Set aside 2 tablespoons pineapple juice. In small bowl, mix pineapple and remaining juice with other salsa ingredients.
Set oven control to broil. On rack in broiler pan, place fish; spray tops of fish with cooking spray. Sprinkle tops of fish with 2 tablespoons reserved pineapple juice, seasoned salt and smoked paprika. Broil with tops 4 to 6 inches from heat 6 to 8 minutes or until fish flakes easily with fork.
Meanwhile, on each of 4 plates, arrange 1 cup spinach. Place broiled fish on spinach. Spoon salsa over fish and spinach.