HR: 1330h
AN: B33E-28    [Abstracts]
TI: Multi-scale Factors Affecting the Distribution of the Critically Imperiled Crayfish, Orconectes williamsi, in the Upper White River Drainage of Missouri, USA
AU: Westhoff, J T
EM: Jacob.Westhoff@mdc.mo.gov
AF: Missouri Department of Conservation, 1110 South College Ave., Columbia, MO 65201 United States
AU: * DiStefano, R J
EM: Bob.DiStefano@mdc.mo.gov
AF: Missouri Department of Conservation, 1110 South College Ave., Columbia, MO 65201 United States
AU: Guyot, J A
EM: guyot@vt.edu
AF: Virginia Tech, Department of Fisheries & Wildlife, 149 Cheatham Hall, Blacksburg, VA 24060 United States
AU: McManus, M G
EM: Mike.McManus@mdc.mo.gov
AF: Missouri Department of Conservation, 1110 South College Ave., Columbia, MO 65201 United States
AB: Orconectes williamsi is known from only a few locations in the upper White River drainage of Missouri and Arkansas. We implemented a stratified (by stream order) random survey to sample for this crayfish in Missouri in 2003-04. Survey objectives were twofold. First, we estimated the overall proportion of stream order segments (segments of streams between points where stream order changes) in the drainage harboring O. williamsi, and then estimated the proportion of first, second and third (or larger) order stream segments harboring this crayfish. Second, we obtained means or ratio estimators (point estimates) and 95 % confidence limits (interval estimates) for 62 environmental variables and conducted overall contrasts of those estimates between segments that did and did not harbor O. williamsi. For significant overall contrasts, we then conducted contrasts partitioned by stream order. We detected O. williamsi at an overall proportion of 0.34 of 50 sampled segments, with no difference between first and second order stream segments. Variables exhibiting differences between segments that did and did not harbor O. williamsi included bankfull width:bankfull depth ratio, wetted width:wetted depth ratio, macrophyte abundance, elevation, and stream connectivity. Results will be used to drive future sampling and conservation efforts.
DE: 9800 GENERAL OR MISCELLANEOUS
SC: Biogeosciences [B]
MN: 2005 Joint Assembly