Effect of urban pollutants on distribution of benthic foraminifera in the Southern of Caspian Sea

摘要

The Caspian Sea has characteristics common to both seas and lakes and listed as the world's largest lake. This study investigates recent foraminifera from sediment samples collected during spring, summer, autumn and winter 2012 from 12 stations (ranging in depths 5, 10, 20 and 50 meters) in the Southern Caspian Sea from Behshahr to Ramsar. Associated factors includes: grain size, Total phosphate, Total nitrate, total organic matter and calcium carbonate concentration were also measured. The benthic environmental factors including temperature, dissolved oxygen, salinity and pH were measured by CTD during the sampling time. Recognized benthic foraminifera species belong to 6 genera of 5 families were identified. Eleven benthic foraminifer's taxa were identified from the samples. They were Ammonia beccarii caspica, Ammonia tepida, Ammonia parkinsoniana, Elphidium littorale caspicus, Elphidium excuavatum, Criboelphidium sp., Ammobaculites agglutinans, Ammotium sp., Miliammina fusca, Milliammina sp. and Cornuspira sp. The cosmopolitan Ammonia beccarii caspica was common in the studied area. The density of benthic foraminifera is significantly correlated with seasons, the highest density being observed in winter, most density of foraminifera was observed in Babolsar stations that showed a good situation for living there and we can use foraminifera such as bioindicator for pollutant area.