Science activity
Science activity #49848, updated 29 April 2022

Impact of Urbanization on Chinook Salmon, Steelhead Trout, and Their Prey: a Case Study of the American River

Description / purpose

The American River provides spawning/rearing habitat for Chinook salmon and steelhead, yet passes through 30 miles of dense urban development. Urban runoff contains pyrethroid insecticides that cause the river to become toxic to standard testing species with every storm event. This study will go beyond observed toxicity, and address toxicity to chironomids, caddisflies, and mayflies, key diet components of juvenile fish in the river. A bioenergetic model will be used to evaluate effects of food web changes on young salmonids. Our key approach is the use of river-side systems with flowing river water that allow us to replicate realistic pesticide exposures, while controlling other variables. We will determine sensitivity to pyrethroids and fipronil of salmonid prey taxa, and expose them, as well as standard testing species, in the flow-through systems through six storm events. We will maintain experimental streams containing riverine benthic invertebrate communities, and measure response to the pyrethroid pulses. To supplement analyses of the indirect, food web-mediated effects, we will measure endocrine effects through vitellogenin induction in salmon and steelhead. Finally, one treatment includes river water from which organic contaminants have been removed by activated charcoal, to help establish cause of toxicity. The goal is to determine if known toxicity in the American River is a threat to benthic invertebrates and, through the food web, to salmon and steelhead.

Linked science activities

None specified

Activity status

  • Awarded / Initiating (2011)
  • In progress / Ongoing (2011 - 2014)
  • Complete

Funding summary

Total allocated funding: $600,000

Label Value
Contract # or labor code 2046
Implementing organization University of California - Berkeley [UC Berkeley]
Funding organization Delta Stewardship Council
Funding Source Proposition 84
Date of award 2011-07-01
Date of fiscal year-end Not provided
Total award amount $600,000
State type of obligation Not provided
Federal type of obligation Not provided
Reimbursability Not provided
Procurement mechanism Not provided


Delta regions

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