(07-24-2016, 11:23 AM)Octo Wrote: I was just reading about beavers and had to bump this thread again.
Evidently not all damn dams are detrimental to fish.
Effects on fish
Beaver ponds have been shown to have a beneficial effect on trout and salmon populations, in fact many authors believe that the decline of salmonid fishes is related to the decline in beaver populations. A study of small streams in Sweden found that brown trout in beaver ponds were larger than those in riffle sections, and that beaver ponds provide habitat for larger trout in small streams during periods of drought. These findings are similar to several studies of beaver effects on fish in North America. Brook trout, coho and sockeye salmon were significantly larger in beaver ponds than those in un-impounded stream sections in Colorado and Alaska. In addition, research in the Stillaguamish River basin in Washington state, found that extensive loss of beaver ponds resulted in an 89% reduction in coho salmon smolt summer production and an almost equally detrimental 86% reduction in critical winter habitat carrying capacity. Migration of adult Atlantic salmon (Salmo salar) may be limited by beaver dams during periods of low stream flows, but the presence of juveniles upstream from the dams suggests that the dams are penetrated by parr. Downstream migration of Atlantic salmon smolts was similarly unaffected by beaver dams, even in periods of low flows. Two year old Atlantic salmon parr in beaver ponds in eastern Canada showed faster summer growth in length and mass and were in better condition than parr upstream or downstream from the pond. The importance of winter habitat to salmonids afforded by beaver ponds may be especially important (and underappreciated) in streams without deep pools or where ice cover makes contact with the bottom of shallow streams. A 2003 study showed that Atlantic salmon and Sea trout (S. trutta morpha trutta) spawning in the Numedalslågen River and 51 of its tributaries in southeastern Norway were unhindered by beaver. In Norway, beaver dams are considered beneficial for Brown and Sea Trout populations (these are potamodromous and anadromous forms of the same species). There, beaver ponds produce increased food for young fish and provide refugia for large adults heading upstream to spawn.
Sorry about the wall of text
Everything has an ecological role to play, but the fish (salmon) have to get to the stream in the first place, hence fish ladders are a vital necessity.
I was reading about wolf and bear activity that creates balance.
I have no issue reading walls of text, but typing them, uh nah...I try to get to the point.
DISCLAIMER / Terms of Service (TOS):
Kritterbox.com - Socialize anonymously, commentary, discussion, oddities, technology, music and more! This website is provided "as is" without warranty of any kind, either expressed or implied. kritterbox.com shall not be liable for any damages whatsoever, including, without limitation, those resulting from loss of use, data or profits, whether or not advised of the possibility of damage, and on any theory of liability, arising out of or in connection with the use or performance of this site or other documents which are referenced by or linked to this site.
This website exists solely for the purposes of exchange of information, communication and general entertainment. Opinions from posters are in no way endorsed by kritterbox.com. All posts on this website are the opinion of the authors and are not to be taken as statements of fact on behalf of kritterbox.com. This site may contain coarse language or other material that kritterbox.com is in no way responsible for. Material deemed to be offensive or pornographic at the discretion of kritterbox.com shall be removed. kritterbox.com reserves the right to modify, or remove posts and user accounts on this website at our discretion. kritterbox.com disclaims all liability for damages incurred directly or indirectly as a result of any material on this website. Fictitious posts and any similarity to any person living or dead is coincidental.
All users shall limit the insertion of any and all copyrighted material to portions of the article that are relevant to the point being made, with no more than 50%, and preferably less of the original source material. A link shall be visible in text format, embedded directly to the original source material without exception.
No third party links, i.e. blogs or forums will be accepted under any circumstances, and will be edited by staff in order to reflect the original source of copyrighted material, or be removed at the sole discretion of kritterbox.com.
Fair Use Notice:
This site may contain copyrighted material the use of which has not always been specifically authorized by the copyright owner. Users may make such material available in an effort to advance awareness and understanding of issues relating to economics, individual rights, international affairs, liberty, science, and technology. This constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C.Section 107, the material on this site is distributed without profit to those who have expressed a prior interest in receiving the included information for educational and/or research purposes.
This Disclaimer is subject to change at any time at our discretion.
Copyright © 2011 - 2017 kritterbox.com