The deep sea is the largest environment on the planet,
the least well known and one of the least studied.
It contains extremely large habitats, and millions
of km2 of continental slopes and abyssal plains. These
incorporate other geological structures, including canyons,
seamounts, reefs, hydrothermal vents, mud volcanoes,
and faults at active and passive margins, which
support unique microbiological and faunal communities.
Despite our limited knowledge of deep-sea biodiversity,
we now know that the Southern Ocean (SO)
deep sea is very speciose within many taxa, and it is
therefore likely that more species occur in the deep
sea than any other biome on earth (Gage&Tyler, 1991).
In many taxa far more than 90% of the species collected
in a typical abyssal sediment sample are new to science,
50% of these appear to be rare
(Glover et al., 2002; Brandt et al., 2007a–c; Ellingsen
et al., 2007; Smith et al., 2008). Some authors have
demonstrated that the occurrence of rare species in
samples is the result of sampling the regional fauna
only (Rex et al., 2005b). However, analyses comparing
abundance across different spatial scales in SO deepsea
isopods have revealed high biological variability,
which indicates patchiness rather than rarity, of most
isopod taxa (Kaiser et al., 2007).
Authors: Brandt, A., De Broyer, C., Ebbe, B., Ellingsen, K.E., Gooday, A.J., Janussen, D., Kaiser, S., Linse, K. ORCID record for K. Linse, Schueller, M., Thomson, M.R.A., Tyler, P.A., Vanreusel, A.
Editors: Rogers, Alex D., Johnston, Nadine M., Murphy, Eugene J., Clarke, Andrew