• Title/Summary/Keyword: Fisheries resources

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Age and growth of the black rockfish, Sebastes inermis, in the Jeonnam marine ranching area in the southern Sea of Korea (한국 남해 전남바다목장해역 볼락, Sebastes inermis의 연령과 성장)

  • Kim, Hee-Yong;Kim, Sang-Hwa;Huh, Sun-Jung;Seo, Young-Il;Lee, Sun-Gil;Ko, Jun-Chul;Cha, Hyung-Kee;Choi, Mun-Sung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.4
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    • pp.346-357
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    • 2010
  • Characteristics of age and growth of the black rockfish, Sebastes inermis sampled in the Jeonnam Marine Ranching Area (JMRA) around Geumo Islands south of Yeosu were investigated using 642 otoliths from March 2009 to February 2010. The opaque zone was formed in September once a year and hence it was used as an annulus. The parturient period was December to January, and therefore the duration from fertilization to the complete formation of the opaque zone was nineteen months. From the parameters calculated using the average length when the year ring was formed, growth of S. inermis were expressed by von Bertalanffy growth equation as $L_t$=23.267 ($1-e^{-0.4406(t+1.1971)}$) for females and $L_t$=22.030 ($1-e^{-0.5312(t+0.6834)}$) for males when is total length in age t. Through the growth equations, the maximum length was determined as 23.27cm for females and 22.03cm for males and the growth factor as 0.4406/yr and 0.5312/yr, respectively. Finally, the growth of female S. inermis is larger than the one of male S. inermis.

Feeding Habits of Yellow Goose Fish Lophius litulon and John Dory Zeus faber in the South Sea of Korea

  • Choi, Jung-Hwa;Sung, Bong-Jun;Lee, Dong-Woo;Kim, Jong-Bin;Oh, Taeck-Yun;Kim, Jung-Nyun
    • Fisheries and Aquatic Sciences
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    • v.14 no.4
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    • pp.435-441
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    • 2011
  • The feeding habits of yellow goosefish Lophius litulon and John Dory Zeus faber were studied by analyzing the stomach contents of specimens collected in the South Sea of Korea. In total, 132 hauls were taken during six experimental trawl survey (Tamgu 1) cruises conducted on a seasonal basis (March 2005-October 2007). The main prey items of the two species were similar. Fishes and crustaceans were the most important prey, with neither species showing ontogenetic changes in preferred species. Specifically, Pennahia argentata was the preferred prey item of L. litulon, whereas Trichiurus lepturus and Engraulis japonicus were preferred by Z. faber. Larger Z. faber (>24 cm) preferred bigger prey such as T. lepturus and Larimichthys polyactis, while smaller Z. faber preferred E. japonicus and Acropoma japonicum.

Diet Composition of Whitespotted Conger Conger myriaster in the South Sea of Korea (한국 남해에 출현하는 붕장어(Conger myriaster)의 위내용물 조성)

  • Jun Hyoung Jo;Jae Mook Jeong;Jung Nyun Kim;Jeong Hoon Lee;Hawsun Sohn;Hyeon Ji Kim
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.57 no.4
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    • pp.423-428
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    • 2024
  • The diet composition of the whitespotted conger Conger myriaster was analyzed using 1,047 specimens collected from the coastal waters of the South Sea of Korea. Specimens sizes ranged from 11.4 to 46.8 cm in anal length. C. myriaster mainly fed on Engraulis japonicus (Pisces index of relative importance 82.1%). The dietary composition of C. myriaster did not differ significantly across size classes. As the body size of C. myriaster increased the mean weight of prey within the stomach (mW/ST) also increased (one-way ANOVA, P<0.05).

Fishing characters of skate ray, Raja pulchra by the offshore longline fishery in Heuksan-do, Korea (흑산도 근해연승어업의 참홍어 (Raja pulchra) 어획 특성)

  • Jo, Hyun-Su;Hwang, Hak-Jin;Kwon, Dae-Hyeon;Jeong, Gyeong-Suk;Choi, Kang-Ho;Cha, Byung-Yeul;Im, Yang-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.4
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    • pp.403-410
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    • 2011
  • Catches, CPUE, fishing season, disc width composition and fishing ground were studied to rebuild skate ray, Raja pulchra resource by the offshore longline fishery in Heuksan-do, Korea. Annual catches and CPUE of skate ray were increased from 2003 to 2010 (CPUE: from 2007 to 2010) continuously. The main fishing season of the skate ray was from December to next May. Disc width at 50% maturity for Raja pulchra by sex were estimated to be 65.83cm, 57.01cm by female and male respectively. The range of disc width was 22.3-112.0cm and the average disc width was 66.9cm, 60.0cm by female and male of Raja pulchra respectively during 2007-2010. Annual average of disc width of female skate ray was decreased from 2007 to 2010. The fishing grounds were formed from the coastal water off Hong-do to the coastal water off Gyeogyeolbiyeol-do, Korea. The center of fishing ground in October was formed in the northwestern coastal water off Gyeogyeolbiyeol-do and separated from that of the other months.

Distribution characteristics of egg and ichthyoplankton in the Cheonsu Bay, Korea (천수만 주변해역에 출현하는 부유성 어란 및 자치어의 분포특성)

  • Byoung il, YOUN;Dong hyuk, CHOI;Yoon seok, CHOI;Seung Hwan, LEE;Dae hyeon, KWON;Maeng jin, KIM
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.4
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    • pp.326-333
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    • 2022
  • To provide information needed for managing fish resources and protecting the ecosystem of Cheonsu Bay, bimonthly variations in species composition and abundance of fish eggs and larvae were investigated. The samples were collected by using bongo net at three different stations from February 2020 to December 2021. Fish eggs were divided into Engrualis japonicas and unidentified eggs, of which Engragulis japonicus accounted for 85.6% of the total eggs collected. A total of 21 species representing 17 families and 6 orders were collected. The three dominant species were Gobiidae spp, Thryssa hamiltonii and E. japonicus and these three species accounted for 74.1% in the total number of individuals. The number of species was highest in August, 2020 and lowest in February, 2020 and 2021; the number of individuals was highest in August, 2020 and lowest in February, 2020. Temporal changes in the abundances of pelagic eggs and larval fishes corresponded with temperature.

Development of artificial spawning seaweeds of the sandfish, Arctoscopus japonicus (도루묵, Arctoscopus japonicus의 산란용 조림초 개발)

  • Yang, Jae-Hyeong;Lee, Sung-Il;Bae, Bong Seong;Cha, Hyung-Kee;Yoon, Sang-Chul;Chun, Young-Yull;Kim, Jong-Bin;Chang, Dae-Soo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.4
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    • pp.234-242
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    • 2009
  • To develop the artificial spawning seaweeds of the sandfish, Arctoscopus japonicus, the effects by the material type of artificial spawning seaweeds were investigated at Dongsan port in Gangwon-do from December 2006 to March 2007. Sargassum fulvellum, S. horneri, rope and net were used as materials for artificial spawning seaweeds, and the most effective thing among them was S. fulvellum. A. japonicus began to attach the egg mass to artificial spawning seaweeds when sea temperature dropped below 10${^{\circ}C}$ in December, spawned heavily when it was around 8${^{\circ}C}$ in January, and completed the behavior when it started to increase over 10${^{\circ}C}$ in February. The hatching period of eggs was estimated to be about 60 days. The middle position in artificial spawning seaweed had the highest number of egg masses and the diameter of the egg mass ranged from 25mm to 62mm. Based on the result for the effects, the artificial spawning seaweeds of A. japonicus were developed and it is possible to use them to form seaweed forests or spawning grounds of other species.

Seasonal variation of fisheries resources composition in the coastal ecosystem of the middle Yellow Sea of Korea (서해 중부 연안생태계 수산자원의 종조성과 계절변동)

  • Lee, Jae-Bong;Lee, Jong-Hee;Shin, Young-Jae;Zhang, Chang-Ik;Cha, Hyung-Kee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.2
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    • pp.126-138
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    • 2010
  • To investigate seasonal variation of fisheries resources composition and their correlationships with environmental factors in the coastal ecosystem of the middle Yellow Sea of Korea, shrimp beam trawl were carried out for the fisheries survey. Fisheries resources of 81 species, 57 families, and 6 taxa totally were collected by shrimp beam trawl in the middle coastal ecosystem of Yellow Sea of Korea. Species were included 6 species in Bivalvia, 6 in Cephalopoda, 22 in Crustacea, 2 in Echinodermata, 5 in Gastropoda, and 40 in Pisces. Diversity indices (Shannon index, H') showed seasonal variation with low value of 2.14 in winter, and high value of 2.67 in spring. Main dominant species were Oratosquilla oratoria, Octopus ocellatus, Acanthogobius lactipes, Cynoglossus joyneri, Rapana venosa venosa, Loligo beka, Chaeturichthys stigmatias, Raja kenojei, Microstomus achne and Paralichthys olivaceus, that were occupied over 58% of total individuals, and 55% of wet weight. Fisheries organism made four coordinative seasonal groups by the principal component analysis (PCA), showing stronger seasonal variation than spatial variation. PC from PCA showed statistically significant cross-correlationships with seawater temperature, $NH_4$-N, TP and chlorophyll a (P < 0.05).

Two New Records of Crangonid Shrimps (Crustacea: Decapoda: Caridea) in Korean Waters

  • Kim, Jung-Nyun;Choi, Jung-Hwa;Choi, Kwang-Ho;Kim, Sung-Tae;Chang, Dae-Soo
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.3
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    • pp.265-268
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    • 2008
  • Two crangonid shrimps, Paracrangon abei Kubo, 1937 and Pontocaris sibogae (De Man, 1918), collected from the northeastern and southeastern waters of Jeju Island, are newly recorded into the Korean fauna. The former is the second species and the latter is the only species of each genus recorded in Korea. Morphological and distributional accounts of these two species are briefly discussed.

Seasonal Variations of Fisheries Resources Composition in the Coastal Ecosystem of the Yongil Bay, Korea (한국 영일만에서 수산자원 종조성과 계절변동)

  • Lee, Jae Bong;Shin, Young Jae;Lee, Soo Jeong;Lee, Jong Hee;Choi, Young Min;Lee, Dong Woo;Kim, Sang Woo;Yang, Jae Hyeong
    • Journal of Environmental Science International
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    • v.21 no.10
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    • pp.1275-1286
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    • 2012
  • Coastal marine ecosystem plays important role of spawning and nursery grounds for fisheries resources. Yongil Bay is one of major coastal marine ecosystems, which is located in the southwestern East Sea of Korea. Species composition and abundance of marine organism in the Yongil Bay were investigated by season from March to November 2009. Gill net and pot fisheries were used for survey of pelagic and demersal species composition, and collected 106 species, 67 families, and 7 taxa of fisheries resources from the coastal ecosystem. Species were included 2 species in Ascidiacea, 2 species in Bivalvia, 6 in Cephalopoda, 22 in Crustacea, 5 in Echinodermata, 12 in Gastropoda, and 57 in Pisces. Diversity indices (Shannon index, H') showed seasonal variation with low value of 2.11 in winter, and high value of 2.63 in autumn. Main dominant species were Asterias amurensis, Pleuronectes yokohamae, Siphonalia spadicea fuscolineata, Trachurus japonicas, Sillago japonica, Conger myriaster, Volutharpa ampullaceal, Engraulis japonicus, Asterina pectinifera, and Portunus (Portunus) sanguinolentus that were occupied over 71.5% of total individuals, and 52.9% of wet weight. Seasonal variations of fisheries resources composition were discussed on correlationships with those of environmental factors in the coastal ecosystem of the Yongil Bay in Korea. Those results from this study will provide scientific data and information to develop the ecosystem-based coastal fisheries assessment and management system in Korea.

A study on the variation of the Korean marine ecosystem through biodiversity attributes (생물다양성 특성 분석을 통한 우리나라 주변 해양생태계 변화 연구)

  • Jong Hee LEE;Young Il SEO;Sang Chul YOON;Heejoong KANG;Ji-Hoon CHOI;Min-Je CHOI;Jinwoo GIM
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.4
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    • pp.315-327
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    • 2023
  • In the last five decades, there has been a consistent decline in the total catch of fisheries in the Korean jurisdiction since the peak in 1986. The decline in catch slowed and slightly rebounded in the 2000s, but changed back to a decline in the 2010s. As indicators that can identify changes in the marine ecosystem, trophic level (TL), biodiversity index (H'), and the ratio between pelagic fish and demersal fish (P/D) were analyzed by each local marine ecosystem. There were some different changes in each local marine ecosystem, but the mean TL and H' decreased and P/D increased in general in Korean waters. Demersal fish, which were dominant in the 1970s and 1980s, declined, and small pelagic fish and cephalopods have dominantly changed since the 1990s. However, these changes are not simple, and they are fluctuating in complex ways relating to each marine ecosystem and the timing. It is believed that changes in marine ecosystems in Korean waters are likely caused by a combination of fisheries and climate change. The ecosystem indicators reflected a change in the total catch, a sharp drop in catch of demersal fish, and increasing catch of pelagic fish since the mid-1980s.