You might have seen the recent press coverage about stormwater pollution killing coho salmon in Puget Sound. Polluted stormwater runoff — the cocktail of heavy metals, oil and petroleum products, fertilizers, and other waste that washes off roads and hard surfaces when it rains — is especially and tragically toxic to coho. And where the pollution is worst, it kills fish before they can spawn, putting many populations in urban areas around the Puget Sound basin at risk of disappearing.

For the last three years Soundkeeper has tracked salmon returning to Longfellow Creek, in West Seattle. The coho come back to Longfellow in the fall, when there’s frequent rain, and many of them are met with a heavy dose of pollution. Although the fish are otherwise healthy, every year we document between 45-90% of the females that die before they spawn. Often we’ll we see fish displaying dramatic symptoms. Affected salmon swim in circles, opening and closing their mouth as if gasping for air, and act disoriented or completely lose their ability to swim. Death usually follows within hours.

This year at our annual Duwamish Alive! River Cleanup event, organizers spotted a dying fish in the Duwamish River, a much larger waterway. The video from the event is a very graphic depiction of these effects.

It’s rare to see the wildlife impacts of pollution so clearly. Polluted stormwater runoff doesn’t just threaten coho salmon. It’s bad for the entire ecosystem, including all of us. The salmon are just one indicator of a problem that threatens our health and the health of the entire Puget Sound watershed. A recent study found that pollution in air, water and soil caused nine million premature deaths nationwide in 2015, more than AIDS, tuberculosis and malaria combined.

Researchers don’t yet know what specific chemical is in the stormwater that makes it so deadly to coho. But we do know how to use smarter development strategies and green infrastructure to help filter and slow stormwater runoff, reducing pollution and protecting homes and public utilities from flooding. This is the future we, the salmon, and the entire Puget Sound deserve.

Fortunately with Soundkeeper’s advocacy we now have these standards written into stormwater permits and building codes, which means newer development will begin to have less impact. But clearly our existing roads, highways, rooftops and parking lots are contributing to the majority of the problem. Significant additional investment is required to protect water quality, save our salmon and defend our communities.

It’s time to get to work.