• Korean Journal of Environmental Biology
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• v.31 no.1
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• pp.45-52
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• 2013

The fish fauna of Munsom in Jeju-do, Korea, was investigated for a total of five times underwater from April 2009 to October 2010. Fish specimens were collected with a small net by SCUBA diving and fish specimens difficult to collect were photographed underwater using a underwater camera and a camcorder. The fish specimens collected from the sea around Munsom were identified as 91 species, belonging to 73 genera, 39 families, and 11 orders. Among them, the largest group was Order Perciformes, comprising 54 species and 21 families, consisting 59.3% in total number of species and the following 19 species of Order Scorpaeniformes was 20.8%. In this study Amblyeleotris sp. of family Gobiidae was discovered as new species by underwater photography in Korea. It was more the demersal fishes (55%) than the pelagic fishes (45%) and in social behavior pattern it was much more species swimming alone than schooling.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.362-366
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• 2007

This study determined the heavy metal contents in fish from the Korean coast of the East Sea (Donghae). The sample were divided into three parts (meat, liver, skin) and digested with acids. Then, contents of lead, cadmium, mercury, and arsenic were analyzed using atomic absorption spectrophotometry. The heavy metal contents in different parts of the fish were as follows: lead of 0.019-0.346 mg/kg (meat), 0.461-0.516 mg/kg (liver), 0.018-0.855 mg/kg (skin); cadmium of ${\leq}0.049\;mg/kg$ (meat), ${\leq}1.224\;mg/kg$ (liver), ${\leq}0.019\;mg/kg$ (skin); mercury of $1.018-2.751\;{\mu}g/kg$ (meat), $3.057-7.023\;{\mu}g/kg$ (liver), $1.068-3.940\;{\mu}g/kg$ (skin); arsenic of $0.938-25.935\;{\mu}g/kg$ (meat), ${\leq}21.082\;{\mu}g/kg$ (liver), ${\leq}3.708\;{\mu}g/kg$ (skin). Contents of heavy metals in the liver and skin from some fish exceeded the maximum CODEX guideline levels, although the contents in meat from all of the fish tested were much lower than the CODEX levels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.541-555
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• 2016

This study determined the concentrations of lead and cadmium in 18 species of commonly consumed fish and assessed the risk based on provisional tolerable weekly (monthly) intakes [PTW(M)I] % as affected by behavioral characteristics, such as migration and settlement. In the 18 species, the mean concentrations of lead and cadmium were higher in the 11 species of migratory fish (llargehead hairtail Trichiurus lepturus, chub mackerel Scomber japonicus, Pacific saury Cololabis saira, skipjack tuna Katsuwonus pelamis, Pacific cod Gadus macrocephalus, anchovy Engraulis japonicus, Alaska pollack Theragra chalcogramm, brown croaker Miichthys miiuy, Japanese Spanish mackerel Scomberomorus niphonius, yellow croaker Larimichthys polyactis, and Pacific herring Clupea pallasii) than in the seven demersal species (red stingray Dasyatis akajei, brown sole Pleuronectes herzensteini, bastard halibut Paralichthys olivaceus, conger eel Conger myriaster, blackmouth angler Lophiomus setigerus, rockfish Sebastes schlegelii, and filefish Stephanolepis cirrhifer). Based on the mean concentrations, the PTWI % of lead and cadmium in commonly consumed migratory fish were 1.900 and 2.986%, respectively, which were higher than the values for lead and cadmium in the commonly consumed demersal fishes (0.257 and 0.318%, respectively). The estimation of weekly (monthly) intakes and target hazard quotients for the toxic elements lead and cadmium revealed that the commonly consumed migratory and demersal fish do not pose any health risks for consumers.

• Ocean and Polar Research
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• v.40 no.3
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• pp.169-176
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• 2018

Recently, the pop-up satellite archival tag (PSAT) is being used in studies as a method of using satellites for monitoring organisms. Because PSATs are attached directly on the organism being monitored, it is used mostly on larger species since the health of the organism is an important concern. For this reason, PSAT-based surveys are lacking in Korea with no studies on the physiological responses of organisms with PSAT attached. Accordingly, as a basic biomonitoring study using PSAT, the present study investigated the physiological changes in fish in response to the attachment of PSAT. The present study used red seabream (Pagrus major) and Korean rockfish (Sebastes schlegelii) as the experimental fish. The PSAT was attached to the muscle below the experimental fish's dorsal fin using a mono filament (n = 3). To investigate the changes in physiological responses according to PSAT attachment, blood samples were collected from all experimental fish, including the control (n = 3), at 1, 7, 14 and 21 days after the attachment. Upon blood sample collection, whole blood was used to measure hematocrit and hemoglobin levels. After separating the plasma, the separated plasma was used to measure the GOT, GPT, glucose, total protein, and cholesterol levels. Meanwhile, the plasma cortisol, superoxide dismutase, and catalase levels were measured using the ELISA method. The results showed that attaching the tag did not have any impact on the immunity and stress response of the experimental fish. The findings in this study also demonstrated the possibility of using PSAT for studying relatively smaller species living in the coastal waters of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.596-600
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• 2003

This study investigated the effect of soybean-curd residues as an ingredient of the formulated diet for juvenile flounder (Paralichthys olivaceus). Three replicates of juvenile fish (averaging weight $1.5\pm0.04\;g$) were fed one of four isonitrogenous $(50\%)$ diets containing $0\%,\;5\%,\;10\%\;and\;15\%$ soybean-curd residues for 7 weeks. Survival, hepatosomatic index and condition factor of the fish were not affected by dietary soybean-curd residues levels. Weight gain, feed efficiency and protein efficiency ratio of the fish fed the diet containing $5\%$ soybean-curd residues were not significantly different to those of the fish fed the control diet, however these values decreased in the fish fed the $10\%\;and\;15\%$ soybean-curd residues (P<0.05). Daily feed and protein intake increased with increasing dietary soybean-curd residues level. Crude protein and lipid contents in the whole body decreased with increasing dietary soybean-curd residues, but no significant differences were observed among control, $5\%\;and\;10\%$ soybean-curd residues diets (P>0.05). Plasma total protein concentration of fish was affected by dietary soybean-curd residues levels (P<0.05). It is concluded that the soybean-curd residues as a substitute for wheat flour can be included up to $5\%$ in the diet for juvenile flounder.

• Journal of Aquaculture
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• v.22 no.1
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• pp.63-67
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• 2009

In order to establish optimum anesthesia concentration, we tested the efficacy of clove oil at five different concentrations in large sized (mean SL $17.1{\pm}2.21\;cm$) and small sized (mean SL $0.6{\pm}0.06\;cm$) dark-banded rockfish Sebastes inermis. Optimal anesthesia concentration for dark-banded rockfish was $150\;mgL^{-1}$ in both large and small sized fish. In general, fish exposed to higher anesthetic doses were rapidly induced but took longer to recover (P<0.05). Recovery time of small sized fish was longer than large sized fish in lower concentrations, while recovery time of large sized fish was longer than small sized fish in higher concentration (P<0.05). Using the established optimum aesthetic concentration, we evaluated the physiological response of dark-banded rockfish to clove oil by measuring plasma cortisol and glucose levels. Following administration of $150\;mgL^{-1}$ clove oil at $20^{\circ}C$ (optimum breeding temperature), plasma cortisol level was highest ($42.2{\pm}11.318{\mu}g/dL$) after 0 hour, while plasma glucose level was highest ($52.5{\pm}10.61\;mg/dL$) after 1 hour. Plasma cortisol and glucose concentrations required 6 and 2 hours, respectively, to return to pre-exposure levels.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.2
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• pp.153-158
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• 2022

A telesounder is a device that can monitor the appearance of fish in the sea on land and store fish detection data. This study was conducted to monitor the appearance of fish resources in coastal or near seas by using LTE communication for data transmission of the telesounder. The purpose of this study was to develop a prototype telesounder that can monitor the appearance of fish groups in the waters about 50 km away from the coast and store fish detection data. In this study, the prototype telesounder including a fish finder, communication device and battery for stable operation at sea was developed. The stability of telesounder buoy, data transmission/reception and expected use time were investigated. The expected use time of the telesounder using LTE communication with a lithium battery (12 V, 120 Ah) was about 274 hours under the conditions of 10 minutes off and 10 minutes on, about 520 hours under the conditions of 30 minutes off and 10 minutes on, and about 142 hours under continuous conditions. As a result of the sea test, it was found that the telesounder can be used in the sea area moved about 34 km from the land and the telesounder buoy was evaluated to have secured basic stability (buoyancy balance, waterproof, antenna strength, etc.) for operation in a marine environment.

• Korean Journal of Ichthyology
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• v.34 no.4
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• pp.253-261
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• 2022

After exposing Olive flounder and Korean rockfish to the concentration ranges of control (0 mg/L), 100 mg/L, 250 mg/L, 500 mg/L, and 1,000 mg/L, to investigate the physiological properties of suspended load on fish AST/GOT, ALT/GPT, ALP and cortisol were analyzed. As a result of the analysis, the AST/GOT, ALT/GPT, ALP and cortisol values were higher in the suspended load concentration section than in the control group. After artificial infection with S. parauberis for Olive flounder and V. harveyi for Korean rockfish exposed to suspended load, the survival rate was higher in the control group than in the suspended load concentration section. These results are related to the previously study results of suspended load that adversely affect fish, suggesting that suspended load affects the health of fish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.7-12
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• 2016

Total mercury (TM) is a hazardous element that is of particular concern to human health. Due to the diversity of dietary habits among fishes, tissue-specific analysis of hazardous elements is necessary. In this study, the tissue-specific TM in cultured fish was analyzed to conduct risk assessment. The highest concentrations of TM were found in the farmed marine fish Pagrus major (0.111 mg/kg) and in the farmed freshwater fish Channa argus (0.162 mg/kg). TM concentration was significantly correlated with total fish length (P<0.01). Significant differences in TM were found between three types of fish tissue, with the concentration in fish muscle being significantly higher than those of gill or liver (P<0.01). Moreover, the tissue-specific TM concentrations of farmed freshwater fish were significantly higher than those of farmed marine fish (P<0.01). According to the risk assessment, the TM body exposure rate of muscle and liver in cultured fishes ranged from 0.001 to 0.389% of the Provisional Tolerable Weekly Intake. Therefore, these results showing the tissue-specific TM contents of cultured fish could be useful to assess the health risks of Korean dietary habits.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.4
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• pp.868-876
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• 2014

This study was conducted to estimate the optimum dietary protein to energy (P/E) ratio in juvenile river puffer. Nine experimental diets were formulated with three energy levels and three protein levels at each energy levels. Three energy levels of 3000, 3750 and 4500 kcal diets were included at 45, 50 and 55% crude protein (CP) levels, respectively (45P3000, 45P3750, 45P4500, 50P3000, 50P3750, 50P4500, 55P3000, 55P3750 and 55P4500). Fish averaging $3.43{\pm}0.02$ g randomly were fed the experimental diets in triplicate groups for 8 weeks. Weight gain of fish fed the 50P4500 diet were significantly higher than that of fish fed the 45P3000, 45P3750, 45P4500, 50P3000 and 50P3750 diets (P<0.05), but there was not significantly different from that of fish fed the 50P4500, 55P3750 and 55P4500 diets. Feed efficiency of fish fed the 50P4500 diet were significantly higher than that of fish fed the 45P3000, 45P3750, 45P4500, 50P3000 and 50P3750 diets (P<0.05), but there was not significantly different from that of fish fed the 50P4500, 55P3000, 55P3750 and 55P4500 diets. Protein efficiency ratio of fish fed the 45P3000 and 45P3750 diets was higher than that of fish fed 50P4500 and 55P4500, but there was not significantly different from that of fish fed the 45P3000, 45P3750, 45P4500, 50P3000, 50P3750, 55P3000 and 55P3750 diets. Based on weight gain, feed efficiency and specific growth rate, diets containing energy levels 4500 kcal/kg diet had an optimum P/E ratio of approximately 111 mg protein/kcal (50% crude protein) in juvenile river puffer.