Greenland police said they apprehended veteran environmental activist and anti-whaling campaigner Paul Watson on an international arrest warrant issued by Japan. Watson, a 73-year-old Canadian-American citizen, is a former head of the Sea Shepherd Conservation Society whose direct action tactics, including high-seas confrontations with whaling vessels, have drawn support from A-list celebrities and featured in the reality television series “Whale Wars.” He was arrested Sunday when his ship docked in Nuuk, Greenland’s capital, a police statement said. He later appeared before a district court to look into a request to detain him pending a decision on his possible extradition to...