Title

Stream ecosystem process responses to stamp sand stabilization in tributaries of Lake Superior

Document Type

Conference Proceeding

Publication Date

5-2015

Abstract

Historical copper-rich mining residue in the form of stamp sands were deposited widely along streams and lakes in the Western Upper Peninsula and are an important source of pollution affecting Lake Superior and its tributaries. The Hills Creek Stamp Sand Stabilization project has taken an innovative approach to stabilize and vegetate riparian aggradations of stamp sand, with the ultimate goals of reducing copper concentrations and benefiting the riverine food web and fisheries. We aimed to enhance understanding of ecological responses to this restoration by measuring ecosystem processes (material retention, nutrient uptake, decomposition, primary production, respiration, and organic matter transfer to fishes) in restored and unrestored reaches of Hills Creek and in two adjacent rivers without stamp sands. We found that different processes respond to varying degrees to restoration activities. For example, ammonium uptake was rapid in the restored and all reference reaches, but not detected in an unrestored reach dominated by stamp sands. However, organic matter retention showed little difference among reaches, and was instead related to presence large woody material. Ecosystem processes may be useful for understanding the mechanisms underlying responses of fish populations and stream food webs to river restoration.

Publication Title

58th Annual Conference on Great Lakes Research