Accumulation of radionuclide and metal contaminants in flesh and osteoderms of estuarine crocodiles (crocodylus porosus): Pathways and histories of catchment-specific exposure

Flesh and osteoderms of estuarine crocodiles (C. porosus) from Kakadu National Park, Northern Australia, were analysed for a range of metals, including uranium, to assess their capability for accumulation, in relation to their catchment-specific exposure to i) uranium mine effluents and mineralisation and ii) lead shot ammunition through their consumption of fauna shot by the traditional owners of the Park. Uranium in osteoderms was significantly (P<0.05) elevated in the East Alligator River catchment, that contains the Ranger and Jabiluka uranium mine sites, relative to two other adjacent catchments. The mean concentrations of other elements in flesh and osteoderms were also significantly (P<0.05) different between catchments. Linear discriminant analysis was used to demonstrate that multi-element signatures in both flesh and osteoderms could be used to classify individual crocodiles to their respective catchments. This approach may be useful for the identification of source catchments of itinerant 'nuisance crocodiles' that find their way into Darwin Harbour, close to dense human habitation. Lead concentrations were significantly (P<0.05) enhanced in flesh and osteoderms of crocodiles sampled within two areas hunted with guns using Pb ammunition. Enhanced ratios of Pb:Ca in the annual laminations of their osteoderms are consistent with their history of continual exposure to elevated anthropogenic Pb sources. Subsequent experimental studies have demonstrated the ability of the crocodilian stomach to retain ingested Pb shot, that is readily solubilised and absorbed into the blood and then archived in the contemporary osteodermal lamination

The IAEA handbook on radionuclide transfer to wildlife

An IAEA handbook presenting transfer parameter values for wildlife has recently been produced. Concentration ratios (CRwo-media) between the whole organism (fresh weight) and either soil (dry weight) or water were collated for a range of wildlife groups (classified taxonomically and by feeding strategy) in terrestrial, freshwater, marine and brackish generic ecosystems. The data have been compiled in an on line database, which will continue to be updated in the future providing the basis for subsequent revision of the Wildlife TRS values. An overview of the compilation and analysis, and discussion of the extent and limitations of the data is presented. Example comparisons of the CRwo-media values are given for polonium across all wildlife groups and ecosystems and for molluscs for all radionuclides. The CRwo-media values have also been compared with those currently used in the ERICA Tool which represented the most complete published database for wildlife transfer values prior to this work. The use of CRwo-media values is a pragmatic approach to predicting radionuclide activity concentrations in wildlife and is similar to that used for screening assessments for the human food chain. The CRwo-media values are most suitable for a screening application where there are several conservative assumptions built into the models which will, to varying extents, compensate for the variable data quality and quantity, and associated uncertainty.Additional co-authors: H Takata, P Andersson, P Dale, J Ryan, A Bollhöfer, C Doering, CL Barnett, C Well

Determinantes da distribuição geográfica de Callithrix flaviceps (Thomas) (Primates, Callitrichidae) Determinants of geographical range of Callithrix flaviceps (Thomas) (Primates, Callitrichidae)

O clima e a vegetação são conhecidos determinantes das distribuições geográficas de várias espécies de mamíferos. Neste estudo foi testada a importância do clima e da vegetação como fatores limitantes da distribuição geográfica do sagui Callithrix flaviceps (Thomas, 1903). As análises com o clima foram feitas a partir de nove fatores climáticos, estimados para cada localidade de ocorrência da espécie em estudo. Métodos não lineares (regressão logística) foram usados para modelar a distribuição geográfica a partir dos dados climáticos. As análises de vegetação foram feitas a partir do mapa digital das eco-regiões. A sobreposição dos modelos de distribuição climática com os mapas dos tipos de eco-regiões sugeriram que estes dois fatores são limitantes na distribuição geográfica de Callithrix flaviceps. Foi ainda discutida a importância das interações interespecíficas como limitantes da distribuição geográfica de Callithrix flaviceps.<br>The climate and the vegetation are known determinant of the geographical range of several species of mammals. Here it was analized the role of the climate and the vegetation as limits of geographical range of the marmosets Callithrix flaviceps (Thomas, 1903). For each locality of occurrence, averages estimates of nine climatic variables and ecoregion data were recorded. A non-linear method (logistic regression) was used to model the climatic geographical distribution. Vegetation analysis was done with data from the digital map of ecoregions. The overlap of the climatic distribution map with ecoregion map suggested that both factors have importance in the limits of the geographical range of C. flaviceps. The role of interspecific interactions as limits to geographical range of C. flaviceps is also discussed