IV-361 



recreation, the most promising approach appears to be through 

 intensive monitoring of indicator organisms coupled with salinity 

 studies. 



Shellfish contamination presents another problem in that the major 

 concern is the ingestion and harboring of pathogenic enterovirus and 

 bacteria by the organism. These viruses can then be passed on to a 

 human host, especially if the shellfish are eaten raw. The relation- 

 ship between the densities of coliform indicator organisms and the 

 presence of enteroviruses is still ill-defined and needs further 

 definitive investigation to assure the adoption of rational public 

 health protecting criteria. At present shellfish closures are based 

 on wery stringent coliform bacteria concentration standards designed 

 to provide a safety factor to insure public health. 



TOXIC MATERIALS 



Among the waste products frequently introduced into the estuarine 

 environment are some directly toxic to marine organisms. Toxic 

 materials may exhibit a short catastrophic impact or a more subtle 

 long-term interference with growth and reproduction processes. The 

 end result is the creation of a biological desert in which no 

 organism can survive. 



The short-term catastrophic type of toxicity usually results from an 

 accidental spill or slug discharge of materials into the water. The 

 impact is immediate and the results are dramatic. 



