List-served, I was wondering if anyone has information regarding the use of algae (all families) in water quality assessments of rivers and lakes. I'm looking for a straighforward conversion between presence/dominance of a particular genera/family and what this means with regards to the water quality at this site. Basic water chemistry will be preformed analysing the basic eutrophic type variable (P, N, D.O., etc) so as to correlate with algal communities, but temporal variability may not reflect what is truly occuring in these systems. Presence of a particular assemblage may give a better representation of what shape the system is in (I hope algal assemblages take more than a flood event to change compositon). Thank you kindly for the help.