Ahh, the Japanese. So admirable in so many ways, so perplexing in some other ways, so utterly endearing in a few ways, and in some ways, well, every culture has its dark side.
The Japanese have a passion for the meat of cetaceans, which is the latin name for the order which consists of whales, porpoises, and dolphins. (Note that the term "marine mammals" is a broader one, which also includes seals, walrus, manatees, some otters, and arguably even the polar bear.)
We all know about the annual slaughter of the Minke whales; Greenpeace makes sure the world hears all about it. But the killing of the Dall's porpoise, (which looks like a mini-Orca), is a more secretive matter.
There are multiple issues here. Sustainability is one issue, the mercury levels in the meat, (4x the max "safe" level), is another issue.
But the crunch here, the real killer, is the issue of sentience. Some cetaceans are the closest thing to other sentient species present on this planet, and arguably are sentient by some definitions. This is an altogether larger issue than mistreatment of species like pigs and cows and mink that are not even vaguely possible candidates for being considered sentient. This is an issue of crucial ethical importance.
And yet it comes at a time when the world has no sympathy to spare, being inundated with human tragedies of grossly unmanageable proportions.