Think of it this way:
Shrimp industry makes heavy use of algae, artemia, zooplankton and bacterial cultures to flourish.
Maintaining/stenthening surrounding mangrove areas are also part of the IMTA for shrimp farming.
So – these cultures are maintained integrated and are at different trophic level with a view to supporting protein growth and efficient conversion by a domesticated marine arthropod – providing one successfully healthy human food output – namely shrimp.