Getting your Omega 3s and vital B12 through fatty fish and shellfish on a regular basis is not easy. Adding in wanting it to be local, quality and sustainably caught makes it even harder and my local Farmer's Market source often sells fish from Alaska or Washington State. Often when I'm out to eat I try to order some kind of fatty fish or shellfish knowing I don't often have it at home for these reasons.
I read this article on the KQED blog and was excited about the CSA (community supported agriculture) concept spilling into the market for seafood. Though this article is bay area specific, I would bet the concept is catching (no pun intended) on in other parts of the country as well!