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HomeMy WebLinkAboutAPA24678730 ., .u. ~I 3.3.>0 susitna Ft a -n-- ALASKA COOPERATIVE WILDLIFE RESEARCH UNIT UNIVERSITY OF ALASKA, FAIRBANKS, ALASKA 99701 PHONE NUMBER 907479-7673 Dr. Olarles L. Elliott Biologist Harza-Ebasco Susitna Joint Venture 711 "B• Street Anchorage, Alaska 99501 tear Dr. Elliott: COOPERATORS: UNIVERSITY OF ALASKA ALASKA DEPARTMENT OF FISH AND GAME UNITED STATES FISH AND WILDLIFE SERVICE WILDLIFE MANAGEMENT INSTITUTE october 10, 1984 HARZA·EBASCO SUSJTNA HYDROELECTRIC PROJI:CT DOCUMENT ROUTING Enclosed is a table that provides information about the ilnporta'lCe to beaver of the 21 sloughs you listed in your letter of 11 September 1984. we just carpleted the beaver cache surveys for autumn 1984. '!he results of this survey and the 1983 cache survey :were used to develop the table. Sloughs listed in your letter were identified on Figues E.3.12 through E.3.17 in SWiitna Hydro.electric Project (Volune 6B, Chapter 3, prepared by ArnFS for the Alaska Power Aut:lx>rity). I had difficulty locating "side channel MS II" =at river mile 115.5 and 115.9, and differentiating bet~en Slough 8A (west) and Slough 8A (east). Also, Slough 22 is not identified on the Figures. Prc>bably the most significant factor in evaluating the inportance of a slough to beaver is whether or not beaver actually ovetwinter along the slough. '!be sites \!#here beaver overwinter provide seeur ity for the family and serve as natal dens. 'lbese oveiWintering sites are critical for the sur vi val of iOOi. vidual beaver colonies. Sloughs that support overwintering colonies are indicatecf on the enclosed table u t:HJ\rl~A 8bH.~t:O. All:oost all sloughs below POrtage Creek are visited by beavers during sl.II111ler and autum. Many of the sloughs provide excellent forage and several are 12 OCT 84 ~iodically dan&ned by beaverso Changing ice and/or overflow conditions probably wuld have little impact upon foraging use, but .relutively stable ice and water levels are needed around overwintering sites through the winter and early spring for beavers to surviveo IS. 1 ~t4A'cf rr ~ .fl0·';t h...Rae-4~ QJfe (,cee ~ ~ r. Enclosure cc: R. sener R. Fairbanks J. WOOlington Jt:/R.f /Zo.~ ~/ Jtd{,~r Sincerel. y~~~ )/·~ /v~}.2. • Philip S. Gipaon Assistant Unit Leader and Associate Ptofessor [}{)£00~£ 0 (g@£®©@ SUSITNA JOINT VENTURE INTRA-OFf-ICE MEMORANDUM Anchorage LOCATION October 31, 1984 DATE ------------------------ TO Gene Gemperline 4.3.3.2 NUMBER ------------------------- Chuck Elliott FROM SUBJECT Beaver-Ice Related Questions in the Susitna Ri~er Listed below is a key to explain the slides I received from Phil Gipson concerning beaver and ice problems in the Susitna River. Duplicate slides accompany this memo. Please pass the key and slides on to the same people in Chicago that received a copy of Gipson's Oct. 10, 1984, letter a SLIDE KEY: Beaver and Ice Related Slides A: Excellent overwintering site. Good food source, deep pools safe from ice damage. Steep mt;.d banks for burrows. B: Poor overwintering site even though food is abundant. steep banks or firm soil for burrows. No deep pools. to ice damage. Problem: no Area subject C: Typical beaver lodge (under red bush) and autumn food cache. D: Old lodge and autumn food cache. E: Site ~~~There beaver family did not survive wird:'.;.r. Lodge/bank den appeared to ha~Je been damaged by ice or high water. F: Lodge/bank den abandoned after receiving damage during spr~ng breakup. G: Cache washed away by high water in late August. hg 410901/11 ,...__