• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.28-34
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• 2010

This study was conducted to assess the validity of fecal coliforms to fecal streptococci ratio (FC/FS) for distinguishing the human from animal origin of fecal pollution in surface water. FC/FS ratio determined in effluent from municipal wastewater and human feces treatment plant (WWTP) and in downstream close to discharge of human feces was above 4 which indicates human origin. However FC/FS ratios determined seasonally in other water zones of the Nakdong River, even in the same sampling site, varied differently (above 4 or less than 0.7) due to different survival time of FC and FS and other environmental factors such as rainfall in watershed. Compared to other season, FC/FS ratios in winter were much lower regardless of the origin. It is concluded that the FC/FS ratio determined in surface water is not always valid for determining the origin of fecal pollution.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.180-183
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• 2018

Fecal sites of the Siberian flying squirrel Pteromys volans were found in the 16 tree species, and 11 species (46.4%) of them were used as fecal sites in winter and only 3 tree species (5.6%) were used for their fecal dropping in summer. In winter and spring, 11 and 10 tree species were used as fecal sites, respectively, indicating that various species of trees are used in those seasons for food sources or resting sites of the flying squirrels. Of total 16 species, the flying squirrels' fecal sites were most frequently found in Quercus mongolica (46.4%) and then followed by Prunus sargentii (25.6%). In winter, Prunus sargentii was preferred more than Quercus mongolica, although trees of Prunus sargentii are less distributed compared with those of various trees of the genus Quercus. In summer and autumn, high productivity of trees makes the flying squirrels use only one or two species they prefer. In winter and spring, however, they should extend their food source to various tree species because of low productivity and less food sources.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.106-111
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• 2004

Fecal coliform bacteria is one of the most common cause of water quality impairments in Virginia, USA. Instream concentrations of fecal coliform (FC) bacteria were routinely monitored to assess surface water quality of the Polecat Creek watershed. Median concentration in water samples collected from 1995 to 2000 ranged from 80 cfu/100 mL to t 70 cfu/100 mL, while geometric mean concentrations ranged from 81 cfu/100 mL to 141 cfu/100 mL. The dilution and deposition by Lake Caroline may cause to lower FC concentration at monitoring site QPB, as compared FC concentration at QPD. Higher in-stream FC concentration occurred during the summer period(June-August), and lower concentration typically occurred during the winter period (December-February). This is due to more cattle in streams, and greater survival and regrowth of FC bacteria under warmer condition. The findings of this study can be helpful in planning the water quality monitoring program to avoid the inaccurate assessment of water quality due to the timing of sample collection.

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.161-165
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• 2008

This study was performed for the purpose of monitoring monthly levels of two pathogenic microorganisms, Cryptosporidium and Giardia, from November 2005 to August 2007 in Sangsa Lake. Water temperatures, pH and DO fluctuated seasonally at the study site. Annual mean values of BOD, COD and SS were $0.8\;mg\;L^{-1}$, $2.3\;mg\;L^{-1}$ and $1.9\;mg\;L^{-1}$ respectively. Although there was distinct seasonal variation in water chemistry and chlorophyll $\underline{a}$ concentration, the lake generally contains low concentrations of nutrients and chlorophyll $\underline{a}$. The relative abundance of coliform bacteria was always greater than that of fecal coliform. The fecal coliform bacteria comprised $8.5{\sim}22.1%$ of total coliform bacteria. Seasonal analysis of Cryptosporidium and Giardia levels in the study site showed that in winter (November through February), Cryptosporidium oocysts and Giardia cysts were most abundant ($1.1{\sim}1.8\;{\times}\;10\;cells\;L^{-1}$ and $3.8{\sim}5.1\;{\times}\;10\;cells\;L^{-1}$, respectively), while in summer (July through September) the abundance was lowest ($0.0{\sim}0.3\;{\times}\;10\;cells\;L^{-1}$ and $0.9{\sim}2.9\;{\times}\;10\;cells\;L^{-1}$, respectively). Molecular identification revealed two subtypes of Cyrptosporidium parvum in Sangsa Lake.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1239-1243
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• 2005

The water quality of the Ian Stream, a tributary of the Na14dong River, was estimated to provide an information in establishment of an ecological restoration plan for fan dam which will be constructed in near future. Seven stations were selected in upstream (3 stations) and downstream (4 stations) of Ian Stream, centering the construction site of Ian dam. Samples were collected at the surface water of 7 stations selected on May 1, June 16, and September 1 in 2004. The values of DO, pH, and BOD are satisfied Grade I for river water standard in nearly all sites. The concentrations of total nitrogen (TN) and total Phosphorus (TP) showed low level with ranges of $1.10\~2.25\;mgN/L,\;5\~14\;{\mu}gP/L$. However, the total and fecal conform bacteria were detected in nearly stations, especially high at the upstream stations. The number of fecal conform bacteria corresponds to the Grade III for river water standard. In addition, some metals (iron, manganese) were detected during dry season. As a consequence, general water quality of Ian Stream satisfied Grade I for river standard and it is expected that pollution loads from watershed is not significant. However, the detection of fecal conform, which is thought to be from livestock and residents, and some metals originating mimes watershed can have a potential health risk exists for aquatic organisms lived in Ian Stream. It needs to be solved by the construction of wastewater treatment plant to diminish the health risk from stream water polluted by fecal conform and metals, and to provide the safe ecological habitat for aquatic organisms.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.4
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• pp.160-172
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• 2020

To understand on-site feeding traits of Noctiluca scintillans with unprecedented high abundances around Dokdo in spring, 2014, the composition and abundance of food items in the digestive vacuole of the species were analyzed. Abundances of N. scintillans ranged from 4,328~17,791 inds.m^-3 around Dokdo during the study. The incidence of preyed items in the vacuole of N. scintillans ranged by averaged 32% (24~50%) in the surface waters around Dokdo. Diverse preyed items consisted of fecal pellet, protozoans, pollen, diatoms, dinoflagellates, copepods and ichtyoplankton, while fecal pellets were dominantly fed by N. scintillans (43%) and next by protozoans (19%), pollen (18%), diatoms (7%) and dinoflagellates (4%). Fecal pellet, protozoans and pollen were relatively preferred by N. scintillans compared to diatoms, dinoflagellates and ichtyoplankton based on the incidence in the food vacuoles. Present results indicated that high abundance of N. scintillans found around Dokdo was likely associated with non-phytoplankton items rather than previously well-known diatoms as prey during the study.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.295-305
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• 2011

Many studies have suggested the positive effects of grazing by large herbivorous mammals on seed dispersal, but little is known about how herbivores could affect the fate of ingested seeds. This study examined the effects of seed ingestion by sika deer (Cervus nippon) on seed fate in a temperate grassland established in an urban park long resided by high densities of sika deer. I compared species composition and seasonal traits of seed abundance and maturity in the grassland community with those in deer fecal pellets. In total, 27 herbaceous species were observed, including the predominant Zoysia japonica. Seed phenology and production differed among the three dominant species (Z. japonica, Digitaria violascens, and Hydrocotyle maritima). Pellets contained at least 26 species of herbaceous seeds, and their abundance differed among species. Of the 26 species, 15 were observed in the vegetation at the study site. The peak of seed abundance in pellets for the dominant species appeared 1 month after the peak of inflorescence production (but most of the inflorescences were immature and susceptible to digestion) and consequently corresponded to the peak of mature inflorescence. Because sika deer are likely to ingest seeds at any maturity stage in the grassland and immature seeds are less hardened, ingested immature seeds can suffer great losses. The results suggested that the survival of germable seeds with great losses of immature seeds may be a factor determining which plant species can be successfully dispersed by herbivores.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.391-397
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• 1989

Population of Aeromonas and environmental parameters were investigated at three sites from August 1986, to December, 1986 in Naktong Estuary. The variation range of Aeromonas was $4.3\times10^{2}-4.6\times 10^{4}$ MPN/100ml. The result of ANOVA indicates significant differences among the populations of Aeromonas in each site. The highest population of Aeromonas occurred at site 2, and the lowest at site 3-B. To scrutinize the effects of environmental parameters on the distribution of Aeromonas spp, principal component analysis and multiple stepwise regression were used. The results showed that distribution of Aeromonas spp. was mainly influenced by outflow of freshwater and inflow of inorganic nutrients and correlated with heterotrophic bacteria, available nitrogen, fecal coliform bacteria, and temperature.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.248-259
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• 2021

BACKGROUND: Contaminated water was a major source of food-borne pathogens in various recent fresh produce-related outbreaks. This study was conducted to investigate the microbial contamination level and correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water by logistic regression analysis. METHODS AND RESULTS: Agricultural water was collected from 457 sites including surface water (n=300 sites) and groundwater (n=157 sites) in South Korea from 2018 to 2020. Sanitary indicator bacteria (total coliform, fecal coliform, and Escherichia coli) and food-borne pathogens (pathogenic E. coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were analyzed. In surface water, the coliform, fecal coliform, and E. coli were 3.27±0.89 log CFU/100 mL, 1.90±1.19 log CFU/100 mL, and 1.39±1.26 log CFU/100 mL, respectively. For groundwater, three kinds of sanitary indicators ranged in the level from 0.09 - 0.57 log CFU/100 mL. Pathogenic E. coli, Salmonella and Listeria monocytogenes were detected from 3%-site, 1.5%- site, and 0.6%-site water samples, respectively. According to the results of correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens by logistic regression analysis, the probability of pathogen detection increased individually by 1.45 and 1.34 times as each total coliform and E. coli concentration increased by 1 log CFU/100mL. The accuracy of the model was 70.4%, and sensitivity and specificity were 81.5% and 51.7%, respectively. CONCLUSION(S): The results indicate the need to manage the microbial risk of agricultural water to enhance the safety of fresh produce. In addition, logistic regression analysis is useful to analyze the correlation between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water.

• Journal of Navigation and Port Research
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• v.35 no.4
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• pp.323-334
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• 2011

Suspended and sinking particles were collected in austral summer during ODP Leg 119 to the Indian Ocean sector of the Antarctic Ocean. Field work was carried out at four sampling sites in Prydz Bay. Two of these sites were located in the Outer Bay, and two in the Inner Bay. At the four locations, a total of ten deployments of a sediment trap array were made. The concentrations of chlorophylls and their degradation products both in suspended and sinking particulate matter in Prydz Bay were analyzed using HPLC. Chlorophylls a and c were the dominant algal pigments both in suspended and sinking particles. Because of the abundance of fecal pellets at Site 740, the mean fluxes at 200 m averaged 6 fold greater than that at 50 m. This implies that a dense swarm of zooplankters, presumably large copepods and/or salps, may "feed and excrete" mainly in between 100-200 m depths at this site, closest to land in Prydz Bay. Interestingly, The flux of phaeophorbide a was generally similar in magnitude to that of chlorophyll a throughout the study areas. This is an evidence that materials escaping from near-surface regions in austral summer derive mainly from the gazing of zooplankters. "New production" from sediment-trapped CHL pigment fluxes in Prydz Bay was estimated using f-ratio of 0.15, ranging from 520 to $1,605\;{\mu}gC\;m^{-2}\;day^{-1}$.