Study the Distribution and Abundance of Zooplankton in Shore Water of South Caspian Sea (Case Study: Chalus and Noshahr Region)

The aim of this study was to evaluate the biodiversity of zooplankton in the Caspian Sea basin in Noshahr and Chalus.

Sampling was carried out in three transects including depths (5–10 and 20 m) in two seasons of 2013 (autumn and winter).  Totally, 8 zooplankton groups were identified during two seasons. In autumn, the highest abundance belonged to bivalve larvae (8060 ind/m3) and the least abundance belonged to polychaetes species N. diversicolor (299 ind/m3). In winter, Rotifera species Asplanchna sp. (6877 ind/m3) had the highest abundance. The least abundance belonged to one of the larval stages of Barnacle (Cypris of Balanus sp.) (372 ind/m3).

In each of the two seasons, the abundance of zooplankton groups had significant differences in most of the stations (P <0.05). Also in autumn and winter, all identified zooplankton groups had uniform distribution. Values of species diversity and richness indices were different in two seasons. In autumn, Shannon diversity and Margalev richness indices in most of the stations were higher compare to winter. However, the values of the Simpson Diversity and the Menhinick Richness indices were higher at most stations in winter. Also, the values of qualitative (Jaccard) and quantitative (Kulczynski) similarity indices were completely different in the autumn and winter.

In autumn the stations were different in terms of qualitative and quantitative similarity indices but in winter all stations were qualitatively and quantitatively similar (100%).