Biochem. Cell. Arch. Vol. 17, No. 1, pp. 301-308, 2017
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ISSN 0972-5075
BIOACCUMULATION OF HEAVY METALS IN FRESHWATER MUSSELS FROM JAYAKWADI DAM, INDIA SHOW SPECIFICITY OF TISSUE AND SPECIES G. D. Suryawanshi Department of Zoology,Yogeshwari Mahavidyalaya, Ambajogai, Dist. Beed - 431 517, India. e-mail :
[email protected] (Accepted 18 February 2017) ABSTRACT : Heavy metals are present in aquatic ecosystems in dissolved form, associated with suspended food particles and insolublesubstratum. Due to its wide technical use and its presence in municipal, agriculture and industrial effluents, levels in rivers, reservoirs and large dams may be elevated. The aim of this study is to assess the levels of heavy metalsfrom freshwater mussels Lamellidens marginalis, Lamellidens corrianus, Parreysia corrugata and Indonaea caeruleusinJayakwadi dam in Marathwada. The eight heavy metals viz. Hg, Ni, Fe, Mn, Zn, Cr, Cd, and Cu analyzed from four different species of freshwater mussels from Jayakwadi dam which is largest dam in Marathwada region. Amongst the Fe, Mn, and Zn was more accumulated by L. marginalis,L. corrianus and I. caeruleus. In P. corrugata the Zn concentration was more followed by Fe and Mn. Overall during study the Hg metal level found at lower concentration and Fe, Mn, and Zn showed its high values of concentrations in all species when it compared with all other metals concentrations. In addition to these it was showed that a difference of heavy metals concentrations in different body parts of L. marginalis and L. corrianus. In results there was no any consistency in body parts of bivalves except gonad in L. marginalis. In gonad there was high amount of Fe and Ni, adductor muscle stored high amount of Zn, foot and hepatopancreas stored low amount of Ni, Zn and Fe respectively. In L. corrianus the Ni, Fe and Zn was more in the body parts like gonad, gill and hepatopancreas respectively.Among the heavy metals in bivalves overall the mercury shows minimum amount and iron was found more in species and even in their body parts.The concentrations of all heavy metals were below the levels regarded as harmful according to the international standards for metals in mollusks compiled by the Food and Agricultural Organization of the United Nations. Key words : Mussels, metals levels, L. marginalis, L. corrianus, P. corrugata, I. caeruleus.
INTRODUCTION Biomagnification of heavy metals has severe health problems to the flora and fauna including humans and other organisms (McCormick et al, 2005). The only reliable way to overcome the problem of the heavy metal pollution is regular and periodic monitoring of the aquatic resources, which helps to keep check on the concentration of the contaminants and prevents the further pollution (Bellingham, 2012). Excess deposition of heavy metals and its accumulation in organism causes toxic effect over the body of organisms (Kwon, 2001; Kaur, 2012; Seongjin et al, 2014). The major source of contaminants is untreated or partially treated effluents of the industries, which directly discharged in to the river streams (Sehgal, 2012). Heavy metals are present in aquatic ecosystems in dissolved form, associated with suspended food particles and sediment. Due to its wide technical use and its presence in municipal and industrial waste waters, levels in rivers and sediments may be elevated (Rodrigues et al, 2012). The most important metals from the point of view of water pollution are As, Cd, Cu, Pb,
Hg, Ni and Zn. Some of them for example Cr, Cu, and Zn are essential trace metals to living organisms but become toxic at higher concentration (Li et al, 2002). People are becoming more aware of the complexity of the nature and the delicate balance that exist within the global ecosystem (Ahmet et al, 2006). Heavy metal accumulated in benthic organisms might be further biomagnified in food webs. Hence consummation of such kind of animals may form a significant pathway in the human being and creating public health problems (Medeiros et al, 2012). Higher trophic level organisms such as fish, bivalves, crabs, shrimp, and gastropods can be exposed to as through waterborne and dietary routes, biotransform, accumulate and retain it inside their bodies (AzizurRahman et al, 2012). The bioaccumulation of heavy metals such as Mg, Fe, Zn and Cu concentration in different body parts and shell of marine neogastropod Cymbiummelo and sediment of its habitat reported by (Shanmugam et al, 2007). The freshwater bivalve Anodontitestenebricosus is a suitable biomonitor of
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contamination by asses the heavy metals (Nugroho et al, 2011). The ability of molluscs to concentrate heavy metals in their tissues to a very high level from the environmental water has been reported by various workers from India (Suryawanshi, 2007; Aradhi et al, 2009; Kesavan et al, 2013; Gaikwad and Kamble, 2014). This property of the bivalve molluscs may be utilized to monitor metallic pollution in the aquatic environment. In molluscs, size and weight along with the age is an important factor which determines bioaccumulation and has been reported by Jordaens et al (2006). Many researchers from Maharashtra devoted to study on the effect of various pollutants on freshwater bivalves in relation to biochemical, O:N ratio, histology, reproduction and other different aspects of body physiology (Andhale, 2011; Waghmare et al, 2012; Shaikh et al, 2012; Waykar and Shinde, 2013; Mundhe and Pandit, 2014). But, very little information is available on base levels of heavy metals in whole body and their different body from study area. Hence, with the afore mentioned lacunae and paucity of information on wild populations of mussels in the Jayakwadi that the present study is aimed to understand distribution of heavy metals like mercury, nickel, iron, manganese, zinc, chromium, cadmium and copper from four species of bivalves. MATERIALS AND METHODS The Jayakwadi project is large sized earthen irrigation project in the Marathwada region. It is multipurpose project constructed on Godavari River at the Jayakwadi village. The dam provides water for drinking and industrial areas of major cities which are located nearby dam. The reservoir is rich in flora and fauna and catchment area is about 21,750 km2 and total submergence area due to the reservoir is approximately 35,000 ha. The surround area of the dam has a garden and a bird sanctuary. The four speciesof medium sizes bivalves viz. L. corrianus, L. marginalis, P. corrugata and I. caeruleus were collected in monsoon from Jayakwadi dam which is 45 km away from Aurangabad and they were brought to the laboratory and kept in plastic troughs containing five ltrs.ofdechlorinated tap water for three days to acclimatize to laboratory conditions. Water from the plastic trough was changed after every 12 hours. The healthy bivalves of approximately same (75-80 mm shell length) size and weight were selected for the experiments. Since the animals are micro feeders no special food was supplied during the experiment. The bivalves were dissected and kept in hot air oven at 920C for 24 hours till constant weight was obtained. The dried product was ground to obtain fine powder for
determination of metals, 500 mg dry powder of animalswere digested with 10 ml mixture of nitric acid and perchloric acid (4:1) at 100oC temperature till a clear solution was obtained. The samples were cooled at room temperature and filtered through Whattaman No. 43 filter paper and these filtrates were then diluted with 0.1N HNO3 up to 25 ml with deionized water. These solutions were analyzed for mercury, nickel, iron, manganese, zinc, chromium, cadmium and copper metals using atomic absorption technique according to the standard methods (APHA, 1998). The data obtained were statistically analyzed for confirmation of the results by ANOVA.The results were calculated using regression equations and expressed in µg/g dry weight. RESULTS The information available on the variation in heavy metal content in freshwater bivalves in adequate. The four species analyzed for heavy metal likemercury, nickel, iron, manganese, zinc, chromium, cadmium and copper from wild populations (Table 1). In present study, the mercury was more in L. marginalis followed by L. corrianus, I. caeruleus and P. corrugata. The nickel was high in L. marginalis followed by P. corrugata, L. corrianus and I. caeruleus. The iron content was high in L. marginalis followed by L. corrianus, I. caeruleus and P. corrugata. The manganese level was high in L. marginalis followed by L. corrianus, I. caeruleus and P. corrugata. The zinc level was more in L. marginalis followed by P. corrugata, L. corrianus and I. caeruleus. The chromium content was high in I. caeruleus followed by L. marginalis, P. corrugata and L. corrianus. The cadmium metal level was high in I. caeruleus followed by L. corrianus, L. marginalis and P. corrugata. The copper metal level was high in I. caeruleus followed by P. corrugata, L. marginalis, L. corrianus. Among the heavy metals in bivalves overall the mercury shows less amount and iron was found more in all species. On the other hand, the metal content when compared with L. marginalis, the mercury showed low level in bivalve species and the rate of low in P. corrugata (64.65%) followed by I. caeruleus (25.26%) and L. corrianus (1.02%). The nickel was low in I. caeruleus (81.51%; P
