Salinization due to rising temperatures and reduced hydrological inputs, and increased heatwave frequencies present an emerging threat to shallow lakes ecosystem structures and functions. Individually, both stressors reduce the richness and diversity of zooplankton species and functional traits and favour smaller bodied taxa in these ecosystems. However, the combined effect of these stressors on zooplankton grazing remains poorly understood. We conducted grazing trials with zooplankton communities from coordinated mesocosm experiments exposed to salinity (low: 4g Cl L^-1 and high: 40g Cl L^-1), and heatwaves (absent and present) in two different eco-regions (Central Anatolian Steppe and Mediterranean). Grazing experiments were performed two weeks period prior to, during, and after the application of the heatwave treatment in the mesocosms. Preliminary results show no differences in grazing rates between high and low salinity mesocosms prior to heatwave application, with heatwaves only reducing grazing rates at low salinity. These results suggest that salinity mediates the effect of heatwaves on zooplankton grazing in shallow lakes.

Primary Presenter: Sarah Hasnain, Middle East Technical University (sarah.s.hasnain@gmail.com)

Authors:

Sarah Hasnain, Middle East Technical University, Limnology Laboratory, Department of Biological Sciences, Ankara, Turkey  ()

Cihelio Alves Amorim, Middle East Technical University, Limnology Laboratory, Department of Biological Sciences, Ankara, Turkey  ()

Meryem Beklioğlu, Middle East Technical University, Limnology Laboratory, Department of Biological Sciences, Ankara, Turkey  ()

Meltem Koru, Middle East Technical University, Institute of Marine Sciences, Mersin, Turkey  ()

Gültekin Yılmaz, Middle East Technical University, Institute of Marine Sciences, Mersin, Turkey  ()

Korhan Özkan, Middle East Technical University, Institute of Marine Sciences, Mersin, Turkey  ()

Erik Jeppesen, Aarhus University, Department of Ecoscience and Artic Research Centre, Silkeborg, Denmark  ()