Characterisation of the nematode community of a low-activity cold seep in the recently ice-free Larsen B area, Eastern Antarctic Peninsula

• Main Authors: Hauquier, Freija, Ingels, Jeroen, Vanreusel, Ann
• Format: Conference Object
• Language: English
• Published: Royal Belgian Zoological Society (RBZS) 2010
• Subjects: Biology and Life Sciences; Antarctic; Antarctic Peninsula; Drake Passage; Weddell; Weddell Sea; Antarc*; Ice Shelf; Ice Shelves
• Online Access: https://biblio.ugent.be/publication/1946973; http://hdl.handle.net/1854/LU-1946973

The metazoan meiofauna of a low-activity cold seep beneath the former Larsen B ice shelf (Eastern Antarctic Peninsula) was analysed with special emphasis on the nematode community. The recent collapse of both Larsen A and B ice shelves (1995-2002) formed an unprecedented opportunity to assess sub-ice-shelf benthic community structure. Following the large-scale disintegration of both ice shelves, new habitats have been discovered in the area, including a methane seep in the trough formed by two glaciers at a depth of 820m. Identification of nematodes from this area was carried out at genus level, and at species level for the dominant ones, and the composition of these seep samples was compared to other recently ice-free Larsen A and B stations and other Antarctic shelf areas (Weddell Sea and Drake Passage). Nematode communities in the seep area differed significantly from the other stations in terms of dominant genera, diversity and abundance. Densities in the seep samples were relatively high compared to adjacent non-seep stations and showed subsurface maxima at a sediment depth of 2-3cm. All samples were dominated by one species of the family Monhysteridae, which was identified as a Halomonhystera species. The combination of high densities, subsurface maxima and dominance of one species indeed implied a dependence upon a chemosynthetic food source, hence cold seep activity. It seems that climate-induced ice shelf disintegration in the Larsen area has uncovered unique and complex benthic communities which will require more detailed studies if we want to understand their ecology to a full extent.