Publikationsdatum:
2014-10-07
Beschreibung:
Effects of increased near-bottom flow velocities on the sedimentary environment and its
associated small biota were studied in a long-term in situ experiment at 2,500 m water depth at the
Deep-Sea Observatory HAUSGARTEN in the eastern Fram Strait. In 2003, the Remotely Operated
Vehicle (ROV) "Victor 6000" was used to install a stainless steel flume of about 8.5 m in length,
consisting out of a 6 m long passageway with a cross-section of 50 x 50 cm and 3-4 m wide funnel-like
doorways to increase bottom currents by a factor of approximately 6. Sediment sampling for
biochemical sediment analyses, bacterial studies and meiofaunal investigations (with special focus on
the nematode communities) was carried out four years after the installation of the flume using the ROV
"Quest 4000". The data showed clearly reduced values for parameters indicating organic matter (food)
availability in the sediments, and corresponding lower bacterial and meiofaunal densities inside the
flume, compared to control sites outside the channel. Results suggest that increased near-bottom
currents and food deficiency not only diminish sediment-inhabiting meiofaunal assemblages but also
alter the meiobenthic composition. Compared to background sediments, the nematode community
inside the flume evidently showed adaptations to the overall reduced food availability and a more
heterogeneous environment due to generally increased and more turbulent flow velocities. The
variable environmental conditions inside the flume have an effect not only on the number of genera
present, but also on the identities of the genera and the functional composition of the nematode
community.
Repository-Name:
EPIC Alfred Wegener Institut
Materialart:
Article
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isiRev
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