The Accumulation of Crimidin in Some Fish Organs

The accumulation of crimidin in total samples and in some organs of five fish species was studied under experimental conditions. The species were Cyprinus carpio, Carassius carassius, Tinca tinca, Scardinus erythrophthalmus and Leucaspius delineatus. Fish were exposed to concentrations of 10 mg · l^?l and 50 mg · l^?1. During short-term experiments water and fish samples were taken at intervals of t = 0, 6, 12, 24, 48 and 72 hours, during the long-term experiment sampling was performed weekly for six weeks. Total samples were analysed for C. carassius, T. tinca, S. erythrophthalmus and L. delineatus. Samples of individual organs and tissues were taken as follows: C. carpio – gills, digestive tract, muscular tissue, kidneys, gonads; C. carassius – gills, digestive tract, muscular tissue, ovaries, testes. Crimidin was determined by gas chromatography. In samples from the short-term experiments at a concentration of 10 mg · l^?1 in the water the amount was roughly 10¹–10 mg · kg^?1, at a concentration of 50 mg · l^?1 in the water roughly 10¹ mg · kg^?1. In most cases the accumulation coefficient was lower than 1.0. The accumulation capacity of individual fish species did not differ greatly. Of the internal organs only the kidneys had a high accumulation capacity, otherwise the highest values were found in muscular tissue and the gills. After one – three weeks the amount of crimidin in most organs falls, and after transfer to clean water there is a general sharp decline. Thus crimidin is not firmly bound in the body.     

Adaptation strategy of bivalve Modiolus modiolus from upwelling regions of the Kuril Islands shelf (Sea of Okhotsk) to heavy metal effects

Cd, Cu, Fe, Mn, Ni, Pb, Zn concentration in the organs (muscle, gonads, mantle, gills, digestive gland, kidney) of mussel Modiolus modiolus was studied. Mussels were collected from shelf upwelling sites of Kuril Is. Sea of Okhotsk (104 and 85 m) and, for comparison, coastal high contaminated and clean sites (Peter the Great Bay, Sea of Japan). It was found that mussels from shelf upwelling regions accumulated unusually high Cd concentration in studied organs, excepting digestive gland. Shelf mussels have evolved passive adaptation to elevated level of ambient heavy metals (distribution of heavy metal load between all organs, especially, muscle). In contrast, mussels from high contaminated sites have evolved active adaptation (strong regulation of metal concentration in the organs at the maximal permissible concentration due to increased kidney function). We supported that under natural condition, passive adaptation of aquatic organisms to increased ambient metal level have been evolved only under constant low-water temperature.     

鄱阳湖流域饶河龙口入湖段优势淡水鱼类对微塑料及重金属污染物的生物累积

水体生态环境中的微塑料与重金属污染问题正日益受到热切关注为探讨微塑料与重金属对水产品的复合生态效应,选择鄱阳湖饶河段优势淡水鱼为研究对象,对鱼体内微塑料及重金属Cu、Cd、Pb、Zn、Cr等元素的生物累积作用进行分析与评价结果表明:调查区域水环境中微塑料的丰度范围10～64 items/L,平均值38.56 items/L. 8种淡水鱼消化道微塑料丰度范围为1.21～9.11 items/g,平均丰度为5.40 items/g;鳃部丰度范围0.61～5.00 items/g,平均丰度为2.87 items/g;微塑料类型主要有碎片类、纤维类、薄膜类和颗粒类4种,其聚合物成分主要为聚乙烯(PE)、低密度聚乙烯(LDPE)、聚丙烯(PP)和聚苯乙烯(PS);颜色以透明及彩色为主;微塑料粒径范围为0.01～9.5 mm,粒径0.5 mm的微塑料所占比例为79.07%,鱼体内与其生存水环境中微塑料的丰度特征(形态、粒径、颜色和聚合物类型组分比例)具有一定相似性各鱼类对微塑料的累积系数(BAF)平均值为178.29,不同鱼类累积微塑料的能力大小次序为:乌鳢(Channa argus)、黄颡鱼(Pelteobagrus fulvidraco)鲦鱼(Hemicculter leuciclus)、草鱼(Ctenopharyngodon idellus)、鲶鱼(Silurus asotus)鲤鱼(Cyprinus carpio)、刀鱼(Coilia ectenes)、鲫鱼(Carassius auratus)鱼体肌肉组织内重金属Cu、Cd、Pb、Zn、Cr的平均含量分别为4.27、0.13、0.28、11.73、0.53 mg/kg,均符合无公害水产品的要求且低于人体消费卫生标准,属于安全食用范围;鱼类对5种不同重金属的累积能力大小次序为ZnCuCdPbCr,不同鱼类对不同重金属的累积能力具有差异性通过扫描电镜(SEM)与能谱分析(EDS)检测到各类型微塑料表面均有上述5种重金属元素,证实微塑料可能成为重金属的附着载体,相关性分析表明微塑料与Cu呈极显著相关,与Cd、Pb均呈显著相关;微塑料的存在一定程度上会增强Cu、Cd与Pb的累积效应,并可能产生复合污染效应.     

Survivality and Impaired Growth in Arsenic Treated Fingerlings of Channa punctatus,a Fresh Water Murrel

The LC₅₀-values of As³⁺-compounds for Channa punctatus are determined for a 48-h exposure to 19.4 (18.02… 21.3) mg/1 and for a 96-h exposure to 14.3 (13.06… 16.80) mg/1. At a long-time exposure to 7.0 mg/1 As³⁺, during the first seven days there does not occur any change of growth, then the growth in length and the increase in weight decreased by 6.6 and 11.7%, respectively, till the 31st day. At the same time, the RNA content of the muscle decreased by 11.5% to 966.7 μg/g fresh weight and the protein content decreased by 12.5 % to 95.39 mg/g fresh weight.     

Assessment of sacrificial anode impact by aluminum accumulation in mussel Mytilus edulis: a large-scale laboratory test

Since the early 1960s, the application of aluminum alloy sacrificial anodes to mitigate marine corrosion has been well known. The aim of this work was to study aluminum bioconcentration in Mytilus edulis by an in vitro test performed in two tanks: the first containing non-contaminated water (NCW) and the second containing aluminum-contaminated water (CW) (530 μg L⁻¹) released by sacrificial anode. The mussels were collected and examined over a period of 8 weeks. A comparison between the aluminum concentrations in the digestive glands of mussels from the CW and NCW tanks shows that the highest value (1700 mg/kg d.w.) was found in the CW mussels collected after 13 days. In NCW, the mean aluminum concentration in digestive glands during the test was 281 mg/kg d.w. The rapid concentration decrease in digestive glands is probably due to the inhibition of filtering activity due to valve closure at the high concentration as well as the induction of the detoxification response.     

沉水植物附植生物膜藻类组成及重金属累积特征

沉水植物表面常富集水体中有机质、泥沙、菌胶团、藻类、微生物等形成附植生物膜,在湖泊生物地球化学循环过程中具有重要作用.在草海选取金鱼藻（Ceratophyllum demersum）、微齿眼子菜（Potamogeton maackianus）和光叶眼子菜（Potamogeton lucens L.）3种不同叶形的沉水植物,研究附植生物膜的形貌结构、理化特征、藻类及其重金属镉（Cd）、铅（Pb）累积特征.结果表明：3种沉水植物附植生物膜上共鉴定出藻类6门8纲17目29科65属81种,主要为蓝藻、绿藻和硅藻,不同附植生物膜藻类功能群组成不同,冗余分析表明,水环境因子能解释藻类功能群变化的88.3%;3种沉水植物附植生物膜铁（Fe）、锰（Mn）、总氮（TN）、总磷（TP）含量变化规律一致,均为：金鱼藻 > 微齿眼子菜 > 光叶眼子菜;附植生物膜中重金属的累积具有选择性,Pb大量累积（11.41~41.31 mg/kg）,Cd累积含量较低（0.59~5.76 mg/kg）且与植物相当（0.44~5.56 mg/kg）,附植生物膜中Pb累积含量与生物膜中隐藻门、硅藻门藻类生物量、Fe、Mn及TN含量呈显著相关,但Cd累积与生物膜各指标均无显著相关性.附植生物膜在草型湖泊污染物归趋转化中的作用值得关注.     

Hyperactivity and changed diurnal activity in flounders,Platichthys flesus,exposed to DDT

Flounders (Platichthys flesus), which had been given oral doses of DDT, developed hyperactivity and abnormal diurnal activity 5–7 weeks after the dosage of DDT was terminated. For the flounder given the highest dose (12.5 mg DDT kg^?1 fresh body weight) a more than 20-fold increase in swimming activity was recorded. The levels of DDT found in various organs (axial muscle, liver and brain) are compared with levels of DDT found in wild populations of fish from the Baltic Sea. The results are also discussed in relation to results obtained in a parallel study on the physiological effects of DDT on the flounder.     

Changes in the Level of Proteins,Free Amino Acids and Protease Activities of Clarias batrachus in Response to Sodium meta‐arsenite Intoxication

Increased hazard of arsenic toxicity at many provinces of India causing extensive contamination of their wetlands. To illustrate the consequences of the arsenic menace on the aquatic fauna, a nutritionally important freshwater catfish Clarias batrachus (Linn.) was subjected to the stress of sublethal concentration (1 mg/L; 5% of 96‐h LC₅₀ value) of sodium meta‐arsenite. The alterations induced by the arsenic salt on certain biomolecules (proteins, free amino acids (FAA), and protease activities) in five tissue components (muscle, liver, brain skin, and gills) of the fish using biochemical techniques were estimated. Significant (p < 0.01) decrease in the concentration of proteins in all the tissues (19.74–44.84% in muscles; 3.17–49.39% in liver; 10.05–36.16% in brain; 12.62–52.01% in skin and 7.34–61.69% in gills), and significant (p < 0.01) increase in FAA (6.84–269.89% in muscles; 125.89–358.03% in liver; 1.07–152.90% in brain; 29.31–401.62% in skin and 38.53–165.07% in gills), and protease activities (43.59–183.33% in muscles; 19.52–131.90% in liver; 8.85–46.72% in brain; 33.33–261.53% in skin and 25.39–50.79% in gills) of the exposed fish were observed. This increase in amino acids and enzyme activity point out toward breakdown of protein leading to their depletion.     

水位对洞庭湖湿地4种典型沉水植物的影响

近年来,受全球变化及高强度人为干扰的影响,湿地退化严重(洞庭湖湿地枯水期提前、枯水期水位持续降低和浅水洼地减少),导致洞庭湖湿地沉水植物大面积消亡.深入研究洞庭湖低水位对沉水植物的生长影响,对指导沉水植物恢复有重要意义.以我国典型通江湖泊洞庭湖典型沉水植物为研究对象,模拟野外沉水植物主要分布区域浅水洼地水文环境,设置4个水位梯度(25、50、75、100 cm),探讨竹叶眼子菜(Potamogeton malaianus)、黑藻(Hydrilla verticillata)、苦草(Vallisneria natans)和金鱼藻(Ceratophyllum demersum)的生长、生物量和生理活性对水位变化的响应.结果显示:(1)前期底质养分含量为:总氮0.09%、总磷0.09%、总钾3.04%、碱解氮20.87 mg/kg、速效磷10.7 mg/kg、速效钾326.67 mg/kg、硝态氮6.97 mg/kg、氨氮6.59 mg/kg、有机碳1.21%、有机质2.09%,2个月后,不同水位的底质养分含量有差异,100和75 cm水池的养分含量高于50和25 cm,氨氮、有机质和有机碳含量在25 cm水位的水池较高;(2)75 cm水位适合竹叶眼子菜和黑藻生长,100 cm水位适合苦草和金鱼藻生长;(3)100 cm水位有利于竹叶眼子菜的繁殖及生物量积累,75 cm水位有利于黑藻和金鱼藻的繁殖及生物量积累,50 cm水位有利于苦草的繁殖及生物量积累;(4)100 cm水位下的沉水植物酶活性强,75和50 cm水位下的沉水植物次之,25 cm水位下的最弱.以上结果表明,4种沉水植物的生长特征和生物量积累随水位变化,在水域生态恢复中应考虑将水位控制在50~100 cm之间,这样有利于促进种群生物量和水生生态系统的恢复.     

鄱阳湖水体沉积物中Zn、Cd对底栖生物的毒性效应及基准验证

以泥鳅（Misgurnus anguillicaudatus）、铜锈环棱螺（Bellamya aeruginosa）、河蚬（Corbicula fluminea）为受试生物,以死亡率、渗血率、体质量变化、行动迟钝率、挖洞率为测试指标,探究沉积物中Zn和Cd对底栖生物的21 d慢性毒性效应,并对鄱阳湖Zn和Cd的沉积物基准值进行了验证.结果表明,沉积物中Cd对底栖生物的毒性效应强于Zn,沉积物中Zn、Cd对泥鳅、铜锈环棱螺、河蚬的LC₅₀（半数致死浓度）分别为644和61 mg/kg、751和54 mg/kg、652和81 mg/kg,EC₅₀（半数效应浓度）值分别为526和49 mg/kg、589和35 mg/kg、474和45 mg/kg.经验证,沉积物Zn和Cd的TEL（临界效应浓度）、PEL（必然效应浓度）值比较合理,具有一定适用性,即当Zn、Cd的加标含量低于TEL值时,Q_TEL<1,不具有毒性;当加标含量高于PEL值时,Q_PEL>1,毒性明显.     

Total and methylmercury residues in cartilaginous fish from Mediterranean Sea

Concentrations of mercury and methylmercury residues were determined in the muscle tissue of three cartilaginous fishes Chimaera monstrosa (ghostshark), Torpedo nobiliana (electric ray) and Myliobatis aquila (eagle ray) from the Mediterranean Sea. The highest mean levels of total mercury were detected in ghostshark (3.14 mg/kg wet weight), followed by electric ray (2.42 mg/kg wet weight), and eagle ray (0.83 mg/kg wet weight). Such a variability is influenced by quite a number of factors, among which size, fish ecology and feeding habits. The percentages of the methylated form to total mercury ranged from a minimum of 72% in eagle ray to a maximum of 83% in ghostshark. Relationship between specimen size and mercury and methylmercury concentrations were found in ghostshark species.     

Acute toxicity of cadmium to Channa punctatus (BLOCH)

Effects of acute cadmium poisoning on survival, its residual values and histopathology in certain organs of a freshwater airbreathing fish, Channa punctatus (BLOCH ) were investigated. The threshold concentration, MATC and LC₅₀ values obtained from 96 h static bioassay, revealed that Channa is more susceptible to cadmium ions at higher temperature. The atomic absorption spectrophotometric determination of cadmium residues differed significantly in organs of specimens having survived and died after 96 h of exposure. The gill accumulate the highest amount of cadmium, the liver accumulated a slightly smaller amount than the gill, while the kidney accumulated the least. The histopathological lesions subjected to sublethal (5.2 mg/l Cd) and lethal (8.4 mg/l Cd) concentrations of cadmium were: detachment and rupture of lamellar epithelium, collapse of pillar cells and hypertrophy in mucus producing gland cells in the gill; vacuolization and coagulative necrosis in hepatic cells of the liver; and expansion, necrosis and accumulation of cellular debris in renal tubules of the kidney. The probable causes for death of fish due to cadmium ions have been discussed.     

水生高等植物马来眼子菜和金鱼藻的初级生产率(黑白瓶法)

用黑白瓶测氧法测定了水生高等植物马来眼子菜(竹叶眼子菜,Potamogeton malaianus)和金鱼藻(Ceratophyllum demersum)的初级生产。按单位鲜重或干重表示的毛生产率,马来眼子菜为0.43—1.50mg O_2/g FWt.h(3.76—13.03mg O_2/g DWt.h);金鱼藻为0.44—0.45mg O_2/g FWt.h(5.12—5.27mg O_2/g DWt.h)。净生产率则分别为0.15—1.44mg O_2/g FWt.h(1.31—12.51mg O_2/g DWt.h)和0.08—0.25mg O_2/g FWt.h(0.93—2.95mg O_2/g DWt.h)。讨论了测定时的样品重量和光照强度对生产率的影响。     

Acute and chronic toxic effects of the carbamate pesticide Sevin on some haematological,biochemical and enzymatic parameters in the fresh water teleost fish Channa punctatus

The effects of exposure to LC₅₀ (10.5 mg/l) for 96 h and to a sublethal concentration (1.05 mg/l) of Sevin for 120 days have been observed on some haematological, biochemical and enzymatic parameters of Channa punctatus. The fish were hyperglycemic and hyperlactemic and the glycogen content of the liver and muscles decreased, but the lactic acid content of two tissues increased. The activity of hexokinase increased in the kidney, intestine, liver and muscles but decreased in the gills and brain. The activity of lactate dehydrogenase decreased in the kidney and intestine, and increased in the liver, muscles, brain and gills. The pyruvate dehydrogenase activity decreased in all the six tissues. Both the exposures produced a decrease in the succinate dehydrogenase activity of the liver. The enzyme activity decreased in the brain, gills and muscles after chronic exposure, whereas the kidney and intestine showed an elevation in enzyme activity.     

Pattern and pathways for mercury lifespan bioaccumulation in Carcinus maenas

Carcinus maenas is an important and exploited natural resource in temperate estuaries, being consumed by local populations and also used as fish bait. Through bioaccumulation and bioamplification processes occurring in polluted estuarine ecosystems, this species may directly or indirectly represent a major pathway for Human contamination. No information is available on the overall lifespan bioaccumulation pattern of mercury for this species, which would be an invaluable tool for assessing the risks associated with C. maenas harvest in contaminated areas. Taking that in mind, the main objectives of this work were to clarify the lifespan bioaccumulation pattern of mercury for this species. A consistent lifespan accumulation pattern was found for this species, both for total and organic mercury, and coherent differences were found between genders, suggesting different physiological responses to contamination. From our results two scenarios emerge: (a) for low mercury contamination areas where the diet is the major pathway for metal uptake, with higher levels in muscle and hepatopancreas (twice as high as in gills) and higher organic mercury fractions (as high as 80-90% in muscle), crabs bioaccumulate with age and (b) on high contaminated areas, environmental exposure is predominant, with higher levels found in gills (reaching 0.8 mg kg(-1)), lower organic fractions and no mercury increment with age. Detoxification strategies, dietary differences and species mobility may account for these two accumulation patterns.     

Amendment of Copper Toxicity in Alluvial Soil Using Iron: Effect on Growth and Yield of Triticum aestivum L.

Pot experiments were conducted in glasshouse under controlled conditions. The effect of copper in alluvial soil on the growth and yield of Triticum aestivum L. (wheat) was worked out. Copper was applied in soil at 5–100 mg L^?1, along with iron supplement. Inhibitory response of copper was significant (p < 0.05) confirmed by the plant growth parameters viz., plant height, fresh and dry weight, moisture content, pigment contents, protein, sugar contents followed by increased catalase and peroxidase activity in the harvest at 30, 60, and 90 days, of treatment, respectively. The plants grown on copper treated soil along with 5 mg L^?1 Cu and iron application showed significant effects (p < 0.05) regarding the increase in plant biomass, plant height (shoot only), pigment contents, protein, sugar contents, grain yield followed by decreased catalase and peroxidase activity in wheat after 30, 60, and 90 days of treatment, respectively. The accumulation of metal in plant tissues was found in order of Fe > Cu coupled by less translocation in grain as compared to the whole plant.     

Lethal and estrogenic effects of 4-nonylphenol in the cockle Cerastoderma glaucum

The lethal and sublethal effects of the xenoestrogen 4-nonylphenol (NP) were evaluated in the cockle Cerastoderma glaucum. In a 96-h lethality test, bivalves were exposed to 0, 0+ acetone, 0.19, 0.38, 0.75, 1.5 and 3.0 mg NP/l. The 96-h LC₅₀ value was 0.3 mg NP/l. No mortality was observed at 0.1 mg NP/l. The potential estrogenicity of NP was studied in both sexually undifferentiated (resting phase) and differentiated (pre-spawning phase) cockles, exposed for 7 and 14 days to 0, 0+ acetone, 0.0125, 0.025, 0.05, and 0.1 mg NP/l. Vitellogenin (Vg)-like protein levels were determined in both haemolymph and digestive gland by the alkali-labile phosphate (ALP) assay. In the resting phase, exposure for 7 days to 0.1 mg NP/l resulted in significant increases in ALP in both haemolymph and digestive gland, compared with controls. A significant increase was also observed in digestive gland of animals exposed to 0.0125 mg NP/l-exposed animals. After 14 days of exposure, haemolymph ALP levels were significantly increased in exposed animals at all NP concentrations tested, whereas no difference was recorded in digestive gland. In the pre-spawning phase, exposure for 7 days to NP significantly increased ALP levels in haemolymph from males exposed at all NP concentrations tested, whereas no significant variations were found in haemolymph from females. NP (0.05 and 0.1 mg/l) was also shown to increase ALP concentrations significantly in digestive gland of males, but not in those of females. Likewise, after 14 days’ exposure, ALP levels significantly increased in haemolymph from males only at 0.1 mg NP/l. Conversely, NP caused significant increases in ALP levels in digestive gland from both males (at all NP concentrations tested) and females (at 0.025 and 0.1 mg NP/l). These results demonstrate that NP induces Vg synthesis in C. glaucum. Interestingly, males were more responsive to NP than females.     

Effects of 4-nonylphenol exposure in mussels (Mytilus galloprovincialis) and crabs (Carcinus aestuarii) with particular emphasis on vitellogenin induction

Since it is often difficult to estimate possible adverse effects due to contamination in selected ecosystems, multi-species biomonitoring may provide more information, taking into account different routes of exposure, ecological roles and metabolic capabilities of animals. In this context, we exposed for 7 days the mussel Mytilus galloprovincialis and the crab Carcinus aestuarii to 4-nonylphenol (NP), a well-known xenoestrogen. In mussels (0–0.2 mg NP l⁻¹), we measured NP bioaccumulation in soft tissues and vitellogenin (Vg)-like protein levels in digestive glands from both males and females by the alkali-labile phosphate assay (ALP). As no reference data were available for crab exposure, the NP 96-h LC₅₀ value was previously determined. Then, in sublethally exposed (0–1.0 mg NP l⁻¹) male crabs, NP bioaccumulation and Vg levels were measured in hemolymph, gonads and digestive gland. Bioaccumulation of NP increased from 43 to 371 μg g⁻¹ d.w. in mussels, and from 3.6 to 37 μg g⁻¹ d.w. in crabs, depending on the NP concentration in water. Dose-dependent Vg-like protein induction was observed in both species, appearing to be related to NP bioaccumulation, although a partial decrease was recorded at the highest concentration tested. A similar trend was observed in both digestive gland and gonad of exposed crabs; Vg increased to a lesser extent, although significantly, in hemolymph. Results demonstrated that NP induces Vg synthesis both in male and female mussels, as well as in male crabs. On the basis of the responsiveness of both species investigated, a multi-species approach is indicated in biomonitoring programmes.     

Downstream composition changes of acidic volcanic waters discharged into the Banyupahit stream, Ijen caldera, Indonesia

The crater lake of Kawah Ijen volcano contains extremely low pH (<0.4) waters with high SO₄ (70000 mg/kg), Cl (21000 mg/kg), F (1500 mg/kg), Al (5000 mg/kg), Fe (2000 mg/kg) and trace metal (Cu 0.5, Zn 4, Pb 3 mg/kg) contents. These brines seep outward through the western crater rim and reappear on the other side as streamlets, which form the headwaters of the Banyupahit stream. The Banyupahit first mixes with fresh rivers and thermal springs in the Ijen caldera and then irrigates a coastal agricultural plain which is 30 km from the summit crater.We discuss the downstream composition changes affecting the Banyupahit waters by using stable isotope, chemical and mineralogical data collected from sites along the stream length. The saturation of the stream waters with respect to minerals was evaluated with SOLVEQ and WATEQ4F and compared with the geochemical observations. An aluminous mineralogy (alunogen, pickeringite, tamarugite and kalinite) develops in the upper part of the Banyupahit due to concentration of the headwaters by evaporation. Downstream attenuation of dissolved element concentrations results principally from dilution and from mineral precipitation. The stream pH changes from 0 at the source to >4 close to the mouth. The δD and δ¹⁸O values and the relative SO₄–Cl–F contents of the Banyupahit waters indicate that the tributaries are mostly meteoric. Dissolved SO₄ in the acidic stream come only from the crater lake seepages and are not involved later in microbially mediated reactions, as shown by their δ³⁴S and δ¹⁸O values. Re-equilibration of the stream SO₄ oxygen-isotope composition with H₂O from tributaries does not occur.Calcium, SiO₂, Al, Fe, K and SO₄ behave non-conservatively in the stream waters. Gypsum, silica (amorphous or poorly ordered), a basic aluminum hydroxysulfate (basaluminite?), K-jarosite and amorphous ferric hydroxide may exert a solubility control on these elements along the entire stream length, or in certain stream sections, consistent with the thermochemical model results. Downstream concentration trends and mineral saturation levels suggest that precipitation of Sr-, Pb-rich barite and celestite consume Ba, Sr and Pb, whereas dissolved Cu, Pb and Zn may adsorb onto solid particles, especially after the junctions of the acidic stream with non-acidic rivers. We calculated that significant fluxes of SO₄, F, Cl, Al, SiO₂, Ti, Mn and Cu may reach the irrigation system, possibly causing serious environmental impacts such as soil acidification and induration.     

Synthesis of Cu-binding proteins in different tissues of mussels exposed to the metal

The results demonstrate that Cu²⁺, when present in sea water at the sublethal concentration of 0.08 ppm, is able to induce, within 48 h, the synthesis of Cu-binding proteins having a molecular weight similar to that of the metallothioneins (12 000), in the gills and in the mantle of the mussels. In the digestive gland of the animals, part of the copper present in the cells is always associated to soluble low molecular weight thionein-like proteins; the level of these copper-binding proteins increases greatly in the mussels exposed to Cu²⁺. In addition, it has also been shown that an extremely low concentration of copper (0.015 ppm)—similar to the Cu²⁺ concentration found in polluted coastal areas—is able to stimulate the synthesis of thionein-like Cu-binding proteins in the three tissues examined within 2–5 days.