Metal bioaccumulation in representative organisms from different trophic levels of the Caspian Sea Item Type article Authors Mirzajani, A.R.; Hamidian, A.H.; Karami, M. Download date 01/10/2021 01:50:17 Link to Item http://hdl.handle.net/1834/37675 Iranian Journal of Fisheries Sciences 15(3) 1027- 1043 2016 Metal bioaccumulation in representative organisms from different trophic levels of the Caspian Sea Mirzajani A.R.1,2; Hamidian A.H.1*; Karami M.1 Received: May 2015 Accepted: October 2015 Abstract The bioaccumulations of metals Cu, Cd, Ni, Cr, Co, Mn, Zn and Fe were measured in bivalves, Cerastoderma glucaum, and four species of fishes including Alburnus chalcoides, Liza aurata, Rutilus frisii and Sander lucioperca from various trophic levels of the Caspian food web. The concentrations of Cd, Cr, Co and Ni in most samples of fish were below the detection limits; while the concentrations were detected in most samples of bivalve C. glucaum. The stable nitrogen isotope ratios varied among the samples from C. glucaum (δ15N=3.5 ‰) to S. lucioperca (δ15N=13.1‰). Among the four fish species, while the highest concentrations of Mn, Ni and Fe were observed in L. aurata, the lowest concentrations of Mn and Fe were observed in S. lucioperca. These species also had the lowest and highest trophic levels with an average of 3.3 and 4.2, respectively. No accumulation of metals with increase in body size was observed in Downloaded from jifro.ir at 9:20 +0330 on Sunday February 25th 2018 muscles of species from different trophic levels. The comparison of metal concentrations with the health guidelines for human consumption showed that those intakes were lower than the legislated limits. While there was a strong relationship between trophic levels and body size of A. chalcoides and R. frisii, no significant slopes were observed between the total lengths (TLs) and the Ln concentrations of metals. It is necessary to determine metal concentrations in food resources of fish species, particularly in R. frisii that has significantly different δ15N in relation to body size. Keywords: Metal pollution, Bioaccumulation, Stable isotope, Caspian Sea 1-Department of Environment, Faculty of Natural Resources, University of Tehran, P.O. Box 4314, 31587-77878 Karaj, Iran 2- Present address; Inland waters Aquaculture Research Center, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Badar Anzali, P.O. Box 66, Iran *Corresponding author's Email: [email protected] 1028 Mirzajani et al., Metal bioaccumulation in representative organisms from different trophic … Introduction concentrations in the Caspian fishes. The Caspian Sea, the largest land- While nearly all of these reports were enclosed drainage area in the world, focused on the Acipenseridae species supports substantial fisheries, while it (particularly Acipenser persicus) and has been endangered by massive loads Rutilus frisii, other commercial fishes of contaminants. The various were less concerned. Furthermore, no environmental pollutants produced by research has been done according to natural and anthropogenic sources are trophic levels of Caspian fishes. discharged from coastal catchment Four species, A. chalcoides, Liza (Glantz, 2000; UNEP/UNDP, 2011). aurata, R. frisii and Sander lucioperca, The hazardous effects of heavy metals have a high commercial value and good on human health are reviewed by market demands in the southern international organizations such as the Caspian regions. These species are WHO (Järup, 2003). traditionally known as zooplankton Caspian fishes, an important source feeders, detritivrous, benthivorous and of protein, are consumed by millions of piscivorous, respectively (Ghadirnejad, people living around the Caspian Sea; 1996; Zarinkamar, 1996; Abbasi et al., therefore monitoring their metal 2004; Abdolmaleki and Ghaninezhad, pollution is essential (Fallah et al., 2007; Neamatparast, 2007). 2011). Stable isotope analysis has been Bioaccumulation is defined as an widely used, as a powerful tool, for increase in the concentration of source identification of changes in pollutants by an increase in age, which aquatic and estuarine ecosystems, and sometimes is reflected in size of the also for assessing pollutant flux in organism (Fernandes et al., 2007). marine ecosystems (Broman et al., Downloaded from jifro.ir at 9:20 +0330 on Sunday February 25th 2018 Metal bioaccumulation is influenced by 1992; Cabana and Rasmussen, 1996; various environmental and biological Vander Zanden and Rasmussen, 1996; factors particularly the feeding source Lake et al., 2001; Jardine et al., 2006). (Agusa et al., 2004; Wang and However the metal concentrations in Rainbow, 2008). Although referring to muscle tissues are reported to be scientific literature, very few data have usually lower than in other organs been published on metal accumulation (Pourang et al., 2005; Kojadinovic et related to size and age (Anan et al., al., 2007; Mashroofeh et al., 2013), the 2005; Pourang et al., 2005; Foroughi turnover rate of δ15N in muscle protein Fard et al., 2008; Pazooki et al., 2009; is much longer and represents the Hoseini and Tahami, 2012). There have integrated diet and contamination of been some research (Sadeghirad, 2002; fishes for a long time (Cabana and Agusa et al., 2004; Sadeghirad, 2007; Rasmussen, 1996; Vander Zanden and Shahryari et al., 2010; Eslami et al., Rasmussen, 1996). 2011; Fallah et al., 2011; Monsefrad et Typically the 13C/12C and 15N/14N al., 2012) presenting metals ratios of a consumer are slightly higher Iranian Journal of Fisheries Sciences 15(3) 2016 1029 than those in its diet. On average, δ13C sample was measured by Vernier and δ15N values of consumers are calipers; and then they were weighed expected to increase by around 1‰ and using a balance at the nearest 0.01g 3.4‰ compared to those of their food, precision. respectively (Minagawa and Wada, The dorsal muscles of fish samples 1984). The nitrogen isotope were individually dissected using a high compositions are particularly well- quality stainless steel knife; rinsed with suited for examining trophic dynamics distilled water and dried at 60 °C for 48 and provide an estimate of their trophic h. The dried samples were ground and position (Minagawa and Wada, 1984; homogenized with a pestle and mortar, Post, 2002) while carbon isotope stored in distilled water washed in elucidates the origin and pathways of plastic bags and kept at -20°C before organic matter in food webs (Le Loc'h the laboratory experiments. Gut organs et al., 2008). and shells of mollusks were carefully In this study, we determined metal removed under stereomicroscope and concentrations in A. chalcoides, L. their soft tissues were pooled (20-30 aurata, R. frisii and S. lucioperca. individuals as one sample). The Furthermore, we studied the metal samples were oven dried at 60 °C for 24 bioaccumulation based on the trophic h. The preparation of samples followed levels in the Caspian food web. the ROPME instructions (1989). Material and methods Chemical analyses Sample collection For metal (Cu, Cd, Ni, Cr, Co, Mn, Zn The collections included Pike-perch (S. and Fe) analyses, a mass of around 0.5 lucioperca) (n=16), Kutum (R. frisii) g of each sample was digested in4 ml Downloaded from jifro.ir at 9:20 +0330 on Sunday February 25th 2018 (n=25), Danube bleak (A. chalcoides) high purity nitric acid (Merck, 65%) (n=20) and Golden grey mullet (L. and 1 mL perchloric acid (Merck, 70%) aurata) (n=16). These species were at room temperature. Digestion freshly collected from Anzali region continued on a sand bath with a (~37 28 N 49 33 E) during winter- maximum temperature of 115 °C, for spring of 2013. Two fishing methods; about 4 h and until the solutions were beach seine and gill net (Gerami and cleared. After cooling, the solutions Dastbaz, 2013) were used for sampling. were filtered through Whatman filter Furthermore about 360 individuals of membranes and were diluted up to 10 the benthic invertebrates bivalvia C. ml in a volumetric flask with deionized glucaum were freshly collected along distilled water. The digestion procedure the beach down to 20 meter depths by followed the ROPME instructions hand and by using a bottom sampler (1989) and Pourang (1995, 1996). (Van-Veen grab: 400 cm²), A HP 4500 ICP-MS, equipped with respectively. The total length of each Asx-520 Autosampler (England) was 1030 Mirzajani et al., Metal bioaccumulation in representative organisms from different trophic … used for the determination of metal of primary consumers (PC; i.e. bivalve concentrations in the samples. In order C. glucaum ), 3.4 and 2 are the mean to control the quality of the δ15N trophic enrichment occurring per measurement for each 25 samples, 2 trophic level and the trophic position of blanks and 2 spiked samples were used. the baseline organism, respectively. Instrumental detection limits for most Commonly, the primary consumers metals was 0.02 µg/g, except for Cd (TL2) are preferred to primary (0.01 µg/g) and Fe (0.1 µg/g). The producers (TL1) for evaluation of recoveries for Cd, Cu, Co, Cr, Ni, Mn, trophic levels (Cabana and Rasmussen, Zn and Fe were 84%, 107%, 79%, 94%, 1996; Vander Zanden et al., 1999; 101%, 86%, 72% and 72%, Vander Zanden and Rasmussen, 2001). respectively. We did not calculate the trophic levels of C. glucaum individuals because the Stable isotope analysis and trophic stable isotopes of particle organic level calculation matter (POM) as its baseline had high The stable isotope signatures were used variations in our sampling. to calculate the trophic levels. Around 1 mg of homogenized powder of each Statistical analyses sample was weighed in tin capsules. No The Kolmogorov-Smirnov and further steps were taken for the Levene’s tests were used to control the elimination of carbonates and lipids normality of distribution and the because this helps us to avoid homogeneity of variances, respectively.