• Korean Journal of Ichthyology
• /
• v.33 no.4
• /
• pp.217-225
• /
• 2021

The family Platycephalidae is a taxonomic group of economically important demersal flathead fishes that predominantly occupy tropical or temperate estuaries and coastal environments of the Indo-Pacific oceans and the Mediterranean Sea. In this study, we for the first time analyzed the complete mitochondrial genome (mitogenome) of the flathead Platycephalus cultellatus Richardson, 1846 from Vietnam by Next Generation Sequencing method. Its mitogenome was 16,641 bp in total length, comprising 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNA genes. The gene composition and order of the mitogenome were identical to those of typical vertebrates. The phylogenetic trees were reconstructed based on the concatenated nucleotide sequence matrix of 13 PCGs and the partial sequence of a DNA barcoding marker, cox1 in order to determine its molecular phylogenetic position among the order Scorpaeniformes. The phylogenetic result revealed that P. cultellatus formed a monophyletic group with species belonging to the same family and consistently clustered with one nominal species, P. indicus, and two Platycephalus sp. specimens. Besides, the cox1 tree confirmed the taxonomic validity of our specimen by forming a monophyletic clade with its conspecific specimens. The mitogenome of P. cultellatus analyzed in this study will contribute valuable information for further study on taxonomy and phylogeny of flatheads.

• Korea Trade Review
• /
• v.44 no.6
• /
• pp.119-134
• /
• 2019

This study focuses on a recent WTO SPS dispute related to Korea Import Bans and Testing and Certification Requirements for Radionuclides (DS495) in order to learn from the case and take proactive measures to prevent potential import restrictions by Japan on Korean seafood. Korean-Radionuclides (Japan) emphasizes the importance of sufficient scientific evidence, especially scientific information from relevant international organizations, in an effort to take preventive measures towards Japan's restrictions on Korean seafood imports. Japan claims that a novel parasite, Kudoa septempuctata, in Korean flatfish causes food poisoning. As food poisoning is a serious concern, there is a low possibility that Japan's enhanced monitoring measures would be more trade restrictive than required as prescribed in Article 5.6 of the WTO SPS Agreement. In addition, Korea is the biggest exporter of olive flounder to Japan. Hence, the possibility that similar conditions could be established is low in relation to non-discriminatory principles under the WTO SPS Agreement. Accordingly, we should collect relevant scientific evidence, improve domestic sanitary management of fishery products, and seek export diversification so that we prepare for potential import restrictions by Japan and minimize implications.

• Korean Journal of Plant Taxonomy
• /
• v.51 no.3
• /
• pp.250-293
• /
• 2021

Limestone areas are sedimentary rock outcrops consisting of calcium carbonate created several hundreds of millions of years ago by calcium-secreting marine organisms and subsequently lifted above sea level by tectonic movement. Limestone areas support very high levels of endemic species of plants and are recognized as biodiversity areas with much biological information. The purpose of this study is to devise a strategy for the comprehensive conservation of the vegetation of limestone areas through analyses of the floristics and plant species compositions in ten limestone areas on the Korean Peninsula. The results of 153 field surveys from April of 2010 to October of 2016 identified 1,202 taxa in total, representing 1,096 species, 18 subspecies, 84 varieties, 2 forms, and 2 hybrids in 530 genera and 133 families. Among them, 55 taxa were endemic plants to Korea, and 38 taxa were red data plants. The floristic target plants amounted to 102 taxa, specifically 27 taxa of grade V and 75 taxa of grade IV. In all, 121 alien plants were recorded in the investigated area. Calciphilous plants amounted to 102 taxa, specifically 14 taxa of calciphilous indicator plants, 30 taxa of superlative most calciphilous plants, and 58 taxa of comparative more calciphilous plants. A cluster analysis showed a high degree of similarity between sites that are geographically adjacent with similar habitat environments. Limestone areas also supported groups distinct from those in non-limestone areas, demonstrating the specificity of limestone flora. Plant geography approaches therefore appear to be crucial to gain a better understanding of the level of biodiversity in limestone areas, not only at the interspecific but also at the intraspecific level. These results highlight the importance of protecting limestone habitats to preserve not only their interspecific but also the intraspecific diversity, which is highly threatened.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.6
• /
• pp.1197-1206
• /
• 2019

Suncheon Bay is a very important natural resource and various efforts have been made to protect it from the environmental pollution. Although the project to monitor the environmental changes in periodically by observing the creatures in tidal flats is processing, it is being done inefficiently by people directly observing it. In this paper, we propose an object segmentation method that can be applied to the method to automatically monitor the living creatures in the tidal flats. In the proposed method, a foreground map representing the location of objects is obtained by using a temporal difference method, and a superpixel method is applied to detect the detailed boundary of an image. Finally the region of crab is extracted by combining the foreground map and the superpixel information. Experimental results show that the proposed method separates crab regions from a tidal flat image easily and accurately.

• Korean Journal of Ichthyology
• /
• v.30 no.4
• /
• pp.224-231
• /
• 2018

Dietary niches can support the coexistence of sympatric species in marine ecosystems, which can lead to the presence of greater abundances of those species. Stomach contents of silver croaker (Pennahia argentata) and Japanese sillago (Sillago japonica) inhabiting the Nakdong River estuary, Korea were analyzed to determine diet compositions and the presence of any size-related and inter-specific feeding relationships. These species were bottom-feeding predators that consumed mainly benthic crustaceans and mollusks, but polychaetes were also important in the S. japonica diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on weight contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences. Size-related change was also significant for P. argentata diets, but not for S. japonica. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. The results from this study provide clear evidence of niche segregation between co-occurring P. argentata and S. japonica in the Nakdong River estuary, which would reduce the likelihood of inter-specific competition for food resources.

• Food Science and Industry
• /
• v.51 no.4
• /
• pp.278-301
• /
• 2018

Although more than 80% of living organisms are found in marine ecosystems, only less than 10% of marine resources have been utilized for human food consumptions and other usages. It is well known that marine resources (fish, shellfish and algae) have exceptional nutritional properties; however, their functional characteristic has not been completely discovered. It is believed that metabolites (organic compounds, proteins, peptides, lipids, minerals, etc.) play an important role to show its biological properties. Marine proteins and peptides are considered to be future drugs due to their excellent biological activities with a fewer adverse side effect. Marine peptides show several biological activities, including antimicrobial, antioxidant, anti-inflammatory, anti-cancer, anti-viral, anti-tumor, anti-diabetic, anti-hypertensive, anti-coagulant, immunomodulatory, appetite suppressing and neuroprotective effects. Therefore, the pharmaceutical, nutraceutical, and cosmeceutical companies have been paid attention to the marine peptides to commercialize into products. This current review mainly focused on the above mentioned biological activities of marine peptides and protein hydrolysates as a functional food and pharmaceutical applications. To commercialize these materials in industrial level required large quantity in high-purity level, and it is complicated to produce huge quantity from the marine resources due to insufficient raw materials, unavailability of raw materials through a year, hinder the growth with geographical variations, and availability of compounds in extreme small quantities. The best solution for these issues is to introduce new modern technologies such as artificial intelligence robots, drones, submersibles and automated raw material harvesting vessels in farming industries instead of man power, which will lead to 4th industrial revolution.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.12 no.2
• /
• pp.112-120
• /
• 2007

This paper reviews the use of parasites as 'biological tags' for studying stock analysis of salmonid fishes. Numerous definitions of stock concepts exist, but most of them essentially define a group of fish as having similar biological characteristics and being self-reproducing as stocks. It is important to manage fish stocks for human consumption and sustainable production and especially for salmonid fishes. Because these fry are considered as each country's property, it is necessary to identify and discriminate each fish stock in the open sea. Methods of separating fish stocks are very diverse. Artificial tags, parasites, otoliths scales and genetic characters have been used for stock analysis and each method has advantages and disadvantages. Of these parasites can be good biological tags because they are applied by nature at no cost. Parasites can be infected with susceptible host fishes when they enter into certain areas. Then if they move to the outside and are caught researchers can infer that the fish had been in the endemic area for a period of time during their life. Hence the host fish can be considered as naturally 'tagged' by parasites. However, if they do not pass the parasites-endemic. area, they will harbour no parasites. Therefore, researchers can discriminate each fish stocks and trace their migration routes with these biological tags. In this paper, several examples on the use of parasites as biological tags for studying salmonids, as well as other species, are listed. The advantages and limitations of parasites as biological tags are also discussed. Chum salmon (Oncorhynchus keta), the main salmonid species migrating to Korea, is distributed all around the North Pacific. Korean chum salmon are generally thought to move to the Sea of Okhotsk, the western North Pacific and the Bering Sea. However, there is no clear information on the distribution and migration pathways of Korean chum salmon, and no markers exist for separating them from others yet. Recent Korean chum salmon stock analysis including parasites information are mentioned.

• Journal of Global Scholars of Marketing Science
• /
• v.5
• /
• pp.1-14
• /
• 2000

김해시에는 약 3,000개가 넘는 기계산업을 중심으로한 전국 두 번째로 많은 중소기업이 있다. 김해국제공항이 10km 이내에 있으며, 부산항과 마산항, 가덕신항만이 자동차로 30분 거리에 있고 서울, 대구, 광주로 가는 고속도로와 울산, 양산, 부산, 창원, 진주를 잇는 동남 공업벨트의 중심지로서 사통팔달의 최적 교통조건을 갖추고 있다. 또 남해바다 해양성기후의 영향을 받아, 화훼, 과수, 채소 등의 신선농산물 재배에도 최적이며 공항을 통해서 50분 거리의 후꾸오까와, 70분 거리에 있는 동경에 이들 농산물의 신속한 수출도 용이하다. 한편 김해시는 가락국의 가야문화권 중심도시로 국립김해박물과의 개관, 문화유적의 복원 등으로 관광도시의 면모도 갖추어 가고 있다. 김해시는 이러한 입지적 요건을 최대한 활용하여 다음과 같은 지역전략산업을 육성하여야 할 것이다. 첫째, 기존의 기계 자동차 금속산업은 지식집약형 기계산업(정밀의료기기 및 첨단 자동차부품포함)으로 특화하여야 할 것이다. 둘째, 화훼 및 농산물수출은 현대화된 재배시설 및 유통시설의 조성, 수출전문생산단지 조성, 대체에너지의 개발 등으로 수출경쟁력을 제고시켜야 할 것이다. 셋째, 기존 기계산업을 정보기술산업과 접목시키는 벤처기업의 육성으로 장기적으로는 하청구조의 산업구조톨 지양하고 기술개발을 통해 경쟁력있는 중소기업을 육성시켜야 할 것이다. 넷째, 유적, 화훼 등의 관광자원을 개발하여 부산과 제주도를 잇는 관광도시로 육성시켜야 할 것이다. 끝으로 인제대학의 특성화분야인 의생명공학을 중심으로 우리나라 최초의 헬씨어밸리(healthier valley)조성올 통해 생물 건강소재산업을 개발하는 것이 바람직 할 것이다. 이상의 특화산업들이 산업연관 효과를 가지고 조화있는 발전을 할 때 21세기의 경쟁력 있는 김해시 건설이 가능할 것이다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.17 no.4
• /
• pp.292-302
• /
• 2012

This paper reviews comparison analysis of current and latest application for stock identification methods of Todarodes pacificus, and the pros and cons of each method and consideration of how to compensate for each other. Todarodes pacificus which migrates wide areas in western North Pacific is important fishery resource ecologically and commercially. Todarodes pacificus is also considered as 'biological indicator' of ocean environmental changes. And changes in its short and long term catch and distribution area occur along with environmental changes. For example, while the catch of pollack, a cold water fish, has dramatically decreased until today after the climate regime shift in 1987/1988, the catch of Todarodes pacificus has been dramatically increased. Regarding the decrease in pollack catch, overfishing and climate changes were considered as the main causes, but there has been no definite reason until today. One of the reasons why there is no definite answer is related with no proper analysis about ecological and environmental aspects based on stock identification. Subpopulation is a group sharing the same gene pool through sexual reproduction process within limited boundaries having similar ecological characteristics. Each individual with same stock might be affected by different environment in temporal and spatial during the process of spawning, recruitment and then reproduction. Thereby, accurate stock analysis about the species can play an efficient alternative to comply with effective resource management and rapid changes. Four main stock analysis were applied to Todarodes pacificus: Morphologic Method, Ecological Method, Tagging Method, Genetic Method. Ecological method is studies for analysis of differences in spawning grounds by analysing the individual ecological change, distribution, migration status, parasitic state of parasite, kinds of parasite and parasite infection rate etc. Currently the method has been studying lively can identify the group in the similar environment. However It is difficult to know to identify the same genetic group in each other. Tagging Method is direct method. It can analyse cohort's migration, distribution and location of spawning, but it is very difficult to recapture tagged squids and hard to tag juveniles. Genetic method, which is for useful fishery resource stock analysis has provided the basic information regarding resource management study. Genetic method for stock analysis is determined according to markers' sensitivity and need to select high multiform of genetic markers. For stock identification, isozyme multiform has been used for genetic markers. Recently there is increase in use of makers with high range variability among DNA sequencing like mitochondria, microsatellite. Even the current morphologic method, tagging method and ecological method played important rolls through finding Todarodes pacificus' life cycle, migration route and changes in spawning grounds, it is still difficult to analyze the stock of Todarodes pacificus as those are distributed in difference seas. Lately, by taking advantages of each stock analysis method, more complicated method is being applied. If based on such analysis and genetic method for improvement are played, there will be much advance in management system for the resource fluctuation of Todarodes pacificus.

• Journal of Marine Life Science
• /
• v.4 no.1
• /
• pp.38-43
• /
• 2019

The deformity occurring at the early developmental stage of red spotted grouper (Epinephelus akaara) causes detrimental effects on the process of juvenile production. In this study, we have compared the expressions of several key genes (insulin like growth factor 1: IGF-1, bone morphogenic protein 4: BMP4, peroxisome proliferator-activated receptors γ: PPARγ, matrix Gla protein: MGP) for morphogenesis between normal and 2 types (cephalic and jaw) of deformed juvenile fish. Expression of these genes were investigated in the brain, liver and muscle of each group of fish (n=20) by real-time PCR. Expression of IGF-1 and BMP4 mRNA in the brain and liver showed significant difference between normal and deformed fish (p<0.05). However, no difference was observed in the expression of PPARγ and MGP mRNA between normal and deformed fish in any tissues. It seems certain that IGF-1 and BMP4 are associated with the state of deformity in juvenile red spotted grouper.