Preface The expedition ARK XIX/3 with the German icebreaking RV ...

parts of the central mound, indicating the need of these suspension feeders
for high current speeds.
- Patches of gorgonians consist of single gorgonians growing on a hard
substrate away from the moving sediments on the bottom, but without being
abundant. Such formations were observed on the mounds as well as off
mound, indicating that the gorgonians tolerate diverse environments.
- Gorgonians on dropstones are another distinct form in which this group
of substrate feeding octocorals is present. Single gorgonians attach and
grow on dropstones that provide hard substrate and elevation above the
sandy bottom.
- Stylasterid fields occur at the central area of the ridge, a peculiar formation
that was not observed in any of the previous dives. The observed
stylasterids were quite large indicating that they are old.
- Cidaris cidaris, black sea urchin and other mobile echinodermates –
this diverse community was observed on sandy tracks of the dive where
there is no hard substrate that allows the growth of nekton fauna. The
predominant species is Cidaris cidaris, with occurrences of black sea
urchins, different astrozoans and other mobile echinodermates. The mobility
of these species allows them to change their position and react to the rapid
changes on the seabed that occur because of sediment transport.
- Crinoides communities – suspension feeding nekton echinodermates that
are found in large quantities in one area on the western side of the mound.
- Antipatharia communities consist of hexacorals (they are not reef
builders) that are attached to the hardground at a few spots on the eastern
side of the mound.
- Crustaceans high concentration – in one area of the mound high
concentrations of crustaceans were observed. The same place is mapped
as an area with the occurrence of Lophelia on dropstones, the crabs use the
corals as shelter.
- Dropstone communities – a term that is used to describe a diverse group
of nekton fauna that grows on dropstones throughout the area. This
includes Lophelia and Madepora, gorgonians, different species of sea
urchins, anemones etc. This community supports a variety of deep sea fish
and crustaceans that use the nekton and the dropstones as a hideout from
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