The Fish Site
30 April 2015
US – Decisions on how best to open up tributaries into the Great Lakes for fish migration have recently been made easier, as researchers have released a tool to help optimise fish habitats at the lowest cost.
Researchers at the University of Wisconsin-Madison Center for Limnology created the first map of all the road crossings and dams blocking the tributary rivers that feed the five Great Lakes a few years ago.
These tributaries serve as migratory highways, providing fish like walleye and lake sturgeon access to headwater breeding grounds.
“It painted a pretty horrifying picture of what it’s like to be a fish in the Great Lakes Basin,” said Peter McIntyre, who led that study.
“Seven out of eight river miles are completely inaccessible to the fish.”
The team’s new study describes a powerful new model to help decision makers maximise the cost-effectiveness of barrier removal projects that also restore migratory fish habitat.
Recent years have seen growing efforts to chip away at the 7,000 dams and 230,000 road crossings that disrupt the basin’s 661 tributaries.
Tom Neeson, lead author of the study, said: “If you’re going to spend money on barrier removal projects, isn’t it critical to know which projects are going to give you the biggest bang for your buck?”