• Title/Summary/Keyword: Sharks

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Bycatch of sharks in Korean tuna longline fishery (한국다랑어연승어업에 있어서 상어류의 부수어획)

  • Moon, Dae-Yeon;Hwang, Seon-Jae;An, Doo-Hae;Kim, Soon-Song
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.43 no.4
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    • pp.329-338
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    • 2007
  • Data collected by on-board observers and from experimental surveys during 2004-2006 were analyzed to figure out the status of shark bycatch in Korean tuna longline fishery. Results obtained from 10 surveys indicated that 14, 13 and 1 species of shark were incidentally caught in Korean tuna longline fishery operated in the Pacific, Indian and Atlantic (Mediterranean) Ocean, respectively, and that shark bycatch accounted for about 29-31% of the total catch. Sharks brought aboard were processed in 3 ways; out of 1,127 sharks observed, 575 sharks (51.0%) were discarded after finning, 299 sharks (26.5%) were stored frozen after finning for future use and 253 sharks (22.4%) were released into the sea immediately after caught. The fin to body weight ratio of sharks was estimated to be about 4.7% which is similar to the guideline of 5% established by the international fisheries organizations. The underestimate of shark bycatch in Korean tuna longline fishery was significant because it was general practice that fishermen on-board did not count the discarded shark as a catch.

Distribution of the White Shark, Carcharodon carcharias and Other Sharks around the Korean Waters (한국 연근해 백상아리와 상어류의 분포)

  • Choi, Youn
    • Korean Journal of Ichthyology
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    • v.21 no.sup1
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    • pp.44-51
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    • 2009
  • Greate white sharks, Carcharodon carcharias, are found in almost all the temperate and tropical coastal waters around the world. There have been 19 appearances reported in Korean coastal waters since June 1996 and seven shark attacks have been reported. There are about 400 species of sharks in the world, and 41 species of them have been found in Korean coastal waters. Thirteen of them belong to the Carcharhinidae family, and five of them belong to the Squalidae family. Of these sharks, 15 species of them live off of the East coast, 18 species live off of the West coast, and the other 40 species are distributed around Jeju Island and the South coast. Eleven species of them, including the great white shark, live off of all the coastal waters of Korea.

Estimation of the Ratio of Fin Weight to Body Weight of Sharks for the Korean Tuna Longline Fishery in the Eastern Pacific Ocean (동부태평양 한국의 다랑어 연승어업에서 상어류 체중대비 지느러미 중량 비율 추정)

  • An, Doo-Hae;Kwon, You-Jung;Moon, Dae-Yeon;Hwang, Seon-Jae;Kim, Soon-Song
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.2
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    • pp.157-164
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    • 2009
  • The National Fisheries Research and Development Institute (NFRDI) conducted a circle hook experiment to compare the catch rates of target and bycatch species between J hook and circle hooks in the tuna longline fishery of the Eastern Pacific Ocean, which is located between $9^{\circ}13'S-1^{\circ}36'N$ and $126^{\circ}00'-138^{\circ}21'W$. Sampling was conducted from September 20 to October 23, in 2006. In this survey, we collected shark data to obtain the ratio of fin weight to body weight of sharks. Overall, 413 sharks belonging to 9 species were caught on 62,464 hooks. The total weight of the sharks caught was 11,093 kg. The ratio of wet fin weight to body round weight of sharks by species ranged from 3.7% to 7.7%, while the mean was 5.4%. The total ratio of wet fin weight to the dry fin weight of sharks ranged 0.38 to 0.70 and the mean value was 0.53. The ratio of dry fin weight to the body round weight of the sharks was estimated to be 2.86%.

Taxonomic System of Sharks (Chondrichthyes: Elasmobranchii) in Korean Waters (한국 해역의 상어류와 분류체계)

  • Jae-Goo Kim;Youn Choi
    • Korean Journal of Ichthyology
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    • v.36 no.1
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    • pp.84-93
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    • 2024
  • The sharks identified in the coastal waters of Korea are known to date to 9 Orders, 21 Families, 32 Genera and 47 Species. Therefore, recent studies and records of shark appearance in Korean waters were reviewed and organized. As a result, Halaelurus buergeri was separated from the Family Scyliorhinidae into the Family Pentanchidae based on the supraorbital crest absent on cranium above eyes. Accordingly, compared to the previous study, Family Pentanchidae, Genus Hexanchus, and 2 Species Hexanchus griseus and the Alopias superciliosus were added, resulting in a total of 49 species of sharks in 9 Orders, 22 Families, and 33 Genera in coastal waters of Korea. A list of these species, a search table, and the history of scientific name changes are provided, and proposed a new Korean name of 'Bul-beom-sang-eo-gwa' of the Family Pentanchidae.

Feasibility Study on the Ratification of 'Convention on the Conservation of Migratory Species of Wild Animals(CMS)' to Korea (우리나라의 「이동성 야생동물종의 보전에 관한 협약」 가입 여부에 대한 타당성 분석)

  • Park, Yong-Ha;Choi, Jaeyong
    • Journal of Environmental Impact Assessment
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    • v.18 no.2
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    • pp.111-122
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    • 2009
  • The impact of Korea's joining the Convention on the Conservation of Migratory Species of Wild Animals(CMS) was analyzed to examine its merits and faults as well as to discuss Korea's opportunities. Results of the analysis based on the agenda and decisions of the Conferences of the Parties, the parties performance, and other committees meetings over the last decades indicated that the affiliation of Korea into the CMS could provide various advantages and opportunities for Korea. First, Korea could upgrade its conservation activities regarding migratory species to the global aspects. Second, Korea could take initiatives for conservation of the migratory species in the Far East Asia. Third, Korea would have a better system in forecasting and problem-solving against the epidermic Avian Influenza through systematic cooperation with the CMS parties and other related international regimes. Finally, Korea will be in a better position to generate statistical data and to develop techniques to reduce the by-catches of the sharks and whales. Korea has already provided a fair and protective institutions for most of the migratory endangered species listed under Appendix I and II of the CMS. This implies that Korea may not require additional major changes to the basic acts and/or legislation. Joining the CMS may negatively impact on the fisheries and related businesses related to whales and sharks around the Ulsan and Pohang provinces. However, the obligation to protect whales and sharks demanded by the CMS is regarded as an acceptable article in Korea according to the analysis of the existing policies and scientific aspects. Nevertheless, if the joining the CMS should generate irreversible hardship for local people's livelihood and cultural aspects, Korea may ask for reservations on particular activities. Overall, we suggest that by joining the CMS, Korea could see various advantages and promotion in national policy.

An ecological risk assessment for the effect of the Korean tuna longline fishery in the Western and Central Pacific Ocean (중서부 태평양해역의 한국 다랑어 연승어업 영향에 대한 생태학적 위험도 평가)

  • Kwon, You-Jung;An, Doo-Hae;Moon, Dae-Yeon;Hwang, Seon-Jae;Lee, Jae-Bong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.1
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    • pp.22-33
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    • 2009
  • Ecological risk assessment(ERA), developed in Australia, can be used to estimate the risk of target, bycatch and protected species from the effects of fishing using limited data for stock assessment. In this study, we employed the ERA approach to estimate risks to tunas, billfishes, sharks, sea turtles and other species by the Korean tuna longline fishery in the Western and Central Pacific Ocean using productivity and susceptibility analyses of the ERA based on low(<1.30), medium(1.30-1.84) and high risk(>1.84). Albacore, bigeye, yellowfin, skipjack and bluefin tunas were generally evaluated in the medium risk. The susceptibility of tuna species, however, had higher risks than the productivity. Billfishes were also at medium risk, while sharks were at high risk by the tuna longline fishery. The risk of productivity was generally high, because most sharks caught by the tuna longline fishery have high longevities, i.e., over 10 years, including ovoviviparous species. Susceptibility, which is related with the selection of fishing gear, was also high, because the longline fishery has no gear modifications to prevent bycatch of protected species. Not only target tuna species were influenced by the tuna longline fishery in the Western and Central Pacific Ocean, but also nontarget species, such as pomfret, mackerels rays, sea turtle were done. Ecosystem-based fishery assessment tools, such as productivity and susceptibility analysis(PSA), have the ability to provide broad scientific advice to the policy makers and stakeholders.

Effect of the Gonadotropin-Releasing Hormone (GnRH) on Induction of Maturation in White-Spotted Bambooshark Chiloscyllium plagiosum (성 성숙 자극호르몬방출호르몬(GnRH) 투여를 이용한 백점얼룩상어 (Chiloscyllium plagiosum)의 성 성숙 유도에 관한 연구)

  • Ki-hyuk Kim;Ji-min Jeon;Hye-na Moon;Jin Namgung;In-kyu Yeo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.56 no.3
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    • pp.309-314
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    • 2023
  • Shark populations are constantly decreasing owing to environmental destruction and overfishing; thus, sharks are now at risk of extinction, with 30.5% of species classified as endangered on the International Union for Conservation of Nature's Red List. Sharks are apex predators and keystone species in balancing the marine food chain; their extinction would create an imbalance in the entire marine ecosystem. Assisted reproductive technology is a last resort for protecting animals facing extinction. Here, as a proactive effort toward building a hormone-induced artificial insemination protocol for endangered wild sharks, we identified the possibility of germ cell maturation by administration of GnRH, a commercially produced synthetic salmon gonadotropin-releasing hormone, and calculated its optimum dosage and injection timing. The experiment was conducted on one shark species, Chiloscyllium plagiosum. Injections were administered in 24 h intervals to C. plagiosum females, and 0.2 mL/kg+0.2 mL/kg were the optimal doses. These doses effectively induced maturation and, and ovulation, and oocyte release. Our results confirm that GnRH is a suitable tool for shark hormone-induced artificial insemination and indicate that this method may facilitate the conservation of endangered shark species.

An Overview of Korean Sharks Listed by the IUCN and CITES (IUCN과 CITES에 등재된 한국산 상어류의 현황)

  • Jeong, Choong-Hoon;Choi, Youn;Oh, Jeong-Kyu;Kim, Min-Seop;Jeong, Seung Jin
    • Korean Journal of Ichthyology
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    • v.28 no.2
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    • pp.125-133
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    • 2016
  • Sharks (Selachii) comprising about 510 valid species worldwide. Forty-three shark species belonging to 30 genera, 19 families and 8 orders have been found in Korean coastal waters, and all these are registered at the IUCN Red List as followings: endangered (EN) 1 species (2.3%) (vs. worldwide 15 spp., 3.2%), vulnerable (VU) 11 spp. (25.6%) (vs. 48 spp., 10.3%), near threatened (NT) 10 spp. (23.3%) (vs. 67 spp., 14.4%), least concern (LC) 9 spp. (20.9%) (vs. 115 spp., 24.7%), data deficient (DD) 12 spp. (27.9%) (vs. 209 spp., 44.9%), and critically endangered (CR) absent (vs. 11 spp., 2.4%). Twelve species among 43 sharks distributing in Korean waters are assessed as Threatened in the IUCN Red List categories and criteria as followings: Sphyrna lewini (EN, A2bd+4bd), Rhincodon typus (VU, A2bd+3d), Cetorhinus maximus (VU, A2ad+3d), Carcharodon carcharias (VU, A2cd+3cd), Isurus oxyrinchus (VU, A2abd+3bd+4abd), Alopias pelagicus (VU, A2d+4d), A. vulpinus (VU, A2bd+3bd+4bd), Carcharhinus plumbeus (VU, A2bd+4bd), S. zygaena (VU, A2bd+3bd+4bd), Squalus suckleyi (VU, A2bd+3bd+4bd), Squatina japonica (VU, A2d+4d), and S. nebulosa (VU, A2d+4d). Eighteen chondrichthyan species are registered in the list of the CITES Appendices, among them five sharks are distributing in Korean waters as Appendix II, i.e., R. typus, C. maximus, C. carcharias, S. lewini and S. zygaena. The scientific name of "Gobsangeo" has been changed from Squalus acanthias of the North Pacific to S. suckleyi, and "Mojorisangeo" from S. megalops of the Northwest Pacific to brevirostris.

Estimation of the Impact of the Inclusion of Sharks in the Appendices of the 'Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)' on Korean Fisheries and Recommendations of the Domestic Measures on the Trade of the Listed Shark Species ('멸종위기에 처한 야생 동식물의 국제거래에 관한 협약'의 상어류 등재가 한국 수산업에 끼칠 영향과 대응 전략)

  • Sohn, Hawsun;An, Du Hae;Kim, Doo Nam;Lee, Sung Il;Park, Kyum Joon
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.6
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    • pp.1278-1295
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    • 2014
  • The Sixteenth Meeting of the Conferences of Parties of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which was held in March 2013 in Bangkok, Thailand, listed five shark species and one genus, and uplisted one sawfish species. All new species listings will be come into force of the eighteen months delay, on the fourteenth of September, 2014. The purpose of the delay is to support the preparation of the domestic measures on shark trade by the parties, as there has been no previous experience in trading the commercially exploited aquatic species in the CITES. The CITES Secretary-General has visited several potential shark trade countries to encourage and facilitate the implementation of the new CITES listings. The newly listed sharks have been caught as a target or non-target species by Korean distant water fisheries and introduced into Korea. So the establishment or change of the domestic laws, regulations, and measures for the implementation of the new CITES species must be prepared before the effective entry date. This paper is prepared to assess the effects of the trade of the CITES listed shark species, and to suggest effective government service measures for the management of Korean distant water fisheries. The Ministry of Environment (MOE) is the general Management Authority of the CITES, and the Ministry of Food and Drug Safety (MFDS) is in charge of the medical trade of CITES listed species in Korea. By law, all imported medicines and medical materials must be inspected by the MFDS during the customs examination; this kind of authority sharing is reasonable and effective way of providing government service. Similarly, the designation of new CITES Management Authority for the trade of commercially exploited aquatic CITES species is critical and the Ministry of Oceans and Fisheries (MOF), which is now in charge of the trade of fisheries products, is the most appropriate governing body for this purpose in Korea. The revision of the National Plan of Action for Conservation and Management of Sharks, initially submitted to the Food and Agriculture Organization (FAO) of the United Nations in 2011 as a practical guideline for shark conservation in all Korean fisheries, could be a effective measure to achieve unification of conservation of endangered species and sustainable use of fisheries stocks. The proper CITES measures for the trade of listed species, such as the establishment of the documenting system for Non-detriment Findings, domestic measures suitable for the "Introduction from the Sea" clause, species specific Harmonized System Codes for the customs service, and an effective shark catch data reporting system should be in place prior to the fourteenth of September 2014.

Biological Characteristics of Skates(Elasmobranchii: Rajidae)

  • Nakabo, Tetsuji
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.463-464
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    • 2000
  • Skates are one of the most favorite food fishes for Korean people. It is, I think, important to know the biological characteristics of skates for protecting the fishes from the extinction caused by overfishing. Femily Rajidae encompasses about 200 species which is one fourth of elasmobranch fishes, and 11 species known from the Korean waters. But, very few biological characteristics of skates have been known Some of them are shown here and discussed comparing with those of other elasmobranch fishes (sharks and rays) and teleost fishes. (omitted)

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