title: Making the most of what we have: application of extrapolation approaches in radioecological wildlife transfer models.
abstract: We will never have data to populate all of the potential radioecological modelling parameters required for wildlife assessments. Therefore, we need robust extrapolation approaches which allow us to make best use of our available knowledge. This paper reviews and, in some cases, develops, tests and validates some of the suggested extrapolation approaches. The concentration ratio (CRproduct-diet or CRwo-diet) is shown to be a generic (trans-species) parameter which should enable the more abundant data for farm animals to be applied to wild species. An allometric model for predicting the biological half-life of radionuclides in vertebrates is further tested and generally shown to perform acceptably. However, to fully exploit allometry we need to understand why some elements do not scale to expected values. For aquatic ecosystems, the relationship between log10(a) (a parameter from the allometric relationship for the organism-water concentration ratio) and log(Kd) presents a potential opportunity to estimate concentration ratios using Kd values. An alternative approach to the CRwo-media model proposed for estimating the transfer of radionuclides to freshwater fish is used to satisfactorily predict activity concentrations in fish of different species from three lakes. We recommend that this approach (REML modelling) be further investigated and developed for other radionuclides and across a wider range of organisms and ecosystems. Ecological stoichiometry shows potential as an extrapolation method in radioecology, either from one element to another or from one species to another. Although some of the approaches considered require further development and testing, we demonstrate the potential to significantly improve predictions of radionuclide transfer to wildlife by making better use of available data.
authors: NERC Centre for Ecology & Hydrology, Lancaster Environment Center, Library Av., Bailrigg, Lancaster LA14AP, UK; School of Environment & Life Sciences, University of Salford, Manchester M4 4WT, UK. Electronic address: nab@ceh.ac.uk.
authors: Nicholas A
authors: NA
authors: Beresford
authors: School of Environment & Life Sciences, University of Salford, Manchester M4 4WT, UK.
authors: Michael D
authors: MD
authors: Wood
authors: Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol, Belgium.
authors: Jordi
authors: J
authors: Vives i Batlle
authors: International Atomic Energy Agency, Vienna International Centre, 1400 Vienna, Austria.
authors: Tamara L
authors: TL
authors: Yankovich
authors: Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-10691, Sweden.
authors: Clare
authors: C
authors: Bradshaw
authors: Centre for Research in Biosciences, University of the West of England, Coldharbour Lane, Frenchay, Bristol BS16 1QY, UK.
authors: Neil
authors: N
authors: Willey
mesh_terms: D000818:Animals; D008962:Models, Theoretical; D011834:Radiation Monitoring / Q000379:methods*; D011848:Radioactive Pollutants / Q000378:metabolism*; D011868:Radioisotopes / Q000378:metabolism*; D014714:Vertebrates / Q000378:metabolism*
chemical_list: D011848:Radioactive Pollutants; D011868:Radioisotopes
keywords: Allometry; Biological half-life; Concentration ratio; Extrapolation; REML; Stoichiometry