Helps Break Down Barriers, Get “Bigger Bang for Your Buck”

by Kelly April Tyrrell, Limnology News – Number 24, Fall 2015

FishWorks will let scientists and resource managers prioritize removal efforts. Photo courtesy Wisconsin Institute for Discovery

A few years ago, researchers, led by the CFL’s Pete McIntyre, created the first map of all the road crossings and dams blocking rivers and streams that feed the Great Lakes. 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,” says McIntyre, an assistant professor in the center, who led that study. “Seven out of eight river miles are completely inaccessible to the fish.”

A new study from the same team, published earlier this year in the Proceedings of the National Academy of Sciences, describes a new model to help decision makers maximize the cost-effectiveness of barrier removal projects that 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.

Notes Tom Neeson, lead author of the study, “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?”

For example, a $70 million investment to remove 299 dams and 180 road crossings — coordinated across the entire Great Lakes Basin — could double the amount of habitat accessible to migratory fish, the model finds. That is roughly the amount spent for such projects over the last decade.

“The bottom line is, you don’t have to spend that much money to get a massive return in terms of the amount of habitat accessible for fish,” says McIntyre.

McIntyre’s group used the model to launch a free, online tool, called FishWorks, to help select barrier removal projects that open more fish habitat at lower cost.

Marrying high-quality data with high-power computing, the researchers found that for a given amount of money, barrier removal projects coordinated across the entire basin are nine times more cost-effective than projects completed at county or local watershed levels.

“It works fine for decisions about Lake Michigan and Lake Superior to be fairly independent of one another,” says McIntyre. “But as soon as you get below that level of coordination — to the county or watershed scale where a lot of decisions are made — the funding gets spread too thinly, and the model shows you’re going to underperform drastically.”

The study also showed that annual distribution of funds over a decade is 10 times less efficient than a single payout of the same amount.

McIntyre illustrates this with an example: “You can give a fishery manager a chunk of funding from a major restoration initiative, but if in year one she can’t afford to tackle the dam at the mouth of the river, then what good is it to upgrade an affordable road crossing upstream when all the fish are still bumping their noses against the dam?”

While coordinating projects can present challenges, it is not unprecedented in this region, where diverse partnerships under the Great Lakes Water Quality Agreement and the Great Lakes Fishery Commission have been very successful, the researchers say. Major restoration efforts have also been coordinated under the Obama administration’s Great Lakes Restoration Initiative, which has provided almost $1.4 billion since 2010.

Note: Tom Neeson was a CFL postdoc when this study was originally published. He is now a new father and Assistant Professor at Univ. of Oklahoma.  Currently, CFL postdocs Allison Moody and Austin Milt work in the McIntyre group on FishWorks projects.