Anti-whaling activists the Sea Shepherd published video evidence Sunday of Japanese whalers slaughtering protected whale species in a marine preservation in the Southern Ocean.

The conservation group obtained footage of three dead minke whales, a protected species, on the deck of the Nisshin Maru, and a fourth whale, also believed to be a minke, being butchered on the ship, the Sydney Morning Herald reports. Crew members are seen mopping up large pools of blood on the deck.

After documenting the slaughter, the three-vessel Sea Shepherd fleet—which includes the Steve Irwin, the Bob Barker and the Sam Simon—drove the five Japanese whaling ships from the New Zealand maritime sanctuary in the first encounter of the current whaling season.

The Guardian reports:

Though condemning the actions of the Japanese whalers, neighboring governments have thus far done little to deter the practice.

According to the Sea Shepherd crew, “there was no sign of either the HMNZS Otago, which is patrolling New Zealand’s southern waters during whaling season, nor an Australian government aircraft, which was put forward by the country’s environment minister Greg Hunt in lieu of the customs vessel he promised before the election.”