More on economic gardening: http://www.andrewalexanderprice.com/blog20130715.php#.W3sAZ5NKiRc
Podcast asking if humans could live in underwater cities: https://www.bbc.co.uk/programmes/w3cswvwz
BBC
BBC World Service - CrowdScience, Could Humans Live in Underwater Cities?
Could oceanic cities become a reality and how might they be built?