Yes. First of all, there was just a sense of wonder when I got to read all of this stuff; there were a couple of hundred papers I had to chug through. And yes, it is extraordinary that they manage to find a host. It's also very interesting about how fast our ability to look at the effects of currents and wind on these tiny particles is; you have to remember that this is going way beyond anything we knew about current movement, about the movement of water, and yet suddenly that's very important, so we have to learn and create models.
Ken Brooks' theories are based on mathematical modelling, in which you take the best information you have, create a model, feed the model with the information, and come out with a conclusion about what you think might be happening. There are other mathematical models, and there are quite a few from Europe, where perhaps the fjords are different, so you can't really extrapolate. So I think we're maybe 60% of the way to understanding how a louse might get from A to B.
Nevertheless, as Bill says, if the salmon farms have a lot of lice on their fish and they're amplifying the numbers of lice that could come from the wild and they're dumping out there, then again, the precautionary approach is to say, okay, this may be causing a problem, so let's see if we can reduce them on the farms, which is, I think, what is starting to happen.