The Associated Press recently published a report on how highly prized salmon were dying from the runoff from busy highways—a toxic mix of “dirt, metals, oil and other gunk that washes off highway pavement after rains and directly into Puget Sound.”
Researchers went to work, and here is an excerpt from the AP story:
When that runoff was filtered through a simple mixture of gravel, sand and compost, however, the outlook was much brighter. Salmon exposed to treated water were healthy and responsive, even after 24 hours.
The research being conducted by scientists with NOAA, Washington State University and the U.S. Fish and Wildlife Service offers a promising solution to stormwater pollution, a major problem for Puget Sound and other streams and lakes in the nation.
With pollution from industrial pipes closely regulated, cities and states are more often tackling stormwater runoff that results from everyday activities: oils from leaky cars, pesticides from lawns and other pollutants that wash off roads and sidewalks and into streams and lakes.
Across the country, there's been an aggressive push for rain gardens and other green techniques that rely on vegetation, soil or natural elements to slow and filter stormwater.
"The results are pretty stark," said Jenifer McIntyre, a researcher with WSU who is part of salmon experiment. "So far, what we're seeing is that, absolutely, things like rain gardens are going to be part of the solution.”
…”It’s really promising, showing that rain gardens and bio-filtration are removing the pollutants that are killing the salmon," said Chris Wilke with Puget Soundkeeper Alliance.