In the course of spawning, salmon are uplifting sediment and changing the course of watersheds.
A study from Washington State University finds that the act of mating by salmon is having an impact on stream beds and watersheds, creating changes to the natural environment. As described in Lab, the report "Sex that moves mountains: The influence of spawning fish on river profiles over geologic timescales"by researchers Alexander K. Fremier, Brian J. Yanites, and Elowyn M. Yager describes how the fish can alter the landscape after generations (counted in millions of years) of spawning.
Alex Fremier, lead author of the study and associate professor in the WSU School of the Environment, said female salmon "fluff" soil and gravel on a river bottom as they prepare their nests, or redds. The stream gravel is then more easily removed by flooding, which opens the underlying bedrock to erosion.
"The salmon aren't just moving sediment," said Fremier. "They're changing the character of the stream bed, so when there are floods, the soil and gravel is more mobile."
FULL STORY: Salmon Sex Linked to Geological Change
Dams on the Way Out on Two California Rivers
The largest dam removal project in U.S. history is about to commence on the Klamath River. Due to a recent development, a dam on the Eel River is also on expected for decommission.
Snohomish River Gains Legal Rights
A new law in one Washington town enshrines the river’s legal right to “exist, regenerate, and flourish.”
Last Dam in Klamath River Removal Project Comes Down
Salmon can now move freely along the river and its tributaries for the first time in over a century.
What ‘The Brutalist’ Teaches Us About Modern Cities
How architecture and urban landscapes reflect the trauma and dysfunction of the post-war experience.
‘Complete Streets’ Webpage Deleted in Federal Purge
Basic resources and information on building bike lanes and sidewalks, formerly housed on the government’s Complete Streets website, are now gone.
The VW Bus is Back — Now as an Electric Minivan
Volkswagen’s ID. Buzz reimagines its iconic Bus as a fully electric minivan, blending retro design with modern technology, a 231-mile range, and practical versatility to offer a stylish yet functional EV for the future.
Healing Through Parks: Altadena’s Path to Recovery After the Eaton Fire
In the wake of the Eaton Fire, Altadena is uniting to restore Loma Alta Park, creating a renewed space for recreation, community gathering, and resilience.
San Diego to Rescind Multi-Unit ADU Rule
The city wants to close a loophole that allowed developers to build apartment buildings on single-family lots as ADUs.
Electric Vehicles for All? Study Finds Disparities in Access and Incentives
A new UCLA study finds that while California has made progress in electric vehicle adoption, disadvantaged communities remain underserved in EV incentives, ownership, and charging access, requiring targeted policy changes to advance equity.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
City of Albany
UCLA Lewis Center for Regional Policy Studies
Mpact (formerly Rail~Volution)
Chaddick Institute at DePaul University
City of Piedmont, CA
Great Falls Development Authority, Inc.
HUDs Office of Policy Development and Research