Cut fish into 1 1/2-inch pieces. Cut shrimp and scallops in half lengthwise. Refrigerate until ready to use.

Heat oil in a large saucepan over medium heat. Add onion, celery, and garlic and cook, stirring occasionally, until tender, about 5 minutes. Carefully stir in 1 cup broth and wine. Bring to a boil. Reduce heat to a simmer and cook for 5 minutes. Stir in drained tomatoes, tomato sauce, oregano, basil salt and pepper. Return to a boil, then reduce heat to a simmer, cover and cook for 5 minutes.

Gently stir in fish and shrimp. Return to a boil, then immediately reduce heat to low. Cover and simmer until the fish flakes easily with a fork and the shrimp are opaque, 3 to 5 minutes. Sprinkle with parsley before serving.