Plate V 



1. Sewage organisms present in l/50th 

 mussel from the Preston Channel 

 near No. 2 Perch on the training 

 wall. 



2. Sewage organisms present in l/50th 

 mussel from the Dovey estuary. 



3. Sewage organisms present in ice of 

 water from the Preston Channel 

 near No. 2 Perch on the training 



wall. 



