Mix together the soy sauce, Worcestershire sauce, onion powder, garlic salt, thyme, black pepper, and chili powder in a small bowl to form a paste. Spread a thin layer of the soy sauce mixture on both sides of each shark steak. Place on a plate and cover. Allow to marinate in the refrigerator at least 30 minutes.
Preheat oven to 325 degrees F (165 degrees C).
Arrange the shark on a baking sheet. Bake the shark in the preheated oven until cooked completely through, about 40 minutes, turning the steaks over once, about half-way through the cooking time.
