Once they are killed they are not utilized. I brought this issue up to the USGS and the Fish and Wildlife Service in the States, as well as DFO in Canada. We're able to operate everything: why not just put out commercial fishery permits for sea lamprey?
The problem is actually a bit more complex than one would think. Mainly at issue is that when you allow people to fish for something, what they will do then is they will take the sea lamprey from one stream, because they don't catch enough, and put it into other streams to make sure they produce enough to make a living. That was sort of the main argument for me—that of course they would do that. We're all human, right? We just want to make money. So if you want a lot of lamprey and you can get only 1,500 from a stream, and your livelihood is depending on it, and nobody sees it, then let's plant lamprey in all those streams.
All kidding aside, though, I talked about this aspect with my colleague. Given that there would be commercial interest and need in Portugal, why not just catch them, put them on ice, ship them overnight, and make money with it? On both sides there would be jobs for people, and obviously there are sea lamprey here.
But there is an added issue here. One, probably neither of the resource management agencies would go for it, because people would just start planting sea lamprey all over the place. Two, I have looked into the very sparse evidence that exists at the present time that sea lamprey, because they're top-of-the-food-chain, feeding on large-bodied fish like salmon, bioaccumulate a lot of heavy metals. Unfortunately, sea lamprey at their adult life stage have so much lead and mercury and what not in their tissue that I think they would pretty much qualify as toxic waste. In all fairness, you couldn't go and peddle it to another country: “Oh, buy some sea lamprey. It's good for you—as long as you eat it only once a month.”