I think there are products available that, if used properly and according to the label instructions, would have no significant impact on non-target organisms.
Can the sea lice be eliminated completely? Probably they cannot. Sea lice come from a group of animals—parasitic copepods—that have been around for a long time, and there are many hundreds of different species. If you are farming fish in the ocean, I think that sea lice will always be around, but I think that sea lice could be managed.
As I said earlier, if you look at sea lice numbers on the west coast you see that the numbers are managed very well within the context of a farming activity. Treatments are minimal at best, and there's very little clinical damage to farm stock, if any. It's very rare that a veterinarian, for example, would treat fish because the fish are clinically impacted to the point that they need significant intervention. That would not be the case in other countries around the world, where people treat because if they didn't, serious harm would occur to the farm stock.