Surprising. Lots of people like fish OTHER than tuna. No orange roughy, sea bass, salmon, etc.? Sea bass and orange roughy, particularly, are VERY mild fish. In addtion, how it's prepared has ALOT to do with it. Fish is, and should be VERY simple to prepare. I give people very simple recipes that even kids like. Why dont' you make it, just out of curiousity? I come across clients all the time that don't fix it because they don't know how they should prepare it.
Regardless, there are other foods that contain omegas...walnuts, avacados, flaxseed. I actually take flaxseed oil rather than the fish oil. I do eat some fish, but also get my omegas from nuts and avacados on a daily & weekly basis.
I'd be careful with doing alot of shrimp. These are bottom feeders. All of your bottom feeders are high in toxins. The "rule" for seafood is that you only eat what has fins and scales (Biblical, too)..... Which would eliminate all bottom feeders. God gives us all kinds of guidelines to try to keep us "safe".