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.

Oligochaetes (Annelida, Clitellata) in the Anzali International Wetland, north-western Iran

“…Although many researchers have studied the Anzali Wetland from the pollutionrelated, faunistic, and ecological points of view (e.g. Ayati 2003;JICA 2005;Charkhabi and Sakizadeh 2006;Akbarzadeh et al 2008;Jafari 2009;Tahershamsi et al 2009;Mirzajani et al 2010;Pourang et al 2010;Jamshidi-Zanjani and Saeedi 2013), there are no data on the species diversity of the Oligochaeta of the region, except the single record of Tubifex tubifex by Pourang (1996). The aquatic Oligochaeta species of Iran are mentioned only in a few papers: Stephenson (1920), Egglishaw (1980), Aliyev and Ahmadi (2010), Ahmadi et al (2011Ahmadi et al ( , 2012, Ardalan et al (2011), Jabłońska andPesić (2014).…”

Molecular responses of the bivalve mollusks from the cooling pond as a model for prediction of contemporary environmental challenges

“…However, novel environmental challenges biorisks are mainly connected to the complexity of harmful effects [6,24,35,38,45]. It is inconstant in time, composition, and its effect is difficult to be predicted.…”

Determination of polychlorinated biphenyls and total mercury in two fish species (Esox lucius and Carassius auratus) in Anzali Wetland, Iran

“…It also serves as an important spawning and nursery ground for the economically anadromous fishes (Talebi 1998). Previous studies emphasized that the environmental quality of this wetland especially eastern part of it has exacerbated during the last years (Pourang 1994(Pourang , 1996Talebi 1998;Akbarzadeh et al 2008;Tahershamsi et al 2009;Pourang et al 2010). These fundamental changes have mainly caused by the discharge of Rasht and Anzali's raw sewage, ground subsidence, and increasing of Caspian Sea level (Yazdanparast et al 2004).…”