Aquatic Sciences Meeting, Albuquerque 2001

SS08 Processes at the Benthic Interface (Environmental Connections)

Date: Wednesday, February 14, 2001, Time: 10:00:00 AM

Location: Ruidoso/Pecos

Coley, T, L, Horn Point Laboratory, UMCES, Cambridge, USA, tcoley@hpl.umces.edu

Cornwell, J, C, Horn Point Laboratory, UMCES, Cambridge, USA, cornwell@hpl.umces.edu

THE RESPONSE OF OXYGEN PENETRATION DEPTH TO FLOW AND ORGANIC CARBON LOADING IN DIFFUSIVELY CONTROLLED SEDIMENTS

Redox species zonation in aquatic sediments is determined by oxygen penetration into the sediments. Two of the primary factors influencing oxygen penetration depth (OPD) in diffusively controlled sediments are organic carbon loading and flow across the sediment surface, which determines the height of the diffusive boundary layer (DBL). A range of flow rates and organic carbon levels were imposed upon homogenized, macrofauna-free fine-grained sediment cores with circular stirring mechanisms. Stir rate was varied from 15 rpm to 100 rpm to manipulate DBL. Organic carbon loading was varied from less than 1 gC/m2 to 44 gC/m2, along with stir rate, to manipulate OPD. Direct measurements of OPD and DBL were made at 3 locations across the radial area of the cores using oxygen microelectrodes. The measured DBL's ranged from approximately 1.2 mm at the low stir rate to 0.23 mm at the high stir rate. The resultant OPD's ranged from 0 mm to 2 mm.

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Aquatic Sciences Meeting, Albuquerque 2001

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