BOB HIRSHON (host):
Restoring salmon and herring runs. I’m Bob Hirshon and this is Science Update.
The springtime migration of millions of salmon, herring and other fish upstream to spawn has all but ended in many parts of the Northeastern U.S., mostly because of the construction of thousands of dams. In the journal Bioscience, fisheries biologist Steven Mattocks and his colleagues at U. Mass-Amherst document the nearly four- hundred-year history of dams, how they blocked fish runs, and changed entire ecosystems.
STEVEN MATTOCKS (Massachusetts Division of Wildlife and Fisheries and U. Mass-Amherst):
When we just look at a dam we just see the dam, the waterfall, an impoundment, and we see a stream below. But you know these little effects that the dams have on not just fish but other organisms can really spread much further than the one system that you’re looking at.
Story by Bob Hirshon