biorock artificial island

In his book, The Millennial Project: Colonizing the Galaxy in Eight Easy Steps, Marshall T. Savage proposed building "seacrete" (ions deposited from sea water) floating islands to be colonized along the equator to relieve stress on the land as populations grew past 10 billions. His method of making seacrete did not work. However, Prof. Wolf Hilbertz developed a technique that makes biorock from sea water that is as strong or stronger than typical concrete, starting with a structure of rebar and welded wire mesh. Principally calcium, magnesium and bicarbonate to precipitate and adhere to that structure.

I propose a kind of 3d biorock printer to make the islands Savage described. He suggested Ocean Thermal Energy Conversion (OTEC) that is more expensive than solar PV. These islands could be used to house people displaced by rising oceans. Given robots are taking our jobs, they may as well build floating cities nice enough to entice people to move onto them. Based on developments in the United Arab Emirates, luxury can be provided in almost any environment. Given these floating islands would be positioned along the equator, their environment would be similar to the UAE.