• Title/Summary/Keyword: coastal fish

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Dynamic Behavior of a Moored Floating Fish Farm in Ocean Waves

  • Matsubara, Yuhei
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1992.08a
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    • pp.126-129
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    • 1992
  • The most of nearshore areas along the coastline of the Sea of Japan are not blessed with the gulfs or natural reefs. So in those areas so many kinds of man-made Fish Aggregation Devices (FADs) and artificial aquatic habitats have been submerged to cultivate and proliferate the aquatic resources. However, to utilize the ocean space furthermore effectively, the technology of offshore aqua-culture must be developed by coastal engineers and oceanographers.(omitted)

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Overfishing and recent risk for collapse of fishery in coastal Mediterranean lagoon ecosystem (Karavasta lagoon, southeastern Adriatic sea)

  • Spase Shumka;Yukio Nagahama;Sarjmir Hoxha;Koji Asano
    • Fisheries and Aquatic Sciences
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    • v.26 no.4
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    • pp.294-303
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    • 2023
  • Beside that the fish species and their sub-populations are highly important as a keystone species in the coastal and marine ecosystem, there are very few studies on their presence, distribution and temporal variations within and around the lagoon ecosystems in Albania. This paper provides an updated review on the life cycle, fishery, exploitation state and management of the main species that are subject of commercial fishing in the Karavasta lagoon, southeastern Adriatic coast of Albania. Due to the fact that lagoons represent a continuum between continental and marine aquatic ecosystems they play a crucial role in species life cycles. Further on in the circumstances of rapid utilizations and environmental changes, anomalies in salinity and temperatures, accelerated anthropogenic influences their rate of vulnerability is highly increased. Following the requirements of the Water Framework Directive, transitional water, coastal lagoons and estuaries there is a need for urgent monitoring and management approaches. The commercial species include: European eel (Anguilla anguilla), species of Family Mugilidae (Mugil cephalus, Liza ramada, Liza salienes and Chelon labrosus), Seabream (Sparus aurata), Seabass (Dincentrarchus labrax), etc. Fish productivity is oscillating from maximum value of 61.95 kg/ha is recorded in period of 1975-80 and lower value of 31 kg/ha in year 2020. Our study highlights importance of fish and fishery long-term monitoring, and contributes to understand the driving factors in productivity, migration patterns and species ecology in the vital coastal ecosystems.

Differentially Expressed Genes in Marine Medaka Fish (Oryzias javanicus) Exposed to Cadmium

  • Woo, Seon-Ock;Son, Sung-Hee;Park, Hong-Seog;Vulpe, Chris D.;Ryu, Jae-Chun;Yum, Seung-Shic
    • Molecular & Cellular Toxicology
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    • v.4 no.4
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    • pp.293-299
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    • 2008
  • To screen the differentially expressed genes in cadmuim-exposed marine medaka fish (Oryzias javanicus), a candidate marine test fish for ecological toxicity, the differential display polymerase chain reaction (DD-PCR) was carried out, since the genome-wide gene expression data are not available in this fish species yet. A total of 35 clones were isolated from cadmium-exposed fish and their nucleotide sequences were analyzed. The differentially expressed gene candidates were categorized to response to stimulus (3); ion binding (3); DNA binding (1); protein binding (6); carbohydrate binding (1); metabolic process (4); biological regulation (3); cellular process (2); protein synthesis (2); catalytic activity (2); sense of sight (1); immune (1); neurohormone (1); signaling activity (1); electron carrier activity (1) and others (3). For real-time quantitative RT-PCR, we selected catalase, glucose-6-phosphate dehydrogenase, heat shock protein 70, and metallothionein and confirmed that cadmium exposure enhanced induction of these four genes.

Game Theory and a Study on Fishery Co-operation System in the Seas Surrounding Korea (게임이론과 한반도를 둘러싼 수산자원의 협력적 관리체계에 관한 연구)

  • Kang, Joon-Suk
    • The Journal of Fisheries Business Administration
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    • v.49 no.3
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    • pp.49-65
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    • 2018
  • The main purpose of this study is to explain fishery relation in the seas surrounding Korea and how the Prisoner's Dilemma (PD), within game theory is applied to the region and suggest possible co-operative approaches in the region. The seas surrounding Korea are very productive fishing grounds with abundant fisheries resources because of the favourable marine environment, including its geographical features and physical oceanography. Nevertheless, Fishery relations among the coastal states in the region have been historically characterized by conflict rather than co-operation. Based on the PD game where there is always an incentive to do better by not co-operating, in order to ensure a share of the short-run benefits, fishing countries in the region have so far pursued the non-co-operative strategy of 'don't fish responsibly' rather than the co-operative strategy of 'fish responsibly'. Considering rapidly deteriorating situations in terms of fishery resources, regional co-operation among coastal states is urgently required to eliminate overfishing and increase fish stocks to sustainable levels. The West Sea/East China Sea and the East Sea, semi-enclosed seas, have unitary ecosystems, and many migratory fish species are shared between coastal states. Therefore, one countries' efforts alone cannot effectively manage and conserve the fishery resources and close co-operation among coastal states is required. The 1982 UN Convention and other international instruments emphasize the role of RFOs in managing and conserving capture fisheries and encourage states to establish Regional Fishery organizations (RFOs) or strengthen existing RFOs to facilitate conservation and management for fish stocks. Therefore, an international regime is worthy of serious consideration in that it provides fundamental advantages for the conservation of fish stocks for the fishery characteristic of the region.

Distribution of ichthyoplankton in the West coastal waters of Korea (서해연안 해역에 분포하는 부유성 난 및 자치어의 분포특성)

  • YOUN, Byoung-Il;LEE, Seung-Jong;SOHN, Myoung-Ho;HAN, Song-hun;LEE, Hyung-been;KIM, Maeng-jin;HAN, Kyung-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.3
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    • pp.243-251
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    • 2019
  • The ichthyoplanktons were sampled by Bongo net to study the distribution of the eggs and larvae in the West coastal waters of Korea during the study period (February, May, August and October of 2017). Collected fish eggs were divided into Engraulis japonicus and unidentified species. The most dominant species, Engraulis japonicus accounted for 79.52% of the total fish egg, which was followed by unidentified species (20.48%). The total of 36 taxa in fish larvae were identified based on morphological and molecular characteristics. Fish larvae were dominant by Gobiidae species. 48.30% of the total catch in abundance, which was followed by Engraulis japonicus (31.86%). These two taxa composed 80.16% of the total collected fish larvae. The seasonal diversity index of species from the collected fish larvae in the West coastal waters in 2017 was 0.625-1.883 and the evenness index was 0.380-0.865. In addition, dominance index was 0.618-0.920 and richness was 0.573-3.189.

Hydroacoustic Survey of Spatiotemporal Stability and Distribution of Demersal Fish Aggregations in the Coastal Region (수산 음향 기법을 이용한 연안 저서 어군의 시.공간 분포 및 안정성 조사)

  • Kang, Dong-Hyug;Lee, Chang-Won;Cho, Sung-Ho;Myoung, Jung-Goo
    • Ocean and Polar Research
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    • v.30 no.1
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    • pp.79-87
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    • 2008
  • Hydroacoustic technique was used to analyze spatiotemporal stability and distribution of demersal fish aggregations in the coastal region to overcome some limitations of the existing methods such as net and diving. The survey was carried out in the Baekeum Bay on the south coast of Korea in January 2007. The bottom depth in the study site ranges from 7 to 25 m. In order to outline aggregations of demersal fish initial scanning using 200 kHz split-beam transducer was randomly conducted over the large area. Having detected fish aggregation in the specific region, intensive acoustic survey of irregular star pattern was carried out along 14 transects across the area in question. The results of the acoustic survey show that all demersal fish aggregations are concentrated about 5 m from sea bottom having a slight slope and remain steady with no spatial or temporal variations during acoustic survey. The hydroacoustic method used in this study offers a new approach to understand vertical and horizontal distribution, spatiotemporal stability, and biomass estimate of demersal fish aggregations in coastal regions. Additionally, the number of individual fish estimated from in situ acoustic target strength data can be used to understand the standing stock of demersal fish aggregation.

Seasonal Variation in Species Composition of Fish Collected by a Bag Net in the Geum River Estuary, Korea (개량안강망에 채집된 금강하구 어류 종조성의 계절 변동)

  • HWANG Sun-Wan;HWANG Hak-Bin;NOH Hyung-Soo;LEE Tae-Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.38 no.1
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    • pp.39-54
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    • 2005
  • Seasonal variation in species composition of fish in the Geum River estuary was determined using monthly samples collected with a bag net from February to December 2003. Of a total of seventy-three species collected, four groups of fishes were distinguished. Estuarine fishes such as Chelon haematocheilus and Synechogobius hasta were collected almost all the seasons and predominated in abundance during cold months. Coastal fish species such as Sardinella zunasi, Konosirus punctatus, Engraulis japonicus, Johnius grypotus and Thryssa kammalensis were dominated from late spring to autumn. Their adults entered into the estuary in spring and a large number of their juveniles were collected in summer and autumn till moving out to deeper waters for over-wintering. A few freshwater fishes were collected when the freshwater was discharged during the rainy season. Anguilla japonica elvers (diadromous fish) and Coilia nasus (amphidromous fish) were collected in spring during their upstream migration. The principal component analysis revealed that the seasonal variation in species composition of fishes was principally determined by water temperature and/or water temperature related factors.

A Study on International Cooperation System for Fisheries Resources Conservation & Management in the Northeast Asia (동북아 수역의 수산자원 보존관리 협력체제에 관한 연구)

  • Shim, Ho-Jin
    • The Journal of Fisheries Business Administration
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    • v.40 no.2
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    • pp.71-103
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    • 2009
  • This study is designed to propose the ways of the multilateral cooperation system for effective management of fisheries resources in the various overlapping zones established by bilateral fisheries agreements between Korea, China and Japan in North East Asia as semi-enclosed sea. It is necessary to build multilateral fisheries cooperation between Korea, China and Japan in North East Asia because conservation & management of transboundary fish stocks could not be guaranted effectively by the management of fisheries resources in the area where piled up the current-fishing-pattern zone, as white zone and the various grey zone as middle zone, and the interim measures zone of bilateral fisheries agreements between Korea, China and Japan are piled up. Fisheries management in Korea, China and Japan by the bilateral fisheries agreements in North East Asia is faced with difficulties manage fisheries resources. International relationship on fisheries is maintained by bilateral fisheries agreements based on UNCLOS. However fisheries resources are over-exploited and the recovery of the fisheries resources is very slow because proper conservation and management of transboundary fish stocks which article 63(1) of UNCLOS defines have not prepared yet. Thus close cooperation among the coastal States for a proper conservation and management of transboundary fish stocks is necessary. Since the transboundary fish migrate within the EEZs of two or more coastal States, there is a need to manage the fish stocks in the region between Korea, China and Japan through a multi-lateral mechanism at ccircumference area of the current-fishing-pattern zone as white zone. Coastal States must guarantee sustainable maintenance of transboundary fish stocks through the regional cooperation for a proper conservation & management because one coastal State alone could not guarantee conservation and management of fish stocks. Thus there is a need to build multilateral fisheries cooperation between Korea, China and Japan in North East Asia. There are many successful instances including the Barents' sea for a proper conservation & management of transboundary fish stocks. The Barents' sea is one of the best research object to study the regional cooperation for a conservation & management of transboundary fish stocks in North East Asia. In conclusion, it is necessary to build a multilateral fisheries cooperation system between Korea, China and Japan in North East Asia to conserve and manage transboundary fish stocks effectively. It seems desirable that the range of the area to conserve and manage fish stocks should may be any partial area in the current-fishing-pattern zone and interim measures zone between Korea and China, Jeju middle zone between Korea and Japan, interim measures zone of bilateral fisheries agreements between China and Japan.

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Proper Sampling Method for Larval Fish in the Western coastal Waters (서해 연안역에서 자어의 적정 채집 방법)

  • 차성식;박명정
    • 한국해양학회지
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    • v.30 no.1
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    • pp.64-68
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    • 1995
  • To investigate a proper sampling method for larval fish in the western coastal waters, the abundances of larval fish sampled at upper and lower layers during the day and nighttime were compared. The difference in the abundances at upper and lower layers seems to be related to the diurnal vertical migration of larval fish. Therefore, samples at upper layer during the day causes an underestimation of the number of species and the abundance. As the abundances through whole water column during the day is not significantly smaller than during the nighttime. samples obtained by oblique tow through whole water column during the day can be used to estimate the abundance of fish larvae.

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Feeding Habits of Brown barracuda (Sphyraena pinguis, Teleostei) in the Coastal Waters of Gadeok-do, Korea (가덕도 주변 해역 꼬치고기 (Sphyraena pinguis)의 식성)

  • BAECK Gun Wook;HUH Sung-Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.6
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    • pp.505-510
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    • 2004
  • The feeding habits of brown barracuda (Sphyraena pinguis) were analyzed using the stomach contents of monthly samples collected from coastal waters of Gadeok-do, Korea from January to December, 1998. Brown barracuda occurred mainly from summer to autumn in the study area, and ranged from 15 to 35 cm in standard length. Brown barracuda was a piscivorous fish which, mainly consumed teleost fish such as anchovy (Engranlis japonicus) and chefoo thryssa (Thfssa kammalensis). Its diet also included small quantities of shrimp and cephalopods. Although smaller fishes (<25 cm SL) consumed shrimp and cephalopods as well as fish, larger fishes (>30 cm SL) consumed exclusively teleost fish. The prey size increased with increase of fish size.