Spray 5- to 6-quart slow cooker with cooking spray. Mix all ingredients except fish, shrimp, clams, crabmeat and parsley in cooker.
Cover; cook on High heat setting 3 to 4 hours.
Stir in fish, shrimp, clams and crabmeat. Reduce heat setting to Low. Cover; cook 30 to 45 minutes longer or until fish flakes easily with fork. Remove bay leaf. Stir in parsley.