Coho Salmon Affected by Urban Pollution

A toxic cocktail of oil, gas, brake dust, and urban sludge that contaminates the Pacific Northwest’s river system during rainstorms can kill the region’s endangered coho salmon in a few hours, a new study has found

 In the same study, conducted by the National Oceanic and Atmospheric Administration Northwest Fisheries Science Center in Seattle, researchers found that if the same pollution was run through a simple filtration system of sand and soil, the toxic effect on fish was practically eliminated.

“Untreated urban runoff is very bad for salmon health,” Julann Spromberg, a research scientist at NOAA, said in a statement. “Our goal with this research is to find practical and inexpensive ways to improve water quality. The salmon are telling us if they work.”

For more than a decade, scientists have known that urban runoff was most likely damaging fish species such as the coho salmon, which were dying off in high numbers before they could spawn. One report focused on West Seattle’s Longfellow Creek, where each year, up to 90 percent of the female salmon were dying before spawning.

In their initial experiments, the scientists mixed crude oil, metal, and other substances to make a synthetic “urban runoff” cocktail. But when they ran it through the test tanks, the fish did fine—no mortalities.

So the scientists decided to go to the source, capturing actual runoff from a downspout along highway 520 near Montlake, Washington. When the team ran that through the tanks, the fish became weak and sick—some died within three hours, and most were dead by the following day.

It was an unexpected result, and the scientists theorize it could show that yet-unknown toxins from automobile exhaust, metals, and other substances coating roads could be the real culprits behind the fish declines.

Source: Yahoo

Read More Related Content On This Topic - Click Here

Media

Taxonomy

• Research
• Pollution
• Water Management