Tuesday August 18, 2026
CDFW —
Steelhead are among California’s most remarkable fish. Born in freshwater streams, these ocean-going rainbow trout can migrate hundreds of miles to the Pacific Ocean before returning to the very streams where they hatched to spawn. Understanding where steelhead live, how they use habitat, and how many adults return each year is critical to conserving these iconic fish.
“The best way to understand and support this unique species is to monitor steelhead throughout the year using a variety of scientific techniques tailored to each season,” according to Deena Hansen, the California Department of Fish and Wildlife (CDFW) senior environmental scientist supervisor who oversees steelhead monitoring across the South Coast Region for the Department in southern California.
Summer through Mid-Fall: Surveying Young Fish
As weather conditions dry out and stream flows recede during the summer and fall, biologists conduct electrofishing and snorkel surveys to assess juvenile steelhead and resident rainbow trout populations. Occasionally, adult steelhead may spend their summers in freshwater, though it is less common.