I think that the Japanese - and I do love Japanese cuisine and adore Japanese food culture - I think that they're going to plow through the entire world's fishing. They're going to eat everything anyways.
There are many things to admire about Japan but this is the one thing I love the most and probably the only time I eat breakfast. Fish, eggs, soup, salad, veggies; all in the tiniest bites. It's a full meal, but it's so refreshing.
If you're going to be a vegetarian, limit yourself to food from a place you can go to in two hours and just eat that.