IV-560 



Toxic materials may exhibit a short catastrophic impact or a more 

 subtle long-term interference with growth and reproduction processes. 

 The end result is to create a biological desert in which no organism 

 can survive. The pesticide group is of particular concern in the 

 estuarine zone. Estuaries are the terminus for most of the major 

 river systems, and as such they tend to concentrate the waterborne 

 materials carried in by the large terrestrial drainage systems. 

 The biological magnification capability of estuarine animals 

 significantly increases the hazard and destructive potential of any 

 contributed pesticides. The ultimate damage is to stress or 

 eliminate parts of the energy conversion chain in the estuarine 

 environment. 



The addition of large quantities of heat from industrial cooling water 

 constitutes a form of pollution which must be considered. The entire 

 ecosystem may be stressed by thermal pollution . The amount of damage 

 is dependent on the resulting temperature of the environment and 

 the species composition of the biotic community. The total range of 

 detriments should be carefully considered on an individual case basis 

 before heat is released to the environment. Heat affects the 

 physical properties of water, the rates at which chemical and 

 biological reactions progress, and can kill living organisms. 



Man's activities may affect the rate at which the natural balance of 

 inflow, deposition, and outflow is reached by purposely or 



