Last year Mainstream Canada, which operates 27 farms off B.C.'s coast, sued Don Staniford for defamation after he claimed online that "salmon farming kills" and "salmon farming is poison".
While the trial judge found Staniford's statements were defamatory, she ruled they were also protected by the defence of fair comment, because readers could make up their make up their own minds about what Staniford was saying.
However on Monday, B.C.'s Appeal Court disagreed, and ruled the facts Staniford relied on weren't sufficiently referenced on his website.
The court ordered Staniford to pay $75,000 in damages and slapped him with an injunction against repeating his claims.
Not backing down yet
But Staniford is already vowing he won't be silenced, claiming the injunction would ultimately bar anyone from criticizing the industry.
"I intend to repeat these allegedly defamatory words," said Staniford, speaking from Ireland.
"This opens up a whole new line of attack by these Norwegian multi-nationals to muzzle free speech," he said, referring to the Norwegian parent company Cermaq, which operates Mainstream and other salmon farming operations worldwide.
Lawyer Gavin Cameron, who represents Mainstream, says Staniford is wrong.
"This judgment means you can be forceful in your criticism, you may not be 100 per cent correct, but you do have to point to some facts that back up what you're saying," said Cameron.
In a statement, Mainstream Canada called Staniford a cyber-bully who carried out a prolonged and malicious attack against the company and its employees.
"We are pleased that the court recognizes that especially in the age of the Internet, public comments need to be backed up by facts," said Laurie Jensen, Mainstream Canada's Communications and Corporate Sustainability Manager in a statement posted online.
Staniford says he plans to ask the Supreme Court of Canada to hear an appeal.