One-Third of American Rivers Have Changed Color Since the 1980s, Studies Say

by Madison Miller

While more and more Americans have been outdoors more in the last year because of the pandemic, they may have noticed a distinct change that’s beginning to happen in our rivers.

Roughly one-third of American rivers have changed from their original color since the 1980s. Like most things, people are to blame.

Shifting to Yellow and Green

The color shift is not slight, either. The shift was so intense that it could be noticed through satellite images since 1984.

According to Geographical Research Letters, 11,269 miles of rivers have become greener. This could also mean they moved on the color spectrum to be closer to violet. Green water, holding a solid 28% in rivers, is due to the water being overwhelmed with algae.

The issue with algae is that it causes oxygen loss and produces toxins. This could be harmful to the ecosystems that exist in the water. Green water is problematic.

Then there are two other major colors associated with colors in rivers: blue and yellow. Blue is often considered water that is seen by most people as clean, fresh, and natural. Right now, only 5% of our rivers are considered blue. Then about two-thirds of the rivers are yellow, which often means there’s an abundance of soil.

Man-Made Climate Change

Why have the rivers in the United States been swapping colors?

Mostly because of us.

The increase in climate change that is a result of people has been continually increasing over the last years and can be detrimental to nature. These man-made issues like fertilizer run-offs, dams, and efforts to fight soil erosion have all lent a hand in the color change. Over time, climate change has also caused water temperatures to increase, which is why algae and other toxic plants could bloom.

According to Tamlin Pavelsky, a professor of global hydrology at the University of North Carolina, the green in the Ohio River is a good indicator of algae becoming a nuisance. This was a result of farm runoff into the water. Less yellow waters mean that soil erosion efforts in the area are working.

A Global Issue

An estimated 180 million tons of waste from mining corporations are getting dumped into oceans, rivers, and lakes around the world, according to Earth Island Journal. The issues with water pollution go beyond just the U.S. In fact, the U.S. has restrictions on things like dumping mine tailings. However, some exemptions have still allowed it to happen. For example, in 2009 the Supreme Court allowed this to happen in an Alaskan lake. There were 7 million tons dumped into the Lower Slate Lake in Alaska, destroying all signs of life.

Sometimes color change can happen seasonally or naturally, but this massive shift in the last few decades suggests a lot of it is far from natural. However, these shifts in color can be used by scientists to warn about environmental change in the future more accurately.

“It shows how most every aspect of our planet is being affected by humans, now including the basic color of our water. That’s pretty profound if you think about it,” Martin Doyle, head of water programs at Duke university, said.

H/T: ABC News, AGU Research