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Pollution is a key factor in efforts to conserve seabirds and their habitats. The Marine Biological Reserve of Rocas Atoll hosts the largest population of seabirds (-23000 individuals) breeding in Brazilian waters. In the present study at Rocas Atoll, liver samples were collected from dead individuals of five species (adults and nestlings): Masked Booby Sula dactylatra. Brown Booby Sulci leucogaster, Brown Noddy Anous stolidus, Black Noddy Anous minutus, and Sooty Tern Onychoprion fuscatus. They were analyzed for three persistent organic pollutants (POPs): polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs). and polybrominated diphenyl ethers. Carbon and nitrogen stable isotopes (513C and SI5N) were also analyzed to assess feeding and foraging habits. PCBs (3.37-189 ng-g1), OCPs (DDTs, 0.5-23.1 ng-g'1), and hexachlorobenzene (0.31-12.3 ng-g ') were predominant overall, and results were generally consistent with previous studies. Despite the low levels of contaminants, intraspecific stratification was found, with lower concentrations in nestlings compared to adults, as expected. Stable isotopes revealed that differences in POP levels and PCB profiles were associated with diet and foraging patterns. Low levels of POPs at Rocas Atoll were consistent with patterns observed in studies of other low-latitude and high-latitude seabirds. [ABSTRACT FROM AUTHOR]

Summary: The Trindade Petrel Pterodroma arminjoniana is a vulnerable species that breeds on Trindade Island, 1,100 km away from the Brazilian coast, and on Round Island in the Indian Ocean. Recent population estimates for Trindade Island by nest counts in accessible areas, and extrapolated to the whole island provided a figure of 1,130 breeding pairs. Using topographic variables and Predictive Nest Habitat Modelling from known breeding sites, we estimated the potential area of nesting and estimated the size of the breeding population. Nests were associated with low to intermediate elevations in areas of steep slopes and high runoff, which limited the distribution of potential breeding sites to the edges of the Island. By extrapolating the density of nests in the known breeding sites to the overall potential breeding area, we estimated 1,228 nests. We discuss the potential implications of our findings in relation to the population status based on the scenario of intense habitat modification of the island over the few last centuries. This species may have suffered declines due to habitat alteration by human activities and introduction of exotic species. Furthermore, we generate an overview of potential areas for nesting and establish relationships with habitats that may be useful for the conservation of the Trindade Petrel, and restoration actions for Trindade Island in the future. [ABSTRACT FROM AUTHOR]

Urban sewage is a concerning issue worldwide, threatening both wildlife and human health. The present study investigated protein oxidation in mangrove oysters ( Crassostrea brasiliana) exposed to seawater from Balneário Camboriú, an important tourist destination in Brazil that is affected by urban sewage. Oysters were exposed for 24 h to seawater collected close to the Camboriú River (CAM1) or 1 km away (CAM2). Seawater from an aquaculture laboratory was used as a reference. Local sewage input was marked by higher levels of coliforms, nitrogen, and phosphorus in seawater, as well as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), linear alkylbenzenes (LABs), and fecal steroid in sediments at CAM1. Exposure of oysters to CAM1 caused marked bioaccumulation of LABs and decreased PAH and PCB concentrations after exposure to both CAM1 and CAM2. Protein thiol oxidation in gills, digestive gland, and hemolymph was evaluated. Lower levels of reduced protein thiols were detected in hemolymph from CAM1, and actin, segon, and dominin were identified as targets of protein thiol oxidation. Dominin susceptibility to oxidation was confirmed in vitro by exposure to peroxides and hypochlorous acid, and 2 cysteine residues were identified as potential sites of oxidation. Overall, these data indicate that urban sewage contamination in local waters has a toxic potential and that protein thiol oxidation in hemolymph could be a useful biomarker of oxidative stress in bivalves exposed to contaminants. Environ Toxicol Chem 2017;36:1833-1845. © 2016 SETAC [ABSTRACT FROM AUTHOR]

Organochlorine contaminants (OCs) and polybrominated diphenyl ethers (PBDEs) were investigated in the eggs of five bird species from the South Shetland Islands. Additionally, OCs and PBDEs were also analysed in embryos of two species. The concentration ranges in eggs were (ng g-1 wet weight) 2.11 to 541 for polychlorinated biphenyls (PCBs), <0.25 to 0.88 for PBDEs, 2.45 to 405 for p,p'-DDE and 1.50 to 603 for mirex. The PCBs were predominant in the eggs of Macronectes giganteus, Catharacta antarctica and Larus dominicanus, whereas hexachlorobenzene (HCB) was the major compound found in the eggs of Pygoscelis antarcticus and Sterna vittata. The PBDE congeners were detected only in the eggs of C. antarctica (PBDE 47 and 153) and S. vittata (PBDE 47). There were differences in OC concentrations of up to two orders of magnitude between M. giganteus embryos which were related to the development stage and OC concentrations in the respective eggs. Trophic ecology and post-breeding dispersal exerted an influence on contaminant patterns. Comparisons with data from the literature indicate an increase in the concentrations of some OCs over recent years. [ABSTRACT FROM AUTHOR]