We make seafood pizzas all the time, every chance we get. In fact, I just got back from working with a pizzeria in Detroit where I demonstrated the making of seafood pizzas....they were great!!
Use your regular pizza dough and open into a dough skin for a thin crust. Lightly brush with olive oil and add just a hint of garlic (I like to use diced garlic), then spread on just enough Alfredo sauce to cover the surface of the dough, leaving a slight exposed rim. Give this a good sprinkling of dried dill weed, then add pieces of shrimp (baby shrimp works well), cod cut into 1/4 to 1/2-inch cubes, and pieces of crab meat, squid, clams, etc., finish by adding some sliced red onion and fresh tomato pieces, for cheese, add only 3 to 4-ounces of Mozzarella cheese for a 12-inch pizza, and about an ounce of shredded Parmesan cheese. Please don't go heavy on the cheese as it will detract from both the appearance and flavor of the pizza. Bake the pizza as you would any regular thin crust pizza.
Tom Lehmann/The Dough Doctor