Melt butter in a Dutch oven over medium-high heat. Add onion, carrot, celery, and garlic to pan; sauté 10 minutes or until lightly browned. Stir in tomato paste; cook 1 minute. Stir in wine; cook 1 minute. Add potato and next 7 ingredients (potato through bay leaf); bring to a boil. Reduce heat; simmer 30 minutes.
Add fish. Cover and simmer 10 minutes or until fish flakes easily when tested with a fork. Discard bay leaf.