Dec 15, 2021 · Try canned mackerel in place of tuna fish, or use it as your main protein in a salad. Like all canned fish, it’s cooked and ready to eat. Cost per package/container. $2.73 per 15-ounce can (One can contains 96 grams of protein, or about 3.8 servings of fish, plus water.) Based on a serving of 25 grams of protein.