Vertical variability of seawater DMS in the South Pacific Ocean and its implication for atmospheric and surface seawater DMS.

Shipboard measurements of atmospheric dimethylsulfide (DMS) and sea surface water DMS were performed aboard the R/V Onnuri across the South Pacific from Santiago, Chile to Fiji in February 2000. Hydrographic profiles of DMS, dissolved dimethylsulfoniopropionate (DMSP(d)), and particulate DMSP(p) in the upper 200m were obtained at 16 stations along the track. Atmospheric and sea surface water DMS concentrations ranged from 3 to 442pptv and from 0.1 to 19.9nM, respectively; the mean values of 61pptv and 2.1nM, respectively, were comparable to those from previous studies in the South Pacific. The South Pacific Gyre was distinguished by longitudinal-vertical distributions of DMS, DMSP(d), and DMSP(p), which was thought to be associated with the characteristic modification of biological activities that occurs mainly due to significant change in water temperature. The averaged DMS maximum appeared at 40m depth, whereas DMSP(p) and DMSP(d) maxima coincided with that of dissolved oxygen content at 60-80m. The sea-to-air fluxes of DMS were estimated to be 0.4-11.3micromold(-1)m(-2) (mean=2.8micromold(-1)m(-2)). A fairly good correlation between atmospheric DMS and sea-to-air DMS flux indicated that atmospheric DMS concentration was more sensitive to change in physical parameters than its photochemical removal process or surface seawater DMS concentrations.

Molecular cloning of vitellogenin cDNA in rockfish (Sebastes schlegeli) and effects of 2,2'4,4'5,5'-hexachlorobiphenyl (PCB 153) on its gene expression.

Many environmental chemicals are known to affect sex steroid production and vitellogenesis through agonistic or antagonistic pathways. To investigate the estrogenic effect of 2,2'4,4'5,5'-hexachlorobiphenyl (PCB 153) on reproductive function, we have constructed a cDNA library and cloned a 320 base sequence encoding a partial VTG mRNA of rockfish (rVTG), Sebastes schlegeli. We have examined the expression level of rVTG mRNA level by northern blot analysis and measured levels of plasma estradiol-17beta (E2) and testosterone (T) by radioimmunoassay (RIA). Plasma concentrations of T in female and male injected with PCB 153 were not significantly different between two dosages of 0.16 mg/kg b.w. and 0.57 mg/kg b.w. However, plasma concentrations of E2 in female fish injected with PCB 153 at 0.16 mg/kg b.w. and 0.57 mg/kg b.w. increased after 12 h and 24 h. An rVTG mRNA transcript of approximately 4.0 kilo bases was extracted from hepatic tissue for northern blot analysis, and the effects of PCB 153 on rVTG mRNA expression in vivo with both male and female juvenile rockfish were examined. The level of rVTG mRNA expression increased only in female rockfish injected with both dose levels of PCB 153 after 48 h of exposure. The results of this study suggest that PCB 153 may produce VTG in female through a synergic effect with E2 resulting in indirect disruption.

Seasonal and spatial distribution of nonylphenol and IBP in Saemangeum Bay, Korea.

In order to investigate spatial and temporal distribution of organic pollutants in the Saemangeum Bay, organophosphorus pesticides (10), alkylphenols (8), chlorophenols (2), bisphenol A were analyzed from the surface seawater taken in 2002-2003. Most of the analytes were not detected in all stations except nonylphenol and S-benzyl-O,O-di-isopropyl phosphorothioate (IBP). Concentrations of nonylphenol and IBP ranged from ND to 298 ng/l and from ND to 1840 ng/l, respectively. The high levels of nonylphenol and IBP were found in the estuary areas of Mangyeong and Dongjin River. The levels of nonylphenol and IBP in surface seawater varied through seasons and the high levels of nonylphenol and IBP were in summer season (August). Based on real time monitoring of IBP and on correlation between concentrations of target compounds and contents of salinity in seawater, physical mixing and diffusion of seawater were found to be the major factors that affect the spatial distribution of IBP and nonylphenol in the Saemangeum Bay environment.

Congener-specific survey for polychlorinated biphenlys in sediments of industrialized bays in Korea: regional characteristics and pollution sources.

Areas of the Korean coastline with heavy industry and major harbors were investigated for polychlorinated biphenyl (PCB) pollution. This investigation paid attention to variations in the PCB congener patterns for a possible source of contamination. Surface sediments from 49 sites were sampled. Although the occurrence of PCBs in coastal marine environment correlates well with shipping and industrial activities, the contribution from shipping activities is considerable because of its enormous economical importance in Korea. The highest concentrations were found in harbors with heavy ship traffic and ship construction. Principal component analysis (PCA) of congener-specific composition of PCBs revealed distinct regional patterns, especially in a harbor and steel manufacturing area. PCB signatures with enhanced higher chlorinated congeners were typical for harbors with shipping activities and correlated well with commercial formulations that were formerly used in ship painting. Lower chlorinated congeners with up to five chlorines were significantly abundant in steel works zones which differed from harbor zones. This distinction was consistent with the congener patterns in the ambient air and the effluent of the steel works as well as in the nearby surface sediments. This study identified steel manufacturing as a recent and ongoing emission source of PCBs in Korea's coastal zone.

Assessment of butyl- and phenyltin pollution in the coastal environment of Korea using mussels and oysters.

Butyl- and phenyltin residues in bivalves were quantified around the coast of Korean peninsula in 1995-1998 and 2001. Butyltin compounds were detected at all the sites surveyed, whereas phenyltins were detected at 41 out of 67 sites in 1995-1998. Tributyltin (TBT) concentrations in bivalves ranged 48-2800 ng Sn/g on dry weight basis. Triphenyltin (TPT) concentrations ranged <3-1820. The mean TPT concentration was 3.5 times less than that of TBT. Spatial distribution of TBT was closely related to boating and dry-docking activities. TPT concentration in bivalves showed significant correlation with TBT. Concentrations of TBT in bivalves, 2001 are not significantly changed compared to those in 1995-1998. However, TPT concentrations in bivalves steeply decreased in 2001. High concentration of TBT and lesser extent TPT and their nation-wide distribution indicate that organotins are one of major organic pollutants in the marine environment of Korea.

Accumulation of butyl- and phenyltin compounds in starfish and bivalves from the coastal environment of Korea.

Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteria pectinifera and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from <2 to 797 ng/g as Sn on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT.

Distribution characteristics of nonylphenols in the artificial Lake Shihwa, and surrounding creeks in Korea.

Nonylphenols were determined from the water, suspended particle, and sediment samples taken from the Lake Shihwa in Korea and its surrounding creeks flowing through municipal and industrial areas, and into the lake. The nonylphenols were detected at the concentration ranges of 0.0-41.3 microg/l, 0.0-116.6 and 0.3-31.7 mg/kg in water, suspended particle and sediment samples respectively. The contamination levels of nonylphenols were increased along the down stream. Considerably high levels of nonylphenols were found at the industrial area compared to the municipal area. No remarkable differences were found between the isomer patterns of nonylphenols for the sample matrices of each sampling site, i.e. water, suspended solids and sediment. Strong correlations between water and sediment with 10(5.2) of the mean partition coefficient (Koc ) were observed. These indicate that most of nonylphenols came from industrial wastewater at high level. It is thought that the water quality of the Lake Shihwa is affected greatly by industrial environments surrounding.

Seasonal and spatial distribution of nonylphenol in Shihwa Lake, Korea.

Alkylphenols (APs) have been known as endocrine disruptors and consequently received much environmental concern. This study focused on seasonal variation and spatial distribution of nonylphenol (NP) in various matrixes including dissolved water, particulates, surface sediment, sediment trap and sediment core taken from Shihwa Lake and its adjacent areas. A total of 11 phenolic compounds including nonylphenol, t-octylphenol (t-OP) and bisphenol A (BPA) were measured in February, June and October 2002. NP is the most abundant chemical among the phenolic compounds and its concentrations in dissolved water, particulates and surface sediments from Shihwa Lake were measured as 17.4-1533.1 ng/l, 4.3-831.2 ng/l and 10.4-5054.1 ng/g dw, respectively. NP concentration in dissolved water varied with seasons and generally showed a decreasing order of June > October > February, while the seasonal trend was hardly found in sediment. High levels of NP were measured in surrounding industrial complexes, the concentrations was decreased gradually with distance from the industrial areas. NP in core samples showed an increasing trend toward the core depth. There exists a reasonable correlation between NP in dissolved water and in particulates, whereas the correlation between NP in dissolved water and in sediments is not significant. APs concentrations in Shihwa Lake were comparable to other highly polluted areas of the world and their possible effects on various organisms in the lake are discussed.

Seasonal flux of nonylphenol in Han River, Korea.

In order to understand the behavior of nonylphenol (NP) in Han River, water, suspended particle and sediment samples were analyzed during summer, autumn and winter. Concentrations of nonylphenol in water ranged from 23.2 to 187.6 ng/l, in suspended particle from 6.8 to 190.8 ng/l and in sediment from 25.4 to 932.0 ng/gdrywt. An increasing trend in the concentration is noticed in all matrices along down the river. In case of water and suspended particle, concentrations were higher in warmer season than in colder season. Percentage of nonylphenol in the suspended particle phase decreased from 67% to 28% with decreasing temperature in water. A reasonable correlation (R2 = 0.63) was obtained for water and suspended particle. The partition coefficient Log Kp is 4.8. No seasonal variation of the concentration in sediment is noticed in this study.

Direct extraction of alkylphenols, chlorophenols and bisphenol A from acid-digested sediment suspension for simultaneous gas chromatographic-mass spectrometric analysis.

The direct extraction of alkylphenols, chlorophenols and bisphenol A from an acid-digested sediment suspension for GC-MS analysis was studied. The sediment was digested with acid while the hydrolyzed analytes were being extracted with dichloromethane. The conditions of the acid digestion and extraction were optimized in terms of time, acidity of digestion, and extracting solvent. It is possible to complete the extraction within 20 min with 5 ml of 0.1 M HCl digesting solution and three portions of 5 ml of dichloromethane. The recoveries of analytes were mostly around 90% with about 10% relative standard deviations. With this technique parallel treatment of large numbers of sediment samples is possible without any expensive special equipment or heating process. The analytical characteristics of this extraction technique were compared with Soxhlet extraction and the pressurized liquid extraction technique. The technique was examined and evaluated for real environmental sediment samples and certified reference material of natural matrix.

Horizontal and vertical distribution of PCBs and chlorinated pesticides in sediments from Masan Bay, Korea.

Horizontal and vertical distributions of organochlorine compounds (OCs) were determined in sediments from Masan Bay. The concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), HCB, hexachlorocyclohexanes (HCHs) and chlordane related compounds (CHLs) in sediments were in the range of 1.24-41.4, 0.28-89.2, 0.02-0.59, nd-1.03, and nd-2.56 ng/g, respectively. The spatial distribution of OCs showed a negative gradient from the inner of the bay to outer part of the bay, indicating that the source of OCs was probably located inside the bay. Compositional pattern of PCB congeners showed a relatively high concentration of high-chlorinated congeners in the inner part of the bay and a relatively low concentration of low-chlorinated congeners in the outer part. In sediment core from Masan Bay maximum concentrations of PCBs and DDTs are observed in the subsurface samples and correspond to an age of early 1980s and late 1960s. The concentration profiles of PCBs and DDTs in sediments of Masan Bay appear to correspond to use of PCBs and DDTs in Korea.

Accumulation of tributyltin in the blood of fish: its application for monitoring in the marine environment.

Accumulation of tributyltin (TBT) in serum, liver, muscle, and gill of olive flounder (Paralichthys olivaceus) was examined in a 30-d static-renewal exposure. Tributyltin accumulated rapidly in the serum of the olive flounder and to a greater extent than in the other tissues. The accumulated TBT concentrations in tissues were in the order of serum > gill > liver > muscle on a dry-weight basis. Tributyltin also was detected in the serum of feral fine-spotted flounder, Pleuronichthys cornutus, collected from the coastal area. The mean TBT concentration in serum (2,470 ng Sn/g) of the fine-spotted flounder was about 40 times higher than that in the liver (60 ng Sn/g) and 200 times higher than that in the muscle (27 ng Sn/g) on a dry-weight basis. The TBT concentrations in serum and sediment demonstrated a positive correlation. The percent TBT composition to total butyltin was much higher in the serum (71%) than in the other tissues and sediment (<47%). These results suggest that the analysis of fish blood serum could be a useful tool for monitoring exposure to TBT in the marine environment.