• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.2
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• pp.87-93
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• 2002

A amphipod, Leptocheirus plumulosus was exposed to Ag contaminated sediments to evaluate relative importance of various uptake routes (sediment, porewater, supplementary food) for Ag bioaccumulation in sediment-dwelling marine invertebrates. Additionally, influence of AVS (acid-volatile sulfide) on the partitioning of Ag to porewater and on the Ag bioavailability was determined to evaluate the utility of AVS criteria for the management of metal contaminated sediment. The experimental sediments were spiked with 4 levels of Ag (0.1-3.3 ${\mu}$mol Ag/g) and AVS concentrations were manipulated to 40 or <0.5 ${\mu}$mol/g, then equilibrated for >2 months to allow pore water/particulate distributions similar to nature. A L. plumulosus was incubated in the contaminated sediments with overlying water for 35d. During the exposure, the amphipods was fed with supplementary food ($TetraMin^{(R)}$) with or without Ag contamination. Following exposure, tissue Ag in L. plumulosus was strongly correlated with the weak acid extractable Ag in sediments ($r^{2}$=0.87, p<0.001). The ratio of AVS to Ag-SEM (Ag extracted simulaneouls with AVS) had a strong influence on porewater Ag concentration, consistent with previous studies. However, Ag bioaccumulation in L. plumulosus was not influenced by AVS concentrations. The amphipods fed Ag contaminated food took up ${\sim}$ 1.8 X Ag accumulated by the amphipods fed uncontaminated supplementary diet. The result suggests that the benthic invertebrates exposed to metal contaminated sediments would accumulate metals largely via ingestion of contaminated sediments and food, with minor contribution from dissolved sources of porewater and overlying water.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.24-29
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• 2013

In the present study, the effects of prebiotics and prebiotics+probiotics on intestinal microflora and fermentation products were evaluated in a pig in vitro fermentation model. The substrates used in this study were iso-malto oligosaccharide (IMO), partially digested chicory-inulin (CI), raffinose (RA), and cyclodextrin (CD) as prebiotics and Lactobacillus reiteri as probiotics. For a pig in vitro fermentation, the experimental diet for growing pigs was predigested using digestive enzymes secreted by small intestine and this hydrolyzed diet was mixed with a buffer solution containing 5% fresh swine feces. The mixture was then incubated with either prebiotics or prebiotics+probiotics for 24 h. Samples were taken at 24 h, and viable counts of microflora, gas, pH, volatile organic compounds (VOCs) and short-chain fatty acid (SCFA) were analyzed. The viable count of Enterobacteriaceae was significantly decreased (p<0.001) in all treatments containing prebiotics and prebiotics+probiotics when compared to the control. However, the number of lactic acid bacteria increased in the prebiotics and prebiotics+probiotics treatment. The pH values in the fermentation fluid decreased in all treatments when compared to the control, and their effects were greater in the prebiotics+probiotics group than prebiotics group. Fermentation with prebiotics resulted in a reduction in malodorous compounds such as ammonia, hydrogen sulfide and skatole when compared to the prebiotics+probiotics group. Short-chain fatty acid production was also higher for treatment with prebiotics+probiotics than treatment with prebiotics. In conclusion, the results of this study demonstrated that fermentation with prebiotics was effective in reducing the formation of malodorous compounds and prebiotics+probiotics was effective in increasing lactic acid bacteria and SCFA and reducing the pH. Moreover, further studies will be needed to determine whether the results observed in the in vitro model would occur in pigs that ingest these prebiotics or probiotics.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.421-428
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• 2014

Total 20 surface sediments were collected in Anjung bay to investigate the physicochemical environment and heavy metal contents. The physicochemical investigation ranged from 6.41% to 11.68% (average $9.52{\pm}1.28%$) for ignition loss (IL), from 17.99 mg/g to 43.84 mg/g (average $27.53{\pm}6.39mg/g$) for chemical oxygen demand (COD), and from 0.05 mg/g to 0.61 mg/g (average $0.17{\pm}0.14mg/g$) for acid volatile sulfide (AVS) with significant correlation between water content (W/C) and COD. A contour of spatial distribution indicated higher organic pollution at the bottom of ascidian, Stylea clava, cultural waters. Most of metals contents was not exceeded the NOAA's effect range-low (ERL). Estimated enrichment factor (EF) ranging 0.96-1.12 indicated that the sediment environment of the studied waters was relatively pristine from heavy metal pollution in spite of increased vessel traffics, so far.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.691-710
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• 2017

This study was performed to investigate the geochemical and benthic environment of three shellfish farms in Suncheon Bay during the period of September 2014 ~ April 2015. Three sampling stations were selected; St.1 is the shellfish farm of razor clam near Jangsan area. St.2 is the shellfish farm of small ark shell near Hwapo area and St.3 is the shellfish farm of razor clam near Yongdu area. Razor clam was the dominant species at St.1, small ark shell and granulated ark shell were dominant at St.2 and St.3, respectively. Granulated ark shell inhabited St.3, although it is not cultured at that station. This station's exposure to air during the ebb tide and sediment composition likely provides the appropriate habitat for granulated ark shell species. Analysis of the number of different species showed that 8 benthos species were found to be distributed at St.1, 18 species at St.2, and 13 species at St.3. Among three stations, the highest Ignition Loss (IL), Chemical Oxygen Demand (COD) and Acid Volatile Sulfide (AVS) values were obtained from the sediment at St.2. The analysis of pore water from St.2 also showed the highest values of Total Organic Carbon (TOC), ammonia ($NH_4^+$), Dissolved Inorganic Nitrogen (DIN) and phosphate ($PO_4^{3-}$). These results are related to the fact that species dominance and richness is the highest in St.2.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.129-135
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• 2006

This study was performed to characterize the seasonal variation of water quality and sediment environment from May, 2004 to February, 2006 in 21 stations of Gwangyang bay. Gawngyang bay is located in the middle of south coast of Korea and semi-dosed with Yeosu peninsula, Gwangyang-city and Namhea-do. Water quality at the west coast of Myo-do were highly deteriorated than other stations. At summer season(July 2005), the concentration of the most analytical items were highly detected than other seasons and the lowest concentration was at the winter season(January 2005, February 2006). Especially, DIP and TP were highly detected around the coast of Yeosu industrial complex. N/P ratio were higher than 16 of Redfield ratio in the spring(May 2005) and winter(February 2006) at the surface layer. While at other seasons and most stations were lower than 16 of Redfield ratio. In the survey of sediment environment, ignition loss(IL), chemical oxygen demand(COD) and acid volatile sulfide(AVS) were in the range of $2.51\sim22.10%,\;2.65\sim48.41mg/g-dry\;and\;0.01\sim8.95mg/g-dry$, respectively. COD in surface sediment was highest at summer season AVS was highest at autumn. In sediment, the corelationship coefficients between COD and IL, COD and AVS were 0.65 and 0.44, respectively.

• The Korean Journal of Malacology
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• v.27 no.4
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• pp.291-297
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• 2011

In an attempt to improve the substrate condition for Manila clam (Ruditapes philippinarum) culture, crushed oyster (Crassostrea gigas) shells were spread on the muddy tidal flat of Namseong-ri, Podu-myeon, Goheung-gun, Jeollannam-do in April 2008. To test the suitability of the crushed oyster shell added substrate, seed clams were transplanted from Taehwa river estuary in Ulsan city in June 2008. Over 23 months of sampling, the mean grain size and the sorting in the experimental site containing the crushed oyster shell were significantly higher than the control site. The ignition loss, water content, chemical oxygen demand (COD) and acid-volatile sulfide (AVS) level were also significantly higher in the crushed oyste shell added substratum. Survival of the clams transplanted to the crushed oyster shell added substratum was significantly higher and all the clams transplanted to the normal muddy substratum died in August 2009, 13 months after the transplantation. At the end of the experiment in April 2010, the transplanted clams reached 36.10 mm in shell length and 8.92 g in total weight with survival of 43.5%. Our study suggested than crushed oyster shell added in the mud dominant substratum greatly improved living condition and survivability of clams.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.392-402
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• 2020

We investigated the concentrations of acid volatile sulfide (AVS), ignition loss (IL), total organic carbon (TOC), total nitrogen (TN), and metallic elements (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn), in August 2015, to determine the spatial distribution and pollution status of organic matter and metals in the surface sediment of Jinju Bay, a spraying shellfish farming area, Korea. The concentrations of organic matter and metallic elements were significantly higher in the southern part of the bay than in the mouth and center of the bay. The C/N ratio (5.7~8.0) in the sediment represents the dominance of organic matter of oceanic origin in the surface sediment of the study area. The concentrations of AVS, TOC, and metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) were much lower than the values of the sediment quality guidelines applied in Korea. Based on the results of the pollution load index (PLI) and ecological risk index (ERI), the metal concentrations in the surface sediment of Jinju Bay have a weakly negative ecological effect on benthic organisms although the sediments with high metal pollution status are distributed in the southern parts of the bay, with high dense shellfish farming areas. Thus, the surface sediments in Jinju Bay are not polluted with organic matter and are slightly polluted with metallic elements.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.225-232
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• 2012

In order to evaluate the relationship of between the contents of inorganic elements in shellfish and surface sediments, we measured the concentration of inorganic elements (As, Ca, Cd, Cr, Fe, Hg, Li, Mn, Ni, P, Pb, Zn) in various shellfish and surface sediments of research area. The enrichment factor (EF) and the index of accumulation rate (Igeo) of the metals showed that the research areas can be classified as moderately polluted, or unpolluted. And also we measured the geochemical characteristics of surface sediments(grain size, chemical oxygen demand (COD), ignition loss (IL) and acid volatile sulfide (AVS). The grain sizes for research areas of surface sediment were similar the ratio of silt and clay in comparison with other sites. The COD and IL in surface sediment ranged from 5.41 to 14.06 mg/g. d.w. (mean $8.78{\pm}3.16$ mg/g d.w.) and from 0.92 to 3.17% (mean $2.08{\pm}0.86%$), respectively. Siginificant differences in metal concentrations also were determinated in the shellfish tissue among the different sites. However, except for metals(Mn, Zn), which showed some elevation of concentrations, the variations in the shellfish tissue were not related to variations in the sediment.

• Journal of Environmental Science International
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• v.17 no.7
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• pp.755-765
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• 2008

To investigate correlation between the distribution of marine bacteria and environmental characteristics in the surface sediments of Kamak Bay, chemical oxygen demand(COD), acid volatile sulfide(AVS), ignition loss(IL), total organic carbon(TOC), and total organic nitrogen(TON) were measured and analyzed at 7 stations in winter and summer. In winter, COD and AVS ranged from 13.45 mg/g to 30.06 mg/g(average: 23.58 mg/g) and from 0.03 mg/g to 1.04 mg/g(average: 0.63 mg/g), respectively. IL, TOC, and TON ranged from 8.03% to 11.41%(average: 9.41%), from 1.17% to 2.10%(average: 1.62%), and from 0.09% to 0.18%(average 0.15%), respectively. In summer, COD, AVS, IL, TOC, and TON ranged from 14.06 mg/g to 32.19 mg/g(average: 24.71 mg/g), from 0.03 mg/g to 1.11 mg/g(average: 0.66 mg/g), from 9.00% to 12.15%(average: 10.96%), from 1.27% to 2.12%(average 1.77%), and from 0.12% to 0.19%(average: 0.16%), respectively. These values were relatively higher than those in winter. Kamak Bay had high C/N ratio that might be resulted from the input of terrestrial sewage and industrial wastewater. The number of marine viable bacteria was $8.9{\times}10^4\;cfu/g$ in winter and $9.7{\times}10^5\;cfu/g$ in summer. The most abundant species were Pseudomonas spp., Flavobacterium spp., and Vibrio spp, in the surface sediments of Kamak Bay. It was found that the concentration of organic matters and viable bacterial cells in the inner part were relatively higher than those in the outer of Kamak Bay. The distribution of viable bacterial cells was closely influenced by environmental factors.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.1
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• pp.80-85
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• 2006

Ninety six crossbred pigs (Landrace${\times}$Yorkshire${\times}$Duroc) were used to determine the effects of essential oils (Fresta F $Conc^{(R)}$) supplementation on growth performance, immune response and fecal noxious gas of weaned pigs. Treatments were 1) NC (negative control; basal diet without antibiotics), 2) PC [positive control; basal diet+CSP (CTC+Sulfathiazole+Penicillin) 0.1%], 3) NCF (basal diet+Fresta F $Conc^{(R)}$ 0.03%) and 4) PCF [basal diet+CSP (CTC+Sulfathiazole+Penicillin) 0.1%+Fresta F $Conc^{(R)}$ 0.02%]. From d 0 to 14, ADFI was increased in pigs fed PCF diet (p<0.05). From d 14 to 28, pigs fed PCF diet had greater ADG and ADFI than pigs fed NC diet (p<0.05). From d 28 to 49, ADG and ADFI in pigs fed PCF diet were higher than in pigs fed NC diet (p<0.05). Through the entire experimental period, ADG and ADFI in pigs fed PCF diet were the highest compared to pigs fed NC and PC diets (p<0.05). There was no significant difference in fecal consistency score among the treatments (p>0.05). No statistical differences (p>0.05) were found in red blood cells (RBC) counts, white blood cells (WBC) counts, lymphocyte counts, total protein and albumin. Serum IgG concentration of PCF treatment was greater than that of other treatments (p<0.05). From d 0 to 14, there was no significant difference in digestibility of dry matter and nitrogen among the treatments (p>0.05). From d 14 to 28, digestibility of dry matter in pigs fed PC, NCF and PCF diets was higher than that of pigs fed NC diet (p<0.05) and treatments with added essential oils were higher than other diets on digestibility of nitrogen (p<0.05). Also, from d 28 to 49, digestibility of nitrogen in pigs fed PCF diet was the highest among others (p<0.05). On d 14 and 28, no statistical differences (p>0.05) were found in volatile fatty acid (VFA), ammonia nitrogen ($NH_3$-N) and hydrogen sulfide ($H_2S$) concentrations among treatments. On d 49, there was no significant difference in VFA concentration among the treatments (p>0.05). $NH_3$-N concentration in pigs fed PCF diet was lower than in pigs fed other diets (p<0.05). $H_2S$ concentration in pigs fed diets with added essential oils was lower than others. In conclusion, the results suggest that the dietary addition of essential oils and antibiotics into diets for weanling pigs improved growth performance, IgG concentration and nitrogen digestibility and decreased noxious gas concentration. Essential oils can be used to partly replace antibiotics in diets for weaned pigs without negative affects on growth performance.