4 skinless salmon fillets, (6 ounces each)
Coarse salt and ground pepper
2 teaspoons chili powder
1 pound medium zucchini, quartered lengthwise, cut crosswise into 3-inch spears (about 1/2 inch thick)
2 tablespoons olive oil
2 packages (10 ounces each) frozen corn kernels (4 cups)
2 garlic cloves, minced
1 cup chopped scallions
1 container (16 ounces) prepared fresh tomato salsa (2 cups)
Lime wedges, for garnish (optional)