Heat oil in a large nonstick skillet over medium-high heat until hot. Add chopped onion, green pepper, and celery; cook 7 minutes or until tender, stirring often. Add Creole seasoning and 1/4 teaspoon pepper; cook 1 additional minute.
Stir in tomatoes and next 3 ingredients. Bring to a boil; cover, reduce heat, and simmer 15 minutes. Add fish; cover and cook 5 to 7 minutes or until fish flakes easily when tested with a fork.