Van Gaever, S.; Raes, M.; Pasotti, F.; Vanreusel, A. (2009). Spatial scale and habitat-dependent diversity patterns in nematode communities in three seepage related sites along the Norwegian Sea margin. Marine Ecology. 31(1): 66-77.
Assessing the relative contribution of local diversity to regional biodiversity
may be the key to understanding large-scale and even global patterns in species
diversity. Here, the contribution of habitat heterogeneity of cold seeps at three
spatial scales [micro-scale (ms), macro-scale (10 to 100s of ms), and mega-scale
(10 to 100s of km)] to the total nematode biodiversity (genus level) along the
Norwegian continental margin is evaluated. Due to the development of higher
resolution bathymetry and increased bottom sampling in recent years, continental
margins, once regarded as monotonous landscapes, are now acknowledged
to have a high degree of habitat complexity and diversity. By calculating
the additive partitioning of gamma diversity in alpha and beta fractions, we
examined to what extent habitat diversity of seep sites significantly increases
the nematode genus composition and diversity at different spatial scales. Siboglinidae
patches and control sediments yielded comparably high levels of nematode
genus richness. They exhibited low turnover rates within and across the
different seep sites. In contrast, the bacterial mats at Ha°kon Mosby Mud Volcano
(HMMV) and the reduced sediments at the Nyegga pockmarks harboured
genus-poor nematode communities with an equally high dominance of one or
two species, which were different for each seep. Different habitats, in particular
at the HMMV, contributed significantly to the seep nematode richness. This
study demonstrates that the presence of distinct habitat types within multiple
seep sites contributes to the high diversity of nematode communities inhabiting
the seeps in the Norwegian deep sea.