Most krill are about 1–2 centimetres (0.4–0.8 in) long as adults (so can’t be contained by nets in the ocean like farmed fish are)
The total global harvest amounts to 150,000–200,000 tonnes annually vs salmon at just under 190,000 tonnes — so they’d have to have massive land space for huge tanks to breed krill in
I don’t think they can be farmed because …