ABSTRACT: Nematode alpha diversity from 3 physically disturbed sites in the deep North Atlantic was compared with reference sites. Nematode diversity at the HEBBLE benthic storm site was statistically, and significantly, lower than at reference sites. Nematode diversity at the Madeira Abyssal Plain site, which was subject to a turbidite dated at 930 BP, also showed a significantly lower diversity than reference sites. However, limited data suggest that diversity was not low at a Venezuela Basin turbidite site. The difference in nematode diversity between the 2 turbidite sites is ascribed to a long term change in sediment conditions at the Madeira site. The Venezuela Basin turbidite site has a sedimentation rate greater than the Maderia site by 1 to 2 orders of magnitude, and this was reflected in the sediment profiles. Another possibility is that the Venezuela Basin turbidite is considerably older, by at least 1000 yr, than the Madeira turbidite, allowing more time for recolonisation. The data suggest that deep-sea nematode diversity may be affected by physical disturbance but that deep-sea nematodes, like their shallow counterparts, are more robust than macrofauna such as polychaetes to such impacts.
KEY WORDS: Physical Disturbance · Deep Sea · North Atlantic · Nematodes
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