Dear Marmam members, I would like to inform you about new short paper on stable isotope ratios of Dall's porpoise. Please request pdf copy to ohizumi@scc.u-tokai.ac.jp. Differences in stable isotope ratios of Dall’s porpoises (Phocoenoides dalli) between coastal and oceanic areas of the North Pacific. Hiroshi Ohizumi and Nobuyuki Miyazaki. Fisheries Oceanography 19:4, 257-261. 2010. ABSTRACT Carbon and nitrogen stable isotope ratios in the muscle of Dall’s porpoises were measured. Samples were collected from the catches of the hand harpoon fishery, incidental catches of drift net, and scientific research on the use of drift nets. Samples were from the North Pacific, Sea of Japan, Sea of Okhotsk, and Bering Sea. Although no variation in d15N was observed, d13C was significantly different between population groups near Japan and the oceanic North Pacific and Bering Sea. The difference may be due not only to local variation in prey species, but also to an overall difference in carbon stable isotope ratios that originate from coastal benthic or oceanic pelagic-based food webs. We differentiated Dall’s porpoise population groups from both areas using carbon stable isotope ratios with an error rate of <5%. Although further study is needed, our results suggest that carbon stable isotope ratios could possibly be an indicator of whether a Dall’s porpoise belongs to a coastal benthic or oceanic pelagic food web. ++++++++++++++++++++++++++++++++++ Hiroshi OHIZUMI Ph. D. Tokai University Department of Marine Biology School of Marine Science and Technology 3-20-1 Orido, Shimizu, Shizuoka 424-8610 Japan Tel: +81-543-334-0411 Fax: +81-543-337-0239 ohizumi@scc.u-tokai.ac.jp ++++++++++++++++++++++++++++++++++