State of zooplankton species in the southwestern Caspian Sea, off Anzali

Zooplankton is one of the best foods with high quality for transfer energy in the food web, they are as biological pump which transfer Co2 from surface layers to the deep waters for fishes. The zooplankton species changed striking after ctenophores invasion in 2001 and during two decades. This study performed seasonal at 4 stations (5, 10, 20 and 50 m depths) in the coasts of Anzali in the Caspian Sea, during 1996 and 2001-2013. A total of 71 zooplankton taxa were identified in the southwestern Caspian Sea. The fifty six of them were holoplankton taxa and fifteen were meroplankton taxa. In zooplankton taxa, 14 genera and species were belonged Rotatoria taxa indicated the influence of the Anzali wetland and river inflows. The funding showed, many of zooplankton native species disappeared between 2001 and 2013, while meroplankton groups as Nematoda, Olighcheata and Polycheata were increased in the sea. Climate changes, man-made and alien species could play on the zooplankton species variations in the southwestern Caspian Sea.