HR: 15:30h
AN: NB44D-01    [Abstracts]
TI: Effects of Lake Trout (Salvelinus namaychush) on Arctic Char (S. Alpinus) Populations in Arctic Alaska
AU: * Keyse, M D
EM: mdkeyse@uncg.edu
AF: University of North Carolina at Greensboro, Department of Biology, Greensoboro, NC 27402 United States
AU: Hershey, A E
EM: aehershe@uncg.edu
AF: University of North Carolina at Greensboro, Department of Biology, Greensoboro, NC 27402 United States
AU: Fortino, K
EM: kfortino@email.unc.edu
AF: University of North Carolina, Department of Environmental Sciences and Engineering,, Chapel Hill, NC 27599 United States
AU: Luecke, C
EM: luecke@cc.usu.edu
AF: Utah State University, Department of Aquatic, Watershed and Earth Resources, Logan, UT 84322 United States
AB: Lake trout (Salvelinus namaychush) and arctic char (S. Alpinus) typically are not found coexisting in arctic Alaskan lakes. Lake trout and artic char are generally top predators in lakes where they do not coexist. During the summer of 2004, I examined the effects of lake trout on dietary and habitat selection of arctic char near the Toolik Lake Field Station in arctic Alaska. I examined lakes containing either lake trout or arctic char as the top predator, and lakes containing both lake trout and arctic char. Natural abundace of Δ ¹⁵N and Δ ¹³C of seston, zooplankton, macroinvertebrates, and fish were used to construct food webs to examine any dietary and habitat shifts of arctic char and lake trout when they coexist. Lakes differed in ¹³C signature of basal resources, but fish tracked benthic ¹³C in all cases. However, lake trout were more enriched in ¹⁵N than arctic char, suggesting greater piscivory. These results strongly suggest that interspecific interactions are not very important in determining the trophic position of top predators in arctic lakes.
DE: 1845 Limnology
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly