Since 2005, the U.S.-based environmental activist group Sea Shepherd has used its ships to disrupt Japan's annual whaling expedition in Antarctic waters.
But this year, Sea Shepherd says it won't send ships because Japanese whalers are using improved technology that helps them avoid the vessels. And the group's founder, Paul Watson, accuses the Australian, New Zealand and U.S. governments of appeasing Japan by not doing more to stop the killing of whales.
Japan is "using military technology. They have real-time satellite coverage of where we are. We cannot close in on them," Watson said in an interview with the Australian Broadcasting Corp.
"It's a waste of time and money to go down there and not be able to achieve anything," he added.
Japanese whalers have also "doubled their killing grounds," the activist group said in a statement, making it harder for the Sea Shepherd ships to reach them.
In 2014, the International Court of Justice ruled that Japan must "revoke whaling permits in the Antarctic and stop granting new ones," NPR's Bill Chappell reported.
Japan argues that it hunts the whales for scientific research, though the ICJ stated that the scientific output from the research "appears limited" — two peer-reviewed papers in nine years.
It resumed hunting whales in 2015, the BBC reports, "claiming that its fleet had satisfied ICJ requirements about conducting scientific research."
But as NPR's Kevin Beesley has reported, "the meat is sold commercially and government agencies say the ultimate goal is the resumption of commercial whaling." Japanese whalers killed 333 minke whales in the Antarctic last year.
The Sea Shepherd says its shift is also due to Japan's new anti-terrorism laws. According to The Guardian, the country has recently passed laws "that make protest ships' presence near whalers a terrorism offence."
"How can we compete with that kind of power?" Watson told the ABC. "We just show up now and we're terrorists. That is different than it was last year or the year before. They're defining laws, manufacturing laws, specifically to stop us."
The Sea Shepherd group says it believes its actions have saved more than 6,000 whales.
"We're not surrendering. We're going to have to find an alternative way to deal with them. And we will," Watson told the Australian broadcaster, without providing details.
Watson is currently on Interpol's red list because he is wanted by Japanese authorities for allegedly "breaking into a vessel, damage to property, forcible obstruction of business, injury."
Australia, New Zealand and the U.S. have publicly criticized Japanese whaling practices. The Guardian reported that the three countries said in a joint statement last year that "our governments remain resolutely opposed to commercial whaling." That same statement also stressed that anti-whaling activists should not partake in "dangerous, reckless or unlawful behavior."
Reuters reports that Japan is not immediately changing its readiness, despite the Sea Shepherd's announcement.
"It's not clear what the real intention of their statement is and we don't know whether the organisation will stop its anti-whaling actions this year," a Japanese official said, according to the news service. "We can't deny the possibility that other anti-whaling groups may take action, so we continue to closely monitor the situation and we're not making any predictions."