HR: 08:45h
AN: NB51C-02    [Abstracts]
TI: The influence of catchment geology on water quality and benthic macroinvertebrate communities in streams from the Colorado Mineral Belt.
AU: * Schmidt, T S
EM: tschmidt@lamar.colostate.edu
AF: Colorado State University, Fishery and Wildlife Department, Fort Collins, CO 80521 United States
AU: Church, S E
EM: schurch@usgs.gov
AF: United States Geologic Service Mineral Resource Team, MS 973 Denver Federal Center, Denver, CO 80225-0046 United States
AU: Wanty, R B
EM: rwanty@usgs.gov
AF: United States Geologic Service Mineral Resource Team, MS 973 Denver Federal Center, Denver, CO 80225-0046 United States
AU: Fey, D L
EM: dfey@usgs.gov
AF: United States Geologic Service Mineral Resource Team, MS 973 Denver Federal Center, Denver, CO 80225-0046 United States
AU: McEachron, L
EM: lucasmc@holly.colostate.edu
AF: Colorado State University, Fishery and Wildlife Department, Fort Collins, CO 80521 United States
AU: Crock, J G
EM:
AF: United States Geologic Service Mineral Resource Team, MS 973 Denver Federal Center, Denver, CO 80225-0046 United States
AU: Adams, M
EM:
AF: United States Geologic Service Mineral Resource Team, MS 973 Denver Federal Center, Denver, CO 80225-0046 United States
AU: Anthony, M W
EM:
AF: United States Geologic Service Mineral Resource Team, MS 973 Denver Federal Center, Denver, CO 80225-0046 United States
AB: The influence of catchment geology on stream geochemistry and aquatic communities in streams located in the central part of the Colorado Mineral Belt was investigated. Catchments (n=44) were selected based on being underlain by a single (n=23) or a combination from among eight lithologies (e.g., pluton, mafic metavolcanic, tuff). Water quality and Hess samples of benthic macroinvertebrate communities (n=5) were collected from one representative riffle area along each stream. Statistical differences observed (ANOVA, Dunnet's C post hoc test, p<0.05) in water quality parameters (e.g., Cd²⁺, Cu²⁺, Zn²⁺, Ca²⁺, Mg²⁺, pH) and benthic community metrics (e.g., richness, EPT-richness) were attributable to catchment geology categorization. Principle components analysis described over 94% of the variation in water quality data and showed both negative [Cd²⁺, Cu²⁺, Zn²⁺] and positive [CaCO₃, Cl^-, Mg²⁺] gradients among streams sampled. Stepwise canonical discriminant function analysis of community composition data resulted in 87% correct classified of apriori catchment geology groupings. Intensity of hydrothermal alteration and/or historical mining activity within geologic units contributed to variability in stream chemistry and community ecology measures. Expansion of the study will include additional stream sampling and the analysis of stream and catchment-scale habitat data.
DE: 0614 Biological effects
DE: 1065 Trace elements (3670)
DE: 4804 Benthic processes/benthos
DE: 4825 Geochemistry
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly