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1.
The occurrence of biomarker variations linked to environmental factors makes it difficult to distinguish the effect of pollution. In an attempt to evaluate spatial and seasonal effects of environmental parameters on biomarker responses, mussels Mytilus edulis chilensis coming from an aquaculture farm were transplanted to several points within Ushuaia Bay (Beagle Channel) for 6 weeks in summer and winter. Activities of superoxide dismutase, catalase, glutathione-S-transferase and levels of lipid peroxidation were measured in gills and digestive gland. Cu, Zn, Fe, Cd and Pb concentrations were also assessed. Results indicated a significant effect of seasons on biological responses as well as in metal bioaccumulation showing the influence of natural factors such as dissolved oxygen, temperature and food availability. The interdependence of those environmental factors is important for the homeostasis of thermoconformers, especially regarding their oxidative metabolism and should also be taken into consideration to distinguish natural from pollution-induced variations. 相似文献
2.
Vlahogianni T Dassenakis M Scoullos MJ Valavanidis A 《Marine pollution bulletin》2007,54(9):1361-1371
Mussels are used as sentinel organisms and bioindicators to evaluate the toxic effects of chemical pollutants in marine organisms, especially heavy metals, representing an important tool for biomonitoring environmental pollution in coastal areas. Antioxidant defence enzymes play an important role in cellular antioxidant defence systems and protect from oxidative damage by reactive oxygen species (ROS). Indigenous mussels Mytilus galloprovincialis of the Saronikos Gulf of Greece were used for monitoring heavy metal pollution in three polluted sites in the area and in one unpolluted site. Seasonal variations of the activity of antioxidant defence enzymes, superoxide dismutase (SOD) and catalase (CAT), as well as lipid peroxidation (LP) were measured as biomarkers in a period of three years in relation to concentrations of trace metals in their gills and mantle and compared to mussels from an unpolluted sampling site. SOD activity increased at least 2 fold at the polluted sites when compared to the control site (the high activity was recorded in the spring time). CAT activity was increased 2-3 times at the polluted sites, with high activity in the winter and spring time, compared to the control site. LP concentration was twice higher at the polluted sites, following the same seasonal pattern. Trace metals contents in mussels collected at polluted sites were 3-4 fold higher compared to the control site and showed moderate variations along the months, with a winter maximum followed by a summer pre-spawning minimum matching the seasonal trends of temperature and salinity. Our results showed that metal pollution in the Elefsis Bay (the most polluted coastal area) causes relatively medium levels of oxidative stress in tissues of mussels due to cellular oxy-radical generation. This study, which is the first in the area, showed that seasonal variations of the activity of antioxidant defence enzymes and LP concentrations in mussels can be used as potential biomarkers of toxicity for long-term monitoring in marine coastal ecosystems. 相似文献
3.
Possible xenoestrogenic effects were investigated, for the first time, in two bivalve species from the Lagoon of Venice (Italy): the clam Tapes philippinarum and the cockle Cerastoderma glaucum. Bivalves were collected far from their reproductive phase at the very early stage of gametogenesis (January), and in the pre-spawning period (June) in six sites. Vitellogenin (Vg)-like proteins (a biomarker of exposure to estrogenic compounds) were measured by the alkali-labile phosphate method (ALP), in both haemolymph and digestive gland from males and females (when it was possible to distinguish sex by microscopic observation of gonadal tissue). Haemolymph calcium concentrations (a parameter considered closely related to the presence of Vg-like proteins) and the bivalve condition index (CI) were also measured. In both seasons, bivalves collected at Campalto (near a sewage treatment plant) and Marghera (a highly contaminated area) had higher Vg-like protein levels, particularly in haemolymph, than animals from the other sampling sites. Interestingly, CI had high values in these polluted sites. In June only, Vg-like proteins and Ca(2+) levels in haemolymph exhibited similar trends in both bivalve species at most sampling sites. The responsiveness of bivalves to environmental xenoestrogens was higher in June, allowing better discrimination among sites. The present study demonstrates that animals from highly polluted areas have increased Vg-like protein levels. As endocrine disruption due to exposure to estrogenic compounds may cause fertility reduction, alterations in the sex ratio, and a decrease in reproductive rate, a condition of potential risk for bivalve populations in estuarine areas is highlighted. 相似文献
4.
Variation of polycyclic aromatic hydrocarbons (PAHs) levels was assessed in Tapes philippinarum from the Lagoon of Venice. Clams were transplanted from a polluted area next to Porto Marghera to two rearing areas of the Southern Lagoon. Analyses of PAHs were made in sediments and clams by GC/MS at first sampling and after 30, 60 and 180 days. Principal component analysis was performed to elucidate bioaccumulation and depuration pattern and input sources. Biota-Sediment-Accumulation-Factor (BSAF) was applied to evaluate the PAHs input sources from sediment. Condition index was calculated to compare the seasonal variation of clam tissue to PAHs levels. To propose results not affected by seasonal changes in flesh weight of clams, the approach based on the calculation of PAHs/SW index was applied. From the results, it was concluded that PAHs/SW index is more recommendable to asses temporal variation of PAHs levels in Manila clams. 相似文献
5.
Specific hydrological and hydrochemical conditions in Kenozero Lake have led to changes in the morphology of fishes at a cellular level. The abnormalities in the function of the respiratory, digestive, and excretory systems were recorded. The degree of pathology depended on the ecological features of the fish. The pathological changes were most pronounced in the gills of the fish species (orfe, perch, and roach) characterized by active mode of life and sensible to oxygen deficiency. The changes in the epithelium of gill filaments had a compensatory significance and were aimed at increasing the area of the functional surface of the gills under the conditions of hypoxia. 相似文献
6.
The aim of this study was to evaluate the usefulness of oxidative stress biomarkers of pollution in native mussels Mytilus edulis chilensis from the Beagle Channel. Spatial and seasonal variations of catalase, glutathione-S-transferase and lipid peroxidation in gills and digestive gland were analyzed in relation to environmental parameters, heavy metals in sediment and in tissue. Four sites with anthropogenic impact and a control site were selected and monitored during the four seasons of 2007. We found significant differences among sites in concentrations of dissolved nutrients and heavy metals in sediments, with the highest values recorded at sites with anthropogenic pressure. Different patterns were observed between concentrations of metals in tissues and in sediments suggesting differences in bioavailability. There were also significant differences in biomarker responses among sites, despite the strong seasonal variability. Our results showed relatively moderate levels of pollution in the study area as a result of urban influences. 相似文献
7.
The effects of 4-nonylphenol on anti-oxidant enzyme (superoxide dismutase and catalase) activity in both gills and digestive gland and re-burrowing capability of the clam Tapes philippinarum were investigated after 7 days' exposure to various sublethal concentrations of nonylphenol (NP). NP caused a significant decrease in superoxide dismutase activity in both tissues from the lowest concentration tested, whereas no significant alteration with respect to controls was observed in catalase activity. NP effects on re-burrowing of clams were evaluated in two experiments. In the first, clams exposed to the highest NP concentrations showed a marked delay in re-burrowing 48 h after the end of exposure. Modifications in normal burrowing behaviour were also observed, suggesting that NP acts via narcosis and/or neurotoxic mechanisms. In the second experiment, the elapsed time for 50% of the exposed clams to re-burrow into the sediment (RT(50)) was also calculated in a 24-h re-burrowing response test. At the highest NP concentrations, it was not possible to estimate RT(50) values, as the percentage of clams showing complete burial was less than 50%. The present study demonstrates that NP causes oxidative stress by inhibiting superoxide dismutase activity and greatly affects the re-burrowing capability of T. philippinarum, even at environmentally realistic concentrations. 相似文献
8.
Bonacci S Browne MA Dissanayake A Hagger JA Corsi I Focardi S Galloway TS 《Marine pollution bulletin》2004,49(5-6):445-455
Marine environments are continuously being threatened by a large number of xenobiotics from anthropogenic sources. Even in sparsely populated and relatively pristine areas, such as Antarctica, hazardous chemicals can pose a serious environmental problem. The main aims of the present study were to (1) validate and optimize an analytical technique utilizing a microtitre-plate photometer to ascertain background levels of esterase activities in the Antarctic bivalve Adamussium colbecki, (2) carry out in situ monitoring of esterase activities to assess any potential environmental impacts of the Italian Scientific Antarctic Base "Terra Nova Bay" on the surrounding marine area. Results showed the presence of organophosphorous-sensitive cholinesterase (ChE) and carboxylesterase (CbE) activities in the gills of A. colbecki and optimal assay conditions were comparable with those found for bivalve species from temperate areas. A higher sensitivity of ChE versus acetylthiocholine activity in A. colbecki to chlorpyrifos compared to species from temperate areas may also be inferred. The in situ study indicated no differences in the environmental quality of the three study sites located around the Italian Base. 相似文献
9.
The present study deals with the seasonal variation of temperature, alkalinity and dissolved oxygen in the Sagar lake. Different abiotic and biotic factors were investigated and a diurnal study was made, too. The investigation shows that the surface water values were always higher than the bottom water values. The water temperature ranged from 16.0 to 31.0 °C, carbonate alkalinity ranged from 0.0 to 46.0 mg/1, bicarbonate alkalinity ranged from 62.0 to 138.0 mg/1, dissolved oxygen ranged between 1.6 and 13.2 ppm. The water temperature was found to be positively correlated with carbonate alkalinity while an inverse correlation existed with bicarbonate alkalinity. Dissolved oxygen had a significant positive correlation with carbonate alkalinity, while a negative correlation was observed with bicarbonate alkalinity during all the seasons. 相似文献
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11.
The clams Ruditapes philippinarum were used to assess the impact of metal contaminants when transplanted to seven study sites along the Maluan Bay (China). Metal concentrations in digestive gland tissues of clams after 7-day in situ cage exposure were determined in conjunction with antioxidant enzyme activities. The results showed the importance of specific antioxidant biomarkers to assess complex pollutant mixtures and their good correlations to the pollutant compositions of deployment sites. Multivariate analysis indicated causal relationship between the chemicals at each study site and the biochemical "response" of the caged clams at these sites and demonstrated the potential presence of two different contaminant sources. This study suggested that the incorporation of tissue residue analysis with biomarkers response in caged clams together with factor analysis can be a useful biomonitoring tool for the identification of causal toxic pollutants and the assessment of complex metal pollutions in marine coastal environment. 相似文献
12.
Temporal and spatial distributions of nutrients under the influence of human activities in Sishili Bay,northern Yellow Sea of China 总被引：1，自引：0，他引：1
《Marine pollution bulletin》2012,65(12):2708-2719
The temporal and spatial distributions of dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON), soluble reactive phosphorus (SRP) and dissolved reactive silica (DRSi) together with chlorophyll-a, temperature and salinity were analyzed monthly from December 2008 to March 2010 at four zones in Sishili Bay located in the northern Yellow Sea. The nutrient distribution was impacted by seasonal factors (biotic factors, temperature and wet deposition), physical factors (water exchange) and anthropogenic loadings. The seasonal variations of nutrients were mainly determined by the seasonal factors and the spatial distribution of nutrients was mainly related to water exchange. Anthropogenic loadings for DIN, SRP and DRSi were mainly from point sources, but for DON, non-point sources were also important. Nutrient limitation has changed from DIN in 1997 to SRP and DRSi in 2010, and this has resulted in changes in the dominant red tide species from diatom to dinoflagellates. 相似文献
13.
Dissolved trace element concentrations (Ba, Fe, Mn, Si, Sr, and Zn) were investigated in the Haicheng River near to the Liaodong Bay in Northeast China during 2010. Dissolved Ba, Fe, Mn, and Sr showed significant spatial variation, whereas dissolved Fe, Mn, and Zn displayed seasonal variations. Conditions such as water temperature, pH, and dissolved oxygen were found to have an important impact on redox reactions involving dissolved Ba, Fe, and Zn. Dissolved Fe and Mn concentrations were regulated by adsorption or desorption of Fe/Mn oxyhydroxides and the effects of organic carbon complexation on dissolved Ba and Sr were found to be significant. The sources of dissolved trace elements were found to be mainly from domestic sewage, industrial waste, agricultural surface runoff, and natural origin, with estimated seasonal and annual river fluxes established as important inputs of dissolved trace elements from the Haicheng River into the Liaodong Bay or Bohai Sea. 相似文献
14.
云南抚仙湖水体营养元素分布及其对人为扰动的响应 总被引：4，自引：0，他引：4
本文分析了云南抚仙湖水体营养元素和溶解氧的分布特征,并结合大洋协会在湖区进行的多金属结核采矿系统试验,探讨了采矿系统在湖底行走而导致的人为扰动对湖区营养元素的影响。研究表明,湖区水体中的营养元素存在着明显的季节性变化,且主要受湖区气候水文条件的影响;采矿系统行走时所扰动的沉积物对水体中的营养元素,尤其是近底层水体的营养元素分布,影响明显,这主要是由于再悬浮的沉积物将原先吸附在沉积物上的营养元素再次释放到水体中而导致的,因此,在评价人类湖底采矿试验活动对湖区环境的影响时还应关注湖底沉积物对水环境的影响。 相似文献
15.
冰封期湖泊与大气的气体交换受冰盖阻碍,影响湖泊溶解氧含量,进而影响湖泊水质.为探究冰封期湖泊溶解氧和新陈代谢速率变化特征及影响因素,本研究通过监测典型季节性冰封湖泊不同深度的溶解氧（DO）、水温和光合有效辐射（PAR）,结合水质检测结果,分析冰封期湖泊DO变化及代谢速率影响因素,对湖泊日新陈代谢速率计算方法进行改进并估算冰封期湖泊新陈代谢速率.结果表明：2021年1—3月间,岱海DO浓度平均值为15.49 mg/L,并出现昼夜变化和分层现象.DO在冰封期变化趋势呈现出先逐渐升高,然后保持稳定,进入消融期（2021年3月2—11日）分层现象逐渐消失的规律.岱海冰封期净初级生产力和生态系统呼吸速率平均值分别为0.11和0.10 mg/（L·d）,在水温未出现分层时净初级生产力呈现较高水平;之后水温沿水深方向出现分层,净初级生产力明显下降;当冰层融化后,PAR显著上升,净初级生产力又逐渐恢复至0.10 mg/（L·d）.统计分析表明,岱海冰封期DO与水温、PAR、总氮等变化具有一定相关关系,且由于湖泊流域生态环境条件及冰封期物候特征不同,岱海与内蒙古其他湖泊相比,冰封期DO变化趋势存在一定差异. 相似文献
16.
洪泽湖轮虫群落结构及其与环境因子的关系 总被引：6，自引：3，他引：3
2010年5月至2011年2月对洪泽湖轮虫进行季度采样,分析了洪泽湖轮虫的种类组成、时空分布及其群落结构与环境因子的关系.结果表明,洪泽湖共观察到轮虫17属34种,优势种为螺形龟甲轮虫(Keratella cochlearis)、前节晶囊轮虫(Asplanchna priodonta)、长肢多肢轮虫(Polyarthra dolichoptera)、萼花臂尾轮虫(Brachionus calyciflorus)和曲腿龟甲轮虫(Keratella valga).轮虫种类的空间分布格局呈现较大差异,种类数在北部成子湖最高(27种),西南部湖区次之(26种),东部沿岸带最低(19种);而密度则表现为西南部湖区略高于成子湖,东部沿岸带最低.轮虫的群落结构季节差异明显,密度和生物量在春季最高,秋季次之,而夏季最低.典范对应分析结果表明,水温、溶解氧及叶绿素a等因子对轮虫种类的季节变化及密度生物量的影响最大;总磷、总氮及可溶性无机氮等水体中的营养盐也是影响轮虫群落结构的重要因素. 相似文献
17.
Rodica Gelca Katharine Hayhoe Ian Scott‐Fleming Caleb Crow Dan Dawson Reynaldo Patiño 《水文研究》2016,30(1):12-29
Water temperature, dissolved oxygen, and concentrations of salts in surface water bodies can be affected by the natural environment and local human activities such as surface and ground water withdrawals, land use and energy extraction, and variability and long‐term trends in atmospheric conditions including temperature and precipitation. Here, we quantify the relationship between 121 indicators of mean and extreme temperature and precipitation and 24 water quality parameters in 57 Texas reservoirs using observational data records covering the period 1960 to 2010. Over time scales ranging from 1 week to 2 years, we find that water temperature, dissolved oxygen, pH, specific conductance, chloride, sulfate, and phosphorus all show consistent correlations with atmospheric predictors, including high and low temperature extremes, dry days, heavy precipitation events, and mean temperature and precipitation. Based on these relationships combined with regional climate projections, we expect climate change to increase water temperatures, decrease dissolved oxygen levels, decrease pH, increase specific conductance, and increase levels of sulfate and chloride in Texas reservoirs. Over decadal time scales, this may affect aquatic ecosystems in the reservoirs, including altering the risk of conditions conducive to algae occurrence, as well as affecting the quality of water available for human consumption and recreation. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
18.
The Burdekin delta floodplain, north Queensland, is highly modified for agricultural purposes. Riparian condition is very poor and exotic aquatic weeds dominate waterways. Historically, most streams and lagoons were highly seasonal, but those now used for the delivery of irrigation water maintain elevated flows and increased turbidity and nutrient loading. These factors have aided exotic weed growth and many major lagoons are covered by dense water hyacinth (Eichhornia crassipes) mats which greatly reduce dissolved oxygen levels, one of the most important water quality variables for aquatic fauna. Mechanical harvesting of water hyacinth from several of these lagoons resulted in rapid and substantial increases in dissolved oxygen saturation, and improved suitability of the habitat to support fish species. Decrease in dissolved oxygen as water passes sequentially through weed-infested lagoons, justified the approach of harvesting upstream lagoons first, however, the channels that connect these lagoons remain weed-infested and are still impacting upon downstream oxygen levels. 相似文献
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20.
Acetylcholinesterase as a biomarker of exposure to neurotoxic compounds in the clam Tapes philippinarum from the Lagoon of Venice 总被引：1，自引：0，他引：1
Measurement of acetylcholinesterase (AChE) is widely used as a biomarker of exposure to neurotoxic compounds in aquatic environments. In the present study, AChE activity was monitored in the clam Tapes philippinarum in the Lagoon of Venice, with the aim of evaluating the possible exposure of animals to neurotoxic compounds. Two sampling strategies were followed. In the first case, temporal and spatial variations of AChE activity were measured in clams collected seasonally (from October 2003 to June 2004) in 3 sites of the Lagoon: Campalto (site 1), near a sewage treatment plant, Marghera (site 2), a highly polluted area, and Poveglia (site 3), a reference site. The condition index (CI) of clams was also calculated. In the second case, AChE activity was measured in clams collected at the end of seasonal samplings in 12 sites located throughout the Lagoon: areas licensed for clam farming (sites 5 to 11), nearby canals characterised by waste waters from agricultural areas (sites 4, 12, 13, 14), and a reference site outside the Lagoon (site 15). Results revealed a significant reduction in AChE activity in clams from Marghera in October, January and April, indicating their probable exposure to neurotoxic compounds originating in the industrial zone of Porto Marghera. A seasonal trend in AChE activity was also observed, enzyme activity being higher in January and lower in June. Clams from Campalto generally had higher CI values than those from Marghera and Poveglia. However, no particular correlation between AChE activity and CI was found. Lastly, marked differences in AChE activity were recorded when comparing enzyme activity of clams from various sites in the Lagoon of Venice with those of clams collected at site 15. Significant reductions in AChE activity were observed in animals collected in both nearby canals and licensed areas, indicating the homogeneous spatial distribution of potentially neurotoxic compounds throughout the Lagoon. It is probable that sediment mobilisation caused by clam harvesting and the passage of shipping plays an important role in resuspension of persistent contaminants having neurotoxic activity. 相似文献