Spatial characteristics of meiobenthic community of Kongsfjorden sediment in the Svalbard Island, the Arctic Sea

Abstract

The community structure of meiobenthos was studied in the sediment of Kongstorden, Spitsbergen of Svalbard Island in the Arctic Sea. Samples of meiobenthos were collected in August, 2003. Meiobenthic organisms were collected by SCUBA and van veen grab or acryl sub-corers 34 mm in internal diameter, and were taken from upper sediment to a depth of 3 cm at each station. A total of 26 meiofaunal groups were found in the sediment of Spitsbergen in Svalbard Island. Nematodes were the most dominant faunal group. Sarcomastigophorans, benthic harpacticoids, and nauplius larvae of crustaceans, were also important components of the meiobenthic community of Kongsfjorden. All of these four faunal groups were comprised of more than 90% of total meiobenthos at every station. The total density of meiobenthos at each station was highest at station MeG 6 (3,583 ± 1,137 inds./10 cm2), and lowest at station MeG 9 (28± 1 inds./ 10 cm2). Meiobenthos in general showed the highest density in the upper 1 cm layer. This may be associated with food and oxygen supply to subsurface. Harpacticoids showed extreme preference at the surface and little presence in layers deeper than 2 cm. These animals may be less resistant to oxygen deficiency, and nauplius also showed the same trend. However, in St. MeG 8 and 9, meiobenthos were dense at depths of more than 0- 1 cm, at especially at depths of 2-3 cm because of relatively easy penetration of oxygen. Based on the results of cluster analysis, three meiobenthos assemblages were distinguished: one was in the outer and two were in the inner fjord. Station SCU 5 was grouped with the meiobenthos assemblage located in the outer fjord. The outer ljord community was characterised by: 1) a relatively low mean number of meiobenthos taxa, 2) a relatively high density of harpacticods and nauplius. One of the inner fjord communities (a group of four stations: MeG 2, 3, 8, 9) was in the proximity of the glaciers. Specifically, it was characterised by: 1) a low mean number of meiobenthos taxa, 2) a low density. The other inner fjord community was characterised by both a high density and great mean number of meiofaunal taxa.