To be fair, it doesn't look like this was entirely fiction. Here's what Wiki has to say on the subject [1]:
> Interest in the potential exploitation of polymetallic nodules generated a great deal of activity among prospective mining consortia in the 1960s and 1970s. Almost half a billion dollars was invested in identifying potential deposits and in research and development of technology for mining and processing nodules.
And in a few cases they actually succeeded in extracting some metals:
> In the late-seventies, two of the international joint ventures succeeded in collecting several hundred ton quantities of manganese nodules from the abyssal plains (18,000 feet, 5.5 km + depth) of the eastern equatorial Pacific Ocean. Significant quantities of nickel (the primary target) as well as copper and cobalt were subsequently extracted from this "ore" using both pyrometallurgical and hydrometallurgical methods.
A lot of R&D money was sunk into this before it even had a hope of commercially viable (and it still isn't to this day), but it wasn't a hoax either.
> Interest in the potential exploitation of polymetallic nodules generated a great deal of activity among prospective mining consortia in the 1960s and 1970s. Almost half a billion dollars was invested in identifying potential deposits and in research and development of technology for mining and processing nodules.
And in a few cases they actually succeeded in extracting some metals:
> In the late-seventies, two of the international joint ventures succeeded in collecting several hundred ton quantities of manganese nodules from the abyssal plains (18,000 feet, 5.5 km + depth) of the eastern equatorial Pacific Ocean. Significant quantities of nickel (the primary target) as well as copper and cobalt were subsequently extracted from this "ore" using both pyrometallurgical and hydrometallurgical methods.
A lot of R&D money was sunk into this before it even had a hope of commercially viable (and it still isn't to this day), but it wasn't a hoax either.
[1] https://en.wikipedia.org/wiki/Manganese_nodule#Proposed_Mini...