Eel River Salmon Restoration Project

December 10, 2007


The Eel River Salmon Restoration Project has monitored portions of the South Fork Eel River since 1983. Our survey work focused mainly on salmon and steelhead populations. Walking the creeks during spawning season (November through March) and counting fish and redds (fish nests) is one way to track adult population trends. As well, we used various "downstream migrant" (DSM) fish-trap designs, allowing us to monitor natural production of salmon and steelhead in their native habitats. In addition, the DSM trap allows us to study "nongame" species (fish, amphibians, reptiles and crayfish) as well. From 1983 to 2005 we operated a fyke-entrance adult fish trap and weir system on Redwood Creek. This adult trap site allowed us to gather measurements from steelhead, coho salmon, Chinook salmon, and chum salmon returning to spawn. This fish trap allowed us to take fertilized eggs for our small-scale natal conservation hatchery and enabled us to supply fertilized salmon eggs to local school children for educational purposes. Sadly, due to recent government policy decisions, we are no longer operating the adult fish trap to collect data and provide salmon eggs to local area school children.

	DSM trapped fish Photo: Mark Zuspan, CA Dept. of Fish and Game

Since 1986, the Eel River Salmon Restoration Project has been involved in developing and using various DSM traps. The geographic range of our DSM trapping has ranged from Bull Creek tributary to the lower-most South Fork Eel River, upstream to the Benbow Lake Area. One year we even assisted sampling the Benbow Dam fish ladder itself. As of late, our DSM trapping has been limited to Sproul Creek, a tributary just downstream from the Benbow Lake dam. Monitoring in Sproul Creek has now provided nine years of continuous information (1999-2007). Population trends were quite interesting this year (2007). We counted the greatest number of Chinook salmon fry (fall run and late-fall run) that we had ever counted in any previous year--over four times (4X) the number of Chinook sampled in any previous year. Both juvenile and young of the year age classes of steelhead populations were strong and comparable to counts made during several of the best previous years trapped. In 2007, we also counted more juvenile coho salmon passing the trap site than in any of the previous eight years.

As habitat quality in Sproul Creek improves further, we might expect a future where the ratio of juvenile coho salmon in the system will increase relative to a decreasing ratio of juvenile steelhead, trending increasingly towards a coho-dominated system. Also increasingly cleaner spawning gravels, having a higher production capacity for salmonid fry and macro-invertebrates, will continue to provided more food directly for juvenile salmonids. This should result in increasing growth rates and larger overall size of fish prior to downstream migration (with the accompanying higher survival rates that larger fish enjoy) on their way to the salty estuary and finally into the ocean world that awaits. As such, we are measuring responses of organisms to biological and physical interactions that comprise an ever changing environment of various multi-cyclic feedback loops. It is our hope that restoration activities and better land-use practices will continue to push feedback loops in a positive direction, compatible with the ever-changing natural cycles.

Monitoring salmon health in Sproul Creek Photo: Mark Zuspan, CA Dept. of Fish & Game

As far as adults spawners this year? Hopes for returning fish rose early, as did stream flows. As Bull Creek rose to near 18 cubic feet per second (cfs) on October 10 and the South Fork Eel River (Sylvandale gauge near Phillipsville) neared 100 cfs on October 11, hope for returning fish increased as well. Just a "flash in the hydrograph" I guess. The rain slacked off and we are past Thanksgiving with low flows and fish unable to move into their spawning grounds. Again we are reminded that fish do indeed need water to survive. Hopefully, by the time you read this, it will be raining and the salmon will be spawning in our local creeks.

For more information: www.hits.org/salmon98


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