Get your money’s worth—UW program to maximize cost effectiveness of Great Lakes restoration projects

By: Margaret Van Meter

MADISON—Researchers from the Center for Limnology at the University of Wisconsin-Madison began mapping road crossings and dams blocking the tributary rivers that feed the Great Lakes basin years ago. The rivers serve as migratory highways for numerous species of fish in search of breeding grounds.

Over the years, humans have disrupted the natural flow of migratory fish life cycles by implementing damns and road crossings.

Migratory fish species including walleye and lake sturgeon carry out their life cycle in a diversity of freshwater habitats. Using rivers to access other parts of the lakes, these fish often migrate to spawning areas to reproduce.

A number of these species contribute to commercial, recreational, and tribal fisheries worth approximately seven billion annually.

The team mapped over 7,000 dams and 230,000 road crossings obstruct fish migration patters in the basin’s 661 rivers.

The result of the project was an enormous database that included the location, passability, and potential removal cost of barriers within the Great Lakes region.

“It’s painted a horrifying picture of what it’s like to be a fish in the Great Lakes basin, said Peter McIntyre, the UW professor that spearheaded the mapping project.

“Seven out of eight river miles are completely inaccessible to the fish.”

Restoration projects coordinated across the basin have begun to degrade barriers to reestablish fish habitats and associated ecosystem services.

“If you’re going to spend money on barrier removal projects, it’s critical to know which projects are going to give you the biggest bang for your buck,” said Tom Neeson of the UW Center for Limnology.

The idea for a new project was prompted—a simple model that would allow decision makers to maximize results of barrier removal projects without spending too much money.

We need the biggest bang for our buck

Agencies looking into restoration projects have limited budgets. Removing only a few barriers economically sensible.

“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 to fish,” said McIntyre.

“There should be a way to determine which barriers would be the most cost effective.”

It comes down to deciding which barriers would give them the biggest bang for their buck.

Using mathematical models, optimization methods can guide decisions about restoration projects in the basin.

A tool in the works

UW computer science professor Michael Ferris collaborated with McIntyre’s team to turn the original database into a publically accessible online tool called FishWerks.

The system takes the same information on barrier passability, removal cost, and habitat gain from McIntyre’s first project to direct users on optimizing investments.

This tells users which barrier’s removal would result in the greatest increase in fish habitat for a given dollar amount.

Underlying complexities within the program simplify a complicated problem.

“We needed to account for cumulative passability,” said Ferris. “If one barrier is changed, it changes the passability of other barriers upstream.”

Ferris and a team of Optimization scientists from the Wisconsin Institute of Discovery (WID) created a model to account for cumulative passability.

Optimization is the process of making something fully perfect or effective as possible. Employing mathematical models, scientists discover more efficient ways to control and manage systems.

Working with WID postdoc Steve Wangen, the model could be changed into an online tool that proved relatively easy to navigate.

FishWerks from the public eye

Accessing the public website is simple. After continuing as a guest login, users view barriers overlaid on a Google map. A menu on the side allows access to multiple filters including passability and removal cost.

The tool has proven to be useful to many local resource managers. Even with minimal training, the easy-to-use interface allows users to choose barriers to assess cost effectiveness.

“The program really takes an interactive approach to find the best solution that you need specifically,” said Wangen.

McIntyre used the model to account for a $100 million budget to find that the area for breeding habitat for migratory fish could be doubled.

Room for refinement

FishWerks launched in 2015 with the intention of improvement from user reviews. To ensure that the most accurate information is available, the program relies on the assistance of the public.

If users know updated information about barriers, including passability or cost of removal changes, requests are submitted through the program.

Administrators can then take in the new information updated by local sources and add it to the primary database, allowing for a more accurate and useful program.