When I first read the topic my first thought was, "That's a stupid idea! Plankton have no way to carry around ration cards."
Oh, THAT Soylent Green? And here I was referring to one of the senior members of that reputable old firm of Glasgow barristers; Plankton, MacManischewitz & Green; who sued the pants off the British government on behalf of those poor sods who contracted e-coli poisoning and intestinal parasites after being force fed dried brackish Clyde River scum, in that test project Historian brought up (literally?). never mind ...