Technical Bulletin No. 0899: The Effects of a Bleached Kraft Mill Effluent on Periphyton and Macroinvertebrates in a Streamside Mesocosm Study – Willamette River, Oregon

A streamside mesocosm study was conducted to evaluate the potential effect of a bleached kraft mill effluent discharge to the Willamette River near Halsey, Oregon. The 28-d study was carried out in circular tanks containing native river riffle substrate which was seeded with river macro-invertebrates and allowed to colonize a growth of periphyton (primarily aquatic algae). The mesocosm system included three replicate control tanks and three replicates each of effluent exposures representing concentrations of 0.