I think it stems largely from an information gap, a data gap. We have been focusing our management efforts on lakes, on large and small lakes that are readily accessible. We know that a lot of fishing goes on in rivers. They tend to be much more difficult to study, which is partly why management is focused on lakes.
It was really an acknowledgment of that information gap, but also of their biological importance to those systems as well. I think that's probably the short answer.