Publication Date:
2015-10-26
Description:
Benthic oxygen and nitrogen fluxes were quantified within the years 2012 to 2014 at different time series
sites in the southern North Sea with the benthic lander NuSObs (Nutrient and Suspension Observatory).
In situ incubations of sediments, in situ bromide tracer studies, sampling of macrofauna and pore water
investigations revealed considerable seasonal and spatial variations of oxygen and nitrogen fluxes.
Seasonal and spatial variations of oxygen fluxes were observed between two different time series sites,
covering different sediment types and/or different benthic macrofaunal communities. On a sediment type
with a high content of fine grained particles (o63 mm) oxygen fluxes of �15.5 to �25.1 mmol m�2 d�1
(June 2012), �2.0 to �8.2 mmol m�2 d�1 (March 2013), �16.8 to �21.5 mmol m�2 d�1 (November 2013)
and �6.1 mmol m�2 d�1 (March 2014) were measured. At the same site a highly diverse community of
small species of benthic macrofauna was observed. On a sediment type with a low content of fine grained
particles (o63 mm) high oxygen fluxes (�33.2mmol m�2 d�1 August 2012; �47.2 to �55.1 mmolm�2 d�1
November 2013; �16.6 mmol m�2 d�1 March 2014) were observed. On this sediment type a less diverse
benthic macrofaunal community, which was dominated by the large bodied suspension feeder Ensis directus,
was observed.
Average annual rain rates of organic carbon and organic nitrogen to the seafloor of 7.44 mol Cm�2 y�1 and
1.34 mol N m�2 y�1 were estimated. On average 79% of the organic bound carbon and 95% of the organic
bound nitrogen reaching the seafloor are recycled at the sediment–water interface.
& 2015 Elsevier Ltd. All rights reserved
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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