Conservationists are outraged that Japanese fishermen have rounded up more than 250 bottlenose dolphins for meat, or to sell into captivity in aquariums.
Fishermen have corralled the dolphins in Taiji Cove in the southeast of the country.
The Sea Shepherd Conservation Society sees the round-up as an unnecessary slaughter. But the fishermen defend it as an annual local custom.
Celebrities have also gone on Twitter to condemn the attack.