Study: Fish use as metric for ecological function
This paper presented an overview of results to date of CWI’s ongoing study to define how nearshore ecological function responds to dam removal sediment delivery through three time phases: 1. Pre-dam removal; 2. Dam removal; 3. Post-dam removal
Sediment delivery has just begun. Numbers change daily, but somewhere between 20-60 percent of the 16 million cubic meters (what an astounding number!) of sediment predicted to be delivered to the nearshore has arrived. Physically, restoration has just begun.
While the story is still unfolding-remember dam removal is not yet complete and sediment is just starting to arrive to the nearshore-we’re seeing the following changes in the Elwha estuary. We attribute these changes with dam removal as we are not seeing these changes in the comparative Salt Creek area.
In a nutshell?
Species Richness is highly variable in the nearshore, and defined by month. Species Richness in the Elwha estuary has not changed significantly since dam removal began, and is not significantly different than that of the comparative area.
We may be seeing some response in Chinook and coho use of the Elwha estuary-hatchery releases make it VERY hard to decipher….
Observations of our chum data are very intriguing. While overall abundance appears to be about the same, when, and the size of, juvenile chum are using the Elwha estuary appears to be changing.
It is vital to stress that these results are preliminary and will undoubtedly change as the Elwha nearshore continues to restore. We will continue to work on these elements in more detail for the upcoming post dam removal phase. Our informal, preliminary observations to date:
Thank you to: