► Vertical distribution of trace metals in core sediment was investigated. ► Significant increase of metal concentrations was observed due to anthropogenic activities. ► Metal concentration in upper ...part of core sediments exceeded the ERL criteria. ► Inadequate planning and management continued to highly accelerate metal pollution.
The vertical distribution of trace metals in sediment cores was investigated to evaluate the extent and the historical record of metal pollution over 30years in the artificial Lake Shihwa in Korea. A marked increase of trace metals after 1980 was observed due to the operation of two large industrial complexes and dike construction for a reclamation project. There was a decreasing trend of metal concentrations with the distance from the pollution source. The enrichment factor and pollution load index of the metals indicated that the metal pollution was mainly derived from Cu, Zn and Cd loads due to anthropogenic activities. The concentrations of Cr, Ni, Cu, Zn, As and Pb in the upper part of all core sediments exceeded the ERL criteria of NOAA. Our results indicate that inadequate planning and management of industrialization and a large reclamation project accomplished by dike construction have continued to strongly accelerate metal pollution in Lake Shihwa.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We present the Mg isotope composition and fractionation of chlorophyll-a and coccoliths using cultured coccolithophores that were grown at three different temperatures. The overall variations in δ
...26Mg values over a range of temperatures from 10 to 25
°C were 1.91‰ and 1.37‰ for chlorophyll-a and coccoliths, respectively. Chlorophyll-a and coccoliths of
E. huxleyi were slightly depleted in heavier isotopes relative to the culture medium. The isotope fractionation of coccoliths relative to culture medium was larger than that of chlorophyll-a. δ
26Mg of chlorophyll-a and coccoliths showed temperature dependence of about 0.10‰/
°C for chlorophyll-a and 0.06–0.10‰/
°C for coccoliths. δ
26Mg values in chlorophyll-a and coccoliths from the stationary phase were isotopically much lighter than those from the late exponential phase. There was a significant correlation between the δ
26Mg values of coccoliths and chlorophyll-a, suggesting that a growth rate-dependent step occurs during the initial acquisition of Mg from the culture medium. Additionally, a positive relationship was observed between ε
26Mg of either chlorophyll-a or coccoliths and the growth rates, indicating that Mg isotopic fractionation could be influenced by the growth rate. Further Mg isotope studies in coccoliths may provide a useful tool for coccolithophores productivity, especially with respect to the coccoliths' growth rate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•TBTs and metals in the sediments of a small marina in Busan, Korea were analyzed.•High concentrations of TBT and metals were observed in sediments from this area.•Coarse-sized antifouling fragments ...were major pollution source of the shipyard.•TBT and metal contaminated sediment grains exhibited high magnetic susceptibility.•Magnetic separation can be used to remove TBT and metals from shipyard sediments.
Bottom sediments near shipyards are often susceptible to receiving accidental spills of TBT and metals or their degradation products from hull scraping of antifouling system paints applied prior to 2008, when the AFS Convention 2001 was not in force. We investigated TBT and metal contamination of sediments near the shipyards of a small marina located in Busan, Korea and found that they were highly contaminated with TBT, Cu, and Zn. To better understand the environmental impacts and to make an optimal remediation plan, we characterized individual antifouling fragments in terms of metal and TBT contents, magnetic properties, and grain-size. Coarse-sized individual antifouling fragments exhibited simultaneously high levels of TBT, metals and high magnetic susceptibility, and appeared to be a major source of pollution in the sediment. Therefore, magnetic separation in combination with size-separation appears to be a cost-effective remediation method to remove the TBT and metals from contaminated shipyard sediments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Coccoliths from cultured specimens of two species of coccolithophores (
Emiliania huxleyi and
Gephyrocapsa oceanica) were sampled during two growth phases (late exponential and stationary), and their ...Mg isotope values (
δ
26Mg) as well as Mg/Ca values were measured in order to investigate whether
δ
26Mg can be used as a temperature proxy. Mg/Ca values were positively related with temperature (~
0.002
mmol/mol/°C), without statistically significant differences between the two growth phases and the two species. Both species were depleted in heavier Mg isotopes relative to the culture medium, and
δ
26Mg values were temperature dependent in both growth phases of
E. huxleyi, although the
δ
26Mg values differed in the two growth phases. In
G. oceanica, a weak correlation between
δ
26Mg values and temperature was seen in the late exponential growth phase only, and the
δ
26Mg values differed between growth phases. The large differences between
δ
26Mg values as measured in calcite formed during different growth phases indicate that Mg isotopes of coccoliths cannot be simply used as a temperature proxy. Our conclusions are preliminary and more data must be collected in order to fully evaluate the use of Mg isotopes of coccoliths as a temperature proxy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Pollution characteristics and ecological risks for metals in non-magnetic and magnetic road dust from steel industrial areas were investigated by applying a magnetic separation method. Metal (except ...for Al, Li, Ti, As, and Sb) concentrations in the magnetic road dust were 1.2 (Sn) to 7.8 (Fe) times higher than those in the non-magnetic road dust. For the magnetic road dust, the geo-accumulation index revealed a strongly to extremely polluted status for Cr, Zn, Cd, and Sb, a strongly polluted status for Mn, Cu, and Pb, and a moderately to strongly polluted status for Fe, Ni, Mo, and Hg. This result indicates that the dominant metal pollution sources of road dust in industrial areas were the traffic activities of heavy-duty vehicles. The mean content of magnetic particles accounted for 44.7% of the total road dust. The metal loadings in the magnetic road dust were 86% (Fe), 77% (Cr), 67% (Mn), 86% (Ni), 76% (Cu), 72% (Zn), 64% (Mo), and 62% (Cd), respectively. Removal of the magnetic fraction from road dust using magnetic separation techniques not only reduces metal contamination but can also improve effective road cleaning strategies or reduce waste generation.
The spatial distributions of dissolved lead (Pb) concentrations and stable Pb isotope ratios in the Ulleung Basin, East/Japan Sea, were investigated to identify the Pb source, the behavior of Pb in ...seawater, and the relationship between Pb isotopes and water masses. The Pb concentrations showed a surface maximum and rapidly decreased with increasing water depth. In the slope area, Pb concentrations increased near the seafloor due to diffusive flux from the sediments. The Pb concentrations in the surface layer were higher than in the Northwest Pacific Ocean and western Philippine Sea due to the proximity and downwind location of the sampling site from a Pb source area. The bottom Pb concentrations were lower in the study area than in the open ocean, indicating a higher scavenging rate due to the presence of well-developed bottom boundary layers from the continental slope to the basin. The Pb isotope ratios obtained from the continental slope and basin area were relatively constant among water masses. The Pb isotope ratios in the surface layer were similar to those of coal from northern China, which may indicate Pb supply from coal combustion in China. Meanwhile, Pb in the bottom water had a similar isotopic signature to Russian ore deposits and coal, indicating that bottom Pb is associated with thermohaline circulation in the East/Japan Sea. The Pb isotope ratios of the intermediate layer were constant across the depths of East Sea Central Water (ESCW) and were similar to aerosols measured previously (in 2003–2004) around Ulleung Island, which may indicate the timing of ESCW formation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The spring phytoplankton bloom is a critical event in temperate oceans typically associated with the highest productivity levels throughout the year. To investigate the bloom process in the Yellow ...Sea, daily data on physical, chemical, and phytoplankton taxonomic group biomass, calculated via the chemotaxonomic approach, were collected from late March or early April to late May between 2018 and 2020 at the Socheongcho Ocean Research Station. During early spring (late March to mid-April), phytoplankton biomass increased, accompanied by a decrease in nutrient levels, with Bacillariophyceae and Cryptophyceae being the dominant groups. As water temperature increased, a pycnocline began to develop in late April, leading to a peak of the phytoplankton bloom dominated by chlorophytes and Cryptophyceae. Network analysis suggested that this phytoplankton bloom was caused by the onset of vertical stratification induced by increased sea surface temperature. The chlorophyte peak induced phosphate limitation above the pycnocline, resulting in succession to Prymnesiophyceae and Dinophyceae. Following pycnocline formation, phytoplankton biomass below the pycnocline was dominated by Bacillariophyceae and Cryptophyceae, with decreasing or fluctuating trends depending on phosphate concentration. Apart from these general patterns, 2019 and 2020 both had distinctive traits. The 2019 data revealed lower phosphate concentrations than the other 2 years, leading to a smaller chlorophyte peak at the surface compared to 2018 and extreme phosphate limitation above the pycnocline. This limitation resulted in decreased biomass of late successional groups, including Prymnesiophyceae and Dinophyceae. Pycnocline formation was delayed in year 2020, and stratification was significantly weaker compared to the previous 2 years. Due to the pycnocline delay, the surface chlorophyte peak did not develop and no succession to late successional groups was observed. Instead, high levels of Bacillariophyceae and Cryptophyceae biomass were observed throughout the water column with no surface bloom. Thus, among various environmental factors, increasing surface water temperature and phosphate concentrations play pivotal roles in shaping phytoplankton bloom dynamics. Distinct yearly variation points to the broader impacts of climate shifts, emphasizing the need for continued marine monitoring.
The disposal of mine tailings into the marine environment is considered an essential option to secure the economic efficiency of deep-sea mining, but it might adversely affects the ecosystem. To ...examine the potential impacts of tailing disposal from polymetallic nodules and polymetallic sulfide mines on phytoplankton communities, addition experiments of crushed fine particles into surface seawater were conducted in the open Indian Ocean and changes in chlorophyll a fluorescence and community composition were analyzed. The addition of tailings had serious adverse effects on phytoplankton fluorescence and photosynthetic activity, regardless of mine type. The adverse effects seemed to mainly be due to the physical properties of the mine tailings. These also showed discriminatory effects on phytoplankton, resulting in great changes in community composition. The results suggest that mine tailings could have significant adverse impacts on phytoplankton assemblages, but the degree of impact greatly varies depending on the phytoplankton groups. The discriminatory impacts would cause changes in biomass, community structure, and thus ecological function.
Jeong, H.; Ra, K.; Kim, K.-T.; Kim, E.-S.; Lee, S.-Y., and Choi, M.-S. 2018. Tracing the pollution source using Pb isotopes in sediments of the coastal region surrounding the national industrial ...complex, Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1456–1460. Coconut Creek (Florida), ISSN 0749-0208. 166 sediment samples from Ulsan Bay and Shihwa Lake that is special management sea area were collected in 2014 not only to study the spatial distribution and pollution assessment of Pb but also to identify anthropogenic pollutions for Pb isotopes. The mean Pb concentrations of road-deposited sediments were higher than those of stream and coastal sediments in the study area. In all sediment samples, Ulsan showed an average concentration of 2 to 4 times higher than that of Shihwa. Pb concentrations in coastal sediments of more than 50 % were below the threshold effect level (TEL) of Korean marine sediment quality guidelines. The high exceedance of probable effect levels (PEL) showed in large harbors and near industrial facilities. Road-deposited sediments in Ulsan and Shihwa exceeded the class 2 (potentially toxic to benthic organisms) of Korean freshwater sediment quality guidelines. For both study areas, Pb isotope ratios tend to decrease with increasing Pb concentrations in sediments. In the case of Ulsan, high concentrations and low 206Pb/207Pb isotopic ratios were observed nearby the smelter and lead ore import harbor, indicating that Pb was released into the road surface during transportation using the vehicle and then moved to the marine area through the stream. However, Shihwa has a lot of small facilities (>19,000), it is difficult to clearly identify Pb pollution sources.
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BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Understanding the relationship between road-deposited sediments (RDS) and total suspended solids (TSS) is essential for managing non-point pollution. Studying the heavy metal concentrations of RDS ...and TSS in rainfall is important to the development of RDS management strategies and to the design of effective stormwater management practices. We investigated the heavy metal (V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Pb) in RDS and TSS in rainfall runoff to assess the metal pollution level and to evaluate the contribution of RDS heavy metal pollution in the TSS. The heavy metal pollution in RDS and TSS in industrial areas was relatively higher in small particles (<125 μm), while TSS had a higher heavy metal concentration than RDS. In addition, the concentration of heavy metals in TSS increased rapidly during the initial rainfall. The amount of particles larger than 125 μm also increased, suggesting that large metal particles accumulated in industrial areas were also discharged in the form of non-point pollution. The amount of RDS per unit of industrial area (g/m2) and the accumulation of heavy metals (Pb, Cu, and Zn) (mg/m2) were 15- and 8–54-fold higher than those of urban areas, respectively. Considering particles <125 μm, which can be easily transported or discharged during rainfall, the contribution rate of RDS to TSS was 41.3%, but the average contribution rate to heavy metals in TSS was 22.1%. The average load of heavy metals from industrial areas in TSS was 77.9%. The load of Cu, Ni, As, Cd, and Sn exceeded 90%, indicating that most of these metals were attributed to industrial activities related to metal processing. Our results suggest the importance of efficient road cleaning and rainfall runoff management strategies to solve the heavy metal pollution problem caused by non-point sources in industrial areas.
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•Heavy metals in road-deposited sediments (RDS) increases with decreasing size.•Heavy metals of total suspended solids (TSS) in runoff was higher that RDS.•Metal pollution in TSS has a greater influence on the industrial activities than RDS.•In industrial area, efficient runoff managements to control pollution is important.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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