As part of this new coordinated area management plan, we're working on sharing the kind of data that comes from the farms and the data we collect in the field, to put them together to do exactly what you described.
I can tell you that in years when the sea lice infestations were very high, the numbers of the sea lice on the farms were about five, six, or seven motile lice per fish. From the perspective of farm husbandry, this would not be considered a problem for the health and well-being of the farmed fish.
However, those numbers correspond to a major problem for the health and well-being of the wild juvenile fish that are migrating by. The reason for this is that the number of fish in a farm is so high--between half a million and a million--and sometimes there are several farms on a migration route, so that the actual production of lice, even if it's only three or four per fish.... If you multiply that by two million or three million fish, that's a lot of lice in the environment.