Why the Prespa Lakes are shrinking Environmental scientists funded by the EU have investigated how to improve predictions for hydrological impacts in the southern Balkans, an area highly vulnerable to future climate change. Climate Change and Environment Food and Natural Resources © siete_vidas, Shutterstock Beautiful Prespa Lakes comprise two freshwater lakes (Great Prespa and Small Prespa) that are of major socio-economic importance to Albania, Greece and the Former Yugoslav Republic of Macedonia. A dramatic, unexplained fall in water level threatens the catchments water quality; which is particularly worrying as the lakes are a global biodiversity hotspot, with endemic fish species and populations of rare Pygmy Cormorants and Dalmation Pelicans. The EU-funded project CLIM-HYDROLAKE (Improving future projections of climate change induced hydrological responses by looking into the past: the Lake Prespa / Aliakmonas River case study in Greece) investigated climate change in the southern Balkans by studying the lakes’ catchment area. Researchers conducted a multidisciplinary study to understand present-day lake level change and obtain a paleohydrological record going back around 1 500 years. Prespa Lakes basin beach ridge sediments were used to reconstruct absolute lake level and past climates, and hydrological changes over a timescale of decades and centuries. The results enabled future climate projections to be made, which showed how the lake and wider region will respond to future climate change. Scientists proved for the first time that annual lake variability is driven by precipitation during the wet season (October to April). They also discovered that wet season precipitation and lake level variability over a several years is linked to the North Atlantic Oscillation weather phenomenon. This connection of the catchment areas with global atmospheric patterns was highly significant for dealing with future impacts and for interpreting paleo-climate records. Furthermore, the dramatic fall in lake levels between 1987 and 1995 was found to be caused by water extraction. This was made worse by a major regional drought, proving for the first time, the significant impact human activity has on lake level variability. Another key discovery with regional implications is that catchment climate changed over the past decades, with average annual rainfall showing a clear downward trend. Researchers also found a significant decrease in average annual snowfall, while droughts are increasing. CLIM-HYDROLAKE will therefore contribute to an effective agricultural adaptation plan and mitigation strategies for conserving the basin’s water resources and biodiversity. Keywords Prespa Lakes, southern Balkans, CLIM-HYDROLAKE, paleohydrological record, North Atlantic Oscillation
