DRIVING OUR WAY TO COHO DECLINE
by Paul Pegany, Spring 2019
Photos & video by John F. Williams except where noted
DRIVING OUR WAY TO COHO DECLINE
By Paul Pegany, Summer 2019
Photos & video by John F. Williams except where noted
can rain gardens help save salish sea coho salmon?
Currently, the mortality rate for salmon in Puget Sound is forty to ninety percent.
Several possible causes of coho mortality have been proposed by researchers: food unavailability, predation, even changes in plankton due to climate change. However, pinpointing an exact cause has remained somewhat elusive.
Developed, impervious surfaces: Seattle, WA. Photo by Steve Stolee
Developed, impervious surfaces: Seattle, WA. Photo by Steve Stolee
Recently, a team of researchers led by WSU’s Jen McIntyre exposed coho to stormwater runoff coming directly from a Seattle area freeway.
McIntyre’s team later isolated the chemicals in tire dust, the fine particles that wear from our tires as we drive, as the leading cause of coho spawner mortality from stormwater runoff within the Salish Sea region. Furthermore, these researchers noted that coho are particularly susceptible to the effects of chemicals that leach from the tire dust, more so than other species of salmon.
Simply looking at the black stew of stormwater that flows from a typical urban freeway, it might not be too surprising that coho and other marine species would have high mortality rates. However, one of the key findings of this research shows that when toxic stormwater was filtered using soil infiltration columns, one hundred percent of coho mortality was prevented. Soil infiltration had the ability to capture pollutants and return the water sufficiently clean for coho survival.
See more about salmon in The Currency of Rainfall in this issue.
Photo courtesy of Kitsap Conservation District
From small homeowner gardens that filter rooftop and driveway flows to larger municipal gardens designed to channel runoff from city streets, rain gardens effectively filter toxins from stormwater runoff, including the tire leachate that has proven so harmful to our native coho.
See more about rain gardens and runoff in Rainbows in this issue.
See more about the importance of soil in this issue.
Table of Contents, Issue #3, Spring 2019
Precipitation
by Leigh Calvez, Spring 2019 Photos & video by John F. Williams except where notedBy Leigh Calvez, Summer 2019 Photos & video by John F. Williams except where notedas a transplanted midwesterner, i am fascinated by the precipitation here in the pacific...
Raindrop
by Amy Roszak, Spring 2019 Photos & video by John F. Williams except where notedBy Amy Roszak, Summer 2019 Photos & video by John F. Williams except where notedalthough most of us think of raindrops as tear shaped,by the time we see them falling through the...
Poems-3
Jenifer Browne Lawrence is the author of Grayling (Perugia Press, 2015), and One Hundred Steps from Shore (Blue Begonia Press, 2006). Awards include the Perugia Press Prize, the Orlando Poetry Prize, the James Hearst Poetry Prize, the Potomac Review poetry award, and...
Rainbow
Rain Gardens Help Rain Find Clean Paths to the Sea by Sharon Pegany Photos & video by John F. Williams except where notedRain Gardens Help Rain Find Clean Paths to the Sea By Sharon Pegany, Spring 2019 Photos & video by John F. Williams except where...
Soil
Partners in Sustaining Life by Sharon Pegany, Spring 2019 Photos & video by John F. Williams except where notedUSDA Public DomainUSDA Public DomainPartners in Sustaining Life By Sharon Pegany, Summer 2019 Photos & video by John F. Williams except where...
Soil Pedestals
by Greg Geehan, Spring 2019 Photos & video by John F. Williams except where notedEarly Indicators of Erosion By Greg Geehan, Summer 2019 Photos & video by John F. Williams except where notedwhat does the rain hit?Rain nurtures Salish forests, and the forest...
Currency
by Ron Hirschi, Spring 2019 Photos & video by John F. Williams except where notedBy Ron Hirschi, Summer 2019 Photos & video by John F. Williams except where notedKITSAP COUNTY SUPPORTS A FAIR NUMBER OF YEAR-ROUND STREAMSUnlike most other western Washington...