Which fish to choose for a good omega 6 to omega 3 ratio without other health drawbacks?

Question

Eating Fish seems to be a good option to improve your omega 6 to omega 3 ratio.

Now the problem is that many fishes contain pollutants, for example mercury, tin compounds, PCB, dioxins or antibiotics. In particular the fat fishs seem to be more pulluted, but that seem to be the best canditates to get some healthy omega 3 fatty acids without too much omega 6.

So what would be good fish choices to improve your omega 6 to omega 3 ratio without the health drawbacks described above?

Do you have some references about that?

Answer 1

Also departing from fish, hempseed oil is known to contain the optimal ratio of omega 3 and omega 6 fatty acids, and does not present any health drawback to my knowledge.

Answer 2

(ok, the text in the comment field says clearly "avoid answering...", but my answer is not a direct answer to your "which fish" question, what should I do? ^^)

Perhaps using supplementary oil capsules is a better alternative:

studies have found that most of the widely available supplements contain little or no mercury, dioxins or PCBs. For one thing, most companies use species of fish that are lower on the food chain, like cod and sardines, which accumulate less mercury. And many companies distill their oils to help remove contaminants.

nytimes article

Another alternative, suitable for vegetarians, would be DHA & EPA containing oil extracted from algae bred in water basins (no mercury pollution). Schizochytrium micro algae as an "Excellent Source of Dietary Omega-3s"