When the vessel arrived in Nuuk, Greenland to refuel, the Danish police immediately boarded and arrested Watson.
The CPWF denounced the surprise arrest, which came as Watson planned to intercept a new Japanese factory whaling ship.
"We implore the Danish government to release Captain Watson and not entertain this politically-motivated request," Locky MacLean, CPWF's ship operations director, said in a statement.
Sunday's arrest came as the M/Y John Paul DeJoria was making its way to the North Pacific via the Northwest Passage after setting off from Dublin. The CPWF team aimed to intercept the Kangei Maru, a new 370-foot, $48 million Japanese factory whaling ship that's equipped with state-of-the-art drones that expedite the killing of whales.
CPWF argues that the launch of the new vessel signals Japan's ambitions to restart commercial whaling on the high seas—international waters—in the North Pacific and the Southern Ocean as early as 2025. Japan long whaled the high seas in defiance of international law, under the guise of scientific research, but in recent years it has shifted to whaling in its own territorial waters, which extend 200 nautical miles from its shores.
Watson, who is known for confrontational tactics, was the star of the Animal Planet television show Whale Wars that ran from 2008 until 2015, in which he lead efforts to disrupt Japanese whaling on the high seas.
Over a dozen police and SWAT team members took part in Watson's arrest in Greenland, an autonomous territory of Denmark. He was handcuffed and taken to local detention. A judge denied him bail on the grounds that he was a flight risk, citing a 2012 case from Germany in which he fled house arrest; he will be held in Nuuk until August 15 as authorities assess his possible extradition to Japan, where he could face up to 15 years in jail, The New York Timesreported.
The nature of Japan's charges against Watson was not specified in media reports. The Interpol arrest warrant cited by Danish police may be an old one, according to CPWF. MacLean said the warrant had "disappeared" from public view a few months ago and may have been made confidential, possibly as a tactic to lull Watson into a false sense of security when traveling internationally.
