The fisheries did rebound. In the late 1950s and 1960s, we saw a collapse of several fish species.
Well, I wasn't completely clear, in the sense that sea lamprey contributed to it, but they weren't the sole factor. Overfishing was also part of it. We managed to bring sea lamprey densities in the 1960s under control, but that was done at the same time as a lot of lake trout and other species were being raised in hatchery operations and released into the Great Lakes to help those species rebound. That has happened, to some extent.