Sunday, January 15, 2012

Elwha River Unchanged?

Olympic National Park glaciers continue to shrink, most recent study finds

Today's article and pictures in the Peninsula Daily News got me thinking about the common wisdom that the Elwha River above the dams is unchanged since the dams were put in.  I often have repeated this when discussing wild fish restoration.

The fact that glaciers are diminishing and the pictures of the Lillian glacier make me wonder what impacts the loss of glaciers since the early 1900's will have on fish returning to the upper watershed for the first time since the glaciers were much larger.  I'm not even sure that the impacts will be negative, but it is certainly interesting to see such major changes in such a relatively short time frame.

Will decreased and warmer summer flows have negative impacts on returning Elwha fish along with other populations throughout the Olympic Peninsula.

2 comments:

  1. interesting point. I actually suspect shrinking glaciers may be a minor positive for the productivity of the Elwha. Its a fairly cold drainage owing to its high elevation headwaters. In the short term the sediment supply may increase as glacial recession exposes more raw glacial deposits but my suspicion is that a healthy floodplain like the Elwha has will quickly store alot of that sediment and come to an equilibrium with its sediment sources and run off regime. This is definitely an issue to watch all around our region and by the end of our life times alot of "glacial" rivers will no longer have glaciers in their drainages.

    ReplyDelete
  2. This link shows that stream flows have already been impacted.

    http://www.nichols.edu/departments/Glacier/elwha%20fact%20sheet.pdf

    certainly will be interesting to see the impacts of this.

    hopefully with the lack of development the impacts will not be felt as much as rivers with degraded habitats.

    ReplyDelete