Hematological and histopathological changes in silver catfish Rhamdia quelen (Siluriformes) exposed to clomazone herbicide in the Madre River,Santa Catarina State,Southern Brazil

This study evaluated the influence of the clomazone herbicide (2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone) contamination on the hematological parameters and histological changes in gills and liver of silver catfish (Rhamdia quelen) from Madre River, Santa Catarina State, Southern Brazil. Fish were collected between March 2010 and January 2012 at two different sites of the Madre River, one site receiving residual water (contaminated site) from rice culture (n = 49) and another that do not receive residual water (reference site) (n = 48). The herbicide clomazone analysis detected 3.40 ± 1.70 μg/L in the contaminated site and 1.1 ± 0.33 μg/L in the reference site. Fish from contaminated site showed increased (P < 0.05) number of monocytes suggesting the possible defense response as a result of chronic exposure to clomazone. On the other hand, no difference was found in the hematocrit percentage, red blood cell count, total thrombocyte number, white blood cell count, lymphocytes, and neutrophils number. Fish from both sites showed histopathological changes in gills and liver, possibly caused by chronic exposure to contamination. The influence of herbicide sub doses on fish health is also discussed.     

In situ studies on growth,oxidative stress responses,and gene expression of juvenile bighead carp (Hypophthalmichthys nobilis) to eutrophic lake water dominated by cyanobacterial blooms

Cyanobacterial blooms have received increasing attention as a public biohazard for human and animal health. To assess the effect of cyanobacteria-dominant lake water on juvenile fish, we measured the responses of specific growth rate, condition factor, body weight and body length, oxidative stress, and related gene expression of juvenile bighead carp Hypophthalmichthys nobilis exposed to in situ eutrophic lake (Chl a was around 7.0 μg L⁻¹). Results showed in situ cyanobacteria-dominant lake water had no effect on the growth performance, but significantly elevated the contents of malondialdehyde, the expression of heat shock protein 70, and the activity of superoxide dismutase, indicating that oxidative stress occurred. Meanwhile in situ lake water significantly decreased the expression of catalase and glutathione S-transferase genes. We conclude that in situ cyanobacteria-dominated lake water was harmful to juvenile bighead carp based on the oxidative stress and changes in the related gene expression levels.     

Evaluation of the Swat River,Northern Pakistan,water quality using multivariate statistical techniques and water quality index (WQI) model

Environmental Science and Pollution Research - This study evaluates the characteristics of water along the Swat River, Northern Pakistan. For this purpose, water samples (n = 30) were...     

Biochemical responses in armored catfish (Pterygoplichthys anisitsi) after short-term exposure to diesel oil,pure biodiesel and biodiesel blends

Biodiesel fuel is gradually replacing petroleum-based diesel oil use. Despite the biodiesel being considered friendlier to the environment, little is known about its effects in aquatic organisms. In this work we evaluated whether biodiesel exposure can affect oxidative stress parameters and biotransformation enzymes in armored catfish (Pterygoplichthys anisitsi, Loricariidae), a South American endemic species. Thus, fish were exposed for 2 and 7 d to 0.01 mL L⁻¹ and 0.1 mL L⁻¹ of pure diesel, pure biodiesel (B100) and blends of diesel with 5% (B5) and 20% (B20) biodiesel. Lipid peroxidation (malondialdehyde) levels and the activities of the enzymes glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were measured in liver and gills. Also, DNA damage (8-oxo-7, 8-dihydro-2′-deoxyguanosine) levels in gills and 7-ethoxyresorufin-O-deethylase activity in liver were assessed. Pure diesel, B5 and B20 blends changed most of the enzymes tested and in some cases, B5 and B20 induced a higher enzyme activity than pure diesel. Antioxidant system activation in P. anisitsi was effective to counteract reactive oxygen species effects, since DNA damage and lipid peroxidation levels were maintained at basal levels after all treatments. However, fish gills exposed to B20 and B100 presented increased lipid peroxidation. Despite biodiesel being more biodegradable fuel that emits less greenhouse gases, the increased lipid peroxidation showed that biofuel and its blends also represent hazards to aquatic biota.     

Endosulfan induces changes in spontaneous swimming activity and acetylcholinesterase activity of Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

We assessed changes in spontaneous swimming activity and acetylcholinesterase (AchE) activity of Jenynsia multidentata exposed to Endosulfan (EDS). Females of J. multidentata were exposed to 0.072 and 1.4 μg L⁻¹ EDS. Average speed and movement percentage were recorded during 48 h. We also exposed females to EDS at five concentrations between 0.072 and 1.4 μg L⁻¹ during 24 h, and measured the AchE activity in brain and muscle. At 0.072 μg L⁻¹ EDS swimming motility decreased relative to the control group after 45 h, while at 1.4 μg L⁻¹ EDS swimming motility decreased after 24 h. AchE activity significantly decreased in muscle when J. multidentata were exposed to EDS above 0.072 μg L⁻¹, while no significant changes were observed in brain. Thus, changes in swimming activity and AchE activity in muscle are good biomarkers of exposure to EDS in J. multidentata.     

Biological effects of diethylene glycol (DEG) and produced waters (PWs) released from offshore activities: A multi-biomarker approach with the sea bass Dicentrarchus labrax

Diethylene glycol (DEG) is largely used during oil and gas exploitation by offshore platforms. The aim of this work was to investigate if this compound induces direct molecular/cellular effects in marine organisms, or indirectly modulate those of produced waters (PWs). Sea bass (Dicentrarchus labrax) were exposed to DEG dosed alone or in combination with PWs from an Adriatic platform. A wide array of analysed biomarkers included cytochrome P450-dependent enzymatic activity, bile metabolites, glutathione S-transferases, acetylcholinesterase, peroxisomal proliferation, antioxidant defences (catalase, glutathione reductase, glutathione peroxidases, glutathione), total oxyradical scavenging capacity, malondialdehyde and DNA integrity (single strand breaks and frequency of micronuclei). Results did not reveal marked effects of DEG, while PWs influenced the biotransformation system, the oxidative status and the onset of genotoxic damages. Co-exposures caused only limited differences of biomarker responses at some experimental conditions, overall suggesting a limited biological impact of DEG at levels normally deriving from offshore activities.     

Distribution of endocrine disruptors in the Llobregat River basin (Catalonia, NE Spain)

The Llobregat basin is a Mediterranean fluvial system with major agricultural, urban and industrial impacts. We combined chemical quantification by liquid chromatography–mass spectrometry with electrospray interface (LC-ESI-MS) and the recombinant yeast assay (RYA) assays to estimate the loads of endocrine disrupting compounds (EDCs) along the basin. Chemical analysis revealed maximum concentrations (at μg l⁻¹ level) of alkylphenols at the lower course of the Llobregat River, which correlated with high levels of estrogenic activity detected by RYA. Analysis by RYA and LC-ESI-MS of influent and effluent waters from four sewage treatment plants (STP) discharging into the basin showed the removal of 80–95% of EDCs by STP treatment. Chemical analysis data and RYA data showed a quasi-linear correlation, demonstrating the complementariness of both methods. Our data suggest that the concentrations of the analysed compounds were enough to explain the total estrogenicity of water and STP samples from the Llobregat basin.     

In situ monitoring of urban air in Córdoba, Argentina using the Tradescantia-micronucleus (Trad-MCN) bioassay

During the last decades, a significant deterioration of ambient air quality has been observed in Argentina. However, the availability of air pollution monitoring stations is still limited to only few cities. In this study, we investigated the genotoxicity of ambient levels of air pollution in Córdoba using the Tradescantia micronucleus assay. The experiment was performed from October, 2004 to April 2005. Pots with Tradescantia pallida were placed in three sites: Córdoba city center, characterized by important avenues with high traffic activity (cars, taxis, and public transport vehicles); the university campus, along a side road with heavy traffic of gasoline and diesel powered vehicles, buses and trucks; and a residential area, with no significant local sources of air pollution. Twenty young T. pallida inflorescences were collected from each sampling site in November, February and April. Micronuclei frequencies were determined in early tetrads of pollen mother cells and expressed as MCN/100 tetrads. Simultaneously, the environmental levels of total suspended particles (24 h mean) were determined for each site. A significant difference in micronuclei frequency was observed among sites (p=0.036). Post-hoc analysis revealed that the residential area exhibited a lower micronuclei frequency than the university and city center areas. In conclusion, we found that the gradients of ambient air pollution of Córdoba are associated with changes in the spontaneous micronuclei frequency of Tradescantia pollen mother cells. These results indicate that in situ biomonitoring with higher plants may be useful for characterizing air pollution in areas without instrumental monitoring techniques, or for exploring the distribution of air contaminants at a microscale.     

Specific biomagnification of polychlorinated dibenzo-p-dioxins and dibenzofurans in tufted ducks (Aythya fuligula), common cormorants (Phalacrocorax carbo) and their prey from Lake Shinji, Japan

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) were detected in waterfowl such as common cormorants, tufted ducks, and their prey, namely fish and bivalves from Lake Shinji, Japan. The concentration of total PCDDs/DFs-TEQ was found to be higher in the muscle tissues of common cormorants than in those of tufted ducks. The results of hierarchical cluster analysis implied that the residue distribution pattern of PCDD/DF homologues was considerably different between these two species. Furthermore, biomagnification factors (BMFs) were estimated from bivalves as prey to tufted duck muscles as target organs. Despite the highest concentrations of 1,3,6,8- and 1,3,7,9-TeCDD in tufted ducks and their prey, however, the BMFs of these isomers were calculated to be lower than those of the toxic 2,3,7,8-substituted PCDDs/DFs. On the other hand, log BMF of toxic 2,3,7,8-substituted PCDDs/DFs were significantly higher for lower chlorinated isomers than those of the higher chlorinated isomers. The biota-sediment accumulation factors (BSAFs) of PCDDs/DFs were also estimated using shijimi clam and fish samples against sediment from Lake Shinji. The average BSAFs were estimated and ranged from 4.0×10⁻³ to 2.2×10⁻¹ and 2.0×10⁻⁴ to 2.0×10⁻¹ for bivalve and fish samples, respectively. Based on calculated BMFs and BSAFs, the total PCDD/DF-TEQ levels in the tufted duck were estimated to have been lowest (2.0 pg TEQ/g dry weight basis) in 1947 and highest (9.8 pg TEQ/g) in 1971.     

Differential accumulation of mercury and other trace metals in the food web components of a reservoir impacted by a chlor-alkali plant (Flix, Ebro River, Spain): Implications for biomonitoring

Comparative studies of biomonitors of trace metal contamination are relatively scarce. We took advantage of a point source pollution in a reservoir (Flix, Spain) to compare trace metal (Hg, Pb, Cd, Se, As, Zn, Cu, Cr) bioaccumulation patterns among 16 food web components. Our results indicate that most organisms are suitable for Hg biomonitoring, whereas other metals are better monitored by only some of them. Biofilms and zebra mussel were the organisms with larger and more diverse biomonitoring capacity. However, we show that using groups of biomonitors increase the scope and strengths of the conclusions and specific goals can be better addressed. We conclude providing an overview of the strengths and weaknesses of the main organisms considered for biomonitoring trace metals in rivers and reservoirs.     

基于溶解氧和耗氧污染物变化的长江流域水质改善过程分析 (2008—2018年)

长江流域以21%国土面积承载了我国40%以上的人口和经济总量。基于长江流域水质监测数据,利用统计和相关性分析方法,分析了长江流域重点断面溶解氧 (DO) 和耗氧污染物 (COD_Mn和NH₃-N) 指标的多年时空变化趋势,探讨了流域水质恢复规律和特征。结果表明：在2008—2018年,长江流域水体的水质整体上呈现好转趋势,重点断面中Ⅰ~Ⅲ类水质占比之和上升,达到95.9%,增加了3.4%。其中,在重点监控断面中年DO平均值逐年升高,大于7.5 mg∙L⁻¹的断面数量占比2018年已经达到85.7%,长江上游区域增加最为明显;年COD_Mn平均值稳定处于Ⅲ类水限值内;年NH₃-N平均值呈现下降趋势,优于地表水Ⅱ类水质标准值 (< 0.5 mg∙L⁻¹) 的断面数量占比已经达到95.2%,下游下降最为明显 (下降13%) 。相关性分析结果表明,DO与COD_Mn和NH₃-N均呈负相关,相关系数分别为−0.40和−0.44;COD_Mn和NH₃-N呈正相关,相关系数为0.36,NH₃-N已成为长江流域水体主要耗氧污染物。长江流域水体DO恢复与耗氧污染物减排密切相关,尤其是对高浓度NH₃-N的控制。长江干流沿线省市的城市环境基础设施投资多年平均占比超过全国的50%,2018年的污水排放量比2008年增加37.9%,平均污水处理率增加23.3%,未处理污水量减少了77.8%。本研究结果表明,长江流域水体耗氧污染得到有效控制,干流水质呈现逐步好转态势,可为制定长江流域污染物控制目标提供参考。     

Antioxidant response versus selenium accumulation in the liver and kidney of the Siberian sturgeon (Acipenser baeri)

The aim of this study was to examine the effects of selenium on concentrations of metabolites and enzyme activities acting as antioxidant markers in liver and kidney of Siberian sturgeon Acipenser baeri. Sturgeons were fed selenium cysteine for 30 and 60 d at 1.25, 5, 20 mg Se kg⁻¹. Selenium level in the control feed was 0.32 mg kg⁻¹. Se concentration was measured in liver, kidney and muscle of every specimen. Sturgeon accumulated Se in tissues with a clear dose-response relationship and the highest Se concentration was recorded in liver. This outcome is lined up with the findings obtained on the antioxidant markers evaluated in both tissues, and in which a dose-response for several biomarkers was recorded in liver. The superoxide dismutase activity in Se-treated fish was generally induced, while catalase activity was lower in liver or unaltered in kidney. The concentrations of glutathione S-transferase, glutathione reductase and total glutathione responded differently for both tissues and were induced in a different way at both endpoints. No changes of glyoxalase I activity were noted for both Se-treated tissues, while for glyoxalase II enzyme in liver a dose-related pattern was found showing a reversible effect (decreased and increased counteractive response) only in the 5 mg kg⁻¹ group. Moreover, the highest Se concentrations did not cause marked changes in malondialdehyde levels of liver and kidney. The enhancement of glutathione peroxidase activity in Se-treated sturgeon might have prevented the lipid peroxidation in both tissues, providing to the Siberian sturgeon a great defense ability versus the prooxidant effect of selenium.     

Temporal trends (1990-2000) in the concentration of cadmium, lead and mercury in mosses across Europe

The European heavy metals in mosses survey provides data on the concentration of 10 heavy metals in naturally growing mosses. The survey has been repeated at five-yearly intervals and in this paper we report on the temporal trends in the concentration of cadmium, lead and mercury between 1990 and 2000. Metal- and country-specific temporal trends were observed. In general, the concentration of lead and cadmium in mosses decreased between 1990 and 2000; the decline was higher for lead than cadmium. For mercury not enough data were available to establish temporal trends between 1990 and 1995, but between 1995 and 2000 the mercury concentration in mosses did not change across Europe. The observed temporal trends for the concentrations in mosses were similar to the trends reported for the modelled total deposition of cadmium, lead and mercury in Europe.     

滇池湖湾大水域种养水葫芦对水质的影响分析

为了探讨大水域种养水葫芦对滇池湖湾水质的影响,于2010年8—10月对滇池白山湾约70 hm2水葫芦种养区域的水质特征进行动态监测。结果表明,水葫芦区水体中总磷、总氮及高锰酸钾指数从9月中旬后开始逐步上升。水葫芦区水体溶解氧、pH较近水葫芦区和远水葫芦区显著降低,但水葫芦区溶解氧仍维持在较高水平;总磷、总氮及高锰酸钾指数较近水葫芦区和远水葫芦区显著升高;在水葫芦周围水体（近水葫芦区）水质得到明显改善,表现为水体透明度显著高于水葫芦区及远水葫芦区,总磷、正磷酸盐、总氮及叶绿素a明显低于水葫芦区及远水葫芦区。     

Larval performance of the mustard leaf beetle (Phaedon cochleariae, Coleoptera, Chrysomelidae) on white mustard (Sinapis alba) and watercress (Nasturtium officinale) leaves in dependence of plant exposure to ultraviolet radiation

Short-term exposure to ambient or attenuated ultraviolet (UV) radiation resulted in shifts in plant metabolite concentrations of the Brassicaceae Sinapis alba and Nasturtium officinale. Leaf quality also varied between plant species and within species due to age. Larvae of the oligophagous leaf beetle Phaedon cochleariae were raised on these different host leaves, in order to investigate the effects of variable plant chemistry on this herbivore. The performance of P. cochleariae was influenced by chemical differences between and within plant species but it responded with high plasticity to plants stressed by ultraviolet radiation. Body mass increase and developmental times of larvae were exclusively affected by plant species and leaf-age. However, developmental differences were fully compensated in the pupal stage. We suggest that the plasticity of herbivores may depend on the degree of specialisation, and insect performance may not necessarily be altered by stress-induced host plants.     

Contamination assessment of a coastal lagoon (Ria de Aveiro, Portugal) using defence and damage biochemical indicators in gill of Liza aurata - An integrated biomarker approach

Fish gill importance in toxicants uptake, bioconcentration and excretion allied to meagre knowledge on branchial damage/protection responses substantiate this study. Five critical sites in Ria de Aveiro (Portugal) were assessed in comparison with a reference site (Torreira), focusing on Liza aurata gill antioxidant defences versus damage (oxidative and genetic). Only in Barra fish displayed damage (lipid peroxidation) though no differences were found in antioxidants. In all other sites, except Rio, antioxidant alterations were found. Thus, fish from Gafanha, Laranjo and Vagos showed higher total glutathione, glutathione peroxidase and catalase. Higher glutathione reductase and glutathione S-transferase activity was also found in the first and the last sites, respectively. In Laranjo, metallothionein levels were higher though lower in Gafanha and Vagos. In general, damage was not accompanied by defences weakening confirming that predicting damage based on antioxidants depletion is not straightforward. The integrated biomarker response index ranked sites as: Gafanha > Barra > Laranjo > Vagos > Rio > Torreira.     

Ecosystem engineering potential of the gastropod Terebralia palustris (Linnaeus, 1767) in mangrove wastewater wetlands - A controlled mesocosm experiment

The effect of different sewage concentrations (0, 20, 60 and 100%), vegetation (Bare, Avicennia marina or Rhizophora mucronata) and immersion periods (immersion/emersion period of 12/12 h or 3/3 days just for 100%) conditions were studied for 6 months on survival and growth rates of Terebralia palustris (Linnaeus, 1767). Gastropods' activity and ecosystem engineering preformed at bare and A. marina planted cells and 3 sewage conditions (0, 20 and 60%) were determined. Survival rates were higher than 70% in all treatments. Growth rate decreased significantly with increasing sewage concentrations (mainly at unplanted conditions) and longer immersion periods. A complete shift (from immersion to emersion periods) and a significant decrease in mobility and consequently its engineer potential, due to sewage contamination, lead to a 3-4 fold decrease in the amount of sediment disturbed. Sewage contamination, primary producers' abundance and environmental conditions may have influenced the gastropods survival, growth and its ecosystem engineering potential.     

Partitioning behaviour of perfluorinated alkyl contaminants between water, sediment and fish in the Orge River (nearby Paris, France)

This paper reports on the partitioning behaviour of 15 perfluorinated compounds (PFCs), including C₄-C₁₀ sulfonates and C₅-C₁₄ carboxylic acids, between water, sediment and fish (European chub, Leuciscus cephalus) in the Orge River (nearby Paris). Total PFC levels were 73.0 ± 3.0 ng L⁻¹ in water and 8.4 ± 0.5 ng g⁻¹ in sediment. They were in the range 43.1-4997.2 ng g⁻¹ in fish, in which PFC tissue distribution followed the order plasma > liver > gills > gonads > muscle. Sediment-water distribution coefficients (log K_d) and bioaccumulation factors (log BAF) were in the range 0.8-4.3 and 0.9-6.7, respectively. Both distribution coefficients positively correlated with perfluoroalkyl chain length. Field-based biota-sediment accumulation factors (BSAFs) are also reported, for the first time for PFCs other than perfluorooctane sulfonate. log BSAF ranged between −1.3 and 1.5 and was negatively correlated with the perfluoroalkyl chain length in the case of carboxylic acids.     

Tissue distribution of inorganic mercury, methylmercury and cadmium in the Asiatic clam (Corbicula fluminea) in relation to the contamination levels of the water column and sediment

The comparative experimental study of inorganic mercury (HgII), methylmercury (MeHg) and cadmium (Cd) bioaccumulation in the Asiatic clam Corbicula fluminea was based on a 14 days' exposure to the water column or sediment compartments, as initial contamination sources. For each contaminant and exposure source, a five-point concentration range was set up in order to quantify the relationships between the contamination pressure and bioaccumulation capacity, at the whole soft body level and in five organs: gills, mantle, visceral mass, kidney and foot. Hg and Cd bioaccumulation at the whole organism level was proportional to the metal concentrations in the water column or sediment. For similar exposure conditions, the average ratios between the metal concentrations in the bivalves - [MeHg]/[HgII] and [MeHg]/[Cd] - were close to 10 and 5 for the sediment source and 8 and 15 for the water column source. Metal distribution in the five organs revealed strong specificities, according to the different contamination modalities studied: kidney and gills were clearly associated with Cd exposure, mantle and foot with MeHg exposure and the visceral mass with inorganic Hg exposure.