• Journal of Korean Society of Environmental Engineers
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• v.33 no.1
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• pp.60-70
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• 2011

The sediment removal index derived from the chemical contaminants, $CI_{HC}$, is currently in use to identify and define the spatial extent of the contaminated sediments in the sea. In order to analyze the sensitivity of the ecological and human risk associated with contaminated sediment, we evaluated five hypothetical contaminated sediments, whose $CI_{HC}$ values are identical but consisted of different contaminant contents, using $TrophicTrace^{(R)}$ model dedicated to evaluate sediment risk, against the resident greenling (Hexagrammos otakii) and humans by calculating No-Observed-Adverse-Effect-Level based Toxicity Quotient (NOAEL TQ) and Lowest-Observed-Adverse-Effect-Level based Toxicity Quotient (LOAEL TQ), and cancer risks and hazard indices (HI), respectively, based on the site conceptual model and exposure assumptions of fish ingestion to human receptor populations. NOAEL and LOAEL TQ values varied as much as a factor of 2 among 5 hypothetical sediments. Chemical element specific contribution to the carcinogenic risk and HI varied also greatly in these sediments. The reason for this significant dissimilarity in ecological and human risk stems from the different risk of each contaminant to the resident fish and human receptor. When the conceptual food web model is constructed for the target biological species for a given site, the ecological and human risk analysis considering trophic transfer of contaminants will add a ecosystem based tool for the management of contaminated sediments.

• Ocean and Polar Research
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• v.32 no.2
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• pp.165-175
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• 2010

Dietary lipid biomarkers (fatty acids, fatty alcohols, and sterols) in adult specimens were analyzed to compare and understand the feeding ecology of the euphausiid, Euphausia pacifica, from three geographically and environmentally diverse Korean waters (Yellow Sea, East China Sea, and East Sea). Total lipid content of E. pacifica from Korean waters was about 10% dry weight (DW) with a dominance of phospholipids (>46.9% of total lipid content), which are known as membrane components. A saturated fatty acid, C16:0, a monounsaturated fatty acid, C18:1(n-9), and two polyunsaturated fatty acids, C20:5(n-3) and 22:6(n-3), were most abundant (>60% of total fatty acids) in the fatty acid composition. Some of the fatty acids showed slight differences among regions although no significant compositional changes of fatty acids were detected between these regions. Phytol, originating from the side chain of chlorophyll and indicative of active feeding on phytoplankton, was detected all samples. Trace amounts of various fatty alcohols were also detected in E. pacifica. Specifically, krill from the Yellow Sea showed relatively high amounts of longchain monounsaturated fatty alcohols (i.e. 20:1 and 22:1), generally found in herbivorous copepods. Three different kinds of sterols were detected in E. pacifica. The most dominant of these sterols was cholest-5-en-$3{\beta}$-ol (cholesterol). The lipid compositions and ratios of fatty acid trophic markers are indicative of herbivory in E. pacifica from the Yellow Sea and East Sea (mainly feeding on dinoflagellates and diatoms, respectively). The lipid compositions and ratios of fatty acid trophic markers are indicative of carnivory or omnivory in E. pacifica from the East China Sea, mainly feeding on microzooplankton such as protozoa. In conclusion, lipid biomarkers provide useful information about krill feeding type. However, further analyses and experiments (i.e. gut content analysis, in situ grazing experiment, etc.) are needed to better understand the feeding ecology of E. pacifica in various marine environments.

• ALGAE
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• v.21 no.4
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• pp.433-443
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• 2006

This study was performed to understand the morphological and ecological characteristics of Peridinium bipes var. occultatum Lindem., which is the organism responsible for freshwater red tides in Sangsa dam and Miryang dam reservoirs. The samples were collected from April to July 2004 when the freshwater red tides occurred. In the study, we were able to differentiate P. bipes var. occultatum from P. bipes, a closely related species, by its smaller antapical horn size. In Miryang dam reservoir the red tide occurred only within the area of the upstream, but it was well developed in all of the water area in Sangsa dam reservoir. In 2004 average LTSI (Lake Trophic Status Index; Yang and Dickman, 1993) of Miryang dam reservoir was 3.53 of mesotrophic state and Sangsa dam reservoir was 8.59 of eutrophic state. It was determined, through culture experiments under various conditions that vitamins, trace elements, phosphorus and nitrogen were important contributing factors to the growth of P. bipes var. occultatum. A rapid toxic effect of P. bipes var. occultatum on aquatic organisms such of Daphnia magna and Oryzias latipes was not identified in this study.

• Ocean and Polar Research
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• v.33 no.spc3
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• pp.349-358
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• 2011

In order to ascertain latitudinal variation of lipid contents and compositions in copepods, we collected warm water copepod species (Euchaeta sp. and Pleuromamma spp.) from four different regions from low (sub-tropical) to mid (temperate) latitudes in the Northwest Pacific Ocean. Total lipid contents of Pleuromamma spp. were about 11 $ug{\cdot}ind^{-1}$ with little latitudinal variation, whereas Euchaeta sp. showed slightly higher lipid content (20 $ug{\cdot}ind^{-1}$) than Pleuromamma spp. with latitudinal gradient (low at subtropic and high at temperate). Wax esters, known as the major storage lipid classes, were found to be the dominant lipid classes (accounting for more than 35% of total lipids) in Euchaeta sp., whereas in Pleuromamma spp., phospholipids, known as cellular membrane components, were the dominant lipid classes. However, the exception was specimens from warm pool region exhibiting dominance in storage of lipids as a form of triacylglycerols. Among fatty acids, polyunsaturated fatty acids (PUFA), especially docosahexaenoic acid (DHA : 22:6(n-3)) (about 35% of total fatty acids), were most abundant in Euchaeta sp., while saturated fatty acids (SAFA), specially hexadecanoic acid (16:0) (about 30% of total fatty acids), were most abundant in Pleuromamma spp.. Among the neutral fraction of lipids, phytol, originated from the side chain of chlorophyll, was found in all samples which generally indicate active copepods feeding on algae. While only trace amounts of short-chain fatty alcohols were found in Pleuromamma spp., significant amounts of fatty alcohols were found in Euchaeta sp.. Particularly, significant amounts of long chain monounsaturated fatty alcohols (20:1 and 22:1), generally found in cold water species, were found in Euchaeta sp. from low latitudes. The latitudinal variation of trophic lipid markers in these copepods could be significantly related with in-situ food availability and species-specific diet preference. The result of this study suggests that the lipid contents and compositions in copepods may not only indicate their nutritional condition and feeding ecology but also provide insight into species-specific living strategies under different environmental conditions (i.e. water temperature, food availability).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.771-781
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• 1997

In order to select an effective and appropriate evaluation method for the marine environmental protection and management, it is necessary to evaluate the present status of environmental conditions and to monitor and regulate the harzadous waste continuously. Among the evaluation methods that use benthic fauna, some graphical methods and biological index methods such as species abundance-biomass (SAB), Rank-frequency diagram (RFD), Abundance-Biomass comparison (ABC), log-normal distribution (LND), and Benthic Pollution Index (BPI) modified by Infaunal Trophic Index were used for the assessments of marine environment in the Inchon coastal area. Even though the graphic methods are convenient for easy glimpse of general trend of environmental condition but because they require sufficient ecological data, those methods do not fit for analysis or comparison of regional and detailed environmental condition. On the other hand, when BPI was applied, it was able to compare the spatial benthic conditions. Through considering the functional aspects of benthic fauna which can not be obtained in the cluster analysis, BPI was made it possible to measure or trace down the source of pollution. In the case of the environmental assessment result analyzed in Inchon coastal area, the north eastern part of Yongjongdo was more influenced by the pollution than the outer area of Inchon. The research indicates that especially Inchon harbor has been greatly affected.