• Ocean Science Journal
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• v.42 no.3
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• pp.179-192
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• 2007

Understanding in climate effects on marine ecosystem is essential to utilize, predict, and conserve marine living resources in the 21st century. In this review paper, we summarized the past history and current status of Korean fisheries as well as the changes in climate and oceanographic phenomena since the 1960s. Ocean ecosystems in Korean waters can be divided into three, based on the marine commercial fish catches; the demersal ecosystem in the Yellow Sea and the East China Sea, the pelagic ecosystem in the Tsushima Warm Current from the East China Sea to the East/Japan Sea, and the demersal ecosystem in the northern part of the East/Japan Sea. Through the interdisciplinary retrospective analysis using available fisheries, oceanographic, and meteorological information in three important fish communities, the trend patterns in major commercial catches and the relationship between climate/environmental variability and responses of fish populations were identified. Much evidence revealed that marine ecosystems, including the fish community in Korean waters, has been seriously affected by oceanographic changes, and each species has responded differently. In general, species diversity is lessening, and mean trophic level of each ecosystem has decreased during the last $3\sim4$ decades. Future changes in fisheries due to global warming are also considered for major fisheries and aquaculture in Korean waters.

• Journal of Soil and Groundwater Environment
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• v.15 no.3
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• pp.7-14
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• 2010

Ecological Risk Assessment (ERA) supports a decision-making process such as establishment of environmental quality criteria. Soil quality criteria (SQC) are essential to protect soil organisms from the exposure to various soil contaminants. In this study, ERA methodologies of advanced countries for soil pollution were extensively compared to propose the ERA approach suitable for soil ecosystem in Korea. The soil ERAs in European Chemical Bureau(ECB), The Netherlands, and Canada can be classified as deterministic ecological risk assessment (DERA), and probabilistic ecological risk assessment (PERA) based on species sensitivity distribution (SSD). We propose three ERA methods according to abundance and reliability of soil ecotoxicity data. The method considered land use such as residential/agricultural, and industrial/commercial uses. The taxonomic groups of soil organism were classified as 'Class' level including different trophic levels (Magnoliopsida or Liliopsida, Clitellata, and Insecta or Secernentea). This study can be used to estimate the soil quality criteria to protect soil biota.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.8-14
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• 2015

Plants grown in metal-contaminated sites have to be managed and disposed of safely even in phytoremediation because heavy metals can be transferred to other organisms through the food chain, which could result in bioaccumulation in organisms of a higher trophic level. However, if the harvested plants could be used for bioenergy, the ecological risk is reduced and phytoremediation improves economic feasibility. This study researched the effects of EDDS (Ethylenediamine disuccinate) on the heavy metal uptake performance of Brassica campetris and Sorghum biocolor, both of which have potential as bioenergy plants. The results showed that EDDS could increase Pb, Cu, Ni, Cd, and Zn concentrations in the roots and shoots of both of these plants. Furthermore, EDDS reduced the metal inhibition of the S. bicolor length growth. The translocation factors (TF) of S. bicolor and B. campestris are smaller than one for all five heavy metals tested and decreased by the following order: heavy metal + EDDS > heavy metals only > uncontaminated soil. The results suggest that with regard to plant growth and metal accumulation, S. bicolor treated with EDDS is more suitable than is B. campestris for the phytoremediation of soils contaminated with multiple metal species.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2025-2036
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• 2000

A physicochemical process called ultra rapid coagulation(URC) was applied as a pilot scale to recover eutrophicated lake water at Inkyung Lake located on-campus in Inha university. The URC was uniquely designed to completely remove the presence of phosphorus up to 95%, which in turn leading to lessen the level of eutrophication of lake. For a pilot test of period, the lake was restored showing Carlson's Trophic State Index(TSI) of mesotrophic state which accounts for the reduction of total phosphorus and chlorophyll-a down to approximately 55 from 70 and 73, respectively. A residual presence of aluminum and additional coagulants in the effluent was tested for their potential effects on Photobacterium phosphoreum. The effect concentration ($EC_{50}$-15 min) observed in the effluent revealed that the bioactivity of Photobacterium phosphoreum was not influenced by the residual presence of coagulants. After the pilot test of period, the lake was consequently restored as a mesotrophic state in obtaining the second grade of lake water quality. The URC may be further applied for restoration of greater scale of lake in eutrophication.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.359-366
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• 2014

For an efficient and reasonable management scheme for protecting the soil environment, a soil ecological risk assessment (ERA) method should be developed prior to utilization, based on the contemporary uses and situations of each country. The Korean environmental policy focusing on soil protection is currently accelerating the development of the soil ecological risk assessment method. The soil ERA requires toxicological data on various trophic levels in the soil environment, and ultimately uses PNEC (Predicted No Effect Concentration), which is derived from collected toxicological data. Therefore, test species that are used to generate toxicity data are essential for conducting reliable ERA. This study aimed to select domestic test species for potential use in a reliable Korean ERA. Copper (Cu) and Nickel (Ni) were identified as target substances, with toxicity data (Cu, Ni) and standard test methods being collected to determine candidate species. The candidate species were first classified by soil trophic level, and then sorted into final domestic species. Forty out of 166 domestic species were determined as potential standard test species, whereas 17 out of 120 species were determined as potential Cu and Ni test species. Finally, this study presented potential soil test species based on the characteristics of the domestic soil environment, and established a preliminary step toward developing a reliable Korean soil ERA method.

• Journal of Environmental Science International
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• v.23 no.10
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• pp.1703-1718
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• 2014

An eco-friendly integrated multi-trophic aquaculture (IMTA) farming technique was developed with the goal of resolving eutrophication by excess feed and feces as fish-farming by-products. A variety of seaweed species were tried to remove inorganic nutrients produced by fish farming. However, there have been few trials to use Sargassum fulvellum in an IMTA system, a species with a relatively wide distribution across regions with various habitat conditions, great nutrient removal efficiency and importance for human food source and industrial purposes. In this regard, our study tried to examine feasibility of using S. fulvellum in an IMTA system by analyzing growth characteristics of the species in an IMTA system comprising of rockfish (Sebastes shlegeli), sea cucumber (Stichopus japonocus) and the tried S. fulvellum (October 2011 - November 2012). We also monitored environment conditions around the system including current speed, water temperature and inorganic nutrient level as they may affect growth of S. fulvellum. S. fulvellum in the IMTA system, which were $15.72{\pm}5.67mm$ long at the start of the experiment in October 2011, grew to a maximum of $1093{\pm}271.13mm$ by May 2012. In September, seaweed growth was reduced to a minimum of $280{\pm}70.43mm$ in length. Then, S. fulvellum began to grow again reaching $325{\pm}196.19mm$ by November 2012. Wet weight of the seaweed was $4.01{\pm}1.89g$ at the start of the experiment and reached a maximum of $109.26{\pm}34.23g$ in May. The weight gradually declined to a low of $15.12{\pm}8.40g$ in September 2012. Weight began to increase once more, rising to $39.27{\pm}21.69g$ by November. During the experiment, the average velocity at the surface and the bottom was 6.5 cm/s and 3.4 cm/s, respectively. The water temperature ranged $5.0-23.5^{\circ}C$, which was considered suitable for growing S. fulvellum. Results of the study indicated no significant differences in inorganic nutrients between pre- and post-IMTA installation. It was thus concluded that S. fulvellum can be a suitable seaweed species to be used in an IMTA system.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.172-182
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• 2009

This study was to analyze characteristics based on tolerance and trophic guilds and to determine the level of total mercury in tissues of sentinel species, Zacco platypus at 3 sampling sites of the Mangyeong River in 2007. Total sampled fishes were 26 species and the most dominant species was Zacco temminckii (47%). Fish community analysis was resulted that eveness index and diversity index showed low value at S1. However, diversity index and richness index at other sites showed high. According to various guilds analysis, relative abundance of sensitive species was 70% and 42% at S1 and S2, respectively. While sensitive species were decreased (1%) and tolerant species were increased (60%) at S3. It was mainly carried to the impacts of wastewater treatment plants near the location. Relative abundance of insectivore species was decreased from up (S1) to midstream area (S3). In addition, chemical water quality, based on analyses of BOD, COD, TP, TN, EC, MPN and SS concentration showed similar trends. Qualitative Habitat Evaluation Index (QHEI) was averaged 164, judged as "good" habitat condition. Average concentrations of total [Hg] was 146.9 ${\mu}g$ $kg^{-1}$. In the muscles of total [Hg] was the highest, and then followed by kidney, vertebrae, liver, and gills. According to FDA standards (500 ${\mu}g$ $kg^{-1}$) of Korea, total [Hg] has not affected to the individual fish health.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.106-111
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• 2008

Six standard methods for marine ecotoxicological tests were established(or applicated) using marine decomposer, primary producers and consumers. Development processes referred to the standard methods established by USEPA(United States Environmental Protection Agency), international organizations and European methods. However, the standard test species were selected among the domestic species generally found in the Korean waters and sediments. The test methods provide the culture/maintenance of test species, test methods, reproducibility and quality acceptance criteria etc. A total of nine test species were designated including bioluminescent bacteria(Vibrio fischeri), diatom(Skeletonema costatum), seaweed(Ulva pertusa), rotifer(Brachionus plicatilis), benthic copepod(Tigriopus japonicus), benthic amphipods(Mandibulophoxus mai, Monocorophium acherusicum), and fishes(Oryzias latipes, Paralichthys olivaceus). These test species represent the decomposer, primary producer and consumers in marine trophic system in Korean coastal ecosystems, and we recommend the "battery test" including at least one species from the each trophic level for marine ecotoxicological test.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.144-154
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• 2007

The acute and chronic toxicity of ambient and effluent water discharged to Lake Shihwa were investigated by using Vibrio fischeri, Daphnia magna and Oryzias latipes. Physicochemical characteristics including biochemical oxygen demand (BOD) and nine heavy metals in a total of 15 water samples were evaluated and were satisfied with relevant Korean Water Quality Standards (KWQS) except for Hg in one sample. Acute toxicity was observed in five samples collected from three sampling locations. When impacts on reproduction and growth after chronic exposure were evaluated with D. magna, all the samples showed significant chronic effects. Reproduction appeared relatively more sensitive endpoint. In 21 days chronic tests on O. latipes, survival, mean egg number per female per day, hatching success rate and time to hatch were affected by increasing sample concentration. The organ-level changes such as gonadosomatic index (GSI), and hepatosomatic index (HSI), and molecular biomarker of vitellogenin (Vtg) induction that evaluated with O. latipes increased as exposure concentrations increased. It is noteworthy that the samples that did not exceed the KWQS resulted in acute and chronic toxicities. The results suggested that numeric criteria based on physicochemical parameters may not be protective of aquatic ecosystem. Acute and chronic toxicity tests with organisms representing different trophic groups should be supplemented in order to provide adequate level of environmental protection.

• Journal of Korean Society on Water Environment
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• v.36 no.5
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• pp.431-444
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• 2020

The relationship between dam construction and water quality has recently come to be considered an important issue. A dam is a physical factor which causes changes to the river system around it. Considering these points, this study was conducted to obtain basic data by analyzing the relationship between water level fluctuations and water quality parameters in the short-term. In terms of methodology, the new construction of the Yeongju Dam (M5) in 2016 was divided into Stage 1 as the lotic system and Stage 2 as the lentic system, with four years in each period, and the water level fluctuations and water quality were analyzed using official data. As a result of this study, M5, a stagnant area in which organic matter and nutrients accumulate, was found to be an important factor in water quality management. In addition, the water level changed rapidly (0.9±0.2 m → 10.9±7.1 m) as the river environment condition was converted from the lotic system to the lentic system. In addition, water quality parameters such as BOD, COD, TOC, and Chl-a significantly changed in the short-term. Further, since the transport of organic matter and nutrients occurred well in the lotic system, sedimentation was expected to be dominant in the lentic system. Therefore, it was determined that when the river flow is blocked, autochthonous organic matter is an important factor for long-term water quality management in the future. This process can increase the trophic state of the water body. As a result of this study, the TSI_KO value was converted from mesotrophic in Stage 1 to eutrophic in Stage 2. Eventually, short-term changes in the river environment will affect not only changes in water level but also changes in water quality. Thus, a comprehensive and strategic approach is needed for long-term water quality management in the future.