Memory of Dr. Seiji Ohsumi 12 July 1930 – 2 November 2019
We very much regret to inform you that Dr. Seiji Ohsumi, aged 89, Chairman of Governing Councilof Cetacean Population Studies (CPOPS) unfortunately died at 7:55 PM on November 2, 2019 due toan acute myocardial infarction.
Dr. Ohsumi had been one of the leading members of the IWC/SC for very long time through the 1960’s
to the 2010’s, serving as head of the Japanese delegation to the IWC/SC during many years in 1990s.

Dr. Seiji Ohsumi was born on July 12, 1930 in Gunma Prefecture, the center of Japan. He had been atemporary member of the Whales Research Institute while he was a graduate student of the Faculty ofAgriculture at the University of Tokyo. Subsequently he became a permanent scientist in 1958. In hisearly days at the WRI he was mainly engaged in field science at numerous places where whalingoccurred as well as laboratory analyses under the supervision of the late Professor Masaharu Nishiwaki(senior scientist at WRI) and the late Dr. Hideo Omura (Director general of WRI). In this way hegained biological knowledge about both large and small cetaceans. His first paper in English waspublished in the Scientific Report of WRI in 1954 [9: 165 – 177] under his original name of Seiji
Kimura and was titled “On the sexual maturity of the sei whale of the Bonin waters”.
His Ph.D. thesis submitted to the University of Tokyo, examined age determination with a focus on
fin whales and titled “A study on age determination of the fin whale”, in which he found and confirmed
annual deposition rate of growth layer in fin whale earplugs, which was one of most important issues
in stock management of fin whales.
Dr. Seiji Ohsumi moved to a government fisheries laboratory in May 1966 and was assigned head ofcetacean population studies at the Far Seas Fisheries Research Laboratory (currently, NationalResearch Institute of Far Seas Fisheries) in August 1967. He served as director general at FSFRL fromOctober 1988 to March 1991.

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After retirement as a government scientist, he was nominated as a trustee on the board directors of theInstitute of Cetacean Research, Tokyo in April 1991. Subsequently, he was nominated as the director
general of the ICR in December 1995. He continued to serve in the position of director general until
December 2003.
Subsequently Dr. Ohsumi was nominated as a senior scientific adviser in January 2004, and as anhonorary scientific adviser in October 2015. He remained in that position until November 2019 andcontinued to travel from his home in Shinjuku to the ICR almost daily until November 1, 2019. Seiji
always said that “I continue to go to the office each day because this is my eternal mission.”
During the period through the 1950s to the 2010s, he made tremendous scientific works and publishednumerous scientific articles on cetaceans over 500 papers including both English and Japanese articles.
One of his academically important papers was on the school structure of sperm whales titled “Someinvestigations on the school structure of sperm whale (Scientific Report of WRI, 23: 1 – 25.)”. During
his academic years he received numerous numbers of awards including the Royal Norwegian Orderof Merit, Special Award of the Mammal Society of Japan, etc.
His public memorial service was held at 13:00 on December 23, 2019 at the Mariners Court HotelTokyo (Harumi, Tokyo), jointly hosted by the Institute of Cetacean Research and Seiji Ohsumi’s family. The co-mourners were Dr. Yoshihiro Fujise (Director general of ICR), Drs. Masako Osumi (wife,Professor Emeritus of Japan Women’s University) and Noriko Osumi (daughter, Professor of theMedical school, Tohoku University).
The next volume, CPOPS Vol. 3, will be designated as “Memorial Volume for Dr. Seiji Ohsumi”, wewould request widely to submit paper contributions from various areas and peoples.
June 1, 2020
Hidehiro Kato
Chairman Alternate, Publication Committee for the Cetacean Population Studies

Cetacean Population Studies (CPOPS)
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