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We analysed dinoflagellate cyst assemblages in four short sediment cores, two of them dated by radionuclides, taken in the south basin of the Caspian Sea. The interpretation of the four sequences is supported by a collection of 27 lagoonal or marine surface sediment samples. A sharp increase in the biomass of the dinocyst occurs after 1967, especially owing to Lingulodinium machaerophorum. Considering nine other cores covering parts or the whole of Holocene, this species started to develop in the Caspian Sea only during the last three millennia. By analysing instrumental data and collating existing reconstructions of sea level changes over the last few millennia, we show that the main forcing of the increase of L. machaerophorum percentages and of the recent dinocyst abundance is global climate change, especially sea surface temperature increase. Sea level fluctuations likely have a minor impact. We argue that the Caspian Sea has entered the Anthropocene. [ABSTRACT FROM AUTHOR]

Abstract: Dinoflagellate cyst assemblages were analysed in four short sediment cores collected in the south Basin of the Caspian Sea for assessing environmental changes over the last few millennia. Two of these cores were dated by radionuclides. The sedimentation rate of one of them was very high, in the order of 20 mm per year. The interpretation of the four sequences is supported by a collection of 27 lagoonal or marine surface sediment samples. A sharp increase in the concentration of the dinocyst occurs after 1967, especially owing to Lingulodinium machaerophorum. Considering nine other cores covering parts or the whole of Holocene, it became clear that this species started to develop in the Caspian Sea only during the last three millennia. By analysing instrumental data and collating existing reconstructions of sea level changes over the last decades, we show that the main forcing for the recent increase of L. machaerophorum percentages and concentration is global climate change, especially sea surface temperature increase. Sea level fluctuations likely only have a minor impact. We argue that the recent increase in L. machaerophorum indicates that the Caspian Sea clearly is in the Anthropocene. [Copyright &y& Elsevier]

Abstract: Two internationally important Ramsar lagoons on the south coast of the Caspian Sea (CS) have been studied by palynology on short sediment cores for palaeoenvironmental and palaeoclimatic investigations. The sites lie within a small area of very high precipitation in a region that is otherwise dry. Vegetation surveys and geomorphological investigations have been used to provide a background to a multidisciplinary interpretation of the two sequences covering the last four centuries. In the small lagoon of Amirkola, the dense alder forested wetland has been briefly disturbed by fire, followed by the expansion of rice paddies from AD1720 to 1800. On the contrary, the terrestrial vegetation reflecting the diversity of the Hyrcanian vegetation around the lagoon of Anzali remained fairly complacent over time. The dinocyst and non-pollen palynomorph assemblages, revealing changes that have occurred in water salinity and water levels, indicate a high stand during the late Little Ice Age (LIA), from AD <1620 to 1800–1830. In Amirkola, the lagoon spit remained intact over time, whereas in Anzali it broke into barrier islands during the late LIA, which merged into a spit during the subsequent sea level drop. A high population density and infrastructure prevented renewed breaking up of the spit when sea level reached its maximum (AD1995). Similar to other sites in the region around the southern CS, these two lagoonal investigations indicate that the LIA had a higher sea level as a result of more rainfall in the drainage basin of the CS. [Copyright &y& Elsevier]