Monitoring Engineered Log Jams: Something to Consider While Waiting for the Forest Service to Start
by Josey Paul / John Woolley
Engineered Log Jams (ELJs) monitoring is difficult and time consuming. It requires specific expertise—such as the ability to recognize salmon redds—and a fundamental understanding of river hydrology as it relates to the various life cycles of salmon. Large Woody Debris (LWD) has both short- and long-term effects on salmon habitat. Those effects are always buried within the noise of natural variability. And the natural variability is itself further confused by a myriad of human interventions, such as harvest quotas and hatchery practices.
There are two long-term goals when monitoring the Dosewallips River project. (Installation was completed in September).
- Protect Olympic National Forest Road 2610 from erosion both to save the road and to protect salmon redds from being smothered by fine sediment
- Increase the number of returning salmon to the Dose, over time, by adding engineered LWD structures to the river. This increased escapement would flow from beneficial habitat changes introduced into the river by engineered LWD structures that create optimal spawning and rearing conditions—mainly pools, hiding places (refugia), and long reaches of clean, stable spawning gravel.
Start by getting the records and field notes for the last 10 years from the various groups that count redds (the little basins that females scoop out to lay their eggs) on the Dose and two rivers nearby, similar rivers that use the redd counters/redd counting agencies. Next, create a scatter graph, overlaid on maps of the three rivers, for each year. The graphs would show the locations within these rivers of all the counted redds, color coded by species. The scatter graphs will show at a glance both overall abundance and key reaches that are specifically important to spawning salmon—pools, beds of stable spawning gravel, and refugia. Track these redds for at least 10 years into the future.
Successful LWD projects should demonstrate:
- Increased escapement into the Dose, relative to the two control rivers
- Increased spawning within the treated reaches, relative to past use
- Increased number of pools, stable spawning gravel, and refugia within and below the treated reaches
In the short term, the important thing to look for is whether the river, as it adjusts to the new structures, destroys redds, either by scouring out the eggs, by burying the eggs under sediment, or by filling in the interstitial spaces in the gravel with fine sediment, causing the eggs to die of oxygen starvation. The field data will indicate whether the treated reaches are the key areas for salmon spawning. If the treated reaches are key spawning areas, the LWD project would have the potential to do long-term, perhaps permanent, damage to the various runs.
OFCO is disappointed that the Forest Service (FS) has not pushed Wild Fish Conservancy (WFC) to initiate their monitoring process. OFCO has continually been told by Olympic National Forest that it is the FS’s responsibility. OFCO does wonder if it is appropriate to fund WFC to monitor its own work.
In addition, 14 ELJs at the lower reaches of the Gray Wolf River and in the Dungeness River are getting closer to the construction phase. For more information on the Dosewallips ELJs project, click here and to view photos of the project while in process and completed during 2013, click here.