Rings proportional to number of 

 polyphosphate body occurrences 

 during period of sanripling. 



Figure 4. Outline map of Saginaw Bay, Lake Huron showing the abundance of 



algal populations containing polyphosphate bodies in different segments 



of the bay (Smith et al- 1977). Average circulation is 



counterclockwise and polyphosphate bodies are most 

 common downstream of the Saginaw River pollution source. 



178 



