Heavy metal concentrations in the soft tissues of swan mussel (Anodonta cygnea) and surficial sediments from Anzali wetland, Iran.
ABSTRACT Concentrations of cadmium, copper, and lead were determined in surficial sediments and the soft tissues (foot and gills) of swan mussel Anodonta cygnea from two sampling sites in Anzali wetland, which is an internationally important wetland registered in the Ramsar Convention. The metal contents in the mussel species from the studied region were comparable to other world areas. In most cases, the levels of the metals either fell within the range for other areas or were lower. There were significant differences between the tissues for the accumulation of Cd and Pb. Only in the case of Pb accumulation in gills significant differences between the specimens from the selected sampling sites could be observed. Age-related correlations were found in the case of Cu accumulation in foot and Cd levels in gills. No weight-dependent trend could be observed for the accumulation of the three elements. There was significant negative width-dependent relationship in the case of Cu. A significant negative correlation was also found between the maximum shell height and Cu accumulation in the gills. The only association among the elements in the selected soft tissues was found between Cd and Pb. Highly significant differences could be found between the sampling sites from the concentration of the elements in sediments point of view. The pattern of metal occurrence in the selected tissues and sediments exhibited the following descending order: Pb, Cu>Cd for gills, Cu>Pb, Cd for foot, and Cu>Pb>Cd for sediments. The mean concentrations of Cd and Pb in the sediments from the study area were higher than the global baseline values and world average shale. In the case of Cu, our results were somewhat higher than the baseline values but well below the world average shale.
- Bulletin of Environmental Contamination and Toxicology 11/2005; 75(4):716-22. · 1.11 Impact Factor
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ABSTRACT: Two bivalve species (Anodonta sp. and Unio pictorum) and two gastropod species (Radix ovata and Viviparus sp.) were tested as bioindicators in moderately metal-polluted Danube River habitats of Vienna. Molluscs, two sediment fractions and water samples were collected between April 1993 and May 1994 at six sampling sites located at five waters in Vienna. The unionid clams were dissected into viscera, gill, mantle, adductor muscle and shell, gastropods into soft body and shell. Analyses of Cd, Pb, Cu and Zn were carried out with atomic absorption spectrophotometry. Bioaccumulation of metals varied strongly according to sampling site, metal and mollusc species. Cd, Cu and Zn loads of the molluscs exceeded environmental concentrations, but not so for the apparently less bioavailable Pb. Sampling site had a significant influence on metal bioconcentrations, e.g. the Neue Donau sampling sites, where traffic emissions probably caused increased metal contents. High environmental metal concentrations in Danube harbours were poorly reflected by the bioindicator species. The gastropods showed about 20-fold higher concentrations than the bivalves. This may indicate a higher Cu regulation capacity of bivalves. The suitability of the investigated mollusc species as bioindicators depends on their specific relationship to the environmental compartment. Anodonta sp. and R. ovata concentrations were more likely related to the contents of the fine sediment fraction, which may be explained by their close association to the sediments. The metal concentrations of the deposit- and filter-feeder Viviparus sp. correlated more closely with suspended matter and filtrate contents.Environmental Pollution 11/2000; 110(1):61-71. · 3.73 Impact Factor
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ABSTRACT: Bioindicator methods were used to study the effects of the pyrethroid insecticide deltamethrin on the filtering behavior of the freshwater mussel Anodonta cygnea L in the laboratory, during short-term (30 min) and long-term (1 week) exposure. In the course of the short-term treatment, the water flow through the outflow syphon was monitored. It was found that 1 and 5 micrograms/liter deltamethrin caused an increase, whereas from 10 to 50 micrograms/liter deltamethrin resulted in a depression, in the open time of the outflow syphon and the water outflow. The inhibitory response was concentration dependent. In the long-term experiments, the valve movement representing the activity of the adductor muscles was recorded. At 1 microgram/liter, deltamethrin had no effect on the active period, but reduced the rest time, causing an increase in the filtration; all higher concentrations (10-50 micrograms/liter) caused inhibition of the filtration activity by reducing the active periods and lengthening the rest periods. The active periods were shortened on increase in deltamethrin concentration, the reduction being 80% of the control at 50 micrograms/liter. Lengthening of the rest periods led to a maximum (207% as compared with the control) at 15 micrograms/liter, with a subsequent decline to levels close to the control at 30 and 50 micrograms/liter. Nevertheless, due to the strong reduction of the active periods, the filtering activity remained depressed at higher concentrations. The results provide evidence that deltamethrin pollution may have an adverse effect on the functioning of the bivalve community in the aquatic environment, which should be considered when this chemical is used in agricultural areas near aquatic ecosystems.Ecotoxicology and Environmental Safety 01/1998; 38(3):195-9. · 2.20 Impact Factor