Creamy Spiced Corn and Salmon Chowder

Name: Creamy Spiced Corn and Salmon Chowder
Ingredients: 4 ears fresh corn, husked and silk removed; 2-1/2 cups water; 2 teaspoons salt (divided); 1 tablespoon vegetable oil; 1 cup diced Walla Walla, Vidalia or other sweet onion; 1 teaspoon ground coriander; 1/2 teaspoon ground cumin; 1/4 teaspoon ground yellow or brown mustard seeds; 1/4 teaspoon ground fenugreek; 1/4 teaspoon ground turmeric; 1/8 teaspoon ground cayenne; 1 pound skinless fresh salmon fillet, cut into 1-inch chunks; 1/2 cup plain yogurt