This is incredible - does the closed loop make the fish or plants more susceptible invasive disease? I imagine it requires far less, or no?, pesticides and whatnot - but if something damaging does get into the closed system does it wreak greater havoc?
Good question! This is indeed one of the worries of the place. The greenhouse has a wide variety of species, so they aren't that sensitive. However, the fish is all the same. One safety measure is that the species of fish they use, Tilapia, is a pretty resistant species. They are less sensitive to environmental changes and diseases. Either way they do monitor this closely.