2023 Early Hearing Detection & Intervention Conference
March 5-7, 2023 • Cincinnati, OH
5/24/2018 | 9:45 AM - 10:00 AM | STREAM BEDFORM AND HYPORHEIC FLOWS: EFFECTS ON METAL BIOAVAILABILITY AND BIOLOGICAL COMMUNITIES IN SEDIMENTS | 410 B
STREAM BEDFORM AND HYPORHEIC FLOWS: EFFECTS ON METAL BIOAVAILABILITY AND BIOLOGICAL COMMUNITIES IN SEDIMENTS
In metal contaminated streams, the direction of hyporheic flow (upwelling or downwelling) may influence sediment redox conditions and metal speciation, resulting in a range of effects for aquatic organisms. This study investigates the potential for metal toxicity in the head (upstream) and tail (downstream) ends of riffles in a Southeastern Michigan stream. In situ experiments were paired with artificial stream mesocosms. Sediments from a stream with low zinc contamination were deployed for 30 days and effects to sediment geochemistry, metal chemistry, biofilms and benthic macroinvertebrates were assessed. The riffle head was more oxidized and had higher pH. The more oxidized conditions correlated with greater bioavailable metals (i.e., (SEM-AVS)/fOC). Similar results from pH and redox were found in the mesocosm experiments. In the in situ experiment, macroinvertebrate community diversity and sensitivity were higher in the riffle head, where risk to metal contamination was higher. Biofilm net primary production declined with increased (SEM-AVS)/fOC. This research suggests that stream bedform location can alter processes in the hyporheic zone by affecting redox conditions, and if metal concentrations are high enough, could increase exposure of metals to aquatic biota.
- Sediment
- Hyporheic
- Biofilm
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Presenters/Authors
Anna Harrison
(), Institute for Great Lakes Research, Central Michigan University, harri25a@cmich.edu;
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Nonfinancial -