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S.; and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 390–394. Coconut Creek (Florida), ISSN 0749-0208. Bathymetry in shallow waters off coastal areas has been measured using conventional methods such as with single-beam and multi-beam echo-sounders installed on the ship. However, shipborne depth data are spatially limited and unevenly distributed over shallow waters off coastal areas. In this study, various methods that use satellite altimetry-derived gravity anomalies and high-resolution remote sensed imagery were explored for the recovery of high-resolution bathymetry data over shallow waters off Gwangyang Bay between Yeosu Peninsula and Namhae Island on the South Sea of Korea. Estimated high-resolution bathymetry data from satellite altimetry-derived gravity anomalies and remote sensed imagery were compared with shipborne depth measurements to validate their accuracy in shallow waters. This study concluded that bathymetry data estimated with the gravity-geologic method (GGM) in shallow waters are better than those predicted by Sentinel-2 imagery.

Acoustic survey for estimating density of anchovy schools in the south sea of Korea

Acoustic survey for estimating density of anchovy schools in the south sea of Korea

Diet Composition of the Chub Mackerel Scomber japonicus in the Coastal Waters of the South Sea of Korea

Diet Composition of the Chub Mackerel Scomber japonicus in the Coastal Waters of the South Sea of Korea

Environmental Characteristics and Macrobenthic Community Structure of Yubu Island, a UNESCO-Designated Migratory Bird Sanctuary in the South Korea

This study investigated the environmental characteristics and macrobenthic community structures of an intertidal flat located on Yubu Island in the western coastal area of the Yellow Sea of South Korea. The study site has been well known for the migratory bird protection designated by UNESCO. We collected the samples of surface and depth core sediments and macrobenthos from the unused saltern and the area surrounding it in July 2017. Our results demonstrated that the means of mud, total carbon, and total nitrogen contents were 50%, 0.35% and 0.05%, respectively, and the origin of sediment composed of marine sources. The sedimentation rate ranged from 0.99 to 1.66 cm y−1, which was higher than other tidal flats in the Yellow Sea. The result of a topographic analysis indicated that the area in the unused saltern was 289.489 m2, and the length and width were 625 m and 500 m, respectively. A total of 13 species occurred with a mean density of 92 ind. m−2 and a mean biomass of 58.6 gWWt m−2. The Heteromastus filiformis (23.1%, 21 ind. m−2) was the most dominant species, followed by Perinereis linea (19.2%, 18 ind. m−2) and Tubuca arcuata (17.3%, 16 ind. m−2). Thus, this environmental information will help to establish policies to protect migratory birds in the future.

Interactions between common heterotrophic protists and the dinoflagellate Tripos furca: implication on the long duration of its red tides in the South Sea of Korea in 2020

Interactions between common heterotrophic protists and the dinoflagellate Tripos furca: implication on the long duration of its red tides in the South Sea of Korea in 2020

Prediction of Sea Surface Temperature and Detection of Ocean Heat Wave in the South Sea of Korea Using Time-series Deep-learning Approaches

Prediction of Sea Surface Temperature and Detection of Ocean Heat Wave in the South Sea of Korea Using Time-series Deep-learning Approaches

서해 끝 무인도‘격렬비열도’의 문화자원 분석

이 연구는 서해 끝 절해고도 무인도인 격렬비열도의 문화자원을 탐구해 섬의 이미지·스토리텔링 구축의 토대를 제공하는 것이 목적이다. 격렬비열도는 2020년 영토수호 여론에 힘입어 정부의 공적 관리 절차가 시작되었다. 이 섬은 화산활동으로 7천만 년 전에 생겨나 1백만 년 전으로 추정되는 제주도의 탄생사보다 깊다. 따라서 연구자는 이 섬의 문화자원을 규명해 섬의 정체성 구축의 핵심 콘셉트로 삼기 위해 민속지학 연구방법을 적용해 2018년 2월부터 2020년 12월까지 3년간 격렬비열도가 속한 태안지역 주민 등 관계자 면접, 섬 탐방 등을 실시하였다. Valentin(2001)과 남치호(2007)의 자원분류 모델을 적용해 섬의 문화자원을 분석한 결과, 섬에서 발견된‘유형문화자원’은 주로 한중 문물 교류의 길목이자 생명을 수호하는 영지(靈地)를 상징하는 것으로 나타났으며, 추출된 섬의‘유형문화 자원’은 생명 수호, 안전, 용맹, 로맨스 이미지에 집중되었다. 이 결과를 토대로 격렬비열도를 문화적 장소성이 뚜렷한 섬으로 이미지텔링 및 스토리텔링 하여 새 단장할 경우 정체성 구축의 핵심 콘셉트는‘사랑의 추억을 재생하게 하는 환황해(環黃海) 중심의 문화생태섬’으로 제안할 수 있다.

Above water remote sensing reflectance dataset on the coastal waters of California and Korea

Remote sensing reflectance (R&lt;sub&gt;rs&lt;/sub&gt;) is a fundamental data of ocean color remote sensing that is used as an input data for algorithm development. In this study, the Rrs spectra acquired from the coast of Korea and California, on the opposite side of the Pacific Ocean, were analyzed and compared. The waters of Gyeonggi Bay and Mokpo had a similar spectrum to those of the waters inside of the San Francisco Bay, although the waters of each region had different characteristics. The South Sea in Korea showed similar spectral characteristics on the waters of Monterey Bay and outside of the San Francisco Bay in California. The upward slope of the Rrs spectra in the range of 400 to 600 nm obtained from the inside of the San Francisco Bay was higher than the coastal waters on the Gyeonggi Bay and Mokpo in Korea. The Rrs spectra showing peaks on 580 nm and 680 ~ 700 nm due to chlorophyll were similarly observed in the South and East Seas of Korea, and the coastal waters of Monterey Bay and the outside of the San Francisco Bay in California.

Morphological description and molecular identification of juvenile of the previously unrecorded species &lt;i&gt;Hoplolatilus chlupatyi&lt;/i&gt; (Malacanthidae) in the South Sea of Korea

Morphological description and molecular identification of juvenile of the previously unrecorded species &lt;i&gt;Hoplolatilus chlupatyi&lt;/i&gt; (Malacanthidae) in the South Sea of Korea

Spatial downscaling of MODIS Chlorophyll-a with machine learning techniques over the west coast of the Yellow Sea in South Korea

Effective water quality monitoring of coastal areas through the measurement of Chlorophyll-a (Chl-a) has remarkably progressed by ocean color remote sensing. Among different sensors, Moderate Resolution Imaging Spectroradiometer (MODIS) Level 3 products provide reliable global representations of the Chl-a concentration. On the other hand, due to the coarse spatial resolution of MODIS data, its applicability is limited for spatially complex coastal regions. To overcome this limitation, a few downscaling techniques have been suggested based on the polynomial regression method. However, this type of regression has some restrictions, such as sensitivity to outliers, and nonlinear types of machine learning algorithms have not been tested in downscaling Chl-a datasets. Therefore, three machine learning (ML) techniques, support vector regression (SVR), random forest regression (RFR), and long short-term memory (LSTM), were developed using the Sentinel-2A/MSI bands as predictors and MODIS Chl-a as a predictand and compared their results with the results of multiple polynomial regression (MPR), to find the most suitable model for downscaling MODIS Chl-a in coastal area of South Korea. The obtained results showed that the 2nd degree MPR and SVR-Radial Basis Function (RBF) illustrate the best performance in the winter and summer days, respectively. In addition, LSTM is less sensitive to the changes in all variables (sensitivity index range from 0.31 to 0.48). Overall, we conclude that the downscaling approach based on ML models, especially SVR-RBF, can serve as a suitable alternative in some cases to produce high-resolution Chl-a maps, especially for coastal marine water quality monitoring.

거제 남동부 내만해역의 식물플랑크톤 군집 월 변화 특성

거제 남동부 내만 해역을 대상으로 식물플랑크톤 군집의 월 변화 특성을 파악하기 위한 현장조사는 2018년 6월부터 2019년 5월까지 월 1회 3개의 정점에서 실시하였다. 결과 출현한 식물플랑크톤 종은 54속 97종으로 여름에서 초겨울까지 급격히 출현 종수가 감소하였고, 겨울에서 봄까지 증가하였다. 출현한 유해식물플랑크톤은 규조류 Pseudo-nitzschia pungens, 와편모조류 Dinophysis acuminata, D. fortii, Lingulodinium polyedra, Gymnodinium catenatum, Margalefidinium polykrikoides, 침편모조류 Heterosigma akashiwo 등으로 다양하였다. 식물플랑크톤 현존량은 표층에서 1월 0.8 cells mLSUP-1/SUP에서 7월 154.4 cells mLSUP-1/SUP까지의 변동 폭으로 변화하여, 평균 32.0 cells mLSUP-1/SUP로 봄과 여름에 높고, 가을과 겨울에 낮은 세포 밀도를 나타내었다. 우점종은 여름에 와편모조류 Prorocentrum triestinum, Tripos fusus 및 규조류 Chaetoceros affinis, Nitzschia sp., Skeletonema costatum-ls, 가을 규조류 Chaetoceros debilis, Paralia sulcata, Thalassionema nitzschioides, 겨울 규조류 Chaetoceros curvisetus, Ch. socialis, Dentoluna pulima, Eucampia zodiacus, S. costatum-ls 그리고 봄은 규조류 Ch. curvisetus, D. pulima, E. striata, E. zodiacus, Pn. pungens, S. costatum-ls 및 와편모조류 P. triestinum, Scrippsiella trochoidea로 변하여, 비교적 계절 천이가 분명하였다. 다양도 지수 및 우점도 지수에 의한 식물플랑크톤 군집구조의 시간적 변화가 큰 특징을 보였다. 즉 거제 남동부 내만 해역의 식물플랑크톤 군집은 계절적 변화가 매우 컸으며, 이러한 변화는 거제도 주변 해역의 쓰시마 난류 및 담수 혼합 등 해수 유동과 밀접하게 관계되는 것으로 판단되었다.