Friday, I had occasion to take another site visit to Lower Hylebos. This time, I saw several fish-wakes
upstream of the 4th Ave bridge. Standing watch, looking for lunch, was a very determined great blue heron. I got with 20 feet of the snag he was on, and while he gave me the stink-eye, he did not budge from his spot. Too much fish action happening. Unfortunately, I did not have my digital camera and had to make do with the Blackberry, so the photos are a bit poor.
After the GBH's photo shoot, I trudged upstream and found that our friend the beavers, have built themselves a dam on the mainstem of the creek!
It's a sizable structure, creatiing about 3 feet of elevation behind and generating a side channel that the little buggers have tried to dam up, as well.
This is an example of the ways in which beavers can create stream channel diversity! Now, having this on the mainstem makes me a bit nervous, as it enhances the chance of upstream flooding.
I also wonder whether it creates a passage barrier for some species of salmon. The coho wouldn't be troubled by it. Pinks and chum, however, I'm not so sure.
One of my fellow ecologists suggested that the heron and beavers may have a deal going, with the beaver pimping salmon for the heron. Crafty. Very crafty.
The word from the local I spoke with, his opinion was the Beaver Dam was blocking the upstream passage for the salmon.
Posted by: Adele | October 19, 2009 at 03:01 PM
Guess the salmon had a differing opinion than the locals. Salmon are making it all the way upstream into Federal Way
Posted by: Adele | November 03, 2009 at 10:26 AM