Politics trumps science when it comes to permitting ecologically pernicious salmon farms in British Columbia. Read all about it in an excellent piece of investigative journalism by The Tyee. Normally those sorts of claims—that policy decisions are political rather than accurate—are hard to substantiate. But in this case the reporter was actually able to obtain proof. In one document from the province’s Fisheries Minister, an admission of salmon farms’ harm was deleted; but the editor helpfully wrote: "Technically correct, but politically problematic."
As knowledge about their true effects increases, salmon farms are becoming ever more unpopular with consumers. Market forces are moving against BC’s lax regulations: A Vancouver Sunarticle today (subscription required) reports that the giant Albertson’s grocery chain (one of the three largest in the U.S.) wants major changes to the way farmed salmon is produced, citing "serious environmental problems."
For more on what’s the matter with farmed salmon, see here.