Lake Peipsi phytoplankton samples (1962-2018) - methods and comments
In the course of time, beginning from the 1960s, methods of sampling, counting and microscoping have changed. More complete handbooks have become available and most importantly, inexperienced students have gradually developed into specialists. Many determinations of species have been questioned several decades later. Important changes in counting methods took place in 1999 when the invert microscope was taken into use and the Utermöhl (1958) method was introduced. A large number of tiny unicellular organisms became visible and enumerated. Macroscopic colonies of Gloeotrichia echinulata were enumerated visually in 500 ml measuring cylinder.