Canadian-US environmentalist and anti-whaling campaigner Paul Watson is to remain in custody in Greenland following his arrest in July pending possible deportation to Japan, police said on Thursday. The Nuuk district court has extended Watson’s detention to September 5, while an international arrest warrant is processed. Watson is to appeal the court ruling. Watson, 73, was arrested after entering Nuuk harbour with the ship, the John Paul DeJoria, on July 21. Watson, who founded the Sea Shepherd Conservation Society, has been an animal rights activist for decades, drawing opposition from vario…