Quantitative distribution of the meiobenthos in the Large Aral Sea in 2003 and 2004

Living meiobenthos samples were collected in the Large Aral Sea in 2003 and 2004 from water depths ranging from 0 to 39 m. The near-bottom water salinity at the sampling sites varied from 88 to 109‰. Meiobenthos, which occurred at all stations, consisted of nematodes, harpacticoides, ostracods and turbellarians. Unicellular organisms (foraminifera) were also present. The density of meiobenthos showed a significant spatial variation. Nematodes predominated in most samples. The maximal abundance of free-living nematodes (1440 specimens/10 cm2) was recorded in 2003 at a depth of 10 m, at a site with 88.9‰ salinity and a water temperature of 13.6 °C. The maximal abundance of nematodes in 2004 was 750 specimens/10 cm2 at about the same depth and salinity, but with a considerably higher water temperature (24.5 °C). The highest value for the harpacticoid copepods density was 116 specimens/10 cm2 at 1 m depth. The high spatial meiobenthos variation is to a considerable extent related to the sediment characteristics at the sampling stations.