If we are going to do long duration space exploration we must have a means for recycling wastes specifically complex organic molecules read human excrement and urine and CO2. Plants in this case Algae are the most efficient organisms on earth at turning those wastes into O2 which we need to breath and complex carbohydrates which we need to eat. Urine turns out is a powerful nitrogen source for plants. Our solid wastes have significant phosphorus contents too. Any attempt at long duration space exploration will be using photobioreactors to process wastes using the most abundant resource in the solar system aka sun light to turn waste water in to live giving O2 gas and food.
There already is a group that has GMO cyanobacteria that use waste water to grow and directly excrete C6 sugars sucrose specifically that is pure carbo food for us monogastrics pigs and chickens too. Given a source of the 9 amino acids we cannot synthesis and pure sucrose plus the essential micro/macro minerals mongastrics can be sustained on just 3 items, protein, sucrose and minerals. In Brazil live stock is raised on sugar cane liquids and soy or fish meal from weening to slaughter. It would be a bland and boring diet but what a pig can eat we can eat too. For a resource limited space flight vegan meals would be the norm with limited amounts of single cell protein culture supplements. The mass balance of launch is such that meat would be to heavy to pack for multiyear missions and live stock would be too resource hungry to "farm" in space. It takes 3-10lbs of carbo/protein feed to produce 1 lb or chicken or pig when that same amount of food would feed a human for a week. This is the only argument for veganism in space meat is too heavy and resource dependent to pack along.
Thanks... I understand all that, though not on the level you posted.
My question was sort of tongue-in-cheek, referring to the lack of large bodies of salt water in space...