ISSN:
1573-5117
Keywords:
sediment oxygen demand
;
interstitial water
;
hypolimnion
;
methane
;
ammonium
;
iron
;
manganese
;
oxidation
;
sediment-water interface
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Sediment pore water concentrations of Fe2+, Mn2+, NH inf4 sup+ and CH4 were analyzed from both diver-collected cores and an in situ equilibration device (peeper) in Lake Erie's central basin. Sediment oxygen demand (SOD) was measured at the same station with a hemispheric chamber (including DO probe and recorder) subtending a known area of sediments. The average SOD was 9.4 mM m−2 day−1 (0.3 g m−2 day−1). From pore water gradients within the near-surface zone, the chemical flux across the interface was calculated indirectly using Fick's first law modified for sediments. These calculations, using core and peeper gradients, always showed sediment loss to overlying waters, and variations between the two techniques differed by less than an order of magnitude for Fe2+ and CH4. The transport of these reduced constituents can represent a sizeable oxygen demand, ranging from less than 1% for Fe2+ and Mn2+ to as high as 26% for NH inf4 sup+ , and 30% for CH4. The average flux of these constituents could account for about a third of the SOD at the sediment-water interface of this station.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00000040
