You mean POSITIVE 15 per mil? If not, this could indicate that these fish come from the sea, where such values are common for carnivorous fish. I don't know if this is your case, but as far as I know salmon are fishes that born in the freshwater, live in the sea and come back. Most of their meat should come from marine sources. Matheus C. Carvalho PhD student Kitasato University - School of Fishery Sciences Japan --- Em ter, 24/6/08, Bjoern Wissel <[log in to unmask]> escreveu: De: Bjoern Wissel <[log in to unmask]> Assunto: [ISOGEOCHEM] high del13C values in stream fish Para: [log in to unmask] Data: Terça-feira, 24 de Junho de 2008, 19:39 HI, we ran a number of salmonid fish muscle and liver tissue samples for a small stream in Quebec and came across fairly high de13C values (around 15 per mil). I assume that terrestrial insects that rely on C4 plants are not an option in temperate regions. Does anyone know what food sources might have such high values, or could it be a physiological effect? I am open to any suggestions and speculations.... Thanks, Bjoern Björn Wissel, PhD EQAL Manager, Faculty of Science Adjunct Professor, Department of Biology 265.2 Laboratory Building University of Regina Regina, SK S4S 0A2 Canada phone 306 585-4890 fax 306 337-2410 e-mail [log in to unmask] Novos endereços, o Yahoo! que você conhece. Crie um email novo com a sua cara @ymail.com ou @rocketmail.com. http://br.new.mail.yahoo.com/addresses