I would like to make a small comment:

Vegan means NO ANIMAL sourced foods at all. NO eggs, no dairy etc. Some Vegans also refuse honey!

Once you give up all animal sourced foods, you have to think about supplying Vitamin B12. B12 is only found in animal sourced foods.

So the distinction is important. If you give up fish, you will not have a source of Omega-3's. This means at least for females in your home, you need to add flax oil or ground flax seed in abundance. Males do not convert to EPA and DHA and so flax is less effective for them.

The bottom line is: you cannot live without Omega-3's and you cannot live without Vitamin B12. Another nutrient often lost is zinc. There are compounds in veggies called phytates, which complex zinc out of the diet. People who do not eat animal protein then can become zinc deficient.

At this point you are following a vegetarian lifestyle. I'd urge you to read up further, so you don't miss out on essential nutrients. Many vegetarian sites have these details on them, and therefore will be easy to find.