Beaver are slowly coming back to the Klamath, recovering from intense trapping that began in the mid-1800’s and continuing for nearly a century after until they were almost extinct. In 1850 alone, famed frontiersman and trapper Stephen Meek and his party reportedly trapped 1800 beaver out of Scott Valley, which at the time was called Beaver Valley. The last beavers in Scott Valley were trapped out by Frank C. Jordan in the winter of 1929-1930 on Marlahan Slough. Beaver throughout much of the Klamath basin suffered the same fate, and even today as they return to less inhabitated areas along the mainstem river and its tributaries, they are still shot and trapped in streams where their dams pose a perceived risk to residential and agricultural property.
It is no coincidence that fisheries biologists looking to restore threatened coho in the Scott River and the larger Klamath system, have identified Marlahan Slough (1) as a key habitat to restore. Low gradient sloughs, blind channels, off-channel ponds, braids, and other low velocity habitats are ideal for rearing coho, and beavers just make them better. Recent studies from Washington and Oregon by Michael Pollock and others are further defining the intimate relationship between beaver, beaver ponds, and coho smolt production (2). A recent multi-year study being prepared for publication by the Karuk Tribe, Yurok Tribe, Larry Lestelle, and others, on the ecology of coho in the Klamath River identifies the lack of low velocity habitats, primarily during winter flood events, as a major potential limiting factor to coho distribution and abundance (3). Further studies are needed to relate the loss of beaver and associated habitats to the loss of coho in the Klamath River. Coho, out of all the salmon in the Klamath River, have born the brunt of human development.
Low gradient valleys and deltas that provide the best farm and ranch lands, and ideal places to build homes, are also the very same habitats that coho require for spawning and rearing. In addition to the loss of beaver, coho have been impacted by channelization for flood protection and floodplain development, excessive temperatures and disconnected habitats resulting from overallocation and use of surface flows, dams that create environments conducive to the production and spread of fish diseases in the the mainstem, and nutrient-loading from fertilizers, and loss of wetlands that lead to poor water quality (low dissolved oxygen, unstable pH, etc.). Further impacts include historic mining (channelized, simplified instream habitats), logging (excessive sedimentation and decreased input of wood), road construction (excessive sedimentation, instream barriers, disrupted groundwater flow), and disrupted fire regimes (decreased input of wood).
A recent study by Pollock et al. summarized the specific affects of the loss of beavers and the dams they are famous for on fishes (4):
Beaver dams alter the hydrology and geomorphology of stream systems and affect habitat for fishes. Beaver dams measurably affect the rates of groundwater recharge and stream discharge, retain enough sediment to cause measurable changes in valley floor morphology, and generally enhance stream habitat quality for many fishes. Historically, beaver dams were numerous in small streams throughout most of the Northern Hemisphere. The cumulative loss of millions of beaver dams has dramatically affected the hydrology and sediment dynamics of stream systems. Assessing the cumulative hydrologic and geomorphic effects of depleting these millions of wood structures from small and medium-sized streams is urgently needed. This is particularly important in semiarid climates, where the widespread removal of beaver dams may have exacerbated effects of other land use changes, such as livestock grazing, to accelerate incision and the subsequent lowering of groundwater levels and drying of streams.
With coho numbers critically low througout the basin, restoration actions are being planned and implemented to improve coho habitat by the Yurok Tribe, Karuk Tribe, Mid Klamath Watershed Council (MKWC), US Forest Service, and others. Many of these projects replicate habitats that would have been created historically by beavers. Last spring, MKWC proposed a project near the mouth of Boise Creek, a tributary to the Klamath near Orleans on property owned by the Coates Vineyard and Winery, that would have used an engineered log jam to re-route the creek around a bedrock cascade barrier at the mouth through a series of existing ponds maintained by several families of beavers (Figure 1). However, before the project could be implemented, the beavers constructed a five foot tall dam across the creek at the exact location of the proposed log jam, diverting a portion of Boise Creek through their ponds, and into the Klamath River at a location that provides adult and juvenile fish access (Figure 2). MKWC and Karuk Tribe biologists have observed thousands of juvenile chinook and coho utilizing these ponds through the summer, and moving through the ponds into Boise Creek above the barrier! This fall and winter, we will see if the beavers have also effectively redesigned the creek to allow for adult spawning chinook and coho salmon to access more than three miles of high quality spawning habitat above the barrier.
In other areas we are working to create high quality off-channel pools that will provide winter and summer rearing habitat in low gradient Klamath tributaries. MKWC, through funding from the US Fish and Wildlife Service and the PacifiCorp Coho Enhancement Fund, is currently implementing a series of off-channel ponds along Seiad Creek, a tributary to the Klamath River that has small but stable runs of spawning coho. Seiad Creek is unique in that it has a large alluvial floodplain for three miles upstream of its mouth that has been constrained by flood control berms to allow for settlement (Figure 3). Historically, Seiad Creek would meander more than a mile upstream or downstream in relation to the Klamath River, creating complex slow water habitats preferred by coho salmon. Based on anecdotal information from landowners along the creek, beaver dams played a major role in damming Seiad Creek and flooding off-channel habitats along the creek.
With cooperation from several landowners along Seiad Creek, MKWC is currently completing excavation of two ponds, and will complete one more this year and one next year as part of a larger floodplain reconnectivity project in coordination with the Karuk Tribe (Figure 4). When designing off-channel habitat projects, having more ponds along a longer section of creek is better than planning fewer larger ponds. Only a certain percentage of fish will encounter the pond entrance, so having more ponds increases the potential for fish finding and occupying created off-channel habitats (Figure 5). Garnering landowner support along prioritized tributaries is critical to the success of habitat restoration projects.
The restoration of threatened coho salmon in the Klamath River system may be intricately tied to enhanced beaver populations and restoration projects that mimic the positive benefits of beaver dams. Educating the public about the critical role of beaver in restoring coho salmon populations in the Klamath River and other coho salmon streams in Northwest California will also help to decrease take of beaver as a nuisance species and allow them to reclaim their role as an ecological process shaping our streams and valleys.
The preceeding content is part of a larger article written by our Executive Director - Will Harling. To read the article in its entirety click here.
State of the Beaver, 2011 by Charles Wickman - MKWC Fisheries Program Coordinator
In early February 2011, the Beaver Advocacy Committee, operating under the umbrella of the South Umpqua Community Partnership, hosted its annual State of the Beaver conference in Canyonville, Oregon. And I was lucky enough to spend three days at the event, trying to soak up what I could about things like beaver and salmon, beaver and water, beaver relocation, and beaver and climate change mitigation. I got all of this and more. Though the presenter I most wanted to hear, Dr. Michael Pollock, speaking on the keystone relationship of beaver and salmon, unfortunately withdrew from the conference, the agenda was packed with venerable voices from around the world presenting on traditional ecological knowledge, research and restoration, and policy and protection.
To get more information on the conference, it's agenda, presenter profiles and more, check out the Beaver Advocacy Committee's website at http://www.surcp.org/beavers/index.html. The most interesting information I gleaned from the conference, though, had to come from what I was not hearing. Specifically, there is a lack of legislative and policy recognition for Castor canadensis here, in California. In the Pacific Northwest, Washington and Oregon lead the way with progressive beaver relocation programs, the use of beavers, and their low cost, high yield water sequestration benefits to mitigate for climate change and aquifer depletion, and of course, the application of the best available beaver science to salmonid restoration projects. All things we could use right here on the Klamath and all over California. Any policy wonks want to take this on?
Favorite quote from the conference: “Most human/nature problems are usually human/social problems.” – Duncan Haley, Research Ecologist, Norwegian Institute for Nature Research, Trondheim, Norway.