CalTrout Survey Finds Juvenile Coho In Cedar Creek After Dam Removal

Last year, when California Trout announced a dam removal on Cedar Creek, a tributary of the South Fork Eel River, the project was expected to open up water for returning salmon and other anadromous fish. Recently, CalTrout reported that coho – plus other species have been spotted in Cedar Creek (see above photo).

Here’s more on the sightings:

In August 2023, CalTrout staff conducted a snorkel survey of Cedar Creek from its confluence with the South Fork Eel River, through the former dam site, and up to the Highway 101 crossing. During this survey, 34 juvenile coho salmon were observed, many of which were upstream of the former dam site. Juvenile steelhead and resident rainbow trout were also observed throughout the survey, both below and above the former dam site. 

Previous surveys of Cedar Creek did not routinely detect coho salmon adults or juveniles, and none had been observed in the past 15 years. Although we cannot rule out the possibility that coho had been present during recent surveys, there would have been so few as to not be detectable. 

The origin of the juvenile coho salmon could not be confirmed as coming from adult coho salmon spawning in Cedar Creek or as non-natal juvenile coho salmon from elsewhere in the South Fork Eel River.  While presence of coho salmon juveniles cannot be directly attributable to removal of the barrier, it is highly likely that the increased opportunity for fish passage allowed better access for adult coho salmon if the observed juveniles originated from within the Cedar Creek watershed. If the juvenile coho salmon were using Cedar Creek for non-natal rearing, then access to habitat above the dam would not have been possible if the dam were still present. Thus, dam removal certainly succeeded in providing additional cold-water refugia and rearing habitat to coho salmon in the South Fork Eel River.