Bull. Jpn. Soc. Fish. Oceanogr. 72(3), Page 165-173, 2008   Quantitative analysis of isada krill (Euphausia pacifica) distribution in the western North Pacific Naoki Tojo1†, Daisuke Shimizu1, Hiroki Yasuma1, Shigeyuki Kawahara2, Hikaru Watanabe2, Shirou Yonezaki2, Hiroto Murase3 and Kazushi Miyashita1 1 Laboratory of Marine Ecosystem Change Analysis, Field Science Center for Northern Biosphere, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido 041-8611, Japan 2 National Research Institute of Far Seas Fisheries, Fisheries Research Agency, 5-7-1 Orido, Shimizu, Shizuoka, Shizuoka 424-8633, Japan 3 The Institute of Cetacean Research, 4-5 Toyomi-cho, Chuo, Tokyo 104-0055, Japan †