We tend to think of the planet’s environmental problems as relatively recent issues. Carbon emissions from cars or factories, cutting down rainforests, or things like oil spills. But humans have been interfering with nature for pretty much as long as we’ve been around, and just because we couldn’t destroy the environment at the same scale we do now, doesn’t mean we weren’t damaging things centuries or millennia ago.
Lewis and Clark, the famous explorers, made their way through the Pacific Northwest in the early 19th century, and they found the rivers there teaming with steelhead trout and beavers. But that discovery led to fishing and trapping, which almost destroyed both species. By nearly wiping out beavers, we had a huge negative impact on the rivers in which they built their dams.
These days we spend billions on restoring rivers, but we’ve largely ignored the value of getting help from beavers to do this. A study by researchers from Utah State University found that, by creating analogs to beaver dams, we could get beavers to build more, and more successful, dams throughout the river. That in turn led to rising water levels (which is good), as well as more successful fish populations.
It shouldn’t come as much of a surprise that beavers have a positive effect on the rivers in which they live. After all, they’ve been building those dams for a very long time, and the rivers were a lot healthier when Lewis and Clark stumbled upon them. The relationship that beavers have with rivers is an excellent example of how nature is full of complex systems that are deeply and intricately interwoven. You can’t remove one piece, like a species, without having an impact on the whole system. This is why it’s so important to conserve species, both plants and animals, as much as possible.