Tuesday, March 15, 2011

Creek at Full Flow

Last summer’s drought caused the creek to remain dry well into late autumn. The flow returned in December, but remained minimal until the successive rains over the last few weeks managed to recharge the ground water levels. Now the creek is at full flow stage. I greatly enjoy watching the clear water flowing over the clean rock bottom. It would be nice to have these conditions year round, but I know that cycling between times of water abundance and absence is necessary to maintain a healthy ecosystem in this small stream.

I use the term full flow to describe that period in a stream’s life when the last of the overland storm flow has passed through the system and the stream is fed by a peak capacity water table. During the full flow period, ground water is entering the stream at its most rapid rate and every drop of water has been filtered through the surrounding soil and bedrock layers. In my mind, this is the way streams were meant to be.

At this time of year, there is no still water in the creek. Every drop of water is moving, some slowly and some quickly, through the stream channel. The cool, oxygen rich water is a wake-up call to those aquatic organisms that have been hidden beneath rocks and in underground burrows since the water disappeared last year. It won’t be long before the water is once again teaming with life.

The water is currently free of fish, but it’s a certainty that fish are now leaving the sanctuary of the permanent streams below to enter these intermittent tributaries in search of suitable spawning sites. Fish are a major predator of aquatic insects and amphibian larvae. The timing of the fish return has a major effect on the breeding success of many small stream aquatic organisms.

It’s likely that Streamside Salamanders are still in the creek. They do their courtship and egglaying beneath large rocks such as this. Judging by the weather patterns we’ve had this year, it’s probably been only a couple of weeks since the adult salamanders left their underground homes in the surrounding woods and entered the stream to breed. The Streamside Salamander is the rarest of the animals dependent upon this stream for their survival. I use the population of this uncommon salamander as an indicator of the health of the stream ecosystem.

3 comments:

  1. Glad to see life coming back to the streams at BJB. Last summer and fall was so dry it's been a pleasure to see rain again...even if it was a bit much recently! I've seen my fair share of Ohio's salamanders but never a Streamside before. I'll have to keep my eyes peeled for these guys in the forested streams and ravines of our property and the Edge.

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  2. I so enjoyed this post. When we were kids my friends and I loved streams like this where we could turn over rocks and find salamanders and other critters. This brought back so many good memories.

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  3. Hi, Andrew. Streamsides look practically identical to small-moutheds. One expert told me that the only way to be sure of the ID is to check the DNA. I'm only sure when I find them breeding, since they use such divergent breeding sites.

    I have some of those same memories, Lois.

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