|A common artefact in estimates of benthic community respiration caused by the use of stainless steel|
Cramer, A. (1989). A common artefact in estimates of benthic community respiration caused by the use of stainless steel. Neth. J. Sea Res. 23(1): 1-6
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
To estimate the marine benthic community respiration, two methods have been widely applied during recent years, viz. in situ measurements using stainless steel bell-jars and shipboard incubations of sediment cores kept under ambient conditions. The results of the two methods applied to sediment cores at one location proved significantly different, with the in situ measurement showing the higher rates of oxygen uptake. Laboratory calibration experiments of the two methods showed that the stainless steel respiration chamber caused serious artefacts in the measurements. In contact with the sediment, stainless steel has a strongly negative potential against a saturated calomel electrode, so that the stainless steel bell-jar is acting as a cathode upon which the oxygen in the enclosed volume of water if the bell-jar is reduced. The reaction, detectable in changes of O2 concentration, pH and alkalinity, is also well known from polarographic techniques and explains most of the differences in oxygen loss found between the two methods applied in the laboratory, as well as between in situ measurements and shipboard incubations.