I'm sure everyone has seen 1973's "Soylent Green is People" clip, and the opening credits are actually pretty fun. And a good reminder that Harry Harrison's Make Room, Make Room, came out in the same era as John Brunner's Dos Passos-inspired pseudo-found novels beginning with 1968's overpopulation-centred Stand on Zanzibar. I'm not sure how the movie money came to be left on the table for Harrison. but he did have the good sense to write a police procedural instead of a quadrology of sprawling, experimental novels. Harrison was, if anything, too succinct for his own good, hence Deathworld not being Dune.
Blue green algae might also be too succinct for its own good. It's small, and short-lived; There have been a million generations since blue-green algae started out being the next big thing in fighting overpopulation and the "limits to growth," and as far as I can tell, we're still waiting. But, then, that's the point of the movie, isn't it? "Soylent" is the food of the future; Blue-green algae would should have been the food of the future, but it turns out that there's a problem.I know, I know, that's a link to a weird and poorly reviewed science fiction novel from the early Seventies. The Ballentine second hands are everywhere, so I suspect it sold well but was received coldly, and I can see why, because it is a strange, if epic, story. And it happens to be the place where the idea of the empty oceans was introduced to me --along with a lot of other very weird stuff. T. J. Bass probably deserves some kind of attention, and the idea of a dead ocean was definitely resonating in the early 1970s, replacing earlier optimism about the bounteous harvest to come of "Fish and plankton, sea greens and protein from the sea." Protein. It's always protein. And cannibalism. Yum!