VANCOUVER - For almost three weeks after David Tarasick published findings about one of the largest ozone holes ever discovered above the Arctic, the federal scientist was barred from breathing a word about it to the media.

Kristi Miller was similarly gagged from granting interviews about her own research into a virus that might be killing British Columbia's wild sockeye salmon, despite going to print in the prestigious journal Science.

Such incidents aren't one-off occurrences, but instead represent a trend of "muzzling" policies being imposed on Canadian scientists by federal agencies under the Conservative government, a panel told their international peers Friday at a global science conference in Vancouver.

"It's pretty clear that for federal scientists, Ottawa decides now if the researchers can talk, what they can talk about and when they can say it," senior science journalist Margaret Munro, with Postmedia News, told a group gathered at the American Association for the Advancement of Science annual meeting.

"We're not talking about state secrets here."

The views were aired in tandem with the release of an open letter by a coalition of six science and communications organizations, who jointly called on Prime Minister Stephen Harper to "tear down the wall" that's been raised over the past four years separating scientists, journalists and the public.

"Despite promises that your majority government would follow principles of accountability and transparency, federal scientists in Canada are still not allowed to speak to reporters without the 'consent' of media relations officers," the letter says.

It adds that far too frequently, journalists encounter "unacceptable" delays and denials for interviews.

"Increasingly, journalists have simply given up trying to access federal scientists, while scientists at work in federal departments are under undue pressure in an atmosphere dominated by political messaging."

Munro, an award-winning reporter who's worked in the field more than 30 years, said news coverage of publicly-funded science has plummeted in the years since the Conservatives took office.

"We used to have a very open system of government, where the scientists were actually free to discuss their research with the media," she said. "But it's now become a very closed system with government taking media and message control to sometimes quite incredible extremes."

Among the first agencies whose strict guidelines restricting the flow of information was revealed was Environment Canada, in 2007. The protocol stipulated that all media requests be streamlined through agency headquarters, and staff divert replies from being answered by the scientist themselves with either "approved lines" or the minister's office.

The government currently employs 4,459 information officers, media handlers and strategists to do such work, Munro said.

"The government, for the most part, won't really admit that there is a problem," she said. "They maintain there is timely, orderly access to scientists."

No official from any of Environment Canada, the Fisheries Department or Natural Resources were available to join the panel. An invitation to Gary Goodyear, the minister of state for science and technology, was not answered.

Panellist Francesca Grifo, a director with the Massachusetts-based Union of Concerned Scientists, has worked to improve accountability of the U.S. government by pushing for broader transparency around the science it conducts.

"This isn't about some abstract right that scientists get to chatter about," she said. "This is about important information that has critical repercussions for our health, our safety, our environment, our world, our future, our children's future.

"And (it's about) the ability to get that information out there so that we as citizens can begin to evaluate and be a part of the decision-making process."

She suggested Canadian agencies take a page from one in the U.S., the National Oceanic and Atmospheric Administration. The body now encourages scientists to speak to the media without any intermediary, and even express their own opinions so long as they indicate they aren't speaking on behalf of their employer.

A third panellist said many scientists are frustrated, but haven't spoken out with a collective voice for fear of being branded "radicals" and losing their funding.

But climate scientist Andrew Weaver noted it's a shame that much good work is going unheard, and suggested that politicians frame the debate in a more positive way.

"It's not about suppressing somehow some message that's going to create some murky controversy, it's about suppressing the success of Canadian scientists," said Weaver, with the University of Victoria.

"Why don't we open it up? There's nothing to be feared from success."

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