Tuesday February 21, 2023


On a winter’s morning, three biologists wade into the American River, leaving their motorboat docked along an embankment. Their directive is straightforward: Keep your eyes peeled for steelhead redds. 

“A redd is essentially a nest that a salmon builds to lay their eggs,” explains Mollie Ogaz, a biologist with Cramer Fish Sciences. “Then, they’re fertilizing there in the gravel and they incubate, and then they hatch.” 

Right now, it’s survey season for steelheads. These surveys typically begin in January and go until April, lining up with the species’ spawning season. This year, these efforts faced some delays; the river is more turbid than usual after January’s succession of intense storms. It’s taken weeks for the water to settle enough that researchers can conduct their search – sometimes on foot, scanning the river floor as they stand hip-deep in it, or by peeking over the side of their boat.

Ogaz says these redds look a little like ice cream cones. A salmon will dig a small ditch into the river floor with its tail. Sediment that’s kicked up in the process will leave a cone-like trail behind the ditch in the direction of the river’s flow. 

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