Analyzing the stomach contents of a whale
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The world’s resources are finite. It is crucial that we don’t consume until everything is gone, that we leave resources for future generations.
For this reason, at times we must determine, “How much can we sustainably catch or harvest?” This is of course true for whales.
The utilization of whales as a sustainable resource requires strict resource management. This responsibility falls on the Ecosystem Studies and Population Biology Division and the Stock Assessment and Management Division at the Institute of Cetacean Research in Japan.
Stay with us as we will speak to the managers of these divisions, who have spent many years working on resource management at the institute, about the kinds of research they conduct each day.
In this interview, we talk with Tsutomu Tamura, who heads both research divisions at the Institute of Cetacean Research.
The full interview article is published in English Whaling Today. Short excerpts follow.
Learning Whales Eat Krill, Fish, and Even Birds!
It sounds like you really wanted to go to the Antarctic?
Yes I did. I even went to Hokkaido University to study Plankton Biology, because I thought that would be the quickest way to get on an Antarctic research trip. I went all the way to graduate school, but at the time I wasn’t thinking about jobs related to whales. I was thinking I would do research on seals.
Just as I was about to travel to Russia for seal research, the Gorbachev government collapsed and my visa application was rejected. I was already taking a leave of absence from my studies at university and I wasn’t sure what to do next.
One of my professors introduced me to a job as a messman on a ship, and so for a while I lived onboard. Maybe because I had that experience, later when I was taken on as a researcher for studying the contents of whale stomachs, I had no problems with sea sickness. And it turned out the research was actually quite interesting.
Their stomachs contain tiny creatures like krill, but also large fish, and even birds that they’ve gulped down while feeding.
Without thinking much about it, I would talk about how interesting and amazing the work was, until someone said, ‘If you feel that way why don’t you make this your research topic?’ And that led me to where I am now.
Impacts of Global Warming: Changing Diet, Warming Waters
Is there a difference in what whales consumed in the past and what they eat now?
For whales that inhabit the southern hemisphere, there is very little change. There is an abundance of krill in the Antarctic, so that is mainly what they eat, although it also depends on the species.
On the other hand, there have been big changes in the feeding habits of whales in the Northern Hemisphere. As an example, in the period from 1990 to 2000, the discovery that minke whales eat saury (known in Japanese as sanma), Japanese squid, and Japanese anchovy was sometimes even picked up in the news. When saury stocks later decreased, whale stomachs contained Japanese sardine and mackerel. [...]
As of October 1, Tsutomu Tamura is the head of both research divisions at the Institute of Cetacean Research. In addition to his research activities, he also travels around Japan to give educational lectures to children.
Author: JAPAN Forward
