Farmed Salmon is naturally sickly grey, not pink, from eating chicken fat and feathers.

They dye pink color into farmed salmon.

Most salmon sold as wild salmon is actually farmed salmon.

More than half of fish sold in restaurants as tuna is not tuna.

It is usually a snake mackerel called escolar, which contains waxy deposits that do a number on your digestive system. 

150+ Reddit comments:

https://reddit.com/r/news/comments/3r1hqn/wild_salmon_may_not_be_as_wild_as_you_think/

The farmed salmon is also full of omega 6. 

Omega 6 is good right? Or are only Omega 3 good?

IMO omega 6 is negative in more than the smallest quantities

Okay but we should still be trying to get lots of Omega-3's, right?

I think keeping Omega 3's high in proportion to Omega 6 is a better goal than trying to consume a lot of either. 

I'm not even sure how many Omega 6's I consume. 

Fish watcher:

http://pandawhale.com/post/73310/is-that-real-tuna-in-your-sushi-now-a-way-to-track-that-fish