I just went vegetarian for a variety of reasons including environmental, ethical and the fact that if you eat any meat it is difficult to all-together avoid battery-farmed, ritually slaughtered and other mistreated animals (especially at a catered university like mine). My choice to go vegie wasn't based on a very strong moral conviction, it was more 'on balance'.
However, now I face the dilemma of whether it is okay to eat fish. I made the usual assumptions about fish having low intelligence, low capacity for suffering and so on that made me think I could include fish in my diet (though I haven't yet). However, many people have challenged me on this and said fish is in fact treated worse, and a much greater number have to be killed than for a dish of meat. Some people have even said that on the grounds I became a vegie, it is worse to eat fish than meat.
So, is it okay to eat fish?