High levels of mercury and low levels of persistent organic pollutants in a tropical seabird in French Guiana, the Magnificent frigatebird, Fregata magnificens

In the present study, trace elements and persistent organic pollutants (POPs) were quantified from Magnificent frigatebirds (Fregata magnificens) breeding at a southern Atlantic island. Stable isotope ratio of carbon (δ13C) and nitrogen (δ15N) were also measured to infer the role of foraging habitat on the contamination. For another group from the same colony, GPS tracks were recorded to identify potential foraging areas where the birds may get contaminated. Fourteen trace elements were targeted as well as a total of 40 individual POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The concentration of Hg in the blood was up to 6 times higher in adults (5.81 ± 1.27 μg g−1 dw.) than in nestlings (0.99 ± 0.23 μg g−1 dw.). A similar pattern was found for POPs. ∑PCBs was the prevalent group both in adults (median 673, range 336–2801 pg g−1 ww.) and nestlings (median 41, range 19–232 pg g−1 ww.), followed by the sum of dichlorodiphenyltrichloroethanes and metabolites (∑DDTs), showing a median value of 220 (range 75–2342 pg g−1 ww.) in adults and 25 (range 13–206 pg g−1 ww.) in nestlings. The isotope data suggested that the accumulation of trace elements and POPs between adults and nestlings could be due to parental foraging in two different areas during incubation and chick rearing, respectively, or due to a shift in the feeding strategies along the breeding season. In conclusion, our work showed high Hg concentration in frigatebirds compared to non-contaminated seabird populations, while other trace elements showed lower values within the expected range in other seabird species. Finally, POP exposure was found generally lower than that previously measured in other seabird specie

Penguins as bioindicators of mercury contamination in the Southern Ocean: Birds from the Kerguelen Islands as a case study

• Hg contamination was evaluated in 4 species of penguins at the Kerguelen Islands. • Adults displayed significantly higher Hg levels than chicks in all species. • Species and feeding habits (δ15N) were major determinants of Hg levels. • Dietary specialisation was essential in explaining Hg levels in gentoo penguins. • Penguins are reliable bioindicators of Hg contamination in the Southern Ocean. a b s t r a c t a r t i c l e i n f o Seabirds have been used extensively as bioindicators of mercury (Hg) contamination in the marine environment, although information on flightless species like penguins remains limited. In order to assess the use of penguins as bioindicators of Hg contamination in subantarctic and Antarctic marine ecosystems, Hg concentrations were evaluated in the feathers of the four species that breed on the Kerguelen Islands in the southern Indian Ocean. Compared to other seabirds, adult Kerguelen penguins had low to moderate feather Hg concentrations, with an average ranging from 1.96 ± 0.41 μg g −1 dry weight in the southern rockhopper penguin to 5.85 ± 3.00 μg g −1 dry weight in the gentoo penguin. The species was a major determinant of Hg contamination, with feather Hg concentrations being lower in the oceanic species (king and crested penguins) than in the coastal one (gentoo penguin). In all species however, feather Hg concentrations were higher in adults than in chicks, reflecting the different periods of Hg bioaccumulation in the internal tissues of the two age classes. The relationship between adult penguin trophic ecology and Hg burdens was investigated using stable isotopes. Feeding habits (reflected by δ 15 N values) had a greater effect on adult feather Hg concentrations when compared to foraging habitats (reflected by δ 13 C values), indicating Hg biomagnification in Kerguelen neritic and oceanic waters. Dietary preferences were crucial in explaining individual feather Hg concentrations, as highlighted by intra-specific variation in Hg levels of gentoo penguins sampled at two different breeding sites of the archipelago. Penguins appear to reflect Hg bioavailability reliably in their foraging environment and could serve as efficient bioindicators of Hg contamination in the Southern Ocean on different spatial and temporal scales

Heavy metals: Cd, Pb, and Hg in the hair of autistic children

Even though autism has been known since a long time ago, the prevalence of autism has become more and more intense; also in Indonesia. It has been a major and social concern around the world. One of the concerns is the contamination of mercury in the children, especially through the vaccination which contains mercury as the preservative. Based on the pros and cons of these issues, a preliminary study has been conducted to analyze the heavy metals contents in the hair of autistic children. It was found out that the concentration of Cd, Hg and Pb in 14 subjects of autistic children were varied from undetectable up to 0.71; 0.30 - 5.75 and 3.1 - 25.3 0g/g of hair respectively. While the hair of non-autistic children and adults showed that the content of mercury in some of the autistic's hair was less than those in the non-autistics; on the other hand, the Pb content mostly was higher in the autistic children's hair. These findings could also propose that the heavy metals pollution is of growing concern to even the young children.This study is conducted to give some insights on the effect of heavy metals contamination in young children, and when necessary will be used as the basic of other continuing studies

Hg concentrations and related risk assessment in coral reef crustaceans, molluscs and fish from New

a b s t r a c t There is a dramatic lack of data on Hg levels in marine organisms from tropical areas, and in particular from New Caledonia. For the first time, this study reports the total Hg concentrations in the tissues of several marine taxa from the New Caledonian lagoon. Seafood from both wild and farmed populations was considered. Hg concentrations varied over three orders of magnitudes according to factors including species, age (size/weight), trophic level, lifestyle and geographical origin. Taking into account the edible tissues, estimations of the amount of flesh that should be consumed by a 60-kg person to reach the Hg Provisional Tolerable Weekly Intake (PTWI) reveal acceptable risk for Human health in general. However, a risk was clearly identified in one site of the lagoon (i.e. Grande Rade) where high Hg concentrations were measured. These concentrations were higher than values reported in the current literature

Evidence of species-specific detoxification processes for trace elements in shorebirds

International audienceThis study investigated sub-lethal effects and detoxification processes activated in free-ranging Red Knots (Calidris canutus) from the Pertuis Charentais on the Atlantic coast of France, and compared the results with previous data obtained on another shorebird species, the Black-tailed Godwit (Limosa limosa). The concentrations of 13 trace elements (Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Zn) were assessed in the liver, kidneys, muscle and feathers. Stable isotope analyses of carbon and nitrogen were carried out to determine whether differences in diet explained variations in elemental uptake. The mRNA expression of relevant genes (cytochrome c oxidase 1, acetyl-CoA carboxylase, superoxide dismutase Cu/Zn and Mn, catalase, metallothionein, malic enzyme), antioxidant enzyme activities (catalase, glutathione peroxidase (GPx), superoxide dismutase), and metallothionein (MT) levels were investigated to shed light on trace element detoxification and toxic effects. Although Red Knots were characterized by elevated As and Se concentrations which were potentially toxic, most elements were usually below toxicity threshold levels. The results strongly suggested a dietary specialization of Red Knots, with individuals feeding on higher trophic status prey experiencing higher As, Hg and Se burdens. Red knots and Godwits also showed discrepancies in elemental accumulation and detoxification processes. Higher As and Se concentrations in Red Knots enhanced catalase gene expression and enzyme activity, while Godwits had higher Ag, Cu, Fe and Zn levels and showed higher MT production and GPx activity. The results strongly suggest that detoxification pathways are essentially trace element- and species-specific

Tracking trace elements into complex coral reef trophic networks

International audienceThe integration, accumulation and transfer of trace elements across the main tropic levels of many food webs are poorly documented. This is notably the case for the complex trophic webs of coral reef ecosystems. Our results concerning the south-west lagoon of New Caledonia show that both abiotic (i.e. sediments) and biotic (i.e. primary producers, consumers and predators) compartments are generally contaminated by trace elements. However, our analyses revealed specific contamination patterns from the sources of organic matter to predators. The trophic levels involved in the sedimentary benthic food web (S-BFW - based on the sedimentary organic matter) and to a lesser extent in the reef benthic food web (R-BFW - based on algal turf) were mainly contaminated by trace elements that originate from mining activities: Ni and associated trace elements (Co, Cr, Fe, and Mn) were preferentially integrated into these trophic structures. Trace elements linked to agro-industrial (As, Hg, and Zn) and urban (Ag, Cd, Cu, Pb, Se, and V) activities were also integrated into the S-BFW, but preferentially into the R-BFW, and to a lesser extent into the detrital benthic food web (D-BFW) supplied by sea-grass plants. Most of the trace elements were biodiminished with increasing trophic levels along trophic networks. However, a marked biomagnification was observed for Hg, and suspected for Se and Zn. These results provide important baseline information to better interpret trace element contamination in the different organisms and trophic levels in a highly diversified coral reef lagoon