Only 16 whales were taken this spring off Miyagi Prefecture under the government's "research whaling" program, a record low since it began in 2003, a government-commissioned whalers' group said Friday.
The maximum catch for minke whales allowed under so-called research whaling this year is 51.
The number of whales captured under the program has been declining in recent years because fewer minke whales are around, possibly due to changes in their dietary environment.
Tatsuya Isoda, a senior official of the regional whaling promotion association, told reporters in Ishinomaki in Miyagi that the number of minke whales that come to Sendai Bay in the Sanriku region has fallen due to a change in marine species that the whales feed on.
The Fukuoka-based association said the whaling was conducted from April 9 to May 25 under research commissioned by the Fisheries Agency to examine what whales eat and to monitor marine resource conditions.
It said the main fish that whales off the Sanriku region used to consume was ammodytes personatus, but their number fell after the March 2011 Great East Japan Earthquake, while the number of sardinops melanostictus increased.
It is unknown if the quake is linked to the change, as the decline of ammodytes personatus is believed to be related to a rise in water temperature, the association said.
The Fisheries Agency is expected to consider waters off Sanriku or other locations for the site of research whaling next year and in light of the March 2014 order from the International Court of Justice in The Hague calling for a halt to whaling in the Antarctic Ocean.