Counting cells in the field?

[John A Gerrath]

Hi there,

I'm the midst of conducting a taxonomic survey of the lithic algae of the 
Niagara Escarpment with the Cliff Ecology Research Group here at Guelph and 
would like some advice on something that may just be impossible.
The taxonomy aspect of the project is going well, so we're beginning to 
plan biomass and physiology experiments for next year (or two).  We were 
wondering if anybody out there knows of an accurate or reasonably reliable 
way to measure the comparative abundance of the components of a 
micro-community (i.e. 40% Pseudopleurococcus sp., 30% Nostoc muscorum, 
10% Gloeocapsa alpina, etc.).  
These numbers may come in handy when we start measuring photosynthesis, 
etc.  You can't just count them under the microscope, can you?  This 
seems a fairly goofy way to do it, but it's what we seem to be stuck with.  
Any ideas are much appreciated.  

Thanks in advance.

John Gerrath,
Research Technician,
University of Guelph.
jagerrat at uoguelph.ca