determination of trace element concentrations in ...

© by PSP Volume 20 – No 8a. 2011

Fresenius Environmental Bulletin

DETERMINATION OF TRACE ELEMENT CONCENTRATIONS IN WATER, SEDIMENT AND FISH SPECIES FROM THE ATATÜRK DAM LAKE (EUPHRATES), TURKEY Mesut Ural1,*, Kazim Uysal2, Arzu Çiçek3, Esengül Köse2, Mehmet Ali Turan Koçer4, Selami Arca5, Gürel Nedim Örnekçi5, Ferhat Demirol5and Songül Yüce5

2

1 Faculty of Fisheries, Tunceli University, 62100, Tunceli, Turkey Departments of Biology, Faculty of Arts and Sciences, Dumlupınar University, 43100, Kütahya, Turkey 3 Environmental Issues Research and Training Centre, Anadolu University, 26100 Eskişehir, Turkey 4 Aqriculture Ministery, Mediterranean Aquaculture Research Institute, 07100 Antalya, Turkey 5 Aqriculture Ministery, Aquaculture Research Institute, 23100 Elazığ, Turkey

ABSTRACT

1. INTRODUCTION

Trace element concentrations were determined in water, sediment and fish samples (Carassius auratus, Capoeta trutta and Cyprinus carpio) collected from Atatürk Dam Lake which is the largest dam lake in Turkey. Trace element analyses were measured with ICP-OES. Cd and Hg were not detected in water, sediment and fish samples. Also, Mn and Ni concentrations were not determined in water. In Atatürk Dam Lake, the accumulation orders of trace elements were found to be Fe >Zn >Cu=Se in water, and Fe >Mn >Ni >Zn >Cu>Se in sediment. In general, the accumulation orders of elements in the tissues of the species were nearly similar to each other. The highest bioaccumulation factors (BAFs) were determined for Zn, in water and in all tissues of the species, except for Fe in the liver of Capoeta trutta. The BAFs calculated in sediment area were generally lower than 1. Mean concentrations for all trace element levels in species muscles were found at permissible levels set by FAO and Turkish legislation. As a result, trace element concentrations of water, sediment and fish samples in Atatürk Dam Lake were not found at the risk levels. But it may be said that some steps should be taken in order to protect the present situation.

KEYWORDS: Atatürk Dam Lake, Heavy Metals, ICP-OES.

* Corresponding author

Some trace elements constitute an important group of chemical pollutants in natural waters. Especially in recent decades, heavy metal levels in aquatic ecosystems have also increased due to mining, industrial and agricultural activities. Concern about the effect of anthropogenic pollution in the freshwater ecosystems is increasing. Trace elements of man-made pollution sources are continually released into aquatic systems, and they become a serious threat because of their toxicity, long persistence, bioaccumulation and biomagnification in the food chain. Fish is widely used as biomonitor in aquatic environment. Much of the trace elements variability in fish tissue has been attributed to the variability of age, life cycle, and feeding habits of species [1-3]. Iron, copper, zinc and manganese are essential metals since they play an important role in biological systems whereas mercury, lead, and cadmium are nonessential metals, as they are toxic, even in traces. The essential elements can also produce toxic effects when the element intake is excessively elevated. Trace elements are continuously introduced into the aquatic environments. Fish in the polluted waters seriously pose a threat to human health due to the bioaccumulation of toxic substances in muscles and other tissues. These contaminants also bioaccumulate in some organs of fish, can cause lethal destruction, and have a variety of sublethal effects [4-6]. In aquatic environment, trace elements in dissolved form are easily taken up by aquatic organisms where they are strongly bound with sulfhydryl groups of proteins and accumulate in their tissues. Fish are often at the top of the aquatic food chain and may concentrate large amounts of trace elements from the water. Heavy metal concentrations in sediments and detritus are many times higher than those in living organisms [7-9]. The aim of this study is to determine the trace element levels in water, sediment and some fish (Carassius

2036



auratus, Capoeta trutta and Cyprinus carpio) in Atatürk Dam Lake.

in such a way as to make their volumes to 100 ml with ultra-pure distilled water. TABLE 1 - Details of the fish species used in the experiments.

2. MATERIALS AND METHODS 2.1. The study area

Atatürk Dam Lake, situated on the Euphrates River, is the largest dam lake in Turkey, and used for irrigation and electrical energy production (Fig. 1). Its surface area and volume are about 81.700 ha and 48.700.000.000 m3, respectively. Recently, agricultural and industrial developments as well as increase in population have substantially increased the contamination in Atatürk Dam Lake. About 28 fish species have been recorded in Atatürk Dam Lake [10-12]. The Atatürk Dam is a rocky dam whose central core is on the Euphrates River, on the border of Adıyaman and Şanlıurfa province in the Southeastern Anatolia Region of Turkey [13].

Species N Age T.L±SD (cm) BW±SD (gr) Capoeta 40 2-6 33.65 ± 4.75 473.12 ± 226.37 trutta (25.9-42.6) (210-1244) Cyprinus 20 4-6 32.45 ± 2.92 681.90 ± 237.65 carpio (28.9-41.5) (502-1622) Carassius 10 4-7 37.10 ± 6.55 1014.80 ± 503.58 auratus (30.5-48.6) (564-1872) N: number of fish; TL: Total Length; BW: Body weight; SD: Standard deviation. Minimum and maximum values are given in parenthesis.

Water samples (1 L) were taken at each sampling point and adjusted to pH 2 by adding 2 ml of HNO3 to each. Before sampling, sample bottles were cleaned by washing them with a detergent and soaking them in HCl for 24 h. Finally, the bottles were washed with water and then rinsed with distilled water. Bottles were kept in 1 % nitric acid before usage. Element levels in samples were determined by ICP-OES (Varian 720 ES). The element analyses in water and fish were recorded as means triplicate measurements [14-17]. 2.3. Statistical analyses

Each result was the average value of three analyses and presented as mean value. The statistical differences of mean metal levels among tissues and species were analyzed using multiple comparison tests (SPSS package program). One-way ANOVA was utilized to compare the data of species and tissues. Results were considered to be significant at p < 0.05 [18]. 2.4. Bioaccumulation factor (BAF)

The BAF was calculated according to the formula BAF = CB/CWT (CB: concentration of heavy metals in fish, CWT: concentration of heavy metals in water [19]. 3. RESULTS AND DISCUSSION FIGURE 1 - Map of Atatürk Dam Lake [21]. 2.2. Chemical analyses

The size and weight values of fish samples are given in Table 1. Fish were caught with the help from local fishermen using trammel nets with 18x18, 24x24 and 50x 50 mm mesh size. Fish samples were caught from Atatürk Dam Lake during the catching season (SeptemberNovember 2008), placed into iceboxes, deep-frozen at about -20 oC, and stored until analyses. Then, fish samples were dissected by stainless-steel (muscle, gill, liver, kidney and gonad) and dried for 24 h at 105 oC. Sediment samples were collected using Ekman dredge and dried for 3 h at 105 oC. Each sample (0.3 g aliquots) was placed in Pyrex reactors of a CEM Star 5 microwave digestion unit. HClO4:HNO3 (1:3 proportion of fish) was inserted in the reactors, respectively. Samples were mineralized at 200 oC for 30 min. Afterwards, the samples were filtered

The heavy metal contents in water, sediment and fish tissues are presented in Table 2. Cd and Hg were not detected in water, sediment and tissues of the fish samples. In general, heavy metal concentrations in Atatürk Dam Lake water were low, and Mn and Ni were not detected. According to the trace element levels in Table 2, Atatürk Dam Lake water was categorized into the first class according to Turkish Environmental Legislation SKKY [20] and EPA [17]. The accumulation order of trace elements was found to be Fe > Zn >Cu=Se in water (Table 2). In sediment samples, the highest concentration was found for Fe (20625 mg kg -1), and the lowest one for Se (1.90 mg kg -1). The accumulation order of heavy metals in sediment of Atatürk Dam Lake was Fe >Mn >Ni > Zn >Cu >Se. In muscle of Capoeta trutta, Fe (18.09 mg kg-1) was found to be highest but Se (1.82 mg kg-1) to be lowest. The accumulation orders of heavy metals were found as

2037



TABLE 2 - Heavy metal contents in water (mg L-1), sediment (mg kg-1) and fish (mg kg-1) of Atatürk Dam Lake.

Carasius auratus n: 10

Cyprinus carpio n: 20

Capoeta trutta n: 40

Water Sediment Fish tissue Muscle Gill Liver Kidney Gonad Muscle Gill Liver Kidney Gonad Muscle Gill Liver Kidney Gonad nd: not detected

Cu 0.01 ± 0.0 35.05 ± 5.02

Zn 0.03 ± 0.03 35.15 ±3.32

Fe 0.18 ± 0.03 20625 ± 12551

Mn nd 407.0 ± 178.19

Ni nd 72.50 ± 28.42

Se 0.01 ± 0.01 1.90 ± 0.98

Cd nd nd

Hg nd nd

4.15 ± 3.77 3.53 ± 8.86 11.19 ± 13.91 5.75 ± 9.61 3.81 ± 5.52 0.49 ± 0.38 3.49 ± 12.78 4.50 ± 5.01 1.10 ± 0.32 0.67 ± 0.48 1.13 ± 1.34 0.74 ± 0.43 10.17 ± 13.83 0.94 ± 0.38 1.28 ± 0.52

9.52 ± 5.88 12.84 ± 16.56 12.52 ± 27.90 16.17 ± 20.63 17.88 ± 46.80 10.61 ± 18.94 77.38 ± 36.34 63.81 ± 54.18 52.47 ± 34.41 27.43 ± 23.98 6.40 ± 7.64 80.38 ± 42.91 44.68 ± 40.49 47.87 ± 37.29 35.83 ± 25.33

18.09 ± 20.82 62.71 ± 38.29 128,48 ± 93.52 84.31 ± 55.90 20.26 ± 20.90 21.04 ± 19.79 58.55 ± 36.65 62.21 ± 27.87 50.35 ± 26.44 21.30 ± 26.38 16.15 ± 14.84 55.21 ± 19.81 75.62 ± 40.03 46.73 ± 23.22 21.90 ± 14.50

1.28 ± 1.31 3.31 ± 2.47 1.49 ± 1.47 3.08 ± 2.80 1.88 ± 1.72 0.20 ± 0.0 2.10 ± 1.60 0.93 ± 1.03 1.80 ± 0.0 1.13 ± 0.40 nd 1.71 ± 1.46 1.50 ± 1.68 nd nd

6.22 ± 9.23 1.23 ± 0.46 0.91 ±0.53 1.22 ± 0.76 1.44 ± 1.17 0.74 ± 0.25 0.70 ± 0.26 0.83 ± 0.41 1.20 ± 0.70 1.31 ± 0.97 1.40 ± 0.62 0.95 ± 0.07 1.30 ± 0.64 0.77 ± 0.33 1.20 ± 0.0

1.82 ± 0.62 2 ± 0.87 2.64 ± 1.20 1.73 ± 0.86 2.03 ± 0.85 2.33 ± 0.63 2.28 ± 0.57 2.29 ± 0.69 2.04 ± 0.49 1.77 ± 0.71 1.95 ± 0.73 1.71 ± 0.81 2.22 ± 1.24 1.83 ± 0.79 1.43 ± 0.87

nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd

nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd

Fe>Zn>Mn>Se>Ni in gill and kidney but Fe>Zn> Cu> Se>Mn>Ni in liver and gonad. Liver Fe concentration in Capoeta trutta was significantly higher (p Fe>Cu> Se>Mn>Ni in gill and liver; Zn>Fe>Se>Mn>Ni>Cu in kidney; and Zn>Fe>Se>Ni >Mn>Cu in the gonad of mirror carp (Cyprinus carpio).

In Carassius auratus, Mn was not detected in muscle, kidney and gonad. Fe accumulation was found to be the highest (16.15 mg kg-1) in muscle of Carassius auratus. The accumulation order of heavy metals was found in the kidney and gonad as Zn>Fe>Se>Cu>Ni. Zn accumulation was found at the highest level and Cu at the lowest one in the gill of Carassius auratus (Table 2). In liver tissues, the accumulation order of heavy metals was Fe>Zn>Cu>Se> Mn>Ni. Fe and Zn levels in the gill and muscle of Carassius auratus were found to be significantly different from each other (p