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This paper presents  the  levels  of total  mercury  (T-Hg)  in  dorsal  muscle,  liver  and  spleen of pike  (Esox lucius) from  Anzali  Lagoon  in Iran.  Sampling were  carried  out from  July  2004 to July 2005. In addition 78 samples were collected. T-Hg concentration  were  calculated  in relation to biometric factors. T-Hg was measured by the LECO AMA 254 Advanced Mercury Analyzer (USA) according to ASTM standard NoD-6722. Each sample was analyzed 3 times. Accuracy of T-Hg analysis was checked by running three samples of Standard Reference Materials; SRM 1633b, SRM 2711 and SRM 2709. Detection limit was  0.001mg/kg  in  dry weight. The minimum and maximum  concentration  ofT-Hg  in  dorsal  muscle  was  0.2ppm  in one year and 1.2ppm in five year class. The mean T-Hg significantly  increased  wit  age increased (P<0.05). The T-Hg mean concentration.  In 1 and 2 year classes was 0.171ppm. Accamulation pattern ofHg was significantly as well as muscle>liver>spleen. T-Hg content in females was higher than males (P<0.05). Acceptable monthly intake without carcinogenic effects due to mercury  for women, men, juveniles and children was 270,  320,  125 and  59g per  month.  Consumption  of pike above 35cm. length should be avoided.

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We assessed muscular concentration of cadmium and lead in carp, mullet and kutum of the Gorgan Bay in south-east of the Caspian Sea. Atomic absorption was used in the process for 90 specimens of the three fish collected during September 2006  to  March  2007.  The average concentration of lead in the three  fish (carp, mullet, kutum) were 0.242, 0.118 and 0.08ppm (Mg/Kg and for cadmium were 0.014, 0.018 and 0.017ppm (Mg!Kg), respectively. One-way analysis of variance (ANOVA) showed no significant difference in concentration of cadmium for the fish species (P=0.251) while this difference was significant for lead (P<0.007). Tukey test showed significant difference for lead concentration between carp and mullet (P=0.028) and also between carp and kutum (P=0.01) but this difference was not significant between mullet and kutum (P=0.927). Pearson's test showed no  significant statistical correlation between lead and cadmium concentrations in the selected fish species (P=0.557). Also t-test showed that the average concentration of cadmium and lead in the fish species are significantly lower than the accepted standard levels (P<0.001) set by WHO and are thus appropriate for human consumption.

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Concentrations of four heavy metals (Cd, Cr, Zn, and Pb) in the common carp (Cyprinus carpio) were assessed in winter, spring and summer seasons of the years 2008. Four coastal areas in the west and east, Gomishan Marsh and Gorgan Bay including 11 sites were sampled. After biometrical measurements of the fish, specimens of muscle (104) and liver (36) tissues were immediately frozen and transferred to laboratory for assessment of heavy metal concentration. Dry ash method and atomic absorption spectrometer (AAS) of Perkin Almer (400 model, German) were used to assess metals concentration. In the process, analysis of variance (ANOVA) and Tukey-test were implemented. Heavy metals concentration in kidney tissue was higher than muscle tissue. In carp muscle tissue, level of zinc was highest and the next categories were those of lead, cadmium and chromium, respectively. A significant difference was observed between chromium concentrations in muscle tissue of Cyprinus carpio with sex (P<0.05). The concentrations of heavy metals in liver tissues were higher than those of the muscle tissues and in all cases they were lower than mean allowable concentrations of international standards (WHO, UK, MAFF and NHMRC).

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Metals concentrations were studied in dominant seaweeds and their adjacent sediments in Bandar Abbas and Bandar Lengeh tidal areas. The status of selected heavy metals (Ni, Cd, Pb, Cu) was determined in sediments and 15 dominant seaweed species including 4 species of Chlorophyta, 4 species of Phaeophyta and 7 species of Rhodophyta. Samples of seaweed and sediment were collected seasonally during November 2007 to August 2008 from intertidal regions of nine sites along the Bandar Abbas and Bandar Lengeh coasts. Powdered samples of sediments and seaweed were digested and analyzed using Atomic Absorption Spectrophotometer (A.A.S). Concentrations of Cu, Pb, Cd, and Ni were 5.24, 20.44, 5.40 and 33.83μg/g-1 dry wt. in sediments. Concentration of these metals in μg/g-1 dry weight in Chlorophyta were 11.11, 25.79, 4.76 and 46.57, in Phaeophyta were 9.18, 17.68, 4.82 and 36.65, and in Rhadophyta were 9.80, 21.03, 4.96 and 50.43, respectively. The marine seaweed species collected during all seasons and sites in Bandar Abbas and Bandar Lengeh were identified as Entromorpha compressa and Padina pavonica, respectively. *Corresponding author

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This study was conducted in vitro to assess lethality, LC50 and the possibility of bioaccumulation of cadmium in various life stages of Artemia urmiana. Artemia is highly used in aquaculture hence the response of the organisms to pollutants, such as cadmium regarding the increase in environmental pollution is of high importance. This experiment was performed in Faculty of Marine science and Technology, Islamic Azad University and Atomic Energy Organization of Iran in 2009. In the first stage, smaller than 1day naupliis were exposed to 10 different concentrations from 0 to 250mg/l Cd. LC50 of Cd in 24h of A. urmiana exposure was 189.33mg/L. Next, the accumulations of Cd in 5, 10, 15 and 20mg/l Cd were examined in 1, 5, 11 and 17 days of Artemia urmiana life. The results showed that Artemia urmiana has the ability of accumulation of cadmium and the accumulation level depends upon the concentration of the cadmium in the environment as well as different living periods of Artemia. We found that increasing the concentration of cadmium in the environment increases its accumulation in Artemia. There was a significant difference in accumulation of Cd between 5mg/l Cd (0.267ppm) and 20mg/l Cd (0.364ppm) in the first day of A. urmiana life (P<0.05). In all treatments of the 11 day Artemia, bioaccumulations of Cd increased with increasing of cadmium concentration. Maximum accumulation of Cd was in 20mg/l Cd in the 11 day Artemia. Results showed that although A.urmiana is resistant to Cd, however in 250mg/l, cadmium has significant toxic effects on Artemia survival (3.33%). *Corresponding author

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A comparative study was conducted on concentration of heavy metals including: Hg, Cd and Pb in the muscle of Otolithes ruber in Abadan and Bandar Abbas Ports in the Persian Gulf. In this study, a total of 42 specimens of Otolithes ruber were collected from coastal waters of Abadan and Bandar Abbas Ports in 2010. Heavy metals were extracted from the muscle tissues using wet digestion method and concentration of metals were measured by Atomic Absorption Spectrophotometer. The results showed that mean (±SD) accumulation of Hg, Cd and Pb in the muscles of Otolithes ruber in Bandar Abbas were 0.058±0.001, 0.279±0.056 and 0.668±0.077mgKg-1 wet weight, and in Abadan were 0.056±0.007, 0.25±0.038 and 0.638±0.087mgKg-1 wet weight respectively. No significant differences were found in concentrations of Hg, Cd and Pb in the muscle of Otolithes ruber between Abadan and Bandar Abbas ports. Accumulation of these metals were higher in the muscle of Otolithes ruber than that Bandar Abbas Port. Concentration of Hg in the muscle of Otolithes ruber was lower than acceptable limit suggested by WHO, MAFF, NHMRC. However concentrations of Pb and Cd were higher. *Corresponding author

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In the present study, accumulation of manganese, cadmium, zinc, iron and copper in the commercially fish species (silver pomfret and tiger tooth croaker) caught from Bandarabbas coasts at 2010 was measured and the risk of daily intake of them in Hormozagan urban population was estimated. The average concentrations (μ/g dry weight) of manganese, cadmium, zinc, iron, and copper in the muscle tissue of silver pomfret were 1.248, 0.217, 14.444, 2.397 and 3.300, respectively, while the concentration of them in tiger tooth croaker were 1.009, 0.403, 12.564, 4.467 and 2.366, respectively. According to fish consumption rate, urban populations of the province were divided into four groups low, medium, high and very high. The target hazard quotient (THQ) in each group calculated separately. The THQ of all groups were much lower than 1 in the two fish. The results showed that urban populations of the province have not any risk due to accumulation of the studied heavy metals.

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This study was carried out in order to measure and compare heavy metals levels (Pb,Cd,Fe, Zn, Ni and Cu) in gill and muscle of Capoeta damascina. 60 fish were caught from 3 stations in Tangeh haft zone from Sezar river. Heavy metals were measured by Atomic Absorption spectrophotometery. The highest concentrations of heavy metals Fe>Zn>Pb>Ni>Cu>Cd, respectively. The average heavy metals concentration in gill and muscle have significant different (P<0.05). Gill has the highest concentration and muscle has the lowest concentration. Heavy metals concentration in different stations don’t have any significant different (P>0.05). The results of this study showed that there were significant difference between heavy metals concentrations in gill, liver and muscle (P<0.05). According to the result of this study concentrations of Pb in Capoeta damascina are height than international standard FAO, WHO, NHMRC, UK (MAFF).

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The aim of this study was to evaluate two heavy metals (Cd and Cr) concentrations in different tissues including muscle, gill, kidney and intestine of Zayandehrood chub, Petroleuciscus esfahani in different stations along the Zayandehrood River. For this purpose, 80 specimens of the fish were collected from 4 different stations including Cheshmeh-dimeh, Khersoonak, Chamgordan and Pol-e-Safaiyeh (each 20 fish) in autumn 2011. The metals were extracted using dry digestion method and measured by Atomic Absorption.The results showed that the concentration of heavy metals increased significantly from up to downstream of the River, with the highest level was observed in Chamgordan station (p<0.05). The highest concentrations of Cd (22.7±0.55) and Cr (50.69±22.78) µg/g dry weight (DW) were measured in the kidney of the fish collected from Pol-e-Safaiyeh and Chamgordan stations respectively (p<0.05). While, the lowest level of Cd (0.8±0.11) and Cr (1.30±0.19) µg/gDW were determined in the muscle of the fish from Cheshmeh-dimeh station located at upstream. The metals concentrations in the muscle were increased significantly from upstream to the downstream (p<0.05). In general, in all studied stations, the highest levels of Cd and Cr were observed in the kidney while, the lowest levels were measured in the muscle. By comparison between the results obtained from this study to the international standards defined by WHO or FAO, it was cleared that the concentrations of both metals in Zayandehrood chub (even at the lowest levels in the muscle) were much higher than permitted levels. The results of this study could show inappropriate environmental conditions of the Zayandehrood River, even in the upstream stations

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This study was carried out in three farmed rainbow trout (Oncorhynchus mykiss) of Guilan Province. Heavy metals (Iron and Lead) were measured using Atomic absorption spectrometry in food, water and fish muscles of farms. The amounts of Iron and Lead (Mean ±SD) in all water samples from studied farms were 55.29±2.71 and 2.066±0.714 µg/L, respectively. The amounts of Iron and Lead (Mean± SD) in consumed feed of studied farms were 494.51± 89.18 and 3.494± 1.462 mg/kg, respectively. Also, the amounts of Iron and lead in fish muscle of studied farms were measured as 7.715± 1.050 and 0.39970± 0.073 mg/kg, respectively. The obtained results revealed the existence of higher amounts of iron in fish muscle above Codex standard, 2001 and lower amounts of lead levels from the mentioned standard in studied farms. The obtained data showed no significant differences in water, food and muscle of fish in studied areas (p>0.05).

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Regarding to the tight association between aquatic hypoxia and heavy metal contaminations in one hand and the role of both parameters on fish respiration, metabolism of carp could be assessed under single and mutual exposures to hypoxia and cadmium. Following measuring LC₅₀-96h of cadmium (43.679 mg/l) for this species, 80 common carp were exposed to 10 different treatments, including control, acute (43.68 mg/l), sub-lethal (21.84 mg/l) and chronic (4.37 mg/l) cadmium as well as hypoxia for immediately (20% of saturation), 24h (40%) and 7 days (60%), and joint exposure of each similar treatment. By using of respirometer technique, we measured oxygen consumption rate in different time spans to calculate each individual standard metabolic rate (SMR), maximum metabolic rate (MMR), aerobic scope (AS), factorial aerobic scope (FAS) and critical oxygen tension (P_Crit). Obtained data show that acute and sub-lethal cadmium treatments led to significant (P<0.05) increases in all metabolic indices in comparison with control group whilst the MMR and AS have been reduced (P<0.05) following hypoxia treatments. Combined treatments of hypoxia and cadmium led to reduce SMR and P_Crit in all treatments and MMR, AS and FAS only in acute and sub-lethal treatments. In overall, hypoxia can act as a limiting stressor in carp while cadmium can account as a loading stressor.

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This study was conducted to determine some heavy metals (Fe, Mg, Cr, Ni) of surface sediment in the southern Caspian Sea during two seasons (Summer and Winter) in 2014-2015. 36 surface sediments samples (with triplicate) were collected at two stations (Tonekabon and Bandar Amirabad). All samples were analyzed using sequential extraction to indicate natural and anthropogenic sources. The results indicated that the percentage of non-resistance fraction in Tonekabon area were measured 3.5,45.0, 22.1 and 6.0 for Fe, Mg,Cr, Ni, respectively and in Amirabad area were 23.0,2.6,1.8 and 4.0, respectively. On the other hand,  the percentage of resistance fraction values were obtained 96.5, 55.0, 77.9 and 94.0 in Tonekabon, and 77.0, 97.4, 98.2, and 96.0 in Amirabad region. The chemical speciation of Fe, Mg, Cr, Ni in most sampling stations were in the order of residual> oxidisable-organic > acid-reducible >exchangeable. The order of total concentration, non-resistance and resistance fraction were observed Fe>Mn>Ni>Cr, Mn>Fe>Ni>Cr and Fe>Mn>Ni>Cr, respectively. As a conclusion, results of total concentration, resistnace and non-resistance of Fe, Mn, Ni and Cr were lower than standard and earth shell (Igeo) in this area. This is shown that surface sediments of this area were not polluted with these heavy metals and bioavaiable fraction provides little indication of potential interactions with the biotic components present in this environment.

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The aim of the current investigation was to determine the concentration of some heavy metals in a number of aquatic invertebraes commnly used as live feed in aquaculture. For this goal, samples of blood worm, sludge worm, earthworm, gammarus, shelled snail, freshwater ghost shrimp and tiny marine shrimp were prepared from aquatic environment or from imported live feeds. Samples were digested chemically and the atomic absorption were recorded as µg/g dry weight. Results showed that the highest level of heavy metals concentration were detected in live feeds as follows: iron (213.4±10.2), cadmium (1.15±0.013) and nickel (20.97±3.6) in earthworm; zinc (105.71±5.8), chrome (19.63±5.3) in sludge worm; copper (37.34±4.2) in freshwater ghost shrimp and lead (24.71±4.7) in tiny marine shrimp respectively. It is proposed that high rates of heavy metals detected in some of live feeds in the present study may eventually have a severe negative impact on fish and human health conditions. Therefore, it is suggested that upper limit concentration of these elements be defined as an import health standard for every permission of importation of live feeds.

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The presence of heavy metals in our environment has been of great concern because of their toxicity when their concentration is more than the permissible level. These metals enter in the environment by different ways e.g. industrial activities. This study was carried out to determine and comparison of heavy metals Cd, Pb and Ni in muscle, liver and caviar of farmed Acipenser baerii from Khuozestan Province, 2014. 30 samples of Acipenser baerii were prepared randomly from five ponds of Hantoshzadeh breeding. Heavy metal levels in fish samples were analyzed by Perkin Elmer 4100 zl atomic absorption. Data analysis was performed with the software SPSS17 and comparison of the mean to T-test. The highest concentration of Ni, Cd and Pb were 1.10±0.23, 0.041±0.002 and 0.35±0.02 µ/Kg in liver of Acipenser baerii. The lowest concentration of this metals were obtained 0.08±0.003, 0.017±0.002 and 0.11±0.02 µ/Kg in caviar this species. Concentration of heavy metals in the liver of Acipenser baerii was higher than muscle and caviar. In this study concentration of Ni, Cd and Pb in muscle and caviar of Acipenser baerii were lower than comparison of WHO, FDA, MAFF and NHMRC standards.

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TThe objectives of the present study were assess the concentrations of heavy metals (Cd, Zn, Ni, and Cu) in the muscle and liver of Longtail tuna (Thunnus tonggol) and Abu mullet (Liza abu) and to evaluate human health risks associated with their consumption Fish samples were obtained from a fish market in the Bandar Abbas city in the spring 2015. The concentrations of. heavy metals were determined using atomic absorption spectroscopy. The concentrations of copper in the muscles of Longtail tuna and Abu mullet were lower than the international standard limits, whereas the concentrations of cadmium in the muscles of Longtail tuna and Abu mullet were higher than the international standard limits of WHO, NHMRC and UKMAFF. The concentration of zinc in the muscle of Longtail tuna was higher than the international standard limits of WHO. Estimation of Target Hazard Quotient (THQ) and Hazard Index (HI) for children and adults by consumption of the muscles of Longtail tuna and Abu mullet were lower than 1. Estimation of THQ and HI for children and adults by consumption of the liver of Longtail tuna and Abu mullet were higher than 1 for cadmium and copper. Therefore, it can be concluded that there is no human health risk associated with the consumption of the muscle of Longtail tuna and Abu mullet whereas consumption of their livers is not recommended more than once a week.
 
 

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The aim of this study was to investigate the bioaccumulation of heavy metals (Cu, Zn, Fe and Se) in the muscle, liver and gill tissues of Pomadasys kaakan from the Bushehr port during the year 2017. Biometry of fish samples was performed. Then, the muscle, liver and gill tissues were separated from the fish samples and chemical digestion of the samples was conducted. Cu, Zn, Fe and Se accumulation levels in various tissues were measured using Graphite furnace atomic absorption instrument (Perkin Elmer 3030). Based on the results, the average concentrations of heavy metals including Cu, Zn, Fe and Se in the muscle of Pomadasys kaakan were 7.620±0.035, 25.710±2.570, 2.620±0.166 and 0.101±0.006 mg/kg dry weight, respectively. The average concentrations of Cu, Zn, Fe and Se in the liver were 8.420±0.149, 31.401±1.020, 3.070±0.155 and 0.108±0.009 mg/kg dry weight, respectively. The average concentrations of Cu, Zn, Fe and Se in the gill were 9.900±0.110, 34.740±1.070, 4.400±0.240 and 0.133±0.011 mg/kg dry weight, respectively. Significant differences in the concentration levels of heavy metals were observed among different tissues (P<0.05). Moreover, the results of this study revealed that the levels of Cu, Zn and Se in the muscle of Pomadasys kaakan from the Bushehr port were lower than the permitted levels by international standards (WHO, FAO, NHMRC, UK (MAFF) and FDA). However, concentration of Fe in the muscle of Pomadasys kaakan from the Bushehr port was higher than the permitted levels by FDA.
 
 

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In this study, the concentrations of Cd, Pb, Cu, Mn, and Co were analyzed in the muscles of Cyprinus carpio collected from Nowshahr on the south of Caspian Sea, Iran in June 2016. Determination of heavy metals concentrations in the studied fish muscles had been carried out by a graphite furnace atomic absorption spectrometer. The range of metals concentrations were as: Cd: 0.10–1.56, Pb: 0.10–1.23, Cu: 0.88–8.23, Mn: 0.34–1.05 and Co: 0.56–1.43 mg/kg wet weight. The results showed that the concentrations of Cd, Pb, Cu, Mn, and Co in the muscles of C. carpio were lower than the proposed limits of the WHO. Health risks to human via dietary intake of fish were assessed by the target hazard quotients (THQs). The THQ values of the five metals (Cd, Pb, Cu, Mn and Co) were below 1 for C. carpio. Metal concentrations in the edible part of C. carpio were assessed for human uses according to provisional tolerable weekly intake (PTWI) and provisional tolerable daily intake (PTDI). In this study, Cd, Pb, Cu, Mn and Co concentrations in the muscle of C. carpio were below the maximum permissible limit of the WHO.
 

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In this study, the concentrations of heavy metals Cu, Fe and Se in muscle, liver and gill tissues of S. guttatus were evaluated in Bushehr seaport during autumn 2016. S. guttatus samples were caught at random from Bushehr seaport (n=30). After biometric measurements the samples were taken from each tissues (muscles, liver and gills) and chemical digestion of the samples were carried out based on MOOPAM, then levels of heavy metals in tissues were measured by Graphite furnace atomic absorption spectrophotometer (Perkin Elmer 3030). Based on the results obtained the mean concentrations of heavy metals Cu, Fe and Se in muscles tissues of S. guttatus were 7.21, 3.07 and 0.094, in liver were 8.35, 3.02 and 0.107, and in gill were 9.87, 3.59 and 0.119 mg/kg dry weight respectively. Moreover, this results revealed that the Cu and Se concentration in muscles tissues of S. guttatus in Bushehr seaport were lower than the levels permitted within the standards of World Health Organization (WHO), Food and Agricultural Organization (FAO), National Health and Medical Research Council (Australia) (NHMRC), Ministry of Agriculture, Forestry and Fisheries UK (MAFF), But Fe concentration was higher than the level permitted within the standard of Food and Drug Administration (FDA).
 

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