However, despite this claim, meat from the dead whales is later sold to be eaten, leading activists to claim the country is conducting commercial whaling.
"The killing of 122 pregnant whales is a shocking statistic and sad indictment on the cruelty of Japan's whale hunt," said Alexia Wellbelove, senior programme manager at Humane Society International, quoted by the Independent.
"It is further demonstration, if needed, of the truly gruesome and unnecessary nature of whaling operations, especially when non-lethal surveys have been shown to be sufficient for scientific needs."
The Japanese teams target the whales using harpoons loaded with a 30g penthrite grenade.
Conservationists are calling on Japan to "put away the harpoons".
"Whales are already facing substantial threats including bycatch in fisheries and marine pollution," Wellbelove said.
"The continued killing of any whales is abhorrent to modern society, but these new figures make it even more shocking. We look forward to Australia and other pro-conservation countries sending the strongest possible message to Japan that it should stop its lethal whaling programme."