IV-CJ 



Hillsborough Bay, an arm of Tampa Bay, is nearly unstratified and 

 quite salty during much of the year. During high flows, however, 

 the Hillsborough River pushes the salt out of the upper part of the 

 Bay and often kills heavy growths of a salt water plant which is 

 not tolerant of fresh water. 



Some very large embayments with small ocean entrances such as 

 Pamilco Sound have very small tidal ranges, very little stratifica- 

 tion, and throughout most of their area, very weak currents 

 (Figure IV. 1.4). Only at the channels to the ocean are currents 

 strong, and there they are often extremely violent and dangerous. 

 Wastes discharged into such embayments tend to remain for long 

 periods and exert their effects in the estuary rather than movinn 

 out to sea. 



NATURAL WATER QUALITY IN THE FSTUARINE ZONE 



Estuarine water quality is the product of both land and water. From 

 the land, erosion and solution in river water bring suspended and 

 dissolved minerals, while decaying vegetation adds dissolved organic 

 material. Sea water itself contains three percent dissolved salts, 

 but negligible quantities of organic matter. 



In the estuarine zone these two different solutions meet and mix. 

 Salt concentrations range from that of the oceans to the almost 

 unmeasurable amounts present in some rivers. Where little stratification 

 exists, sea salt dominates mineral concentrations in estuarine 



