We specialise in water plant surveys, i.e. macrophyte surveys. Jari Venetvaara and his assistants examined some 50 lakes in 1989 - 2002, drawing up more than 300 water plant transects on the basis of these. He has refined this material into the plant matrix transect method that can be used for follow-up purposes. Known as 'the Venetvaara method', it represents Finland in EU's CEN that is working on a water plant standard connected with the Water Frame Directive.