Certainly. Again, as Anne has pointed out, I don't really see it as a change in definition. It's simply a matter of clarity that when people think about something like a non-native species, if there was a moniker, people were thinking everything was harmful and then they were finding examples where they weren't. Judicious stocking of species to create fisheries, for instance, could be of benefit.
So looking at some of the harm that we see from things, there can be very direct harm, such as predation, feeding on another organism. There can be disease transmission and other things, and loss of habitat. Zebra mussels and quagga mussels have fundamentally changed the way the Great Lakes ecosystem operates, having in essence hardened the bottom of the lake. They've intercepted the movement of material. That food ultimately feeds the rest of the food web, so when we look at the harm it can be things that are very observable and direct and immediate to the public and to other people, and there can be things with delayed responses. Some of these delayed responses have really required us to broaden our thinking about the invasive species and accept that the level of harm is not always something that is immediate and has a direct visible economic effect.