Modern assemblage changes of benthic algae as a result of hypersalinization of the Aral Sea

Variability in precipitation, temperature and river runoff in W Central Asia during the past ~2000yrs

“…Relatively low lake levels can further be identified by horizons enriched in molluscs, which are confined to the photic zone because they are feeding on algae (Sapozhnikov et al, 2009). They can therefore be used for tracing either later regressive or early transgressive phases (Fig.…”

Diatom assemblage variations in the Aral Sea core C2/2004 over the past two millennia.

“…3). Diatoms that are generally considered to be oligohalobous (C. placentula, N. fonticola) and are frequently used as indicators of low salinity presently occur in the Aral Sea at salinities exceeding 100 ‰ (saPozhnikov et al 2009). Therefore, their abundance may be controlled by factors other than salinity.…”

“…The salinity range of this species is wide, e.g. its reported optimum varies from saPozhnikov et al 2009). High abundances of Navicula digitoradiata (GreGory) ralfs (Fig.…”

“…This species is mainly abundant when the sediment contains a very high diatom concentration that point to a relatively low dissolution rate of the frustules within the water column. Although A. octonarius is a marine diatom it was a dominant species in the Aral Sea in 1960(mirabdullayev et al 2004). saPozhnikov et al (2009 pointed to the dependence of diatom assemblage composition on water depth.…”

“…1 to more than 100 ‰ (saPozhnikov et al 2009) in the Western Basin. At least from 1853 until 1961, the Aral Sea had been a relatively stable water body with secular variations of the water level less than 3 m (kawabata et al 1997).…”