Zooplankton communities in Mediterranean temporary lakes: the case of saline lakes in Cyprus

Abstract

Temporary saline lakes are diverse ecosystems mostly located in arid areas. In the Mediterranean region they are among the most remarkable, but also the most threatened habitats; thus, effective management and conservation plans need to consider their special hydrological and ecological features and requirements. They are mainly fishless systems and so zooplankton is the driver of the trophic cascade. Our aim was to determine zooplankton communities' composition and biomass in seven temporary saline lakes of Cyprus and investigate their relation with environmental variables. Salinity ranged between <2 and 300 ppt and was a key factor shaping zooplankton community. In hyposaline conditions zooplankton communities exhibited higher species diversity than in meso- and hypersaline conditions. Hyposaline lakes were dominated by Arctodiaptomus salinus (Daday, 1885), Daphnia magna Straus, 1820 and Moina brachiata (Jurine, 1820) in terms of biomass, while meso- and hypersaline lakes by anostracans Artemia salina (Linnaeus, 1758) and Phallocryptus spinosus (Milne-Edwards, 1840) or M. brachiata and D. magna highlighting competition as another factor shaping the zooplankton community. We conclude that zooplankton reflects environmental pressures, such as salinity fluctuations which are closely related to water level fluctuations, in the mostly fishless Mediterranean temporary saline lakes. Moreover, salinity fluctuations should be considered a key factor for typological considerations in quality assessments, restoration and management plans in temporary saline systems since it can reflect the hydrological variations on the communities across different years and seasons by salinity gradient even for the same water body.