   Trophic relationships and mercury biomagnification in Brazilian tropical coastal food webs; Lepoint, Gilles  ; et alin Ecological Indicators (2012), 18(0), 291-302 The present study investigated trophic relationships and mercury flow through food webs of three tropical coastal ecosystems: Guanabara, Sepetiba and Ilha Grande bays. The investigation was carried out ... [more ▼] The present study investigated trophic relationships and mercury flow through food webs of three tropical coastal ecosystems: Guanabara, Sepetiba and Ilha Grande bays. The investigation was carried out through carbon and nitrogen stable isotopes (δ13C, δ15N) and total mercury (THg) determination in muscle from 35 species, including crustacean, cephalopod, fish and dolphin species. Detritivorous species showed the lowest average δ15N values in all bays. These species were 13C enriched in Sepetiba and Ilha Grande bays, suggesting the presence of 13C enriched macroalgae in their diet. The highest mean δ15N values were found in fish and benthic invertebrate feeders, as well as in species presenting demerso-pelagic feeding habit. The carbon and nitrogen isotopic findings showed different trophic relationship in food webs from Sepetiba, Guanabara and Ilha Grande bays. Guanabara Bay showed to be depleted in δ15N compared to both Sepetiba and Ilha Grande bays. The latter finding suggests substantial contribution of atmospheric nitrogen fixation by cyanobacteria. A positive linear relationship was found between log THg concentrations and δ15N values for Guanabara and Ilha Grande bays, but not for Sepetiba Bay. Our findings showed trophic magnification factors (TMF) above 1, demonstrating that THg is being biomagnified up the food chains in Rio de Janeiro bays. Highlights ► The δ13C and δ15N findings showed different trophic relationship in food webs from Rio de Janeiro bays. ► Guanabara Bay showed depleted δ15N values compared to Sepetiba and Ilha Grande bays. ► Ilha Grande Bay showed significant depleted δ13C values. ► Our findings indicate THg biomagnifications up food webs in Rio de Janeiro bays. ► Ilha Grande Bay food web showed the highest trophic magnification factor. [less ▲] Detailed reference viewed: 66 (10 ULg) Anthropogenic and naturally-produced organobrominated compounds in marine mammals from Brazil; ; et al in Environment International (2010), 36(1), 60-67 Liver samples from 51 cetaceans, comprising 10 species, stranded between 1994 and 2006 in a highly industrialized and urbanized region in Southeast Brazil, were analyzed for polybrominated diphenyl ethers ... [more ▼] Liver samples from 51 cetaceans, comprising 10 species, stranded between 1994 and 2006 in a highly industrialized and urbanized region in Southeast Brazil, were analyzed for polybrominated diphenyl ethers (PBDEs) and methoxylated-PBDEs (MeO-PBDEs). A concentration range of PBDEs (3-5960 ng/g lw) similar to that observed in Northern Hemisphere dolphins was found. MeO-PBDE concentrations in continental shelf (CS) dolphins from Brazil are among the highest detected to date in cetaceans (up to 250 µg/g lw). Higher [Sigma]MeO-PBDE concentrations were measured in CS and oceanic dolphins than in estuarine dolphins. The [Sigma]PBDE/[Sigma]MeO-PBDE ratio varied significantly ranging from a mean value of 7.12 to 0.08 and 0.01 for estuarine, CS and oceanic species, respectively. A positive correlation was observed between [Sigma]PBDE and year of stranding of male estuarine dolphins (Sotalia guianensis), which suggests temporal variation in the exposure. Placental transfer of organobrominated compounds was also evidenced in S. guianensis. [less ▲] Detailed reference viewed: 34 (9 ULg)High Accumulation of Perfluorooctane Sulfonate (PFOS) in Marine Tucuxi Dolphins (Sotalia guianensis) from the Brazilian Coast; ; et al in Environmental Science & Technology (2008), 42(14), 5368-5373 Perfluorooctane sulfonate (PFOS) and other perfluoroalkyl compounds (PFCs) were measured in liver samples from 29 marine tucuxi dolphins from Rio de Janeiro state (RJ), Brazil. PFC measurement combined ... [more ▼] Perfluorooctane sulfonate (PFOS) and other perfluoroalkyl compounds (PFCs) were measured in liver samples from 29 marine tucuxi dolphins from Rio de Janeiro state (RJ), Brazil. PFC measurement combined liquid chromatography and mass spectrometry, using a CapLC system connected to a Quadrupole- LIT mass spectrometer. PFOS was the only PFC detected and it was so in all samples. PFOS concentrations (ng ·g-1 dw) of dolphins (n)23) from the highly contaminated Guanabara Bay (in RJ) varied between 43 and 2431 as well as between 76 and 427 from areas of RJ other than the quoted bay (n ) 6). Concentrations of three fetuses and one neonate varied between 664 and 1590. Fetus/mother ratios were calculated in two situations (2.75 and 2.62). It seems that mother-to-calf transference plays important role for relationships between PFOS and age. When a one-year-old male calf presenting 2431 ng ·g-1 dw was excluded from the test, significant correlations were observed between PFOS concentrations and both age and total length. Despite the placental transference, PFOS concentrations were not significantly lower in females than in males. PFOS levels in marine tucuxi dolphins from Guanabara Bay are among the highest detected to date in cetaceans, andthismayrepresentathreat to the small population concerned. [less ▲] Detailed reference viewed: 65 (10 ULg)PCDD, PCDF AND PCB DETERMINATION IN DOLPHINS REVEALS A WORLD HOTSPOT FOR PCBS IN GUANABARA BAY, BRAZIL; ; Eppe, Gauthier et alin Organohalogen Compounds (2008), 70 The main objective of the present study was to determine the current concentrations of PCDDs, PCDFs and PCBs in dolphins from a region of high industrialization and urbanization in the Southern Hemisphere ... [more ▼] The main objective of the present study was to determine the current concentrations of PCDDs, PCDFs and PCBs in dolphins from a region of high industrialization and urbanization in the Southern Hemisphere. Since most of these compounds biomagnify in food chains and changes in ratios of stable isotopes of nitrogen (15N/14N) have been used to elucidate trophic relationships 7, measurements of these isotopes have been carried out in marine tucuxi dolphins and their prey in Guanabara Bay. Stable isotopes were measured, firstly, to quantitatively assess the trophic level of the dolphin, and, secondly, to provide information for future human risk assessment investigations related to fish consumption [less ▲] Detailed reference viewed: 58 (10 ULg)Concentrations of organobrominated compounds of natural and industrial origin in top predators from Brazilian waters; ; et al in Organohalogen Compounds (2008), 70 The main objective of the present study was to determine the current concentrations of organobrominated compounds in odontocete species from a highly industrialized and urbanized region in the Southern ... [more ▼] The main objective of the present study was to determine the current concentrations of organobrominated compounds in odontocete species from a highly industrialized and urbanized region in the Southern Hemisphere. [less ▲] Detailed reference viewed: 34 (10 ULg)LINK BETWEEN MARINE MAMMAL EXPOSURE TO PERFLUOROOCTANE SULFONATE (PFOS) AND STABLE-CARBON ISOTOPE RATIOS IN NERITIC AND OCEANIC WATERS OFF BRAZIL; ; et al in Organohalogen Compounds (2008), 70 The main objective of the present study was to determine the current concentrations of PFOS in dolphins from neritic and oceanic waters of a region of high industrialization and urbanization in the ... [more ▼] The main objective of the present study was to determine the current concentrations of PFOS in dolphins from neritic and oceanic waters of a region of high industrialization and urbanization in the Southern Hemisphere. Since stable carbon isotopes can be used to point out relative contributions to the diet of different potential primary sources in trophic networks, indicating for example the inshore versus offshore contribution to food intake 7,8, stable carbon isotope measurements were carried out in the same dolphins in order to clarify inter-species differences. [less ▲] Detailed reference viewed: 54 (6 ULg) |
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