Healthy salmon by use of wrassefishes in Norway:

US$200 paid for each live fish weighing 0.3 kg!

Google this:(fvn.no > Ny oppdrettsfisk er gull verdt) This money will be paid in Norway for delivery of wrasse-fishes to the salmon farms! These fishes eliminates the need for chemicals and antibiotics in salmon farming, because they eat lice (Gyrodactilus salaris) directly from the skin of salmon.

See 2 friends diving among this kind of fish at the Norwegian coast:

DIVING IN BISHOP HARBOR