• Journal of Aquaculture
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• v.1 no.2
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• pp.121-133
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• 1988

Strongylocentrotus pulcherrimus is one of the very important fishery stock in this country since its high demand for raw gonad. Although the demand has been continuously increasing, the natural stock of this species seems to be decreasing. Since fresh macroalgae are not always available, the substitution of terrestrial vegetables for algae as a principal food was examined for the intensive indoor culture of the sea urchin. The results from the studies on selective and non-selective feeding habits and nutritional efficiencies using 13 food stuffs (6 macroalgae, 5 vegetables and 2 animal products) indicate that algae can be substituted with vegetables in sea urchin culture. Although the growth of body weight was the highest when sea urchins were fed Undaria Pinnatifida, the gonad index of the sea urchins fed on spinach, radish leaf and lettuce was higher than that of this brown alga. Considering the different food efficiencies of body and gonad growth, spinach and radish leaf will be adequate during gonad growth season, while lettuce and Chinese cabbage will be suitable for test growth season. In particular, radish leaf, which is usually not eaten by humans, could be highly beneficial and very economical in the sea urchin culture.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.3
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• pp.170-174
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• 1998

The water quality of offshore waters around the Korean coast was evaluated by bioassay using gametes, embryoss and early development systems of a sea urchin species Hemicentrotus pulcherrimus. The results show that despite the inflows of several river systems, the west coast maintain the grade II water. This is thought to be due to the decrease in pollutant input resulting from the purification of inflow rivers (e.g., the control of waste water discharge and the construction of sewage treatment facilities), and the dilution of pollutants by a strong tidal mixing with a large difference between the ebb and flood tides. However, Asan, Hampyong and Chonsu bays, where circulations of water are relatively poor, and the Kunsan and Mokpo harbors which are influenced by pollutants from neighboring cities have shown the grade III water. The south coast has maintain the grade II or III because developments of sea urchins were moderately or strongly inhibited. Also, Kangjin, Duekryang, Kwangyang, Masan, and Jinhae bays where water circulations are relatively poor, show the grade III water, with strong inhibitions of the early development of sea urchins. The east coast has maintained the grade I and II due to monotonous coastlines and smooth circulation of sea water. However, Chongcho Lake shows the worst water quality due to the breakwater which is constructed to maintain port functions.

• ALGAE
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• v.29 no.3
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• pp.203-215
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• 2014

As global warming continues over the coming century, marine organisms will experience a warmer, more acidic ocean. Although these stressors may behave antagonistically or synergistically and will impact organisms both directly (i.e., physiologically) and indirectly (i.e., through altered species interactions), few studies have examined the complexities of these effects in combination. To address these uncertainties, we examined the independent and combined effects of elevated temperature and $pCO_2$ on the physiology of the adult sporophyte stage of giant kelp, Macrocystis pyrifera, and the grazing of the purple sea urchin Strongylocentrotus purpuratus. While elevating $pCO_2$ alone had no effect on M. pyrifera growth or photosynthetic carbon uptake, elevating temperature alone resulted in a significant reduction in both. However, when M. pyrifera was grown under elevated temperature and $pCO_2$ together, growth and photosynthetic carbon uptake significantly increased relative to ambient conditions, suggesting an interaction of these factors on photosynthetic physiology. S. purpuratus held under future conditions generally exhibited reduced growth, and smaller gonads than urchins held under present-day conditions. However, urchins fed kelp grown under future conditions showed higher growth rates, partially ameliorating this effect. Feeding rates were variable over the course of the experiment, with only the first feeding rate experiment showing significantly lower rates for urchins held under future conditions. Together, these data suggest that M. pyrifera may benefit physiologically from a warmer, more acidic (i.e., higher $pCO_2$) ocean while S. purpuratus will likely be impacted negatively. Given that kelp-urchin interactions can be important to kelp forest structure, changes to either of these populations may have serious consequences for many coastal environments.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2004.11a
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• pp.49-50
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• 2004

• Ocean and Polar Research
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• v.45 no.3
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• pp.173-183
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• 2023

The barren ground phenomenon in Korea began to occur and spread in the southern coast region and in Jeju Island in the 1980s, and since the 1990s, the damage has become serious in the east coast region as well. Korea has enacted the fisheries resource management act to manage such barren ground through the installation of sea forests among projects for the creation of fishery resources. Until now, projects related to the identification of the cause of barren ground have focused on the density of crustose coralline algae, sea urchins and seaweed, so the original cause of barren ground has not yet been identified. In order to manage barren ground, it is necessary to identify the cause of barren ground. To identify these causes, it is necessary to comprehensively consider i) studies on spatial characteristics such as rock mass distribution, slope and water depth, ii) studies on ecological and oceanographic characteristics such as water temperature, salinity, El Niño, and typhoons etc, iii) studies on organisms such as crustose coralline algae, macroalgae, and sea urchins, and iv) studies on coastal use such as living and industrial sewage inflow. Next, as with regard to legislative policy proposals , it is necessary to prepare self-management measures by the government, local governments, and fishermen as well as address management problems related to the use of sea forests by fishermen after their creation . In addition, when creating a sea forest, a management model for each resource management plan is required, and evaluation indicators and indexes that can diagnose the cause of barren ground and guidelines for barren ground measures should be developed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.694-700
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• 2016

Specimens of Callionymus beniteguri (n=89) were collected from the waters off the coast of Taean, Korea, between April 2008 and January 2009, and their feeding behavior was observed. C. beniteguri (4.0-15.5 cm SL) was found to be a bottom-feeding carnivore that primarily preyed on gammarid amphipods, and secondarily consumed polychaetes but also ingested bivalves, shrimps, cumaceans, and sea urchins. Six additional minor prey groups also contributed to its diet, but the index of relative importance (IRI) for these groups was relatively low (<1.0). C. beniteguri exhibited size-related dietary changes. Small individuals (<10 cm SL) mainly consumed amphipods. As fish size increased, amphipods tended to decline in IRI, while the contributions of bivalves, sea urchins, and polychaetes became more important.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.686-693
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• 2012

The seaweed community and stomach contents of the dominant herbivorous sea urchins Anthocidaris crassispina and Hemicentrotus pulcherrimus were examined from November 2008 to October 2009, in coastal areas of Tongyeong, Korea. Thirty-five seaweeds including two green, nine brown, and 24 red algae, were found over the study period. Seventeen seaweeds (two green, two brown, and 13 red) and two invertebrates were found in the stomachs of A. crassispina. In H. pulcherrimus, stomach contents were two green, one brown, 11 red seaweeds, and two invertebrates. The shell diameter of A. crassispina and H. pulcherrimus ranged from 22.3 to 62.3 mm and 15.3 to 40.1 mm, respectively. Total body weights ranged from 48.5 to 86.7 g for A. crassispina and from 7.7 to 25.9 g for H. pulcherrimus. The total weight of stomach contents were 5.1 to 25.8 g in A. crassispina and 1.7 to 11.8 g in H. pulcherrimus. The range of gonad weight was 3.6 to 17.0 g in A. crassispina and 0.8 to 4.0 g in H. pulcherrimus. The gonad index (GI) for A. crassispina peaked in July and reached a minimum in December, whereas the GI for H. pulcherrimus was highest in February, and lowest in May.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.1
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• pp.40-49
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• 2004

An ecological study on a sea urchin population, Strongylocentrotus nudus, a key role species in recovery of macroalgal bed, was conducted in Hosan, Samcheok area on the east coast of Korea. Three experimental plots, namely, AMB (artificially-restored macroalgal bed), BG (barren grounds) and NMB (natural macroalgal bed) were established after a pilot survey in June 2002. Distribution and abundance, grazing rates, predation pressure and predator guilds on S. nudus were estimated in three plots bimonthly from Aug. to Dec., 2002. Abundance of S. nudus was lowest, but median test diameter of the urchin was highest (Kruskal-Wallis test, p-value, p<0.001 in Aug. and p=0.003 in Oct.) in NMB In-situ grazing rate of S. nudus estimated by enclosure cage experiment in NMB was about 12 times higher in Aug. (160.0 mg seaweed/g sea urchin/day) than in Oct. (13.8). Predation intensity measured by tethering experiment was higher in NMB. Most of the predators on S. nudus were invertebrates and no fish predators were found. Predator guilds identified by the fish trap experiment using live or dead sea urchins included who]ks Neptunea arthritica, starfish Asterina pectinifera, hermit crabs Pagurus of. samuelis, Paguristes barbatus, brown shawl crabs Atergatis integerrimus and crabs Actaea subglobosa. High predation pressure on S. nudus in natural macroalgal beds was the likely cause of its low density. Elevated sea urchin density and the consequent lasting deforestation of macroalgae in barren grounds demonstrate the importance of predation pressure on sea urchins.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.43-50
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• 2020

The aim of this study is toxicity assessment using two types of sea urchins (H. pulcherrimus, M. nudus) that can representative primary consumers in potential coastal environments pollutants, Zinc undecylenate (ZU), which is used for various purposes, such as pharmaceutical agents and anti-bacterial and anti-fungi. The Fertilization rate and normal embryogenesis rate of H. pulcherrimus and M. nudus were concentration-dependent decreased. Besides, EC₅₀ of fertilization rate with H. pulcherrimus and M. nudus were 11.27 mgl^-1 and 1.48 mgl^-1, and EC₅₀ of normal embryogenesis were 0.94 mgl^-1 and 3.78 mgl^-1. NOEC of normal embryogenesis were 0.20 and 0.78 mgl^-1, respectively. In addition, to find the safety criteria of the ZU on the marine environment. PNEC value was 0.0094 mgl^-1, calculated using the toxicity values of two species of sea urchin derived from this study and the acute toxicity results of the coastal area through literature research. The above results will be used as basic data for establishing environmental protection strategies for marine environmental pollutants.

• Animal Systematics, Evolution and Diversity
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• v.22 no.1
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• pp.105-108
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• 2006

Some sea urchins were collected from the subtidal rocky bottom along the coastal line in Jeju Island by SCUBA diving in April 2005 and identified on the basis of their morphological characteristics. Among them, Asthenosoma ijimai Yochiwara, 1897 was newly recorded from Korea and redescribed based on the specimen collected at 20m deep in southern breakwater of Seogwipo harbor. The order Echinothurioida including family Echinothuriidae and genus Asthenosoma was firstly recorded in Korea. Seventeen species of echinoids are reported to be distributed in Jeju Island of Korea.