They haven't certified any open-net pen aquaculture. The five organizations that they're part of are vehemently opposed to open-net pen aquaculture. Various scientists within their organization, the David Suzuki Foundation, are well-respected and have helped to establish criteria for what are deemed sustainable farm salmon. They may be opposed to open-net pen, but they have contributed to developing criteria on what would be deemed sustainable.
On December 6th, 2011. See this statement in context.