• Title/Summary/Keyword: FISH POPULATION

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Marine Ecotoxicological Evaluation on HNS Spill Accident : Nitric Acid Spill Case Study (HNS 유출사고가 해양생물에 미치는 생물독성 영향평가 : HNO3 유출사고 대상)

  • Kim, Tae-Won;Kim, Young Ryun;Jo, So Eun;Son, Min Ho;Lee, Moonjin;Oh, Sangwoo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.6
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    • pp.655-661
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    • 2015
  • This study intends to evaluate the effect of nitric acid($HNO_3$) spill accidents on the marine ecosystem, while $HNO_3$ is known as one of the typical HNS. For this purpose, we performed (1) the growth inhibition test by using phytoplankton(Skeletonema costatum), (2) acute and chronic toxicity test by using invertebrate(Brachionus plicatilis and Monocorphium acherusicum), (3) fish(Cyprinodon variegatus) and (4) bacteria(Vibrio fischeri). In these tests, we observed the (1) pH changes induced by the nitric acid spill and (2) changes in nitrate($NO_3$) concentration disassociated from nitric acid after the accident, respectively. The toxicity test result on pH changes induced by $HNO_3$ shows that the no observed effect concentration(NOEC), lowest observed effect concentration(LOEC) and 50 % effect concentration($72h-EC_{50}$) values of M. acherusicum are pH 7 (0.3 mM), pH 5(1.1 mM) and pH 5.2(1.4 mM), respectively, indicating that M. acherusicum is the most sensitive species. The chronic toxicity test (population growth rate test) on $NO_3{^-}$ of B. plicatilis show that the NOEC, LOEC and $96h-EC_{50}$ are 5.9 mM, 11.8 mM and 32.6 mM, respectively, indicating that B. plicatilis is the most sensitive species. In conclusion, toxic effecst on the marine organism caused by the nitric acid spill accident is determined to be so slightly except for the most adjacent area of the ship in pH scale and such concentration of nitrate, to the extent of directly influencing the survival and reproduction of the marine organism, is determined practically not to be applicable in the typical accidents in the sea.

Trend of Foods and Nutrients Intake for the Periold of 1970 - 1979 in Korea (우리나라의 식품(食品) 및 영양소(營養素) 섭취(攝取)의 변화(變化)에 대(對)한 고찰(考察))

  • Han, Yang Il;Kim, Eul Sang;Lee, Kyu Han
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.2
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    • pp.137-145
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    • 1983
  • Trend of foods and nutrients intake per person per day in Korea from 1970 to 1979, based on reports on national nutrition survey, was analyzed. The average rates of population, GNP and per capita national income were 1.7, 9.6 and 536.2%, respectively. The consumption of cereals, pulses and potatoes was decreased; whereas that of fresh vegdtables, fruits, meat, fresh fish and shells, eggs, milks, and fats and oils was increased. Calorie intake was remained essentially constant, but protein and fat intake was increased by 11.6% and 52.3%, respectively, in ten years. The main sources for calcium, iron and vitamin A were vegetables. Among various nutrients, intake of riboflavin and animal protein were less than RDA.

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Comparison of Estimated Daily Dietary Intake of Dioxins in Coastal, Rural, and Urban District (어촌, 농촌, 도시 지역별 주민의 식품을 통한 다이옥신의 섭취량 추정)

  • Park, Jung-Duck;Huang, Ming-Ai;Im, Ruth;Choi, Byung-Sun;Yang, Jae-Ho;Bae, Yun-Jung;Jun, Ye-Sook;Choi, Mi-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.3
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    • pp.325-332
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    • 2008
  • The human population is mainly exposed to dioxins through the diet. The purpose of this study was to estimate the daily dietary intake of PCDDs and PCDFs in Korean adults residing in different regions. Subjects were recruited and divided into three groups according to the districts where they lived: rural (n=213), coastal (n=193), and urban district (n=187). Subjects were interviewed using a general questionnaire and 24-hour recall for dietary intake. The daily intake of dioxins was estimated through the use of the database of dioxins contents in 35 Korean foods. The average age of the subjects were 61.5 years for coastal district, 57.6 years for rural district, and 49.4 years for urban district. Daily energy intake was 1707.7 kcal for rural district, 1596.5 kcal for urban district, and 1493.8 kcal for coastal district. There was no significant difference in total food intake by regions. The intakes from fishes of coastal district, those from cereals, vegetables, meats, and seasonings of rural district, and those from sugars, pulses, eggs, seaweeds, milks, oils of urban area were higher than those of the other two districts. The daily dioxins intake of coastal district (0.70 pgTEQ/kg/day) was significantly higher than those of rural district (0.32 pgTEQ/kg/day) and urban district (0.46 pgTEQ/kg/day). The dioxins intake from cereals, pulses, vegetables, fishes of coastal district and those from eggs and milks of urban area were the highest among the districts. The daily dioxins intake was positively correlated with the intakes of meats, eggs, fishes, oils, and seasonings. Therefore, it could be concluded that the daily dioxins intake of coastal district is higher than that in other districts and the fish is one of the main sources in dioxin intakes. However, daily dioxins intakes of the three regions were below the level of tolerable daily intake (TDI).

Distribution of Larval Fishes off the East Sea, Korea (동해 근해에 출현하는 어류 자치어 분포 특성)

  • Choi, Hee Chan;Jung, Hae Kun;Cho, Jeong Hyun;Youn, Seok Hyun;Oh, Hyun Ju
    • Korean Journal of Ichthyology
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    • v.34 no.3
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    • pp.186-200
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    • 2022
  • In order to understand the species composition and distribution characteristics of larval assemblages in the East Sea, Korea, larvae were collected at 13 stations every other month from February to December 2018. Fish larvae were identified through DNA barcoding along with morphological methods, and as the result, a total of 104 taxonomic groups appeared during the survey. Among these, Engraulis japonicus, which accounted for 76.2% of the total population, was the most dominant species, followed by Maurolicus japonicus, which accounted for 15.0%. In addition, Ammodytes personatus, Champsodon snyderi, Scomber japonicus and Echelus uropterus appeared more frequently than other taxa. The above six species accounted for 93.2% of the total catch. The number of taxa and the amount of larvae collected in the survey area were higher during the high water temperature periods (June to October) than during the low water temperature periods (February, April and December). Analysis of similarity (ANOSIM) showed a statistically significant difference in monthly larval assemblages. The results of the canonical correspondence analysis (CCA) show that the distributions of larval community were mainly affected by sea surface temperature during low water temperature periods, and various environmental factors such as salinity, dry weight of zooplankton, and the concentrations of nutrients during high water temperature periods.

Interaction between Invertebrate Grazers and Seaweeds in the East Coast of Korea (동해안 조식성 무척추동물과 해조류 간 상호작용)

  • Yoo, J.W.;Kim, H.J.;Lee, H.J.;Lee, C.G.;Kim, C.S.;Hong, J.S.;Hong, J.P.;Kim, D.S.
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.3
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    • pp.125-132
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    • 2007
  • We estimated the distribution of predator-prey interaction strengths for 12 species of herbivores (including amphipods, isopods, gastropods, and sea urchins) and made a regression model that may be applicable to other species. Laboratory experiments were used to determine per capita grazing rate (PCGR; g seaweeds/individual/day). Relationship between the biomass of individual grazers and fourth-root transformed PCGR was fitted to power curve ($y=0.2310x^{0.3290}$, r=0.8864). This finding supported that the grazing efficiency was not even as individual grazers increase in size (biomass). Therefore, the biomass-normalized PCGR was estimated and revealed that smaller size herbivores were more effective grazers. Grazing impact considering density of each taxon was calculated. The sea hare Aplysia kurodai had greatest grazing impact on the seaweed bed and the sea urchin Strongylocentrotus nudus and S. intermedius were ranked in descending order of the impact. The amount of seaweed grazed by the amphipod Elasmopus sp. (>4,000 $ind./m^2$) and Jassa falcata (>2,000 $ind./m^2$) were 3.435 and $1.697mg/m^2/day$ respectively. The combined grazing amount of herbivores was $5,045mg/m^2/day$ in the seaweed bed. Although sea hare and sea urchin had strong impacts on seaweeds, the effects of dense, smaller species could not be seen as negligible. Surprisingly, the calculated grazing potential of sea urchins with a mean density of 3 $ind./m^2$ exceeded the mean production of seaweed cultured in domestic coastal waters in Korea (ca., 5 ton/ha). Small crustaceans were also expected to consume up to 16% of the seaweed production if their densities were rising under weak predation conditions. Considering that the population density of herbivores are strongly controlled by fish, human interference like overfishing may have strong negative effects on persistence of seaweeds communities.

Malacological Studies on Parafossarulus manchouricus(Gastropoda: Prosobranchia) in Korea (한국산(韓國産) 왜우렁(Parafossarulus manchouricus)의 패류학적(貝類學的) 연구(硏究))

  • Chung, Pyung-Rim
    • The Korean Journal of Malacology
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    • v.1 no.1
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    • pp.24-50
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    • 1985
  • Five different populations of Parafossarulus manchouricus (Chongpyung, Chinju and Kunsan, Korea; and Japan and Taiwan), a population of Bitbynia (Gabbia) misella (Gongju, Korea) and two different populations of Bithynta tentaculata (Michigan, U.S.A. and Bodensee, Germany) were compared in regard to eff-laying characteristics, morphology, chromosome cytology, natural infections of parasites and ecology of habitats. A satisfactory culture method was devised for laboratory rearing of the snails. Tropical fish food (Terra SML) and powdered green leaves (Ceralife) were used as the main food sources for the snails. Benthic diatoms such as Navicula and Gomphonema from the periphyton were also essential for satisfactory growth, especially for the baby snails. The aquaria were stabilized with small stones from a local stream. Young P. manchouricus snails grew to adult size in about 54 days after hatching. They laid eggs 150-156 days after hatching. The whole cycle (birth to egg-laying) took approximately 5 months. The three species of bithyniid snails are iteroparous and lay eggs once a year. There were no major morphological differences in the shells of genera or subgenera studied here. They did exhibit the following rather minor differences. The shell of Parafossarulus has spirally raised ridges, and its apex is usually eroded; the other two genera lack these characteristics. The shell of B. (Gabbia) misella is small, nor exceeding 7.5 mm in length, while the shells of the other two species are larger, being more than 10 mm in length. Scanning electron microscopy (SEM) of the protoconch of P. manchouricus reveals nearly smooth sculpture with small, low, spiral wrinkles. This sculpture is quite different from that of the Hydrobiidae, a family to which the bithyniids are frequently assigned. Scanning electron microscopy of the radulae of the three bithyniid species showed that their radular morphologies are very similar, but there are some small differences, which may be species-specific. There were some statistical differences in shell heights between the Korean and the other populations of P. manchouricus, and between this species and the other two bithyniids as well. The shell differences between the several populations of Korean P. manchouricus may be related to environment. Edtails of the chromosome cycle of these bithyniid snails are similar to those reported for other snails. No specific differences were observed in the chromosome cycle between the various species and populations of snails employed in this study. Reporred for the first time in molluscs are two darkly stained "nucleolar organizers" during pachyterne stages of meiosis. Two different chromosome numbers were observed in the three bithyniid species: n=17 in B. tentaculata and P. manchouricus, and n=18 in B. (G.) misella. no sex chromosomes or supernumerary chromosomes were seen. There were no morphological differences in karyotypes of three Korean strains of P. manchouricus. The infection rates of cercariae of Clonorchis sinensis in Chinju and Kunsan strains of P. manchouricus were 0.14% and 1.25%, respectively. However, Clonorchis cercariae were found in Chongpyung strain of P. manchouriceu and Gongju strain of B. (G.) misella. The habitats of P. manchouricus around Jinyang Lake were relatively clean without any heavy pollution of aquatic microorganisms and organic materials during the period of this study. The levels of dissolved oxygen (D.O.) and biochemical oxygen demand (B.O.D.) of the water specimens sampled from the study areas ranged from 6.0 to 9.6 ppm and from 0.4 to 1.6 ppm, respectively. Eight metalic constituents from the water samples were also assayed, and all metalic ions detercted were remarkably low below the legal criteria. However, calcium ion in the water samples from the habitats of P. manchouricus was considerably higher than others.

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