1. Thaw fish and shrimp, if frozen. Rinse fish and shrimp; pat dry with paper towels. Cut fish into 1- ½-inch pieces. Cut shrimp in half lengthwise. Cover and chill fish and shrimp until needed.
2. In large saucepan, cook onion, celery, and garlic in hot oil until tender. Carefully stir in 1 cup broth and wine. Bring to boiling; reduce heat. Simmer, uncovered, for 5 minutes. Stir in tomatoes, tomato sauce, oregano, salt, and pepper. Return to boiling; reduce heat. Cover and simmer for 5 minutes.
3. Gently stir in fish and shrimp. Return just to boiling; reduce heat to low. Cover and simmer for 3 to 5 minutes or until fish flakes easily with a fork and shrimp are opaque. Sprinkle with parsley.