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Something to bless or to blame...

Started by mattknepley , Mar 28 2014 07:08 PM

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12 replies to this topic

#1 mattknepley

NANFA Member

Smack-dab between the Savannah and the Saluda.

Posted 28 March 2014 - 07:08 PM

... to hijack a line from a Waylon Jennings song.

We've gone around about the impact of human-constructed dams on our waterways, and what should be done with them. But what about these constructions?

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Beaver activity has skyrocketed in my area the last few years. Numerous streams, that just recently were free-flowing are now impounded. Some of the dams are puny, like this one, but others have flooded up to an acre or slightly more. Now I am sure these rodent constructions are much more navigable for our finny friends than the ones we people build, but do beaver have a long-term negative impact on our stream dwellers? A positive one? A balance of both, depending on the species involved?

I'm really pretty ignorant on the topic. But between the heavy siltation from massive logging and strong rains in my area the last year or so, and the beavers, many streams in my area are not at all what they were, in appearances at least, a short time ago. I'll have to continue to play around at the outflows of Mr. and Mrs. Beaver's, and try fishing in the ponds. Maybe that'll help clear things up for me..

Matt Knepley
"No thanks, a third of a gopher would merely arouse my appetite..."

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#2 Guest_Skipjack_*

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Posted 28 March 2014 - 08:01 PM

In my opinion, beaver don't count. I reckon it does not matter what they do, whether it be positive or negative concerning fish. It is natural. Let the beavers be beavers, and the fish be fish.

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#3 Guest_Uland_*

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Posted 28 March 2014 - 08:45 PM

I see it much like Matt. Sure some riffles will no longer be riffles and riffle fishes will suffer. On the other hand, pool fishes will thrive. The beaver dam will not last forever and then populations will switch. In either case, not all riffle fishes or all pool fishes will be eliminated so only a temporary change in the always changing stream.

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#4 Guest_fundulus_*

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Posted 29 March 2014 - 01:20 AM

Seeing these streams with beaver dams here and there is seeing natural streams, what you might have seen in 1500. To eradicate beavers in any big way is to work to maintain the landscape of 1900.

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#5 Guest_Subrosa_*

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Posted 29 March 2014 - 05:29 AM

The difference now is that in most of the lower 48, man is the only check on beaver populations.

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#6 Guest_Casper_*

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Posted 29 March 2014 - 12:41 PM

I am kinda keen on beaver pelts. A fashion statement.

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#7 olaf

NANFA Member

Posted 29 March 2014 - 02:58 PM

I've never seen a beaver dam constructed against a man-made structure before.

Redhorse ID downloads and more: http://moxostoma.com

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#8 Michael Wolfe

Board of Directors

North Georgia, Oconee River Drainage

Posted 29 March 2014 - 07:28 PM

Oh, it is quite common even in areas of culverts and such... the small rodent brains hear that running water and the urge to "plug the whole in the dam" is just too strong for them to resist. If you Google "beaver culvert" you will get a whole lot of hits and pictures about beaver exclusion devices.

Either write something worth reading or do something worth writing. - Benjamin Franklin

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#9 Guest_FirstChAoS_*

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Posted 30 March 2014 - 01:44 AM

I have seen some beaver dams and the water flow fluctuates, sometimes going over or through them in high water. Sometimes the dam breaches for a bit (I think something happens to the beaver or it moves on when this happens) for a bit. I do not think it is that much of an impact in the long run, and have even heard the pools from it can give stream fish more room to grow.

Though I admit I never researched the topic to know for sure. The only time I ever heard of a beaver dam harming fish was when other factors were already having an impact. The Banff longnose dace was already hurting from chemical spills and introduced species when the beaver dam blocked the spawning streams. The dam was just one of many stressing factors that lead to the subspecies demise.

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#10 Guest_gerald_*

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Posted 30 March 2014 - 08:02 PM

Unfortuantely THAT IS EXACTLY the case in far too many situations, especially for rare species with little suitable habitat left. Yes beaver dams are natural, but when a fish, mussel or crayfish species has dwindled down to a few small isolated populations, natural disturbances (storms, beavers, fire, disease) that would have once had only a minor impact may now be the nail in the coffin for localized populations that have lost the ability to disperse and recolonize. I cant speak for other states, but in NC the vast majority of endangered and threatened aquatic species are those that require flowing waters, not pool species. Beavers may be over-abundant in many areas, with few natural predators left.

The only time I ever heard of a beaver dam harming fish was when other factors were already having an impact.

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#11 Guest_fundulus_*

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Posted 31 March 2014 - 09:56 AM

Beavers may be over-abundant in many areas, with few natural predators left. Adult beavers rarely are preyed on because of both size and living in water. It's young ones who are vulnerable to attack by wolves, coyotes, bears and various cats as the young have to migrate overland to new habitat. Is this another case where only humans can wisely manage nature? (ha!)

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#12 Guest_sbtgrfan_*

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Posted 31 March 2014 - 05:31 PM

Beavers may be over-abundant in many areas, with few natural predators left. Adult beavers rarely are preyed on because of both size and living in water. It's young ones who are vulnerable to attack by wolves, coyotes, bears and various cats as the young have to migrate overland to new habitat. Is this another case where only humans can wisely manage nature? (ha!)

SC allows the hunting of beavers on private land year round during daylight hours. We allow the trapping of beavers Jan 1 to Mar 1. Not sure if your post was intended to be sarcastic or not, but I certainly agree humans are the number 1 predator to beavers. While I don't think they are a nuisance to say fish species as questioned in the original post, they are a pretty large nuisance for land owners.

As far as damming up a culvert like that, I don't think I've ever seen it in person, but I've learned through my wildlife classes at Clemson and labs where we've build beaver pond levelers, that any sound of running water or they sense any type of flow, it will cause the beaver to dam it up if it's in his territory.

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#13 Guest_fundulus_*

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Posted 31 March 2014 - 09:11 PM

I'll be doing a fish survey on city-owned park land with beavers in the stream system this summer in Huntsville, I'll report what I find in different spots in the system. Luckily they're letting it function with beavers which will probably enhance plant diversity over time as different pockets of soil systems emerge from ponds coming and going.