Question about Brook Trout

**steve z** · 09-29-2009, 11:09 AM

So there is this creek that is unnamed and unmapped. It springs up out of the ground at the head and at the end it goes right back into the ground from whence it came.

In the center of the mile long stream there is a series of large waterfalls, one is a 5 foot drop that is a total free fall for the water; a true water fall.

There are several other ranging between five to twenty feet where the water rushes down a groove in the bed rock.

There is a healthy population of Brook Trout in the lower half, there did not seem to be any in the mid-section waterfalls/pools.

I haven't yet checked the upper section for trout.

What's going on here? Think there would be trout above the falls? Why aren't there trout in the falls? How high can a trout jump if it were to try and migrate up the falls?

What happens at the tail of this creek where the water pools up at the bottom and just seems to stop flowing. There is a good flow throughout the river but the final hole just stops. Is there a tube under the ground or does the water flow through a semi-permeable layer of silt/dirt/rock.

About 50 feet below the final pool, the water emerges again but with barely any flow, I have not yet checked this section for trout.

If the falls are impassible and the creek seeps back into the ground at the bottom, than this entire population of Brookies is self contained within this half mile stretch of stream.

What do you guys think? I am looking for any insight based on what I've said here as I will take this streams location with me to the grave.

Two main questions: how high of a waterfall can a brook trout jump? How does a pretty solid flow just vanish into the ground.

alanb_ct · 09-29-2009, 11:38 AM

If it is river born of natural circumstance, I am sure there are brookies throughout the stream. Nature rarely lets any habitat go to waste. For example, let's say an earthquake formed that place one thousand years ago. At that time perhaps a natural dam allowed fish to escape only in to the lower part from a tributary nearby. Over the seasons, an osprey might hunt the lower river and occasionally drop its catch in the upper and so on. "Nature finds a way."

As far as scaling waterfalls, salmonoids actually use the force of the downstream current to push off with their tails, exactly like a tacking sailboat. They can scale impressive heights. Even in a large waterfall there may be smaller places to swim vertically. "Nature finds a way."

**steve z** · 09-29-2009, 11:47 AM

At one time in history this river was a raging torrent.

Where the stream is just a few feet wide today, the bed rock is carved out an additional 5-10 feet in either direction. There are also places where now dead rivers used to flow into it but all that is left are the exposed rocks where the river cut the ground away.

It is indeed an old river, according to topo maps, the stream cut up to 220 feet into the mountain side.

**SperryWater** · 09-29-2009, 12:38 PM

Steve,

Regarding the stream dissapearing into the ground it is pretty common - all depends on the geology. This is particularly common in karst limestone formations, which large parts of PA contain. Karst formations contain large underground voids, even caves, where water has dissolved the limestone over the course of thousands of years.

If you tell me where the river is I can help you figure it out