Bake the thawed Mahi-Mahi filets at 350 degrees for about 30 minutes (or until flaky).
While the fish filets are baking, mix the greek yogurt and water in a bowl.
Place shredded lettuce, baked fish filet (sliced), and avocado in each tortilla.
Drizzle the yogurt and water mixture over each taco.
Top each taco with paprika, crushed red pepper, and salt.