EXPLORING SEDIMENT STABILITY, TURBIDITY, AND NUTRIENT FLUX USING EROSION MESOCOSMS

The UMCES Gust Erosion Microcosm System (U-GEMS) is a tool for assessing the erodibility of aquatic sediments and can be adapted to a wide variety of applications and research questions. To date, the U-GEMS has been used in studies ranging in topic from erodibility and suspended solids loading to contaminant mobilization from sediments. Here, we present two case studies highlighting the adaptability of this tool and its utility for studying aquatic health in response to ecosystem changes affecting sediment erosion or resuspension. The first case study details how the U-GEMS was used to measure internal phosphorus loading related to sediment resuspension in several reservoirs experiencing harmful algal blooms (HABs). Sediments with the highest potential for resuspension, as determined by the U-GEMS experiments, also contained the highest concentrations of total phosphorus, which will have consequences for long-term lake health and HAB mitigation. In the second case study, the U-GEMS was used to assess the stability of sediments within wildrice stands in northern Michigan. Wildrice is susceptible to sediment disturbance via uprooting in low density sediments. Sediment cores were collected from five lakes with variable amounts of wildrice to investigate the relationship between wildrice plant density and sediment stability. Generally, results indicated that lakes with less erodible sediments had higher densities of wildrice and more consistent wildrice densities from year-to-year.

Primary Presenter: Marissa Kneer, US Army Corps of Engineers - Engineering Research and Development Center (marissa.l.kneer@usace.army.mil)

Authors:

Marissa Kneer, US Army Corps of Engineers - Engineering Research and Development Center  (marissa.l.kneer@usace.army.mil)

Nia Hurst, US Army Corps of Engineers - Engineering Research and Development Center  (Nia.R.Hurst@usace.army.mil)

Kevin Philley, US Army Corps of Engineers - Engineering Research and Development Center  (kevin.d.philley@usace.army.mil)

Jacob Berkowitz, US Army Corps of Engineers - Engineering Research and Development Center  (jacob.f.berkowitz@usace.army.mil)