ERRP estimated that 2000-3000 Chinook salmon entered the Eel River in the first half of October 2016, then we got two feet of rain in some parts of the basin! After a slow start, there are high densities of spawners in many locations in headwater areas, indicating that we have an increase over last year’s run. Check out videos posted at the ERRP Vimeo channel. News of fall Chinook surveys is also posted regularly by Eric Stockwell on the ERRP FaceBook page.
ERRP began lower river dives surveys in 2012 after successful dives had been conducted in 2010 and 2011 by other groups. Methods used are the same as U.S. Forest Service and California Department of Fish and Wildlife summer steelhead and spring Chinook techniques used in the Klamath-Trinity basin and in the Central Valley. Teams of divers swim abreast through pools and count fish that pass them moving upstream. Methods are fully described in our annual reports. Findings in Butte Creek in the Central Valley indicate that divers counting from the surface tend to slightly under-estimate the number.
Read ERRP Reports for Lower Eel River Dive Monitoring of Chinook Salmon
The upper South Fork Eel River has one of the last large populations of coho salmon and they spawn in tributaries from the headwaters near Branscomb and west side South Fork Eel River tributaries downstream such as Hollow Tree, Indian Creek and Sproul Creek. In October 2016, ERRP once again found coho salmon juveniles in upper South Fork Eel tributaries while retrieving temperature probes (see video). Steelhead juveniles were wall-to-wall in Red Mountain (see video) and Cedar Creek (see video), which flow from the Red Mountain Wilderness Area.
Steelhead yearling in lower Red Mt Creek, October 2016. (see video),
Steelhead on the left, coho salmon on the right. Dutch Charlie Creek, SF Eel River.
School of fall Chinook salmon in Fortuna pool. 10/13/16 See video
A group of coho salmon fry in Dutch Charlie Creek
ERRP fish watchers throughout the Eel River Basin have been observing lamprey spawning in the upper Van Duzen, the North Fork, the Middle Fork and in all reaches of the South Fork. On May 1 we saw lamprey redds and numerous dead lamprey in the lower East Brach South Fork and in the main South Fork. The Middle Fork Eel has seen extensive spawning in the reach below the Black Butte River on the Capistran Ranch. We documented Pacific lamprey spawning in an upper South Fork Eel tributary on May 18. See video.
The origin of this year’s abundance is a year class circa 2010 and 2011 during a period of wet winters and springs. Twenty percent of the diet of the Sacramento pikeminnow is Pacific lamprey larvae. Decreased predation by pikeminnow due to high flows and fluctuation in their population may have facilitated lamprey recovery.
The Pacific lamprey spend three to four years as a blind larva living in sand and mud in the margins of pools, where they eat invertebrates. They swim out to sea and live there for 2-3 years. They use their suction cup mouths to hook onto fish, or even whale,s and feed on their blood, which is not usually fatal to the animal being parasitized. Able to ascend streams further than steelhead by using their sucking disc to wriggle up water falls, lamprey have access to a vast amount of habitat. Like salmon, lamprey die after spawning.
A Pacific Lamprey and its circular nest.
Lamprey mouth showing sucking disc.
Many Eel River watershed residents love the salmon and relish the opportunity to watch them migrate and spawn, so we have an active network of volunteers who report what they see.
Salmon watchers observe migration at vantage points like bridges and count the number of fish they see passing in a time period. Others, who live closer to spawning areas, report when fish begin to build redds and count the number of redds that they can see.
Volunteers can also provide photos and video of salmon migrating and spawning as a means of documenting the run. Let us know if you want to share your observations.
During the prolonged period of recent drought, low flows resulted in large amounts of spawning in lower river reaches best accessed by boats.
ERRP fall Chinook monitoring coordinator Eric Stockwell leads these surveys when they are possible, recording the location of redds, the number and condition of fish on the redds, and the occurrence and length of carcasses.
In 2015, Eric mapped the redds on the lower Eel River from Dyerville to Scotia and these results will be made available soon.
We also note the abundance of the native Sacramento sucker, which appeared to decline sharply after the pikeminnow were introduced to the river, but is now showing signs of coming back.
These suckers were seen in an isolated pool in Soda Creek, Upper Eel River.