A controversial dolphin hunt which takes place in Japan every year is underway.

Fishermen in Taiji in western Japan drove more than 200 bottlenose dolphins into a secluded bay ready to kill them or sell them into captivity at marine parks.

On Monday they killed at least 30, hiding the activity from animal rights activists, reporters and TV cameras behind a tarpaulin.

Fishermen waiting in the shallow waters by the shore, some in wet suits with snorkelling masks on their faces, wrestled the dolphins into submission and tied their tails with ropes to stop them from escaping.

A large pool of blood seeped under the tarpaulin and spread across the cove.

Activist, Melissa Sehgal, from the Sea Shepherd Conservation Society, called the slaughter process brutal.

“The process is called pithing, where they hammer a metal rod into the spinal cord of the dolphin. These dolphins do not die immediately. It takes up to 20 to 30 minutes for these dolphins to die, where they bleed out, suffocate or drown from the process of being dragged to the butcher house,” said Sehgal.

Diplomats speak out

The killing has been condemned around the world.

The US Ambassador to Japan, Caroline Kennedy, has even stepped in saying she is “deeply concerned” by the “inhumaneness”.

“UK opposes all forms of dolphin and porpoise drives; they cause terrible suffering. We regularly raise (the issue) with Japan,” said the British Ambassador to Japan, Timothy Hitchens, in a tweet on Monday.

Japan defends the killing

The Japanese government defends the practice, saying it is part of its culture and traditions.

“I believe dolphin fishing is one of Japan’s traditional fishing industries and is carried out appropriately in accordance to the law. Furthermore, dolphins are not within the management of the International Whaling Commission and it is left to the respective nations to manage this resource,” said Chief Cabinet Secretary Yoshihide Suga.

The dolphin hunting season runs yearly from September to March. Sea Shepherd said around 600 marine mammals had been killed this season before Tuesday’s slaughter.

A dead dolphin sold for meat can fetch around 450 euros.

Yoshinobu Nisaka, the governor of Wakayama prefecture where Taiji is located, told reporters: “Dietary culture varies and it is the wisdom of civilization to mutually respect other standpoints unless the world faces a lack of resources.”