Tuesday, August 11, 2009

into the alders

For my job today I got to spend some time exploring a stretch of Sand Creek upstream from my place. I run by the downstream end of that part of the creek nearly every day now, but I've never gone more than a short distance upstream. The 80 acre parcel the creek flows through there is owned by the state, and managed by my office for brook trout habitat.

Brook trout are particular about habitat, even more so than rainbow or brown trout, which are not native here. They need cold clean water with a variety of habitat including deep pools and gravel substrate for spawning. They do well in the larger streams on the North Shore of Lake Superior, but I have also seen them in very small streams.

This stretch of Sand Creek was mostly narrow (10 feet wide) and shallow, with sand for substrate. Much of the stream was shaded by alders that hung so low we had to lift them up to pass through or crawl underneath. Alders have a way of doing that. The shade keeps the water from warming in the sun, but the branches limit all but the most determined angler.

The water was cool. Cold, even. In a deep pool I held my hands underwater and had it not been such a hot day, it would have been uncomfortable after a short time. I have been in a few small streams around the area lately, but none with water nearly as cold as this. The source of much of the water became apparent as I moved upstream; here and there along the banks were flowing springs. I lost count of how many there were. Very unusual for streams in this part of the state! My theory is that this part of Sand Creek lies close to an ancient bedrock fault, and the bedrock is close enough to the surface to keep a layer of cold groundwater just under the soil's surface. The water table has been pretty low around here lately with the drought; I think in a more normal year those springs would have been flowing even more.

We were successful in sampling brook trout: three small adults and one young-of-year. We also sampled one mottled sculpin, which is a good indicator species for trout streams. I'll bet there were some more trout and sculpin in the deep pools we could not sample well. All were released unharmed.

Tomorrow I may be on Sand Creek again, a bit closer to home. I'll try to have the kids bring the camera out if we sample there!


Floridacracker said...

I had a good time trout and chub watching on my float down the Toccoa River in GA. I have to be honest, the diversity of life in a coldwater stream is not as high as the teeming saltwaters I'm used to, but I still enjoyed it.

Pablo said...

When you said you were "sampling" the trout, I had a different idea in mind.

cindy said...

Deb, not sure if you are near Barnum or not, but Monroe Crossing will be at the Carlton County Fair on Sunday, August 16.

dharma bum said...

Very cool!

RuthieJ said...

sounds like a pretty stream.....can't wait to see some pictures!

Deb said...

FC- Not much for diversity here, but I'll take sculpins and brook trout (and burbot, also known as eelpout, a member of the cod family, a bit downstream).

Pablo- They were way too small to sample in a culinary sense!

Cindy- Thanks for the heads up. I saw them there two years ago; maybe we'll stop by. They are definitely one of the best bluegrass bands in the Midwest!

Dharma Bum- I would like to go back there by myself and explore where those springs come from. There is more to that stream than meets the eye.

RuthieJ- We haven't gotten to the part by my house yet, which is not as picturesque. But when we do I'll have one of the kids take a picture of me in my waders. :)