As the Biden administration prepares to make the biggest investment in U.S. infrastructure in more than a decade, there’s much discussion about how systems like roads, bridges and electric power grids affect people’s daily lives. Here’s an angle that’s received less attention: Wildlife depends on infrastructure too.

I’m studying how human-made structures affect salmon migration between freshwater streams and the Pacific Ocean. Washington state is home to five species of Pacific salmon: chum, pink, and the locally endangered sockeye, coho and Chinook. Salmon are commercially, environmentally and culturally important to the Northwest, and many people here follow their migrations.

To travel out to the sea and back inland to spawn, salmon have to pass through thousands of culverts — tunnels that carry streams beneath roads or railways. When culverts fall into disrepair or are blocked, water might still be able to pass through, but fish can’t. This can be a death sentence to fish that migrate.

Washington state has thousands of culverts that need repairs. Salmon are in critical decline, and fixing culverts could increase fish migration and reproduction.

This issue isn’t unique to the Pacific Northwest. Atlantic salmon in the U.S. Northeast are listed as endangered under the Endangered Species Act. State and federal agencies have undertaken significant habitat restoration and conservation efforts, particularly in Maine, to boost salmon populations. These initiatives, which are projected to cost hundreds of millions of dollars over the coming decades, involve actions such as removing river dams. New infrastructure investments could help salmon, as well as people, get where they need to go.

Most salmon are anadromous: They are born in streams, dine on aquatic insects and then make their way downstream to live the majority of their adult lives in the ocean. Then, one to seven years later, depending on the species, they return to the streams where they were born to reproduce.

Read the full article about infrastructure impacting wildlife by Ashlee Abrantes at GreenBiz.