Cook onion, green pepper, mushrooms and garlic in margarine in large saucepan or Dutch oven over medium-high heat until tender crisp.
Stir in tomatoes and juice, broth, red pepper, thyme and basil. Bring to a boil. Reduce heat; simmer, uncovered, 10 to 15 minutes. Stir in okra, fish and shrimp; simmer until fish flakes with fork, 5 to 8 minutes.