Food Navigator - Scottish salmon safe to eat, says EU
"But according to the CORDIS report, a spokesperson for EU Health and Consumer Protection Commissioner David Byrne said:'We agree with the assessment made by the UK food standards agency that the levels [of chemicals] in our European salmon do not exceed EU limits.'
The UK Food Standards Agency had earlier stressed that the levels of dioxins and PCBs found in farmed salmon during the US led study were within World Health Organisation and EU guidelines. Those guidelines, which are based on scientific advice, were 'accurate and valid,' added the Commission spokesperson.
The Scottish salmon industry has accused the American researchers of being 'deliberately misleading'."

Here's the twist in the story. The EU says that the story from US researchers was "hype" and that PCB and dioxin levels in farmed Salmon were within acceptable limits. This begs the question of "what was the origin of the US recommendations of no more than 2 oz. of Scottish Salmon per month"?

Nonetheless, it appears that farmed fish are less healthy than free-running fish. It's just that not all fishmongers label the fish origin.