Crossposted from Headwaters

A cold April rain fell on the Green River but the research carried on. Chris Gregersen and Dan Lantz, ecologists from King County’s Science Section, floated down the river’s mainstem and poked into its tributaries listening for loud, electronic beeps from their tracking antennas. Each beep meant a juvenile Chinook salmon (Oncorhynchus tshawytscha) – previously tagged by our team or other researchers – was swimming below. Every beep was a reason to celebrate, especially in weather like this.

But as they paddled up Kent’s Mill Creek in search of more Chinook, Chris and Dan noticed something strange in the water. On both sides of their small craft, distressed coho salmon (Oncorhynchus kisutch) were floating, circling, and flopping on their sides near the surface. The ecologists immediately recognized this behavior as a possible symptom of urban runoff mortality syndrome (URMS). This tragic cause of death is not uncommon for adult coho spawners in urban waterways polluted by the toxic tire chemical 6PPD-quinone (6PPDQ). Read more.