UV absorption reveals mycosporine-like amino acids (MAAs) in Tatra mountain lake phytoplankton**This paper was carried out within the framework of the SatBałtyk project funded by the European Union through European Regional Development Fund, (contract No. POIG.01.01.02-22-011/09 entitled ‘The Satellite Monitoring of the Baltic Sea Environment’). Partial support for this study was also provided by the MNiSW (Ministry of Science and Higher Education) as research project N N306 066434 in 2008–2011 and also as part of the statutory Research of the Pomeranian University and IO PAN.