I Hate Beavers

[Mike Ormsby]

I believe that beaver baffles can be a solution -- years ago TU and Credit Valley Conservation Authority built one on a branch of the Credit in response to concerns over beaver dam and the effects on the resident brook trout, specifically the change in water temperature.

Here's some links to more on beaver baffles:

http://www.usroads.com/journals/rmej/9804/rm980401.htm
http://www.loudounwildlife.org/HHBeaverBaffles.htm
http://www.westhillbb.com/photos.htm...9696043975&s=2
http://wdfw.wa.gov/wlm/regions/reg5/2005/feb0705.htm
http://www.hsus.org/wildlife/urban_w...h_beavers.html
http://www.usda.gov/news/pubs/newsle...7/article5.htm
http://lists.envirolink.org/pipermai...08/012903.html
http://www.vtfishandwildlife.com/lib...Newsletter.pdf
http://northernwoodlands.org/outside...ss_of_beavers/

[pharper]

A dam is a dam whether man made or beaver made. Very few dams are beneficial to trout and beaver dams are not bottom draw. They raise water temps and do not lower temps.

Don't kid yourself, beaver dams are temporary partial barriers, they don't compare to a real dam. They actually increase subsurface flows and moderate temperatures in the whole system, but yes summer water temperatures, especially in the sun, can be increased... offset by other benefits.

They kill trees in the flood plain by drowning their roots. This happens in a little as 6 months. This removes overhead shade, further warming the water.

Dead trees add habitat critical to trout. There is more water available to surrounding trees and edged with vegetation.

They prevent upstream migration of trout to their spawning areas in feeder creeks. Less spawning areas = fewer trout. Any increase in trout biomass is temporary until thermal pollution and spawning losses take over.

Beaver dams are temporary. I doubt there are any population effects- trout upstream of the dam can still spawn and those that are downstream and can't pass; they spawn elsewhere. They are rarely complete barriers anyways.

They build riparian areas? If you mean by "riparian" a pond then yes. If you mean a river, then, nope! What they do is widen the and destroy rivers. Dams increase still water not moving water.
They do build a flood plain - great for ducks and water fowl, bad for trout in the long run.

The deposition of sediment and organics in the slow moving areas of beaver dams creates excellent soil material. Perfect meandering channels form through filled in beaver ponds creating lush streams with stable banks. And the process continues.

The improve aeration at the dam? Really? Does that make up for the aeration lost over the expanse of the dam? Nope. There is a net loss in aeration when running water is replaced by still water.

Have you measured the O2 above, through, and below? Depending on the gradient of the stream, water trickling over and through a dam or series of dams can have a very positive effect on oxygen levels. My point is that it is not always a bad thing.

Only in high gradient (mountainous) flows or where the average water temperature remains too cold (high altitudes) are there benefits to a beaver dam. Here they can form areas of trout water where there is little and delay runoff to even out the runoff. At high altitudes the warming of ice cold runoff by a beaver dam can benefit trout by increasing insect life in the pond and the water below. But in Wisconsin and the eastern USA, beaver dams are a net negative as the following body of research shows.
See the following Cold Water Fisheries research from the Wisconsin DNR and the University of Wisconsin College of Natural Resources on the effects of beaver on trout streams:
Research paper by Ed Avery of the Wisconsin DNR Cold Water Fisheries Research Center:

http://dnr.wi.gov/org/es/science/pub..._RS_731_91.pdf
http://www.amazon.com/temperatures-n.../dp/B0006DBYD8

"Much of Wisconsin's current trout stream habitat management focus on implementing in-stream structures and bank stabilization, beaver dam removal, and streambank debrushing even though these activities have resulted in questionable success rates in trout habitat improvement."

Trout stream management does not mean doing what is best for the trout, it is a balance for landowners, rec users, wildlife, and sportfish. Reread the last line... "even though these activities have resulted in questionable success rates in trout habitat improvement".

http://www.uwsp.edu/cnr/wicfru/Research/Cross.aspx
"Beaver (Castor canadensis) dam building activities create many longtern affects on stream ecosystems. Beaver dams may negatively influence trout fisheries by creating physical barriers to spawning areas, increasing sediment retention, and increasing water temperatures. The U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) Animal Damage Control (ADC) program in Wisconsin, entered into cooperative agreements with the Wisconsin Department of Natural Resources (WDNR) and the U.S. Forest Service (USFS) on the Nicolet National Forest from June through September,b1988, to remove beaver and beaver dams from priority classed trout streams."

http://digitalcommons.unl.edu/cgi/vi...context=ewdcc4

This is a 20 year old document for an wildlife damage control conference.

"One of the biggest challenges facing stream restorers now is the overabundance of the beaver. With trapping rates lowering over the past few years, the beaver population keeps growing, as do their dams.
Monitoring is really helpful is getting information reported about beaver dams, which devastate the trout streams, Hlaban said. I'm sure there are a number of dams we wouldn't have discovered if it wasn't for stream monitors being in there and understanding what to look for."
Trout Unlimited Chapters receive special written permission from the state DNR to trap on public land or permission from the owner of private lands to trap beavers during the offseason."

http://watermonitoring.uwex.edu/pdf/...utdoorNews.pdf

http://www.wisconsintu.org/LinkClick...bid=58&mid=372

This is a newspaper article

"Since the trout stamp began in 1978, the DNR has restored more than 750 miles of trout stream, kept more than 700 miles free of beaver dams and maintained the good condition of many miles of trout streams throughout Wisconsin."

http://dnr.wi.gov/news/DNRNews_Artic...kup.asp?id=459
"Beaver dams cause trout streams to become silted and warmed. Dams prevent trout migration and result in a lowered trout population."

http://www.timberwolfinformation.org...web/beaver.htm

"kids only zone" on a website.

Much peer reviewed research today will tell you that beaver dams increase fish species richness, especially in slow water streams. They are temporary and partial barriers, they do have some negative effects, but a net positive impact on the fishery... the biggest issue is that they have to be left to fill on their own. In areas where beaver dams have been managed, you'll have to keep managing the dams... you've created a man made issue that can only be fixed by letting nature take its course- beaver dam succession.
You will see a false positive when dams are removed- you've temporarily increased flows (flushing flows), you've instantly changed the temperature, you forced forge fish (fish food) into marginal habitat> increasing prey availability to trout, you uncover coarse stream beds (flushing downstream and up), and you've forced trout to redistribute in the stream. But to get that affect you have to allow beavers to build a dam and then remove it. A stream not allowed to change will stagnate, diversity will drop, and anglers will leave.
I'm not saying it is all bad, I'm just making a point, that, there can be a net benefit if the system is allowed to naturally grow.
We tried to stabilize banks here with log cribs... now it is a worse problem because they are all failing. We have had (and still have) beaver dam removal programs... those streams are starting to stagnate.

1955 Rupp (AFS- BEAVER-TROUT RELATIONSHIP IN THE HEADWATERS OF
SUNKHAZE STREAM, MAINE) found:

ABSTRACT
The effect of beaver, Castor canadensis(Kuhl), on an eastern brook trout,
Salvelinus fontinails( Mitchill), population was studied in the vicinity of five
beaver dams in the headwaters of Sunkhaze Stream. The beaver dams were found to present a serious obstacle to trout movements but they were not a complete barrier. Estimated unit-area production of bottom organisms was poor in the beaver ponds but the beaver had so increased the bottom area that total production of the stream section was probably more than doubled. Forage fishes appeared to be somewhat more abundant in the beaver ponds than in the open stream and constituted an unexpectedly high percentage of the food of 6- to 10-inch brook trout taken in the ponds. Measurable but not serious waterquality reduction was found in and below the beaver ponds.

1955 and those aren't bad results, especially considering the increase of food to brook trout.

In North Dakota SCHLOSSER and KALLEMEYN (2000) found that

The presence of a productive and diverse fish assemblage in headwater streams
of north-temperate areas requires the entire spatial and temporal mosaic of successional habitats associated with beaver activity, including those due to the creation and abandonment of beaver ponds.

(sorry I don't have an electronic copy).

And the 1998 paper by Snodgrass and Meffe from S. Carolina>

beavers have a positive effect on fish species richness in low-order, blackwater streams, but maintenance of this effect requires preservation
of both spatial and temporal dynamics of beaver pond creation and abandonment

(INFLUENCE OF BEAVERS ON STREAM FISH ASSEMBLAGES: EFFECTS OF POND AGE AND WATERSHED POSITION-sorry no electronic copy either)

A paper from Sweden showing the benefits of beaver ponds to Brown trout:
http://www.sciencedirect.com/science...168d01fb2404f1
(Effects of beaver dams on the fish fauna of forest streams. H?gglund and Sj?berg 1999)

[pharper]

I believe that beaver baffles can be a solution -- years ago TU and Credit Valley Conservation Authority built one on a branch of the Credit in response to concerns over beaver dam and the effects on the resident brook trout, specifically the change in water temperature.

Hey Mike,
Baffles work to control water level, but they are barriers to fish movement.

(A good thing on the Credit... prevent the upstream movement of rainbows and browns into the brookie beaver dam habitats.) There are some baffles that are supposed to pass fish, but not sure if they actually work (no attraction flows, not sure of fish swim velocities).

I worked on the Credit (and other Rivers in S. Ontario) for a couple of years... was amazed with the fish in your neck of the woods... We had piles of brookies living in "agricultural drains" that were considered ditches by most. Its amazing what those upwellings will support on the landscape!
Very cool helping stock Atlantic salmon a few years back too!!

If you want to check out some great brookie streams, head out with the Hamilton Area Fly Fishers and Tyers... they've done some good work on brookie streams.

[Silver Creek]

Pharper,

I am pleased to engage you in a discussion. My opinion is that you have overstated a position and now feel you must defend it. Obviously, you probably think I am wrong in this view.

Also let me state from the beginning that, although I disagree with you on this subject, that we may indeed agree on many other subjects. I truly appreciate your civil reply to me. Thank you.

Trout stream management does not mean doing what is best for the trout, it is a balance for landowners, rec users, wildlife, and sportfish.

Actually trout stream managment to remove beaver dams is doing what is best for the trout, so dam removal does apply. The point is that you said that beaver dams were good for trout; therefore your statement that trout stream management is not about what is best for trout is a bit puzzling to me. Frankly, I do not understand it in the context of this discussion. It is a red herring .

This is a newspaper article

"Since the trout stamp began in 1978, the DNR has restored more than 750 miles of trout stream, kept more than 700 miles free of beaver dams and maintained the good condition of many miles of trout streams throughout Wisconsin."

http://dnr.wi.gov/news/DNRNews_Artic...kup.asp?id=459
"Beaver dams cause trout streams to become silted and warmed. Dams prevent trout migration and result in a lowered trout population."

http://www.timberwolfinformation.org...web/beaver.htm

These are both articles published by the Wisconsin DNR.

You did not deal with the fact that the DNR considers beaver a threat to trout. Your position is that they are not a threat, but a benefit. Therefore, you need to show where the DNR is wrong and you are right. You cannot discount it by saying it is "newspaper article", when it was actually published in the Quarterly Magazine of the Wisconsin DNR.

Although, you may not have intended to, that's another red herring attempt to change the subject.

Remember when you criticized me for quoting:

This is a 20 year old document ......

Then you quote this an article from 1955, that is 54 years old. You cannot have it both ways, criticizing me for the age of my reference and then using one that is almost 3 times older.

1955 Rupp (AFS- BEAVER-TROUT RELATIONSHIP IN THE HEADWATERS OF
SUNKHAZE STREAM, MAINE) found:

"ABSTRACT
The effect of beaver, Castor canadensis(Kuhl), on an eastern brook trout,
Salvelinus fontinails( Mitchill), population was studied in the vicinity of five
beaver dams in the headwaters of Sunkhaze Stream. The beaver dams were found to present a serious obstacle to trout movements but they were not a complete barrier. Estimated unit-area production of bottom organisms was poor in the beaver ponds but the beaver had so increased the bottom area that total production of the stream section was probably more than doubled. Forage fishes appeared to be somewhat more abundant in the beaver ponds than in the open stream and constituted an unexpectedly high percentage of the food of 6- to 10-inch brook trout taken in the ponds.

Measurable but not serious water quality reduction was found in and below the beaver ponds.

1955 and those aren't bad results, especially considering the increase of food to brook trout.

I read the abstract. I don't know how the serious obstacle to trout migration, water warming vs an decrease in food density (per area) although total food was greater and a "somewhat" increase in forage fish is a good trade.

I take it you think, according to the article you present as a positive for beaver dams, that a modest increase in food is worth increasing thermal pollution and a high grade blockage preventing migration during spawning. I disagree.

In North Dakota SCHLOSSER and KALLEMEYN (2000) found that (sorry I don't have an electronic copy).

"The presence of a productive and diverse fish assemblage in headwater streams of north-temperate areas requires the entire spatial and temporal mosaic of successional habitats associated with beaver activity, including those due to the creation and abandonment of beaver ponds."

And the 1998 paper by Snodgrass and Meffe from S. Carolina> (INFLUENCE OF BEAVERS ON STREAM FISH ASSEMBLAGES: EFFECTS OF POND AGE AND WATERSHED POSITION-sorry no electronic copy either)

I would be nice to know how high these dams were and the gradient and whether they were above the major spawning areas. High dams in headwaters benefits do not mean dams are beneficial to middle or lower sections of streams, as you well know.

This is really a form of hasty generalization, implying that what is good in a special situation applies to most or all situations. I already mentioned some exceptions (cold and high gradient areas) where dams are beneficial. They have also been found to benefit juvenile salmon and enhance survival. But these are special situations so the above article does not counter what I stated previously.

I believe the crux of the issue is your original post below. This is why I say that you overstated your position. I would not have disagreed if you said that sometimes beaver dams can be beneficial or if you had somehow qualified your statement.

However, your original contention was that beaver dams are beneficial without stating any exceptions or qualifications:

I like beaver dams and I think in the long run they are very beneficial to trout habitat...

Your statement above places a steep burden of proof upon you because it requires a level of proof showing by a predominance of the evidence. This level of proof, in my opinion, cannot be met and has not been met.

A paper from Sweden showing the benefits of beaver ponds to Brown trout:
http://www.sciencedirect.com/science...168d01fb2404f1
(Effects of beaver dams on the fish fauna of forest streams. H?gglund and Sj?berg 1999)

Here is what your article actually says:

"The beaver (Castor fiber) was exterminated in Sweden, but now, after re-introduction, again occurs in high densities. The activities of beaver ? felling of trees and construction of dams ? are important ecological factors in forest streams. The proportion of wetlands and open water in the forest landscape is increased, and new stream sections with slow-running water are created. This change of habitat characteristics is predicted to have consequences for the composition of stream fish communities. We studied the fish fauna in seven small to moderate-size streams with beaver in central Sweden, using electro-fishing. Beaver ponds and adjacent riffle sections were compared to unaffected reference sections. The two most common species were minnow (Phoxinus phoxinus) and brown trout (Salmo trutta). Three additional species occurred in lower numbers: Bullhead (Cottus gobio), burbot (Lota lota) and pike (Esox lucius). Brown trouts were more common in reference sections than in beaver-affected sections, while the opposite tended to be the case for minnows. The numbers of brown trouts and minnows in separate sections were negatively correlated. The size composition of the two species also differed between sections. Brown trouts captured in the ponds were larger than those in the riffle sections, while the opposite was true for the minnows. Shallow areas of the beaver ponds were important habitat for minnow fry. Beaver ponds are likely to serve as habitat for larger trouts in small streams during drought periods. Minnows appeared to spread from ponds to surrounding riffle areas. We conclude that beaver-mediated habitat changes have important effects on the relative abundance of fish species in Swedish forest streams, and that they may enhance fish species diversity."

So basically the article says that diversity of fish species increases, e.g. more minnows but fewer trout. Trout that are present in the pond are bigger. No mention of actual lbs. of trout per lineal foot were greater in reference or pond and the article totally ignored the effects of stream blockage (this was not a stated purpose of the study)

No where in the abstract did it say that the beaver pond "benefited" brown trout as you state. It said in the pond there were fewer but larger brown trout.

The study title shows that they were studying only the population changes of fish and fauna due to a pond and not whether it was better for trout or not.

Remember when you criticzed me for the age of my article? Would it be fair to say that at least it was from the midwest of the USA and not from a far northern scandanavian county bearing little resemblence to the topography of the midwest or the east coast of the USA.

When you criticize the the references of those with whom you disagree, it is not even more incumbent upon you then to make sure your citations are above the same reproach? I'm just pulling your chain a bit here. Please forgive me.

I've tried to fairly evaluate your reply, and if I have misstated or misinterpreted what you said, my apologies in advance.

Take care, tight lines, and good fishing!

[pharper]

Thanks for the response... I love arguing about beaver dams. Excellent reply, thanks for not taking offence to anything.

The in my last post I was limited to 10000 characters, but I did have a few more things to say.
The bulk of my reply was in this

Much peer reviewed research today will tell you that beaver dams increase fish species richness, especially in slow water streams. They are temporary and partial barriers, they do have some negative effects, but a net positive impact on the fishery... the biggest issue is that they have to be left to fill on their own. In areas where beaver dams have been managed, you'll have to keep managing the dams... you've created a man made issue that can only be fixed by letting nature take its course- beaver dam succession.
You will see a false positive when dams are removed- you've temporarily increased flows (flushing flows), you've instantly changed the temperature, you forced forge fish (fish food) into marginal habitat> increasing prey availability to trout, you uncover coarse stream beds (flushing downstream and up), and you've forced trout to redistribute in the stream. But to get that affect you have to allow beavers to build a dam and then remove it. A stream not allowed to change will stagnate, diversity will drop, and anglers will leave.
I'm not saying it is all bad, I'm just making a point, that, there can be a net benefit if the system is allowed to naturally grow.
We tried to stabilize banks here with log cribs... now it is a worse problem because they are all failing. We have had (and still have) beaver dam removal programs... those streams are starting to stagnate.

But I never finished...
I am actually realy busy right now getting ready to leave for my flight to Washington DC in a few hours.
When I get back to this computer I will post a reply that actually states my position and backing better (I just need to go through my report folder).

[Silver Creek]

When I get back to this computer I will post a reply that actually states my position and backing better (I just need to go through my report folder).

I actually think that we will come to the agreement that there needs to be a balance. By that I mean that in Wisconsin, with the drop in fur prices and the loss of natural predators, beaver have taken over many of our prime feeder creeks and even the main sections of trout streams. They have dammed up the outlets of natural spring ponds that feed into and cool our rivers.

I can accept that there are instances where they are beneficial. I will need some convincing that with the decrease in trappers and natural predators, they are on balance beneficial.

I look at this as an opportunity for us to learn from each other. Thanks for taking the time and I look forward to learning under what conditions they are beneficial.

Very sincere thanks,

[maodiver]

my only question:

Are/were beavers and/or trout native to the watershed?


If in historical times, trout and beavers co-existed then the trout will survive, after all, that was the plan.

If the trout weren't there, but the beaver were, then keep the beaver. After all, the trout are planters or descendents of them, and the beaver are just fulfilling the plan. Don't let fishing get in the way of that.

If the trout were, but the beaver weren't, by all means get rid of the dam, and let the native trout fulfill the plan. Don't let a love of beavers get in the way of that.

[Mike Ormsby]

"Dammed if we do and dammed if we don't" I suppose is the lesson here -- and pharper, there are some excellent brookie watrs here in southern Ontario -- and Hamilton Area Fly Fishers and Tyers are an incredible group too -- a beaver baffle was used in the example I cited to allow for the flow of water to continue with less impediment thus allowing the water temperature to remain cooler -- yes, the dam and baffle would prevent the fish from moving -- and are both barriers perhaps -- but the main concern was the water temperature rising in waters dammed up

The baffle is just one tool that can be used -- and the beaver and trout have co-existed for centuries -- but sometimes it is beneficial though if man "interferes" in a positive way -- like reintroducing Atlantic salmon into waters that they haven't been in for years -- or helping to regulate the water temps of valuable brook trout habitat

[ducksterman]

----Reply Letter---- Dear Mr. Price: Re: DEQ File No. 98-20-0006; T11N, R10W, Sec 20; Hamilton County Your certified letter dated 06/20/98 has been handed to me to respond to. You sent out a great deal of carbon copies to a lot of people, but you neglected to include their addresses. You will, therefore, have to send them a copy of my response. First of all, Mr. Ryan DeVries is not the legal landowner and/or contractor at 2088 Gray Road, Westfield, Indiana - I am the legal owner and a couple of beavers are in the (State unauthorized) process of constructing and maintaining two wood "debris" dams across the outlet stream of my Cool Creek Pond. While I did not pay for, nor authorize their dam project, I think they would be highly offended you call their skillful use of natural building materials "debris." I would like to challenge you to attempt to emulate their dam project any dam time and/or any dam place you choose. I believe I can safely state there is no dam way you could ever match their dam skills, their dam resourcefulness, their dam ingenuity, their dam persistence, their dam determination and/or their dam work ethic. As to your dam request the beavers first must fill out a dam permit prior to the start of this type of dam activity, my first dam question to you is: are you trying to discriminate against my Cool Creek Pond Beavers or do you require all dam beavers throughout this State to conform to said dam request? If you are not discriminating against these particular beavers, please send me completed copies of all those other applicable beaver dam permits. Perhaps we will see if there really is a dam violation of Part 301, Inland Lakes and Streams, of the Indiana Natural Resource and Environmental Protection Act, Act 451 of the Public Acts of 1994, being sections 324.30101 to 324.30113 of the Indiana Compiled Laws annotated. My first concern is - aren't the dam beavers entitled to dam legal representation? The Cool Creek Pond Beavers are financially destitute and are unable to pay for said dam representation - so the State will have to provide them with a dam lawyer. The Department's dam concern that either one or both of the dams failed during a recent rain event causing dam flooding is proof we should leave the dam Cool Creek Pond Beavers alone rather than harassing them and calling their dam names. If you want the dam stream "restored" to a dam free-flow condition - contact the dam beavers - but if you are going to arrest them (they obviously did not pay any dam attention to your dam letter-being unable to read English) - be sure you read them their dam Miranda rights first. As for me, I am not going to cause more dam flooding or dam debris jams by interfering with these dam builders. If you want to hurt these dam beavers - be aware I am sending a copy of your dam letter and this response to PETA. If your dam Department seriously finds all dams of this nature inherently hazardous and truly will not permit their existence in this dam State - I seriously hope you are not selectively enforcing this dam policy - or once again both I and the Cool Creek Pond Beavers will scream prejudice! In my humble opinion, the Cool Creek Pond Beavers have a right to build their dam unauthorized dams as long as the sky is blue, the grass is green and water flows downstream. They have more dam right than I to live and enjoy Cool Creek Pond. So, as far as I and the beavers are concerned, this dam case can be referred for more dam elevated enforcement action now. Why wait until 8/31/98? The Cool Creek Pond Beavers may be under the dam ice then, and there will be no dam way for you or your dam staff to contact/harass them then. In conclusion, I would like to bring to your attention a real environmental quality (health) problem; bears are actually defecating in our woods. I definitely believe you should be persecuting the defecating bears and leave the dam beavers alone. If you are going to investigate the beaver dam, watch your step! (The bears are not careful where they dump!) Being unable to comply with your dam request, and being unable to contact you on your dam answering machine, I am sending this response to your dam office. Sincerely, Jerry Bayne Owner of Cool Creek Pond cc: PETA

[Mike Ormsby]

Like I already said "Dam if we do or dam if we don't"!!! And ducktersman thanks for sharing -- funny stuff -- and those "dam" beavers.....