• Title/Summary/Keyword: Marine mammals

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A Study on a Fisheries Management system of united nations convention on the law of the sea (국제 해양법상의 어업 관리 제도에 관한 연구)

  • 이봉우
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.1
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    • pp.165-168
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    • 1998
  • United nations convention on the law of the sea was actopted by third united nations conference on the law of the sea in 1982. and it came in to force on Novemver 1966. It involves exclusive economic zone, highly migrated species, marine mammals, anadromous stocks and high seas. in this paper, I analyze these issues, especially EEZ and high seas.

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International community's efforts to mitigate sea turtle bycatch and status of implementing relevant measures by Korean tuna longline fishery

  • Mi Kyung Lee;Youjung Kwon;Jung-hyun Lim;Youngsin Ha;Doo Nam Kim
    • Fisheries and Aquatic Sciences
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    • v.25 no.12
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    • pp.589-600
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    • 2022
  • Longline fishery targeting tunas and tuna-like species is known to produce a significant amount of catch not only for the target species, but also for ecologically related species like sharks, marine turtles, sea birds and marine mammals. Recognizing this seriousness, tuna related regional fisheries management organizations (t-RFMOs) have established conservation and management measures (CMMs) to reduce bycatch and/or interaction with ecosystem vulnerable species including sea turtles and are obliged to implement bycatch mitigation measures and guidelines on safe release to their member countries. Along with development and strengthening of those measures, various case studies have been conducting to verify the effectiveness of bycatch mitigation for ecologically related species. This study examines the background and progress on developing CMMs of t-RFMOs and regulation programs of the United States related to sea turtles, which have recently become one of the main issues, and reviews case studies on sea turtle bycatch mitigation measures to find out the effectiveness of reducing bycatch rate and impacts to the fisheries. In order to respond the consultation process on certification determination with the United States, it was confirmed the current status of implementation on related measures conducted by Korean tuna longline fishery based on scientific observer data and survey for captains. Even though all Korean tuna longline fleets belong to the deep-set longline fishery (100-300m), which is not subject to the obligation of those mitigation measures, they are voluntarily implementing both measures, use of circle hook and whole finfish bait, regardless of which RFMO's Convention area they operate. And the national regulatory and management programs for sea turtle bycatch prevention adopted by Republic of Korea seems to be comparable in effectiveness to that of the United Stated. However, Korea needs to take preemptive measures in establishing sustainable fisheries, including the protection of the marine ecosystem and environment, as stronger requests are anticipated to be made by the international community on this matter.

Molecular Phylogenetic Analyses of Scyliorhinus torazame (Carcharhiniformes) Inferred from Cu,Zn Superoxide Dismutase (두툽상어(Scyliorhinus torazame) Cu,Zn-SOD의 분자 계통학적 분석)

  • Kim, Keun-Yong;Nam, Yoon Kwon
    • Korean Journal of Ichthyology
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    • v.18 no.4
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    • pp.293-299
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    • 2006
  • Copper,zinc superoxide dismutase (Cu,Zn-SOD) plays a key role to the first antioxidant defense system against oxidative stress in diverse aerobic organisms. Due to the housekeeping action of Cu,Zn-SOD, it was reported that the structure and function have been conserved during evolution. In this study Cu,Zn-SOD from cloudy catshark Scyliorhinus torazame was subjected to phylogenetic analyses to know its evolutionary relationship in the vertebrate lineage. Molecular phylogenetic trees inferred by NJ, MP, ML and/or Bayesian analyses showed two shark species, Prionace glauca and S. torazame grouped together with high statistical supports. In general, they placed at the separated position from bony vertebrates. Thereafter, bony vertebrates composed of teleosts and birds/mammals (amniotes) formed a monophyletic group. Each teleost and amniote clade was also supported by relatively high statistical values. These phylogenetic relationships are well congruent with the phylogenetic hypothesis of the ancestral position of cartilaginous fishes to bony vertebrates.

Classification of bearded seals signal based on convolutional neural network (Convolutional neural network 기법을 이용한 턱수염물범 신호 판별)

  • Kim, Ji Seop;Yoon, Young Geul;Han, Dong-Gyun;La, Hyoung Sul;Choi, Jee Woong
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.2
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    • pp.235-241
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    • 2022
  • Several studies using Convolutional Neural Network (CNN) have been conducted to detect and classify the sounds of marine mammals in underwater acoustic data collected through passive acoustic monitoring. In this study, the possibility of automatic classification of bearded seal sounds was confirmed using a CNN model based on the underwater acoustic spectrogram images collected from August 2017 to August 2018 in East Siberian Sea. When only the clear seal sound was used as training dataset, overfitting due to memorization was occurred. By evaluating the entire training data by replacing some training data with data containing noise, it was confirmed that overfitting was prevented as the model was generalized more than before with accuracy (0.9743), precision (0.9783), recall (0.9520). As a result, the performance of the classification model for bearded seals signal has improved when the noise was included in the training data.

An Analysis on the Characteristics and Compilation Purpose of Japanese Useful Fisheries Classification Table (「일본유용수산분류표」의 특징과 편찬 목적에 대한 분석)

  • Kyung-Soon Seo;Kun-Woo Rhee
    • The Journal of Fisheries Business Administration
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    • v.54 no.3
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    • pp.69-92
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    • 2023
  • The 'Japanese Useful Fisheries Classification Table', published in advance before the publication of the "Useful Fisheries of Japan", is the first data to classify and introduce fisheries animals and plants in a single table. Therefore, it had received public attention immediately. However, The academy of animal studies at that time quickly pointed out that this classification table was a mixture of traditional and modern classifications, and that there were too many errors. However, Yoshio Tanaka, who was in charge of revising Yamamoto Arikatana, that wrote the classification table, was not an adherent of traditional taxonomy, nor was he ignorant of modern taxonomy. Nevertheless, the classification table, which was quite different from the well-known zoological classification at that time, was prepared. For example, the top classifications of marine organism are not at the same level, but rather a mixture of phylum and class, while the water insect contains several phylums, including Arthropoda, Echinodermata, Mollusca, and Coelenterata. As such, the method of classification of animals in the classification table was hard to understand in the zoological academy at that time. The reason for this unusual taxonomy was that the classification table showed classification of useful fisheries products, not intended to convey academic classification. In other words, it is not for the purpose of academic classification of all fishery products, but for the purpose of presenting standards that can be easily understood by those engaged in the collection, manufacture, and aquaculture of fishery products. This principle of 'Useful Fisheries of Japan' is also ascertained in the "Fishing Methods of Japan" and "Fishery Products of Japan". Regarding the collection and processing of marine products, it could have shown how to catch whales, which are mammals, and how to dismantle whales and obtain oil and meat, according to academic classifications. However, the first appearances in the book include dried squid, abalone, shark fins, and sea cucumbers. In other words, the most important fishery products at that time are presented first. The contents of the classification table, which is considered somewhat bizarre, show where the purpose to compile Useful Fisheries of Japan.

Radiocarbon for Studies of Organic Matter Cycling in the Ocean (방사성탄소를 이용한 해양 유기탄소 순환 연구 동향)

  • Hwang, Jeomshik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.3
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    • pp.189-201
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    • 2012
  • Radiocarbon is a powerful tool for studies of carbon cycling in the ocean. Development of measurement technology of accelerator mass spectrometry has enabled researchers to measure radiocarbon even in specific compounds. In this paper, a brief introduction on radiocarbon measurement and reporting of radiocarbon data is provided. Researches that used radiocarbon measurements on bulk organic matter, organic compound classes, and specific organic compounds are reviewed. Examples include works to understand the cycling of particulate and dissolved organic matter, biochemical composition of particulate organic matter, post-depositional transport of sedimentary organic matter, selective incorporation of fresh organic matter by benthic organisms, chemoautotrophy by archaea, and sources of halogenated chemical compounds found in marine mammals.

A report of 12 unrecorded prokaryotic species isolated from gastrointestinal tracts and feces of various endangered animals in Korea

  • Kim, Pil Soo;Lee, Ki-Eun;Tak, Euon Jung;Kang, Myung-Suk;Bae, Jin-Woo
    • Journal of Species Research
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    • v.9 no.1
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    • pp.35-45
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    • 2020
  • In 2016 and 2017, as part of a comprehensive investigation to identify the prokaryotic species in Korea, a total of 12 bacterial strains were isolated from the gastrointestinal tract and/or fecal samples of four endangered species, including reptile, bird, and marine and terrestrial mammals. Phylogenetic analysis with the 16S rRNA gene sequence was used to assign these strains to the phyla, Firmicutes, Actinobacteria or Proteobacteria. Furthermore, most of the strains Firmicutes belonged to the order Lactobacillales. Interestingly, 12 of the isolated strains have not been previously reported from the Korean Peninsula. Also, based on their high 16S rRNA gene sequence similarities(>98.7%) and formation of strong monophyletic clades with the closest type species, each isolated strain of isolates was assigned to an independent, predefined bacterial species. Gram-stain reaction, colony and cell morphology, biochemical characteristics, isolation source, and NIBR IDs are described in the species description section.

Anisakiasis Involving the Oral Mucosa

  • Choi, Sang Kyu;Kim, Cheol Keun;Kim, Soon Heum;Jo, Dong In
    • Archives of Craniofacial Surgery
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    • v.18 no.4
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    • pp.261-263
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    • 2017
  • Anisakis is a parasite with life cycles involving fish and marine mammals. Human infection, anisakiasis, occurs with the ingestion of raw infected seafood and usually presents with acute or chronic gastrointestinal symptoms from esophageal or gastric invasion. We report a rare caseinvolving the oral cavity. A 39-year-old male presented with oral and sub-sternal pain of one day duration after eating raw cuttlefish. Physical examination revealed areas of erythema and edema with a central white foreign particle on the labial and buccal mucosa. With microscopic field we could remove the foreign material from the lesions. The foreign material was confirmed to be Anisakis. Anisakis was also removed from the esophagus by esophagogastroduodenoscopy. The patient was discharged the following day without complication. Anisakiasis is frequently reported in Korea and Japan, countries where raw seafood ingestion is popular. The symptoms of acute anisakiasis include pain, nausea, and vomiting and usually begin 2-12 hours after ingestion. The differential diagnosis includes food poisoning, acute gastritis, and acute pancreatitis. A history of raw seafood ingestion is important to the diagnosis of anisakiasis. Treatment is complete removal of the Anisakis to relieve acute symptoms and prevent chronic granulomatous inflammation.

Microphallus koreana n. sp. (Trematoda: Microphallidae) Transmitted by a Marine Crab, Macrophthalmus dilatatus

  • Guk, Sang-Mee;Chai, Jong-Yil;Sohn, Woon-Mok;Kim, You-Me;Sim, Seo-Bo;Seo, Min
    • Parasites, Hosts and Diseases
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    • v.46 no.3
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    • pp.165-169
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    • 2008
  • Microphallus species occur primarily as intestinal parasites of birds and mammals, and metacercariae of a new species belonging to this genus have been discovered from the crab, Macrophthalmus dilatatus, in the Republic of Korea. The metacercaria of this fluke was round with 2 thick walls, and the excysted one had mature genital organs. The adult flukes recovered from experimentally infected chicks had numerous intrauterine eggs, well-developed pars prostatica, widely bifurcating ceca, and prominent uterine bulge. After observing internal structures, it was concluded that this species is different from any other known Microphallus spp. Based on the morphology of metacercariae and adult flukes, we describe this specimen as a new species, Microphallus koreana n. sp.

Production and bioactivity of recombinant tilapia IL-$1\beta$

  • Hong, Su-Hee
    • Journal of fish pathology
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    • v.22 no.2
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    • pp.147-153
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    • 2009
  • To study the biological activity of interleukin-$1\beta$(IL-$1\beta$), a proinflammatory cytokine, in nile tilapia, Oreochromis niliticus, the recombinant tilapia IL-$1\beta$ was produced in E. coli cells based on pQE vector. Ni-NTA (nitriloacetic acid) metal affinity chromatography was used to purify recombinant protein. The eluted fractions exhibited a single band of protein with a molecular weight of about 25kDa, which is in close agreement with 25.4 kDa predicted by the cDNA sequence. The biological activity of the purified recombinant tilapia IL-$1\beta$ was tested through its effects on IL-$1\beta$ gene expression, which are known as IL-$1\beta$ inducible genes in mammals and fishes. IL-$1\beta$ gene expression induced by poly I:C, a synthetic double stranded RNA, was also assessed in tilapia head kidney cells. IL-$1\beta$ gene expression was analysed using QPCR (quantitative polymerase chain reaction). The ratio of the indicated gene expression was expressed as the relative mRNA level to $\beta$-actin mRNA level, which is constitutively expressed in macrophages. Consequently, head kidney cells incubated for three hours with rIL-$1\beta$(10, 2, 1 $\mu{g}$/ml) showed a dose dependent increase in IL-$1\beta$ mRNA levels and 1 $\mu{g}$/ml of poly I:C was also able to induce IL-$1\beta$ gene expression in head kidney in tilapia.