首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Hepatic microsomal 7-ethoxyresorufin O-deethylase (EROD) activities (indicative of exposure to polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs)) were measured in eel Anguilla anguilla from the Thames Estuary. Fish were collected from up to 13 sites during November 1997, May and August 1998 and October 1999. Throughout this period no clear seasonal variation could be identified at every site along the Thames. However, during the summer months, fish sampled from sites in the middle to the upper estuary (Woolwich, Greenhithe and West Thurrock) reported up to 3-fold higher EROD activities compared to sites either at the upper reaches (Richmond and Brentford) at the same time of the year, or fish sampled in winter, along the entire length of the estuary. A laboratory exposure experiment demonstrated a 3-fold elevation of EROD activity 2 days after injection with β-naphthoflavone (β-NF). However, higher levels of activity could be determined in fish sampled from the Weston canal near the Merseyside. The lowest levels of A. anguilla EROD activity were observed in fish sampled from the upper reaches of the River Tamar, Devon, and were comparable to activities determined in fish from the Wear and Humber estuaries. A. anguilla sampled along the Thames, Tyne and Tees estuaries reported between 2.5- and 7-fold higher EROD activities compared to fish collected from the Tamar. These results indicate that a low to moderate induction of A. anguilla CYP1A had occurred (indicative of low to moderate exposure to PAHs and planar PCBs) in fish collected from the Thames, Tyne, Wear, Tees, Humber and Tamar estuaries. However, the highest level of EROD activity was observed in fish from the Weston Canal (Merseyside).  相似文献   

2.
The outflow of brackish waters from the Tees estuary on an ebb tide forms a plume which is initially spread by the action of gravity. Under quiescent conditions, the rate of vertical mixing of the brackish field is relatively slow and an area of low salinity may form in the surface waters as a result of the superimposition of the outflow plumes from successive tides. A field area of some 70 km2 has been observed to be enclosed by the 34.2 × 10?3 contour.Averaged over a tidal period, the estuary outflow from the Tees forms a broad plume of low-salinity water which extends to seaward of the 20-m contour. The movement of the field thereafter depends on the residual coastal drift which runs either to the northwest or to the southeast with a typical speed of 0.015 m s?1. The tidally averaged vertical mixing coefficient in this offshore field was estimated to be about 10?4 m?2 s?1, which is similar to that off the Wear estuary and an order of magnitude smaller than that calculated for the waters off the Humber.  相似文献   

3.
The determination of hepatic ethoxyresorufin O-deethylase (EROD) has been used to assess the induction of the mixed function oxygenase system (MFO) of flounder (Platichthys flesus) in UK estuaries. Induction of the MFO system denotes possible exposure to certain organic contaminants (e.g. polycyclic aromatic hydrocarbons, polychlorinated biphenyls) and its measure has been incorporated in national monitoring programmes. This study presents EROD monitoring data from 5 UK estuaries taken between 1999 and 2001 and builds on data from previous years. The results reveal that for all sampled estuaries EROD values have been significantly (p < 0.05) elevated on the majority of occasions in comparison with the reference estuary, the Alde in Suffolk, UK. However, the limited temporal scale of the reported monitoring does not allow any conclusions to be drawn with respect to trends in the data. Possible factors influencing the data (size, gender, seasonality, reproductive status, etc.) are discussed and recommendations for continued monitoring are made.  相似文献   

4.
The modifications of several biomarkers were investigated in flounder (Platichthys flesus) when exposed in the laboratory to sediment samples collected from the Northern Adriatic Sea. Besides clean sand used as a control substrate, fish were exposed to sediments sampled offshore the delta of the Po River, the harbour of Trieste, and from the industrial harbour of Venice (Porto Marghera). After six days of exposure, the enzyme activities ethoxyresorufin-O-deethylase (EROD), UDP glucuronyltransferase (UDPGT), glutathione S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx), were assayed in fish liver. In addition, the contents of reduced glutathione (GSH), nonprotein thiols (SH), total sugars and extractable lipids were also determined in hepatic tissue, as well as the number of micronucleated hepatocytes and biliary concentrations of fluorescent aromatic compounds (FAC). Despite some variability within treatment groups, differences among exposed organisms were evident and consistent with known contaminant levels of sampled areas. Microsomal activities (EROD, UD-PGT) and FAC levels were the most sensitive exposure indicators. Variations in the other biomarkers showed only tendencies which although not statistically significant were generally consistent with the contamination pattern.  相似文献   

5.
A variety of sources of organic contaminants to the Great Barrier Reef lagoon and near-shore environment exist including boating activity, agriculture and urban run-off. Cytochrome P-450 1A activity as measured by ethoxy-resorufin O-deethylase (EROD) activity has been widely used as an indicator of the exposure of fish to organic contaminants such as polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH) and some organochlorine pesticides. This study demonstrates the successful application of EROD measurements in a common Australian tropical estuarine fish species, Acanthopagrus berda (Pikey Bream), to identify areas under potential stress from organic contaminants. Fish were captured from four creeks draining agricultural land, a creek draining urban land and two creeks with less disturbed catchments. Significant induction of cytochrome P450-1A was observed in fish captured from Ross Creek (urban catchment, 7.4-fold) and Cromarty Creek (agricultural catchment, 6.4-fold). Increased activity was also observed in fish captured from other creeks draining agricultural land (Plantation Creek, Victoria Creek, Seymour River, 1.9–2.6-fold) as compared to those captured from creeks in undisturbed catchments (Baldy Creek, Fisher Creek, 67–114 pmol/min/mg protein).  相似文献   

6.
Factors affecting longitudinal dispersion in estuaries of different scale   总被引:1,自引:0,他引:1  
Traditionally, the overall diluting capacity of an estuary is characterized using a coefficient of longitudinal dispersion, Kxe, which is given by the ratio of the dispersive flux of a dissolved substance to its tidally averaged longitudinal gradient. A steady-state model, which assumes a balance between the dispersive and non-dispersive fluxes and an exponential increase in estuary cross-sectional area towards the sea, has been used to derive expressions for the axial salinity distribution and the dispersive flux of salt. The model was set up assuming either a constant dispersion coefficient along the estuary or one that increased with distance towards the sea. By comparing salinity predictions with data from five UK estuaries, estimates were made of the maximum dispersive salt flux and the corresponding maximum salinity gradient for each system. The results indicated that there was an approximately linear relation between the fluxes and gradients, and the slope of a line plotted through the origin provided an estimate of a common Kxe for all five estuaries. The magnitude of Kxe was found to be about 90 m2 s–1 with a standard deviation of approximately ±32 m2 s–1. It is concluded that a representative value of 100 m2 s–1 for Kxe is a reasonable first choice when setting up a cross-sectionally averaged estuary model. The results also showed that larger systems, such as the Thames, had lower salinity gradients and lower dispersive salt fluxes, whilst smaller estuaries displayed the opposite characteristics. The model was used to predict the variation in the non-advective flux of salt along an estuary. The distribution was found to be similar to the corresponding flux distribution estimated from observations at the seaward end of the Tees estuary, despite appreciable spatial variations in the individual flux components. Allowing for a small decrease in freshwater flow, the model indicated that there was a decrease in the maximum dispersive flux between neap and spring tides. It is argued that such a reduction in flux can result in a seaward shift in the salinity distribution to a region of greater cross-section, where the freshwater transport per unit area again balances the reduced upstream dispersive flux, as found in the neap to spring response in the Tees estuary.Responsible Editor: Hans Burchard  相似文献   

7.
The purpose of this study was to compare enzymatic biomarker activities in fish caged at two sites, Masan Bay (contaminated) and Haeguemgang (reference). In the present study, ethoxyresorufin O-deethylase (EROD), brain acetyl cholinesterase (bAChE), muscle acetyl cholinesterase (mAChE) and butyryl cholinesterase (mBChE) in caged rockfish (Sebastes schlegeli) were measured 0, 1, 3, 7, 14, 21 and 30 days after caging. The level of CYP1A mRNA and Protein expression was induced higher in Masan Bay at 1, 3, 7, 14 and 30 days after caging. EROD activity in the caged fish was significantly higher in Masan Bay than in Haeguemgang 3 and 7 days after caging, but not at 14 and 30 days after caging. bAChE activity was significantly inhibited at 7 and 14 days after caging in Masan Bay. However, mBChE activity was not significantly inhibited during the experiment. Taken together, the data suggest that the caged fish were exposed, at least transiently, to CYP1A inducers and ChE inhibitors, which is consistent with our previous observations.  相似文献   

8.
The results of the present study are based on enzyme biomarker measurements in flounder (Platichthys flesus), a flatfish species that is widely distributed in Baltic coastal waters. The fish were collected from known pollution gradients and from reference areas regarded as relatively free of anthropogenic input. Muscular cholinesterases (ChEs), hepatic glutathione S-transferase (GST), and hepatic ethoxyresorufin-O-deethylase (EROD) activities were measured in each sampled specimen of flounder. Generalized linear models (GLM) were used to analyze the dependence of the enzyme activity on sampling year and area as well as on the biological parameters of the fish. Statistically significant differences in the activities of the measured biomarkers were observed between reference and contaminated sites. ChEs and GST activities differed with gender. The results of this study suggest that the location and year of sampling have a significant impact on the activity of all the measured biomarkers.  相似文献   

9.
Studies into the partitioning of trace metals between the dissolved phase and suspended solids have been performed on two major UK estuaries, the Mersey and the Humber. Aqueous phase trace metal concentrations were determined, along with partitioning data (Kp) determined from both laboratory equilibration experiments and by chemical leaching techniques.

Dissolved trace metals in the Humber essentially exhibited conservative behaviour (or a slight positive deviation). In the Mersey, however, removal of zinc, chromium, and, in particular, copper and cadmium occurred in the low salinity region.

Sequential extraction data gave an indication of the nature of trace metal bindings to suspended sediment, and revealed total extractable trace metals on the Mersey suspended sediment to be a factor of two greater than that found in the Humber. Similarly, partition coefficients in the Mersey were approximately an order of magnitude greater than in the Humber. Chloro-complexation was shown to control the partitioning of cadmium within estuaries. Copper, however, exhibited a distinct trend of increasing Kp with increasing salinity.  相似文献   


10.
基于鱼类江海洄游与否的电子探针耳石锶和钙微化学判别手段,对2020年5月采于赣江炉子窑江段的21尾刀鲚的生态表型进行了生活史重建的探索.研究发现,16尾为典型的溯河洄游型刀鲚,其占总刀鲚标本数量的比例达76%,远高于迄今鄱阳湖及其通湖水系所报道的相关比率.赣江中应该存在洄游型刀鲚的产卵场.这些首次确证了赣江中溯河洄游型刀鲚的存在,并体现出了在长江生态大保护及2019年2月1日业已开始的相关禁渔等国策下,赣江水域洄游型刀鲚资源量和栖息地有恢复向好的趋势.宜尽快开展赣江下游相关类群分布区和产卵场等及水利工程、河道挖沙等潜在威胁因素影响的全面调查,以便有效保护该水域的刀鲚资源及其关键栖息地.  相似文献   

11.
The fish fauna in the northern part of the upper river Rhine close to the city of Karlsruhe (Germany) was analyzed by collecting fish from the cooling-water intake of a power plant (impingement method) between 1989 and 2001. With this method a total of 36 fish species were recorded. The results were compared between the years as well as with other studies on the fish fauna in this area. Particularly with regard to the physical structure of the river bed and banks, the pre-technical situation of the river Rhine has not been restored. However, the number of fish species has been augmented since the 1970s mainly due to improvements in the water quality and almost all autochthonous fish species are present again. Altogether only three introduced fish species (Sander lucioperca L., Lepomis gibbosus L., and Carassius auratus gibelio were found in this study. Among the long-distance migrating species three freshwater spawners (Lampetra fluviatilis, Petromyzon marinus and Salmo trutta trutta) were detected in addition to the catadromous eel. The eudominant fish species varied between years, i.e. the European eel, Anguilla anguilla, was the eudominant species 1989, whereas this species occurred in much lower numbers during the subsequent sampling campaigns. This clearly indicates that the high dominance of eels is mainly caused by stocking activities in the upper Rhine. In the following years roach, Rutilus rutilus was the eudominant fish species. Overall a positive development of the fish fauna in the upper Rhine over the last 15 years could be observed in terms of fish populations as well as in terms of species richness.  相似文献   

12.
Sprat (Sprattus sprattus) larvae and mixed zooplankton were collected from sites in the southern North Sea across three transects running north, north-west and west from the Elbe and Weser estuaries (Germany). Sprat larval sub-cellular fractions (13,500 g supernatants) were assayed for the antixoxidant enzymes catalase (EC 1.11.1.6) and superoxide dismutase (SOD; EC 1.15.1.1), and levels of polychlorobiphenyls (PCBs), p,p'-DDE and polycyclic aromatic hydrocarbons (PAHs) were determined in the mixed zooplankton (fish larval diet). Higher levels (p < 0.05) of SOD and catalase activities were observed at sites closest to estuaries corresponding to sites with the highest levels (p < 0.05) of total PCBs and p,p'-DDE. Antioxidant enzymes activities decreased in samples collected from sites further from the estuaries across a northern and north-western transect; however this was not observed across a western transect. Larval antioxidant enzyme activities are discussed in relation to potential processes affecting them including plankton contaminant level distributions.  相似文献   

13.
A suite of biomarkers were measured in barramundi (Lates calcarifer) from five North Queensland estuaries along a perceived pollution gradient. The biomarkers selected were 7-ethoxyresorufin-O-deethylase (EROD), cytochrome P450, fluorescent aromatic compounds (FACs), DNA integrity, RNA:DNA ratio, cholinesterase activity (ChE), condition factor and hepatosomatic index. The resulting database was subjected to uni- and multi-variate analyses in order to assess the most suitable biomarkers to assess pollution in North Queensland estuaries and to classify the environmental quality of the sites. Principal components analysis (PCA) on the biochemical markers revealed that EROD, EROD/P450, DNA damage and to a lesser extent ChE and FACs were found to be responsive to contaminants in the environment while cytochrome P450, condition factor and the hepatosomatic index were found to be less responsive biomarkers. This study has demonstrated the utility of applying a multibiomarker approach in conjunction with traditional analysis of contaminants in providing valuable information in environmental risk assessment.  相似文献   

14.
15.
Petroleum and PAH contamination of the Black Sea   总被引:19,自引:0,他引:19  
Concern has been expressed regarding the extent of contamination of the Black Sea. Analyses of coastal sediments taken from throughout the region indicate, however, that levels of petroleum hydrocarbons (2-300 microg g(-1) dry wt total hydrocarbons) are generally comparable to those encountered in the Mediterranean and are lower than concentrations reported for highly contaminated areas such as the Gulf, Hong Kong, Taiwan and New York Bight. Highest concentrations of total hydrocarbons (>100 microg g(-1) dry wt) were associated with discharges from Odessa, Sochi and the River Danube. Chronic/degraded petroleum was the major contributor at these sites. Samples from the Ukrainian coastline were comparatively clean (<10 microg g(-1) dry wt total hydrocarbons). Major contributions of fresh oil (as indicated by sigma n-C14-34) occur through the River Danube. Concerning total PAH, concentrations (7-638 ng g(-1) dry wt) compare to relatively unpolluted locations in the Mediterranean and are much lower than levels reported for polluted UK estuaries (e.g. Mersey, Tyne, Thames). Both pyrolytic and petrogenic PAH are present in most samples, although petroleum derived PAH are dominant at Sochi and pyrolytic sources are prevalent in the Bosphorus region. The absence of a correlation between total hydrocarbons and PAH (R2 = 0.04) indicates different primary sources for the two.  相似文献   

16.
17.
In order to evaluate the health status of fish inhabiting Port Phillip Bay, Australia, southern sand flathead (Platycephalus hassensis, N = 133) were collected at six stations throughout the Bay. Fish had a similar serum sorbitol dehydrogenase (SDH) activity level (p = 0.12), indicating that they were not experiencing hepatocellular injuries. Ethoxyresorufin-O-deethylase (EROD) activity was generally lower in the non-urbanized and non-industrialized southern part of the Bay. The highest EROD activity was observed in Hobson Bay, the closest station from Melbourne city. Naphthalene-type biliary metabolites were also highest in Hobson Bay with intermediate levels found in Corio Bay where refineries are present. An opposite trend was observed with the pyrene-type bile metabolites, the highest levels being observed in Corio Bay while intermediate levels were found in Hobson Bay. The ratio of naphthalene-type to benzo(a)pyrene (B(a)P)-type metabolites indicate that relatively to other sites sampled in Port Phillip Bay, Corio Bay is subjected to enriched petroleum hydrocarbons of pyrolytic origin. Temporal trends indicate that the availability of xenobiotics to fish remained unchanged over the 1990s.  相似文献   

18.
An analytical protocol is described which allows parallel quantification of sewage, oil and PAH pollution on the same sample, thus maximizing the information gained for the effort expended. Capillary gas chromatography-flame ionization detection (GC-FID), now a routine technique in many laboratories, has been selected as the method for quantification. The protocol described is evaluated, and analyses of sediments from estuaries of the Rivers Mersey, Dee and Tamar, UK, are given as examples of how to interpret results achieved using the technique.  相似文献   

19.
《Marine pollution bulletin》2009,58(6-12):599-606
The purpose of this study was to compare enzymatic biomarker activities in fish caged at two sites, Masan Bay (contaminated) and Haeguemgang (reference). In the present study, ethoxyresorufin O-deethylase (EROD), brain acetyl cholinesterase (bAChE), muscle acetyl cholinesterase (mAChE) and butyryl cholinesterase (mBChE) in caged rockfish (Sebastes schlegeli) were measured 0, 1, 3, 7, 14, 21 and 30 days after caging. The level of CYP1A mRNA and Protein expression was induced higher in Masan Bay at 1, 3, 7, 14 and 30 days after caging. EROD activity in the caged fish was significantly higher in Masan Bay than in Haeguemgang 3 and 7 days after caging, but not at 14 and 30 days after caging. bAChE activity was significantly inhibited at 7 and 14 days after caging in Masan Bay. However, mBChE activity was not significantly inhibited during the experiment. Taken together, the data suggest that the caged fish were exposed, at least transiently, to CYP1A inducers and ChE inhibitors, which is consistent with our previous observations.  相似文献   

20.
Baseline information is presented on embryo malformation rate and biomarkers in fish as indicators of sub-lethal stress caused by pollution in coastal waters of Xiamen, PR China. Fish and eggs were sampled from several areas in Xiamen coastal waters (Xiamen Harbour, Maluan and Tongan Bays and East Channel), where varying levels of pollutant input have been documented. Comparative sampling was done at a "cleaner" reference site at Dongshan Island. Embryonic malformation rates, which indicate general water quality, varied with location and species of fish, and exceeded background levels for unpolluted waters (assumed approximately 5%) by up to eightfold at some sites. Generally, sites around Xiamen Harbour show signs of poor water quality having highest mean levels of embryo deformity (20-30%) and these decreased towards open waters (Tongan Bay, Eastern Channel) where abnormalities approached background levels. An indication that toxic contaminants may be having a localised effect in the region, particularly in the harbour was reinforced by the biomarker assays. However, activities of the biomarkers ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase in fish livers indicate no clear pattern, and there is no evidence that fish from the four sampling areas have been more or less exposed to PAHs and other compounds that induce these biomarkers. Antioxidant biomarkers (glutathione peroxidase, catalase, superoxide dismutase, and reduced glutathione) suggest that exposure to xenobiotics appears to be lowest in Dongshan and Maluan and highest in the harbour and Tongan. Inhibition of acetylcholinesterase in fish muscle indicated possible effects by organophosphate and carbamate pesticides in Xiamen waters and these effects may be greatest in the area of the harbour.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号