When water from that feeder canal coursed into the Welland Canal at the crest, it then flowed in two directions in the Welland—south toward Erie and north toward Ontario. So a lamprey, nature-built to always swim upstream, would have sensed the downstream switch in current at the crest and headed into the feeder canal and, the theory goes, likely would have ended up in a tangle of upland streams and soggy ditches draining agriculture lands—a biological dead end and, if the story ended there, a life saver for fish in the upper Great Lakes.
