The Coho salmon are splashing and rolling their way up Seattle's Longfellow Creek.
It's a success story. Several groups helped restore the neglected creek over the last 10 years. They improved passage by uncovering sections of the creek and installing wider culverts and bridges. They restored some of its meandering course and installed large chunks of trees and stumps that were lost when West Seattle's industrial area and neighborhoods were carved out of the forest.
Coho responded right away and started migrating up the creek to find suitable spawning areas, lay their eggs and die leaving behind a nutrient-rich carcass. Unfortunately many will not survive long enough to complete that life cycle.
"After a rain storm we will find them either sick or dead," said WSU Extension Biologist Dr. Jennifer McIntyre, who walked up the creek Thursday inspecting salmon dead or alive.
"They didn't have a chance to spawn," said McIntyre as she held up a female carcass full of eggs.
McIntyre said evidence is mounting that toxic chemicals in storm water runoff is killing them when they come up Longfellow Creek.
"Every time it rains, we'll find dead fish or sick fish," she said.
Puget Soundkeeper Chris Wilke has been inspected the creek too. He said the solution to this problem is already known.
"Filtering the storm water, doing smart development with techniques like rain gardens, pervious pavement have been shown to work," said Wilke, whose group has successfully created new rules requirement developers to adopt such techniques.
He said Coho are victims of their own instinctual design. They are compelled to head upstream when the rains come and are most sensitive than other salmon to the contaminated storm water the rains flush downstream.
A highly urban stream like Longfellow Creek may never completely escape the challenges of toxic storm water runoff but some salmon get the job done each year and that will keep them coming back generation after generation.