Oxidative stress in Nile tilapia (Oreochromis niloticus) and armored catfish (Pterygoplichthys anisitsi) exposed to diesel oil

Considering that diesel oil is one of the most common aquatic contaminants, we compare the oxidative stress between two species of fish with different habitats (Pterygoplichthys anisitsi, benthic and Oreochromis niloticus, nektonic) exposed to diesel oil. Malondialdehyde concentrations (MDA) and the activities of ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase were all analyzed in the fishes' livers and gills after 2 and 7 days of exposure to different concentrations of diesel (0.1 and 0.5 mL/L). In the tilapia, MDA levels and the activities of EROD and GST activity in the liver, as well as MDA levels and the activities of GST and SOD in the gill had statistically significant differences between the treatments and between the times of exposure. For the catfish, the same occurred in the case of MDA, EROD, and SOD in the liver and in CAT and SOD in the gills. There were significant differences in the enzyme activity and lipid peroxidation between the species. Although the activity of most enzymes seemed to be more expressive and responsive to diesel in O. niloticus, diesel oil also caused significant effects on oxidative stress parameters in P. anisitsi, even though this species is benthic and thus has less access to insoluble fractions of diesel oil. Therefore, both species can be used as sentinel organisms in environmental biomonitoring of diesel contamination.     

Preliminary investigation of sensitive biomarkers of trace metal pollution in mussel (Mytilus galloprovincialis) from Izmir Bay (Turkey)

The aim of this study was to identify possible relationships between biochemical- superoxide dismutase (SOD), glutathione peroxidase (GPx), thiobarbituric acid reactive substances (TBARS) of mussels (Mytilus galloprovincialis) and chemical (Hg, Cd, Pb, Cr, Cu, Zn, Mn and Fe) contaminants from relatively clean area (Middle Bay) and heavily polluted area (Inner Bay) of the Izmir Bay. Sampling of mussels was performed in the beginning of May 2004. Mussel digestive glands have been used for biochemical assays. Trace metal content was determined by atomic absorption spectrophotometer using standard procedures. Metal contents in mussels collected at polluted site increased compared to the middle part of the bay. While there was a positive correlation between metals and SOD enzyme activity, there was a negative correlation between metals and GPx enzyme activity. An increase was observed in SOD enzyme activity and a decrease of GPx enzyme activity at the inner part of the bay.     

Oxidative DNA damage levels and catalase activity in the clam Ruditapes decussatus as pollution biomarkers of Tunisian marine environment

Levels of the oxidative DNA damage 7, 8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG) and catalase (CAT) activity were measured in the digestive gland and gills of clams Ruditapes decussatus, related to the presence of pollutants along Tunisian marine environment. Increased levels of CAT were observed in tissues of clams from all the sites studied, compared to control values, and elevated 8-oxodG levels were observed at specific sites. Results obtained in this work indicate that the measurement of 8-oxodG levels and CAT activity in tissues of R. decussatus is promising in pollution monitoring studies of the Tunisian marine environment.     

水生态环境质量评价方法及在黄河流域的应用进展

开展水生态环境质量评价方法研究,建立合适的河流健康评价体系是解决河流健康问题的前提和实现河流健康管理的重要手段。黄河自上而下生态环境现状迥异,水生态环境脆弱,寻求一种或多种适合黄河流域水生态环境质量的评价方法具有重要意义。该文介绍了国内外水生态环境质量评价方法及在黄河流域的应用进展,总结了鱼类生物完整性指数(F-IBI)、底栖无脊椎动物完整指数(B-IBI)、着生藻类生物完整性指数(P-IBI)及水生态环境质量综合评价法的主要指标,以及黄河流域不同区域生物种类的评价指标,分析了各评价方法优缺点及应用范围,并根据目前研究基础评述了黄河流域水生态环境质量评价存在的问题,对黄河流域水生态环境质量评价方法、指示生物的选择及水生态环境质量综合评价法的研究等提出了具体建议。     

Oxidative stress response in zebrafish (Danio rerio) gill experimentally exposed to subchronic microcystin-LR

The worldwide occurrence of cyanobacterial blooms makes it necessary to perform environmental risk assessment procedures to monitor the effects of microcytins on fish. Oxidative stress biomarkers are valuable tools in this regard. Considering that zebrafish (Danio rerio) is a common model species in fish toxicology and the zebrafish gill is potentially useful in screening waterborne pollutants, this study investigated the oxidative stress response in zebrafish gill exposed to subchronic microcystin-LR (MCLR) concentrations (2 or 20?μg/l) via measurement of toxin accumulation, protein phosphatase (PP) activity, and the antioxidant parameters (glutathione-S-transferase-GST; glutathione-GSH; superoxide dismutase-SOD; catalase-CAT; glutathione peroxide-GPx; glutathione reductase-GR), as well as levels of hydroxyl radical (OH) and lipid peroxidation (LPO). The results showed that after 30?days exposure, MCLR accumulated in zebrafish gill and MCLR exposure induced PP activity in gill. A linear inhibition of GST activity and GSH content was observed in the gills, revealing that they were involved in the first step of MCLR detoxification. The 2?μg/l MCLR treatment neglectably affected OH content and the antioxidant enzymes (SOD, CAT, GPx, and GR), however oxidative stress was induced under the 20?μg/l MCLR treatment in which an enhanced OH content and alterations of the antioxidant enzymes were observed in the treated gills, although both treatments exerted little effect on LPO level. The principal component analysis results indicated that the most sensitive biomarkers of MCLR exposure were GST and GSH in zebrafish gill. So, D. rerio could be regarded as a suitable bioindicator of MCLR exposure by measuring CAT, GR, GST, and GSH as biomarkers.     

Lipid peroxidation and antioxidant defense enzymes in Clarias gariepinus as useful biomarkers for monitoring exposure to polycyclic aromatic hydrocarbons

The toxicological evaluations of crude oil, xylene, toluene and benzene were carried out against juvenile stages of Clarias gariepinus. On the basis of LC(50) value, benzene (0.017 ml/l) was found to be the most toxic followed by xylene (0.086 ml/l), toluene (0.398 ml/l) and crude oil (2.219 ml/l) was the least toxic. The results of the lipid peroxidation assay showed that the level of malonaldehyde (MDA) in liver and gills of fish exposed to all the test chemicals increased significantly (P < 0.05) when compared to control. Measurement of activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) in liver and gill of fishes exposed to sublethal concentration of the test chemicals over a 28-day period was found to decrease significantly (P < 0.05) when compared to control. The observed reduction in the activities of antioxidant defense enzymes such as SOD, CAT and GST in conjunction with an increase in MDA levels in the gill and liver tissues of test animals exposed to aromatic hydrocarbon compounds were recommended as a good battery of biomarkers for early detection of pollution during biomonitoring programmes.     

Use of biological monitoring in the assessment of effects of mining wastes on aquatic ecosystems of the alligator rivers region,tropical Northern Australia

The primary objective of the biological monitoring program of the ARRRI is to develop techniques and procedures to monitor and assess effects of the mining and processing of ores on aquatic ecosystems of the Region. Studies have been made in a seasonal tributary (Magela Creek) of the East Alligator River near the Ranger Uranium Mine, and in the upper South Alligator River (SAR) near the Coronation Hill gold, platinum and palladium prospect. Ranger and Coronation Hill are enclosed by Kakadu National Park, environmental safeguards for which require the minimization of impairment of water quality in the aquatic ecosystems. Present studies on Magela Creek are designed to verify the adequacy of release standards, based on biological tests, in protecting the aquatic environment during and after releases of waste-water from Ranger during the Wet season. Detection of short-term effects will be sought by either creekside orin situ monitoring methods. The detection and assessment of any longer-term impacts, however, will rely chiefly on comparisons of post-release data with those of historical baselines. Such baseline information is provided by studies on the structure of macroinvertebrate and fish communities and/or on concentrations of elements in organisms in those communities, in Magela Creek and SAR catchments.     

水生态监测方法研究进展及在黄河流域的应用实践

水生态监测能够为水生态环境监督、管理和保护提供重要的数据和技术支撑。加强黄河水生态监测,维护流域水生态系统健康,对促进黄河流域高质量发展具有重要意义。从常规水质监测、生境监测和生物监测3个方面,分析了中国水生态监测方法的研究进展及在黄河流域的应用实践。结合黄河流域水生态监测尤其是生物监测相对滞后的现状,探讨了流域水生态监测的发展方向。建议加快黄河流域水生态监测能力建设,建立适用于黄河流域的水生态监测与评价标准体系,探索新兴监测技术与传统技术的有机结合。     

黄河、海河和辽河水体中3种常用除草剂的分布特征

系统研究了黄河、海河和辽河中3种常用除草剂 MCPA、2，4-D 和 Bentazone 的分布特征及其来源。结果表明，3种除草剂除 Bentazone在黄河水体中未检出外，其余均有检出。季节和空间分析表明，大部分目标物丰水期质量浓度高于枯水期，可能与夏季农作物除草剂使用量较大有关；从上游到下游化合物质量浓度逐渐升高，可能是河岸面源污染引起。水生态风险初步分析显示，3种除草剂对研究水体中的水生生物均为低风险。     

黄河流域水生生物资源评估及问题诊断

近几十年来,随着全球气候的变化和社会经济的发展,受筑坝建闸、河道断流、水质恶化、酷渔滥捕、人工引种、海水入侵、调水调沙等因素影响,黄河流域水生生物多样性及资源量呈下降趋势。在目前流域内多目标同步推进的要求下,黄河流域生态保护和高质量发展正不断面临新的挑战。通过分析黄河流域水生生物多样性和资源量在时空分布上的演变规律,明确了是水资源短缺、工程建设、水环境恶化等因素的共同作用导致了黄河流域的水生态危机。基于绿色生态、高质量发展的科学管理理念,提出了新时代黄河流域水文-环境-生态协同保护与修复的发展策略,为促进黄河流域水资源保护和生态系统可持续发展提供数据支持与理论参考。     

Integrated survey of water pollution in the Suquía River basin (Córdoba, Argentina)

We report a combined two-year seasonal monitoring of Suquía River basin using both chemical parameters and biomarkers measured in Jenynsia multidentata, aiming to correlate external levels of contaminants with the response of oxidative stress biomarkers in this fish. Identified pollution sources correspond to city sewage as well as agricultural and small industry activities downstream from Córdoba city. Physicochemical parameters integrated into a water quality index (WQI) were measured in Suquía River during dry and wet seasons. Ag, Mn, Cu, Cr, Ni, Fe, Pb and Zn were also monitored in water and sediment samples. Biomarkers include detoxication and antioxidant enzymes: catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR). Enzymes showed a pollution dependent response, with increased activities in fish collected close to the sewage exit and progressive drop further downstream, matching changes in the Water Quality index. The combined use of biomarkers with water quality parameters allowed both the identification of pollution sources and the evaluation of effects of contaminants on the aquatic biota.     

中国北方山区水库与引黄水库富营养化特征

于2012年10月—2013年8月对中国北方地区2种典型水库:山区水库(卧虎山、锦绣川)和引黄水库(鹊山、玉清)进行了采样调查,对其水质特征和富营养化现状进行分析研究。结果表明:2类水库水质的最大差异在于山区水库的氮含量显著高于引黄水库,这主要与水源、氮素来源和水库的进水方式有关。山区水库中SD与藻类生物量、TP关系密切;而引黄水库中,影响SD的环境因素较复杂,除藻类生物量和氮、磷外,碱度和水温也与SD密切相关。全年水平上,卧虎山水库营养状态指数显著高于其他水库,属中-富营养水体,锦绣川水库、鹊山水库和玉清水库均属中营养水平。时间上,同类型水库的营养状态指数季节变化基本一致。参与营养状态计算的4个因子中,Chla和TN对营养状态指数的贡献最大,表明这两者是引起2类水库营养状态加重的重要原因。典型的水源及进水方式、流域人类活动类型和强度是影响山区水库和引黄水库营养状态的主要外部因素。     

黄河口的水质、底质污染及其变化

分析了2001年在黄河口附近所取的3处水样和3处泥样中污染物的含量,并与历史数据进行了比较.利用<地表水环境质量标准>(GB3838-2002)和美国国家海洋大气管理局(NOAA)水体泥沙质量标准等分别对水体和底泥中的重金属(砷)和氮磷污染进行了评价.认为黄河口的水污染严重,主要污染物为汞和氮;泥沙污染尚不严重,但污染物的增长率高;水体中较高的氮含量和泥沙中氮含量的迅速增高可能会对渤海湾的富营养化情况产生影响.     

An Effective Means of Biofiltration of Heavy Metal Contaminated Water Bodies Using Aquatic Weed Eichhornia crassipes

Various aquatic plant species are known to accumulate heavy metals through the process of bioaccumulation. World’s most troublesome aquatic weed water hyacinth (Eichhornia crassipes) has been studied for its tendency to bio-accumulate and bio-magnify the heavy metal contaminants present in water bodies. The chemical investigation of plant parts has shown that it accumulates heavy metals like lead (Pb), chromium (Cr), zinc (Zn), manganese (Mn) and copper (Cu) to a large extent. Of all the heavy metals studied Pb, Zn and Mn tend to show greater affinity towards bioaccumulation. The higher concentration of metal in the aquatic weed signifies the biomagnification that lead to filtration of metallic ions from polluted water. The concept that E. crassipes can be used as a natural aquatic treatment system in the uptake of heavy metals is explored.     

Study on Fish and Amphibian Embryo-Larval Toxicity Test

In China, it is necessary to establish short-term biomonitoring methods for evaluating the chronic toxicity of industrial wastewater. In this paper, the aquatic toxicity of four important pollutants in petrochemical wastewater, including acrylonitrile, acetonitrile, sulphocyanic sodium and dimethyl formamide, was studied with fish and amphibian embryo-larval toxicity tests using Cyprinus carpio and Rana nigromaculata as test organisms. The objective is to present some useful data for establishing short-term chronic toxicity test methods used to perform biomonitoring in China. The results indicate that the chronic toxicity of acrylonitrile to fish and amphibians was the highest of the four test pollutants, followed by NaSCN, acetonitrile and DMF. The sensitivity of the carp embryo- larval test to chemicals was greater than that of the R. nigromaculata embryo-larval test.     

Using condition factor and blood variable biomarkers in fish to assess water quality

The condition factor and blood variables, including erythrocyte lipid peroxidation (LPO) and the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), in two ecologically distinct fish species (Astyanax fasciatus and Pimelodus maculatus) were evaluated at five sites in the Furnas Hydroelectric Power Station reservoir (Brazil) to assess water quality. Aldrin/dieldrin, endosulfan, heptachlor epoxide, and metolachlor were detected at different concentrations in four of the sites. Condition factor was not directly affected by such contaminants. A negative correlation between hematocrit and heptachlor was detected in P. maculatus. Positive correlations between red blood cells and heptachlor as well as an interactive effect of metolachlor and aldrin/dieldrin were detected in A. fasciatus. The erythrocytes of both species collected from the contaminated sites showed high levels of LPO, an increase in SOD and GPx activities and a decrease in CAT activity. Although the leukocyte number and the differential percentage of leukocytes varied among the sites, the hematological variables, the LPO levels, and the antioxidant enzyme activities could be used to assess water quality, regardless of the differences in the responses of the fish species.     

Contaminant concentrations in Asian carps, invasive species in the Mississippi and Illinois Rivers

Populations of invasive fishes quickly reach extremely high biomass. Before control methods can be applied, however, an understanding of the contaminant loads of these invaders carry is needed. We investigated differences in concentrations of selected elements in two invasive carp species as a function of sampling site, fish species, length and trophic differences using stable isotopes (delta (15)N, delta (13)C). Fish were collected from three different sites, the Illinois River near Havana, Illinois, and two sites in the Mississippi River, upstream and downstream of the Illinois River confluence. Five bighead carp (Hypophthalmichthys nobilis) and five silver carp (Hypophthalmichthys molitrix) from each site were collected for muscle tissue analyses. Freshwater mussels (Amblema plicata) previously collected in the same areas were used as an isotopic baseline to standardize fish results among sites. Total fish length, trophic position, and corrected (13)C, were significantly related to concentrations of metals in muscle. Fish length explained the most variation in metal concentrations, with most of that variation related to mercury levels. This result was not unexpected because larger fish are older, giving them a higher probability of exposure and accumulation of contaminants. There was a significant difference in stable isotope profiles between the two species. Bighead carp occupied a higher trophic position and had higher levels of corrected (13)C than silver carp. Additionally bighead carp had significantly lower concentrations of arsenic and selenium than silver carp. Stable isotope ratios of nitrogen in Asian carp were at levels that are more commonly associated with higher-level predators, or from organisms in areas containing high loads of wastewater effluent.     

Macrobenthic Monitoring in the Lower St. Johns River, Florida

The macrobenthos in the oligohaline 132 km reach of the Lower St. Johns River, Florida, is an unusual blend of freshwater and marine organisms within the annelid, mollusk, aquatic insect, and crustacean groups. During 1993–1994, the community composition was freshwater-oriented in the 47 km (seg I) and estuarine-dominated in the lower 85 km (seg II). Of the total 146 taxa collected, 89% were euryecious 'eutrophic' and 'pollution-tolerant' organisms. Densities ranged between 5000 and 20 000 individuals/m² ann av and maximum densities (85 000 individuals/m²) occurred in the muck substrate at the confluence of major tributaries and embayments. Throughout the lake-like seg II, benthic hypoxia existed during much of summer through fall. Biotic index values for grab, artificial substrate, and sled trawl samples reflected greatest stresses to the macrobenthos then. Both low taxonomic diversity and densities of organisms at the most downriver stations nearest the port of Jacksonville indicated that toxic substances also adversely affected the macrobenthos. Maintenance of the narrow band of littoral submerged aquatic vegetation (SAV) and adjacent shoreline riparian vegetation is important to sustain macrobenthic communities and other kinds of aquatic life in the river.     

Water level management and contaminant exposure to tree swallows nesting on the Upper Mississippi River†

The U.S. Army Corps of Engineers conducted a water drawdown on Navigation Pool 8 of the Upper Mississippi River during the summers of 2001 and 2002 to increase aquatic vegetation production and thereby improve fish and wildlife habitat. Flooding of previously dried wetlands, however, may increase the rate of mercury methylation and make mercury more available to terrestrial vertebrates that feed in aquatic environments. Our objective was to determine if mercury, other elements, and organochlorine contaminants were more available to vertebrates following the 2001 drawdown. Tree swallow (Tachycineta bicolor) eggs and nestlings were collected at two sites on Pool 8 and a nearby Reference site in 2000 (pre-2001 drawdown), 2001 (pre-2001 drawdown) and 2002 (post-2001 drawdown) and tissues were analyzed for mercury, other elements, and organochlorine contaminants. Bioindicator measurements of genetic damage, oxidative stress, ethoxyresorufin-O-dealkylase activity, and the ratio of liver to nestling mass were also measured in nestlings at all sites and all years. Based on a multivariate analysis, the 2001 drawdown of Pool 8 did not influence element concentrations, organochlorine concentrations, or bioindicator response. Concentrations of inorganic and organochlorine contaminants in tree swallow eggs and nestlings were not at toxic levels. Hatching success did not differ among years and was comparable to the nationwide average.     

Cell phone electromagnetic field radiations affect rhizogenesis through impairment of biochemical processes

Indiscriminate adoption and use of cell phone technology has tremendously increased the levels of electromagnetic field radiations (EMFr) in the natural environment. It has raised the concerns among the scientists regarding the possible risks of EMFr to living organisms. However, not much has been done to assess the damage caused to plants that are continuously exposed to EMFr present in the environment. The present study investigated the biochemical mechanism of interference of 900 MHz cell phone EMFr with root formation in mung bean (Vigna radiata syn. Phaseolus aureus) hypocotyls, a model system to study rhizogenesis in plants. Cell phone EMFr enhanced the activities of proteases (by 1.52 to 2.33 times), polyphenol oxidases (by 1.5 to 4.3 times), and peroxidases (by 1.5 to 2.0 times) in mung bean hypocotyls over control. Further, EMFr enhanced malondialdehyde (an indicator of lipid peroxidation), hydrogen peroxide, and proline content, indicating a reactive oxygen species-mediated oxidative damage in hypocotyls. It was confirmed by the upregulation in the activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, catalase, and glutathione reductase) suggesting their possible role in providing protection against EMFr-induced oxidative damage. The study concluded that cell phone radiations affect the process of rhizogenesis through biochemical alterations that manifest as oxidative damage resulting in root impairment.