If you read enough science fiction, you’ll learn that on those long space voyages we’re going to be eating a lot of hydroponically grown food, most of which will be blue-green algae. Heck, even on Star Trek, I’ll bet they’re eating algae… they’ve just run it through the replicators so it looks like fried chicken with mashed potatoes and gravy.
Makes that plomeek soup all the more appetizing, doesn’t it?