Publication Date:
2017-07-05
Description:
Little is known about the production of fluorescent dissolved organic matter (FDOM) in the anoxic
oceanic sediments. In this study, sediment pore waters were sampled from four different sites in the
Chukchi-East Siberian Seas area to examine the bulk dissolved organic carbon (DOC) and their optical
properties. The production of FDOM, coupled with the increase of nutrients, was observed above the
sulfate-methane-transition-zone (SMTZ). The presence of FDOM was concurrent with sulfate reduction
and increased alkalinity (R2 〉 0.96, p 〈 0.0001), suggesting a link to organic matter degradation. This
inference was supported by the positive correlation (R2 〉 0.95, p 〈 0.0001) between the net production
of FDOM and the modeled degradation rates of particulate organic carbon sulfate reduction. The
production of FDOM was more pronounced in a shallow shelf site S1 with a total net production ranging
from 17.9 to 62.3 RU for different FDOM components above the SMTZ depth of ca. 4.1 mbsf, which
presumably underwent more accumulation of particulate organic matter than the other three deeper
sites. The sediments were generally found to be the sources of CDOM and FDOM to the overlying water
column, unearthing a channel of generally bio-refractory and pre-aged DOM to the oceans.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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