Mercury in Wetland Birds of Iran and Iraq: Contrasting Resident Moorhen, <Emphasis Type="Italic">Gallinula chloropus,</Emphasis> and Migratory Common Teal, <Emphasis Type="Italic">Anas crecca,</Emphasis> Life Strategies

We document mercury distribution in tissues of two waterfowls; moorhen (Gallinula chloropus; n = 6), and Common Teal (Anas crecca; n = 6) from Shadegan wetlands in Southwestern Iran. Mean value of mercury in moorhen liver was (0.36 Hg μg g⁻¹ dry weight), Common Teal had (4.34 Hg μg g⁻¹ dry weight) mercury. In all tissues, Common Teals had significantly higher mercury concentrations than moorhens (U test, p ≤ 0.05). Mercury was 12, 9, 8, and 6 times higher in liver, muscle, kidney, and feather of Common Teals. These birds have comparable diets but Common Teals are migratory and moorhens are residents of Shadegan wetlands.     

Metal Concentrations in Two Bioindicator Fish Species, <Emphasis Type="Italic">Merlangius merlangus</Emphasis>, <Emphasis Type="Italic">Mullus Barbatus</Emphasis>, Captured from the West Black Sea Coasts (Bartin) of Turkey

The Black Sea is very vulnerable to originating from land based human activities and its health is equally dependent on the coastal and non-coastal states of its basin. Total concentrations of cadmium, copper, zinc, lead, nickel, aluminum, iron, manganese, boron and chromium concentrations were determined in Merlangius merlangus (whiting) and Mullus barbatus found in Amasra in the West Coast of the Black Sea (Turkey). The metal contents that were measured in head and muscle was expressed in μg g⁻¹ wet weight. On average, while the highest Fe (344.25 μg g⁻¹), Mn (10.35 μg g⁻¹), Cr (0.96 μg g⁻¹) and Al (76.77 μg g⁻¹) concentrations were measured in the heads of M. merlangus and the highest Zn (77.99 μg g⁻¹), Cu(8.53 μg g⁻¹), B (44.83 μg g⁻¹), Ni (1.96 μg g⁻¹), Cd (0.40 μg g⁻¹) and Pb (6.80 μg g⁻¹) concentrations were detected in the muscles of M. merlangus. There were significant differences between metal levels of muscles in these two species. In terms of permissible levels reported by WHO FAO and TSE, there is not any risk for human consumption for both M. merlangus and M. barbatus, for Pb.     

Mercury and Selenium Content in <Emphasis Type="Italic">Otolithes ruber</Emphasis> and <Emphasis Type="Italic">Psettodes erumei</Emphasis> from Khuzestan Shore,Iran

In this paper the level of selenium and mercury is analyzed in edible part and liver of Psettodes erumei and Otolithes ruber two commercial fish in Persian Gulf. The average concentration of Hg and Se in edible parts of P. erumei was 0.077 ± 0.062 and 0.044 ± 0.018 (μg g⁻¹ww), and in liver was 0.127 ± 0.122 and 0.132 ± 0.610 (μg g⁻¹ww) respectively. In O. ruber, the average concentration of Hg and Se in edible parts was 0.348–0.27 and 0.06 ± 0.021 (μg g⁻¹ww) and in liver was 0.176 ± 0.174 and 0.093 ± 0.022 (μg g⁻¹ww), respectively. P. erumei has higher mean molar ratio Se/Hg (1.98) compared to O. ruber (0.88).     

The Extent of Arsenic and of Metal Uptake by Aboveground Tissues of <Emphasis Type="Italic">Pteris vittata</Emphasis> and <Emphasis Type="Italic">Cyperus involucratus</Emphasis> Growing in Copper- and Cobalt-Rich Tailings of the Zambian Copperbelt

The extent of arsenic (As) and metal accumulation in fronds of the As hyperaccumulator Pteris vittata (Chinese brake fern) and in leaves of Cyperus involucratus, which grow on the surface of an old flotation tailings pond in the Zambian Copperbelt province, was studied. The tailings consist of two types of material with distinct chemical composition: (1) reddish-brown tailings rich in As, iron (Fe), and other metals, and (2) grey-green tailings with a lower content of As, Fe, and other metals, apart from manganese (Mn). P. vittata accumulates from 2350 to 5018 μg g⁻¹ As (total dry weight [dw]) in its fronds regardless of different total and plant-available As concentrations in both types of tailings. Concentrations of As in C. involucratus leaves are much lower (0.24–30.3 μg g⁻¹ dw). Contents of copper (Cu) and cobalt (Co) in fronds of P. vittata (151–237 and 18–38 μg g⁻¹ dw, respectively) and in leaves of C. involucratus (96–151 and 9–14 μg g⁻¹ dw, respectively) are high, whereas concentrations of other metals (Fe, Mn, and zinc [Zn]) are low and comparable with contents of the given metals in common plants. Despite great differences in metal concentrations in the two types of deposited materials, concentrations of most metals in plant tissues are very similar. This indicates an exclusion or avoidance mechanism operating when concentrations of the metals in substrate are particularly high. The results of the investigation show that Chinese brake fern is not only a hyperaccumulator of As but has adapted itself to high concentrations of Cu and Co in flotation tailings of the Zambian Copperbelt.     

Mixture Toxicity Assessment of Nickel and Chlorpyrifos in the Sea Bass <Emphasis Type="Italic">Dicentrarchus labrax</Emphasis>

The present research work was designed to study Dicentrarchus labrax biotransformation and detoxification responses to acute exposure to nickel (Ni) and chlorpyrifos (CHP). Sexually immature sea bass were treated by intraperitoneal injection of nickel chloride (500 μg kg⁻¹), chlorpyrifos (10 mg kg⁻¹), and their binary mixture for 1, 3, and 7 days. Ni and CHP accumulation was quantified in liver after the exposure periods. The following biological responses were measured: (1) NADPH cytochrome P450 reductase (NCR) activity, as phase I biotransformation parameter; (2) gluthathione S-transferase (GST) activity as a phase II conjugation enzyme, acetylcholinesterase activity, and metallothionein (MT) content. Ni bioaccumulation in the liver resulted in an increasing uptake up to 15.48 μg g⁻¹ wet weight (Ni-treated animals) and 16.73 μg g⁻¹ wet weight (mixture-treated animals) after 7 days of exposure. CHP accumulation showed a distinct pattern in animals exposed to the mixture of chemicals in comparison with CHP-treated animals. NCR activity exhibited a marked activation in CHP and mixture-treated animals. GST activity was significantly increased starting from 1 day exposure in CHP-treated animals and after 3 days in Ni-treated animals. MT accumulation increased in all conditions, with a marked synergetic effect after 7 days of exposure. These data should be carefully considered in view of the biological effects of mixture pollutants, particularly in fish farming conditions.     

Concentrations of Mercury and Other Toxic Elements in Orange Roughy, <Emphasis Type="Italic">Hoplostethus atlanticus</Emphasis>, from the Mid-Atlantic Ridge

Concentrations of the elements mercury, arsenic, cadmium and lead were measured in the muscle tissue of Orange roughy (Hoplostethus atlanticus) obtained from the Mid-Atlantic Ridge during the Mar-Eco expedition in the North Atlantic Ocean in 2004. The age of the fish varied from 1 to 139 years. To the best of our knowledge, the concentration of the heavy metals presented here is for one of the oldest fish in the literature, in addition to the fact that very little information on arsenic in Orange roughy has been previously published. The concentration of mercury in the fillet of the fish varied between 0.06 and 1.1 μg g⁻¹ w.w. Mercury was the only element that was positively correlated to the age. The concentrations of mercury were found to be below the maximum limits for Orange roughy set by EU at 1.0 μg g⁻¹ w.w, except for a 134 year fish sample with a concentration of 1.1 μg g⁻¹ w.w.     

Selective Bactericidal Potential of Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L. var. <Emphasis Type="Italic">japonica</Emphasis>) Hull Extract on <Emphasis Type="Italic">Microcystis</Emphasis> Strains in Comparison with Green Algae and Zooplankton

We examined the selective inhibitory potential of rice hull extract on the toxic cyanobacterium Microcystis aeruginosa, in comparison with inhibitory effects on two green algae (Ankistrodesmus convolutus and Scenedesmus quadricauda) and a zooplankton (Daphnia magna) species. The inhibitory effect of rice hull extract, measured by algal growth or zooplankton survival using four different concentrations of extract (1, 10, 100 and 1000 μg L⁻¹), was highest on Microcystis strains (average: 98%, range: 95%–99%), followed by D. magna (average: 22%, range: 10%–47%), A. convolutus (average: 20%, range: 16%–24%), and S. quadricauda (average: 8%, range: 0%–15%). Rice hull extract had only a small effect on the growth of the green algae and Daphnia, particularly in the range 1–100 μg L⁻¹, and the inhibitory effect was somewhat diminished even at the 1,000 μg L⁻¹ level, at the end of the experimental period, especially for Daphnia. Our study indicates that rice hull extract has a strong specific algicide potential when used to combat M. aeruginosa.     

Mercury and Selenium in a Top-Predator Fish, <Emphasis Type="Italic">Trichiurus lepturus</Emphasis> (Linnaeus, 1758), from the Tropical Brazilian Coast,Rio de Janeiro

Muscular mercury and selenium were assessed in a voracious fish from three Brazilian coastal areas with different environmental conditions. Mercury was higher in specimens from Ilha Grande Bay (0.35 ± 0.17 μg g⁻¹) than in cutlassfish from Guanabara Bay (0.30 ± 0.15 μg g⁻¹) and Buzios coast (0.13 ± 0.08 μg g⁻¹), respectively. No difference was found regarding selenium among these areas. Mercury was positively correlated with fish length and size intervals (sub-adult, small and large adult), suggesting that larger and older fish bioaccumulated more mercury. A large excess of molar selenium in relation to mercury was observed.     

Temporal Variation of Metals in Water,Sediment and Tissues of the European Chup (<Emphasis Type="Italic">Squalius cephalus</Emphasis> L.)

The aim of this study was to analyze seasonal variation of levels of Chromium (Cr), Manganese (Mn), Nickel (Ni), Copper (Cu), Zinc (Zn), Cadmium (Cd) and Lead (Pb) in water, sediment and tissues of Squalius cephalus (L., 1758) taken from five different stations chosen at Yamula Dam Lake (Kayseri, Turkey). Concentrations of metals were generally sorted as water<tissue<sediment. The highest concentration of metals in water was observed in the samples taken in the summer (Mn, 1.04 ± 0.15 mg L⁻¹; Ni, 0.42 ± 0.12 mg L⁻¹; Cu, 1.25 ± 0.88 mg L⁻¹; Zn, 3.61 ± 1.53 mg L⁻¹; Pb, 0.58 ± 0.09 mg L⁻¹). While the highest Zn (24.85 ± 21.82 μg g⁻¹) and Pb (10.89 ± 4.2 μg g⁻¹) concentrations in sediment were observed in the winter samples, the highest Mn concentration (167.2 ± 99.37 μg g⁻¹) was observed in the summer. Cd pollution was determined in sediment according to international criteria. The highest metal concentration in tissues was generally observed in the liver and the other tissues; following liver were gills and muscles. In liver tissues, while the highest accumulation of Zn (110.34 ± 13.1) and Mn (22.5 ± 14.85 μg g⁻¹), which are essential for the body, were observed in the winter, Pb (22.58 ± 7.83 μg g⁻¹) and Cd (11.77 ± 7.83 μg g⁻¹), which are toxic, were found to be higher in the summer. Also, concentrations of Mn, Cd and Pb in muscle tissues were found to be above the limits permitted.     

Impact of Elevated CO<Subscript>2</Subscript> and O<Subscript>3</Subscript> Concentrations on Biogenic Volatile Organic Compounds Emissions from <Emphasis Type="Italic">Ginkgo biloba</Emphasis>

In natural environment with ambient air, ginkgo trees emitted volatile organic compounds 0.18 μg g⁻¹ h⁻¹ in July, and 0.92 μg g⁻¹ h⁻¹ in September. Isoprene and limonene were the most abundant detected compounds. In September, α-pinene accounted for 22.5% of the total. Elevated CO₂ concentration in OTCs increased isoprene emission significantly in July (p < 0.05) and September (p < 0.05), while the total monoterpenes emission was enhanced in July and decreased in September by elevated CO₂. Exposed to elevated O₃ increased the isoprene and monoterpenes emissions in July and September, and the total volatile organic compounds emission rates were 0.48 μg g⁻¹ h⁻¹ (in July) and 2.24 μg g⁻¹ h⁻¹ (in September), respectively. The combination of elevated CO₂ and O₃ did not have any effect on biogenic volatile organic compounds emissions, except increases of isoprene and Δ3-carene in September. Foundation item: The National Natural Science Foundation of China (No. 90411019).     

Mercury Levels in Sediments and Mangrove Oysters, <Emphasis Type="Italic">Crassostrea rizophorae,</Emphasis> from the North Coast of Villa Clara,Cuba

Total mercury levels were quantified in sediments and oyster tissues (Crassostrea rizophorae) from the Sagua la Grande River estuary and offshore mangrove keys 19 km downstream of a chlor-alkali plant (CAP) in Villa Clara, Cuba. Relatively elevated total mercury levels were found in sediments from the estuary itself, ranging from 0.507 to 1.81 μg g⁻¹ dry weight. However, levels were lower in sediments from the keys farther from the estuary. Oyster mercury levels were always acceptable for human consumption, although levels significantly correlated in sediments and oysters across sampling sites (p < 0.05), which suggests that mercury from the CAP is impacting coastal water quality conditions.     

Chlorpyrifos-Induced Toxicity in <Emphasis Type="Italic">Duttaphrynus melanostictus</Emphasis> (Schneider 1799) Larvae

This study investigates the effects of continuous exposure to a widely used organophosphate pesticide, chlorpyrifos, on survival, growth, development, and activity of larvae of the Asian common toad, Duttaphrynus melanostictus Schneider 1799. Larvae were continuously exposed to six different concentrations (1–1,500 μg l⁻¹) of commercial-grade chlorpyrifos for 14 days and monitored for 1 additional week. Chlorpyrifos at ≥1,000 μg l⁻¹ caused significantly high and dose-dependent mortality, and the weekly LC50_{7 day–21 day} values ranged from 3,003 to 462 μg l⁻¹. Larvae surviving exposure to ≥500 μg l⁻¹ chlorpyrifos showed significant growth impairment, delays in metamorphosis, and decreased swimming activity. Tail abnormalities were the most common morphologic deformity at concentrations of 1,000 and 1,500 μg l⁻¹ chlorpyrifos. The findings of the present study highlight the need to recognize the potential risk that agrochemicals pose to amphibians inhabiting agricultural landscapes in Sri Lanka and other Asian countries.     

Dissipation of Pendimethalin in Soil and Its Residues in Chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) Under Field Conditions

Disappearance of pendimethalin in the soil of chickpea (Cicer arietinum L.) at 0–110 days, and terminal residues in plant samples have been studied under field conditions. Pendimethalin was applied as pre-emergence herbicide at 750, 350 and 180 g a.i. ha⁻¹ in winter, in chickpea crop. The dissipation of pendimethalin in the chickpea field soil conditions followed first order kinetics showing a half-life of 11.23 days averaged over all doses. Low pendimethalin residues were found in plant samples. 0.025, 0.015, <0.001 μg g⁻¹ residues of pendimethalin were found in grains at 750, 350 and 185 g a.i. ha⁻¹ treatments, respectively. Much lower pendimethalin residues were found in straw viz. 0.015 to <0.001 μg g⁻¹ at 750, 350 and 185 g a.i. ha⁻¹ treatments, respectively.     

Effect of Copper on Growth and Enzyme Activities of Marine Diatom, <Emphasis Type="Italic">Odontella mobiliensis</Emphasis>

The 72-h IC₅₀, 7-d no observable effect concentration (NOEC), low observable effect concentration (LOEC), Chronic values were derived for copper on the growth of marine diatom, Odontella mobiliensis. The effect of copper was also studied on cell morphology, size, nitrate reductase and antioxidant enzymes (Catalase, Superoxide dismutase and peroxidase). The 72-h IC₅₀ of 298.4 ± 28.3, NOEC of 15.6, LOEC of 29.6 and chronic value of 21.5 μg Cu L⁻¹ were found in the present study. The chlorophyll a was significantly decreased with increasing concentrations of copper. The length of the cell (apical axis) was extended from 30.14 ± 5.98 μm at control to 71.4 ± 6.29 μm at 574 μg Cu L⁻¹, the spines were absent at 574 μg L⁻¹ and the cell structure was entirely damaged at 926 μg Cu L⁻¹. The antioxidant enzymes viz. Catalase, Peroxidase activities and Melondialdehyde were increased whereas the Nitrate reductase and activity was reduced at 21.5 μg Cu L⁻¹ during 7 days exposure.     

Toxicity of Cadmium,Lead, Mercury and Methyl Parathion on <Emphasis Type="Italic">Euchlanis dilatata</Emphasis> Ehrenberg 1832 (Rotifera: Monogononta)

Acute toxicity tests with Cd, Pb, Hg, and methyl parathion were developed to compare the sensitivity of the rotifer Euchlanis dilatata with other model organisms used in aquatic ecotoxicology. Cd was the most toxic chemical (LC50 = 14.8 μg L⁻¹), while methyl parathion was the least toxic (LC50 = 864.2 μg L⁻¹). E. dilatata was more sensitive that other rotifer species, particularly of the genera Brachionus and Lecane. However, E. dilatata was less sensitive to mercury and methyl parathion than the crustacean, Daphnia magna. The high sensitivity of E. dilatata suggests that it may be an adequate benthic model to use in toxicity assessments of metal-contaminated sediments.     

Bioaccumulation of Aluminum by <Emphasis Type="Italic">Lemna gibba</Emphasis> L. from Secondary Treated Municipal Wastewater Effluents

In this study, Lemna gibba as a sample aquatic plant was used to remove Al from a municipal secondary waste water effluence. Lemna gibba was acclimatized to the effluent in situ. The concentration of Al in the plant samples was examined for 7 days. Lemna gibba accumulated 500 μg Al g⁻¹ on the first day and reached saturation level with an increase of 100 μg g⁻¹ on the second day. The results indicated that Lemna gibba can be used as an effective aquatic plant at low costs for the treatment of municipal secondary waste water effluent. It was also noted that the plant should be harvested every 2 days for obtaining maximum efficiency.     

Survival,Growth, and Body Residues of <Emphasis Type="Italic">Hyalella azteca</Emphasis> (Saussure) Exposed to Fipronil Contaminated Sediments from Non-Vegetated and Vegetated Microcosms

We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g⁻¹) ranged from 0.72–1.26, 0.01–0.69, 0.07–0.23, and 0.49–7.87 for fipronil, fipronil-sulfide, fipronil-sulfone, and fipronil-desulfinyl, respectively. No significant differences in animal survival or growth were observed between non-vegetated and vegetated microcosms during wet or dry exposures. Mean animal body residue concentrations (ng g⁻¹) ranged from 28.4–77.6, 0–30.7, and 8.3–43.8 for fipronil, fipronil-sulfide, and fipronil-sulfone. Fipronil-desulfinyl was not detected in any animal samples.     

Organochlorine Pesticides in Green Mussel, <Emphasis Type="Italic">Perna viridis,</Emphasis> from the Cienfuegos Bay,Cuba

The green mussel, Perna viridis, was used to measure bioaccumulated levels of organochlorine pesticides in the marine environment of Cuba. Samples were collected in the Cienfuegos Bay between January and December 2010. The organochlorine pesticides (i.e. DDT, Dieldrin, Chlordane, Endosulfan, HCB, Aldrin, Heptachlor and Lindane) were quantified by gas chromatography. The sum of all organochlorine pesticides in P. viridis was 6.31 ng g⁻¹. The concentration ranged from 3.53 to 4.42 ng g⁻¹ dry weight (dw) for DDTs (i.e. sum of pp’ DDT, pp’ DDD, op’ DDE and pp’ DDE); 1.7–1.9 ng g⁻¹ dw for Dieldrin; 0.17–0.20 ng g⁻¹ dw for Chlordanes; 0.14–0.16 ng g⁻¹ dw for Endosulfan; 0.11–0.17 ng g⁻¹ dw for HCB; 0.07–0.11 ng g⁻¹ dw for Aldrin; 0.046–0.054 ng g⁻¹ dw for Heptachlor and 0.035–0.039 ng g⁻¹ dw for Lindane. These levels can be considered as low when compared to reported values from similar studies conducted elsewhere in the world. The concentrations of all organochlorines residues detected in this study fell below the EU Maximum Residue Limits.     

Dissipation of Flubendiamide in/on Okra [<Emphasis Type="Italic">Abelmoschus esculenta</Emphasis> (L.) Moench] Fruits

A field experiment was undertaken at Indian Agricultural Research Institute, New Delhi during kharif (rainy season) in the year 2010 to evaluate the residue persistence of flubendiamide in/on okra fruits following foliar application of Belt 39.35% SC formulation at 24 (standard dose) and 48 (double dose) g a.i. ha⁻¹. After HPLC analysis study revealed that residues of flubendiamide in/on okra persisted till 5th and 7th day after the last spray at standard and double dose, respectively. The residues of flubendiamide were reported as parent compound, and des-iodo flubendiamide, a metabolite (photo product) of flubendiamide, was not detected in/on okra at any time during the study period. The initial deposits of 0.28 and 0.53 μg g⁻¹ in/on okra fruits reached below determination level of 0.01 μg g⁻¹ on the 7th and 10th day at standard and double dose, respectively. The half life of flubendiamide in/on okra fruits ranged from 4.7 to 5.1 days at standard and double dose, respectively. Soil sample collected from the treated field on the 15th day after the last spray revealed residues of flubendiamide or its metabolite below determination level (0.01 μg g⁻¹) at single and double dose.     

Accumulation of Microcystins in Nile Tilapia, <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> L., and Effects of a Complex Cyanobacterial Bloom on the Dietetic Quality of Muscles

The aim of this study was to investigate the kinetics of accumulation and elimination of microcystins in the tissues of Nile tilapia (Oreochromis niloticus) and to evaluate the effect of cyanobacterial exposure on fish muscle quality (levels of total fat and ash, protein, dry matter and the composition of saturated, monounsaturated and polyunsaturated fatty acids). Fish were exposed for 28 days to a natural cyanobacterial bloom with total microcystin concentration around 1,200 μg g⁻¹ biomass dry weight. The hepatopancreas accumulated microcystins up to 350 ng g⁻¹ fresh weight, but concentrations in muscle were generally below the detection limit (2 ng g⁻¹ fresh weight). Following the exposure, fish were moved to the clean water, but only minor microcystin removal from the hepatopancreas was observed during a 4 week depuration period. Exposures of tilapia to the complex cyanobacterial bloom had only minor and temporary impacts on the investigated parameters of dietetic quality.