Diversity and distribution of larval and juvenile fish in nearshore waters of the Southeastern Caspian Sea and Gorgan Bay

Abstract

Occurrence and distribution of larval and juvenile fish was investigated in nearshore waters of the southeastern Caspian Sea including the Gorgan Bay. Samples were collected during seven surveys using a fine mesh beach-seine in five sampling sites from July 2014 to June 2015. A total of 15500 individuals mostly juvenile were captured, representing 18 species from 8 families. Most juveniles belonged to Liza saliens, Atherina caspia, Neogobius pallasi and Neogobius melanostomus. The juveniles of Alburnus chalcoides, Vimba persa, Syngnathus caspius and gobies Neogobius caspius and Ponticola syrman occurred in low number (relative abundance 0.1% - 9.3%). Highest number of juveniles were caught in summer season. The occurrence of larval fish in coastal waters of southern Caspian was recorded for the first time (Atherina caspia with minimum length of 12 mm in Caspian and 9.5 mm in Gorgan Bay). In spring, early juveniles of mullet, Liza aurata, increased in the Caspian sites but they moved up to deeper waters by the end of the season. Based on results, the density of juvenile fish (specially Liza saliens) in Gorgan Bay was several times more than Caspian sites so it could be considered an important nursery ground in the region