Cladocera abundance from sediment cores (2008-2011) from six lakes of Sierra Nevada Mountains (Spain)

This dataset presents relative abundance data of subfossil cladoceran remains obtained from sediment cores retrieved from six lakes at Sierra Nevada Mountains (Granada, Spain) during 2008 and 2011. The files show data over the past 180 years approximately. Sediment cores were taken from the deepest part of the lake by a slide-hammer gravity corer (Aquatic Research Instruments, USA), with a 6.9 cm inner diameter during the summer of 2011, except for Río Seco Lake core which was sampled in 2008. The cores were sectioned on-site into 0.25 cm thick layers for the upper sections of the cores and into 0.5 cm intervals for the remainder of the cores, except for Río Seco Lake core which was sectioned at 0.5 cm contiguous intervals for the entire core length. Sediment cores were dated using gamma spectrometry (DSPec, Ortec®) techniques by measuring activities of radioisotopes (210Pb, 214Bi and 137Cs) and sediment ages were estimated from unsupported 210Pb activities using the constant rate of supply (CRS) model. Cladoceran samples were processed by heating them in 10% KOH and sieved through a 38 µm mesh. The samples were mounted onto microscope slides using glycerol gelatin dyed with safranin. A minimum of 200 remains were identified and enumerated from each sediment interval under a light microscope at 200x magnification.