I wonder if this holds lessons for farming in space? They're both rather closed environments, though the sea obviously provides extra water (and more). There won't be cloudy days in space!

For those worried about negative environmental effects of structures on the seafloor, people actually sink old ships to create artificial reefs: https://oceanservice.noaa.gov/facts/artificial-reef.html

Though if this was industrialized too much, I bet delivering a bunch of chemical fertilizers probably would create environmental problems.