Year of Award


Document Type


Degree Type

Master of Science (MS)

Degree Name

Systems Ecology

Department or School/College

College of Forestry and Conservation

Committee Chair

Benjamin P. Colman

Commitee Members

Robert O. Hall, Sean P. Sullivan


metal accumulation pathways, dietary bioaccumulation


University of Montana

Subject Categories

Natural Resources and Conservation


It is well established that aqueous exposure and dietary exposure both lead to the accumulation of metals and metalloids in aquatic organisms living in a contaminated environment, but the relative contribution of each remains unclear. To examine how a contamination gradient affects patterns of metal(loid)s among periphyton, BPOM (benthic particulate organic matter), water, and sediment, we collected samples from multiple sites across a 210km stretch of the mine-contaminated Upper Clark Fork River, Montana. To investigate metal(loid) accumulation patterns among basal resources and aquatic insects, we collected samples of periphyton, BPOM, and larval insects from discrete habitat types at a single site. We analyzed all samples for the metalloid arsenic (As) and the metals cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn). We found that patterns in the aqueous metal and metalloid concentrations on a longitudinal scale did not show complete alignment with patterns of concentrations in BPOM and sediment and did not fully align with concentrations in periphyton. The disconnect between concentration patterns suggests that aqueous metal concentrations may not be driving metal accumulation in these environmental compartments. We also found that basal resources and aquatic insects differed in metal(loid) concentration depending on the habitat they were collected from, with wood habitats seemingly a driver of accumulation through diet. We suggest that feeding strategy, and thus diet, is partly responsible for overall accumulation patterns in aquatic insects living in a contaminated river.



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