(25 mg/1 ) chlorophyll A concentration in the State. Tampa Bay was the only 

 estuary in the area with a concentration less than 5 mg/1. 



All estuaries except Hillsborough Bay and Peace River had benthic diver- 

 sity values above 3.1. Tampa Bay had the highest diversity (3.95) in central 

 Florida. Estuaries in Southwest Florida generally had average to good water 

 quality. The Hillsborough Bay and Peach River tidal zone had the poorest 

 water quality in the area. 



The most serious water quality problems are in the Greater Tampa Bay 

 area. The following discussion examines the nature and extent of the water 

 quality problems there. 



Tampa Bay is a large shallow estuary with low tidal flushing, especially 

 in the Old Tampa Bay area. The tides rarely exceed 2 ft because of a rather 

 extensive causeway system. For water quality assessment, Tampa Bay is divided 

 into East Tampa Bay, including Hillsborough Bay and the eastern half of Tampa 

 Bay proper, and West Tampa Bay including the western half of Tampa Bay from 

 the mouth northward, and Old Tampa Bay. Land use in the area adjacent to the 

 Bay is primarily urban, and major sources of pollution come from domestic 

 sewage, industrial effluents, and urban stormwater runoff from the metropoli- 

 tan areas of Tampa, St. Petersburg, Clearwater, and Bradenton. 



In Old Tampa Bay, concentrations of total phosphorus average between 0.73 

 to 0.81 mg/1, and peak at 0.91 mg/1. From this point to the entrance of Tampa 

 Bay southward, high concentrations of phosphorus are evident. A similar trend 

 is evident for concentrations of TKN, nitrate-nitrite, and fecal coliform bac- 

 teria. High dissolved oxygen concentrations and high pH are typical. 

 Although somewhat variable, macroinvertebrate diversity in Old Tampa Bay is 

 reportedly good. Violations of total and fecal coliform bacteria standards 

 are rare. Water quality in West Tampa Bay in recent years has improved. Con- 

 centrations of total phosphorus, NO3-NO2, TKN, and fecal coliform have 

 decreased substantially. This improvement in water quality is especially 

 notable where Old Tampa Bay and Hillsborough Bay meet. 



In East Tampa Bay, concentrations of total phosphorus are high and aver- 

 age about 1.4 mg/1 near Hooker Point in Hillsborough Bay, and 1.5 mg/1 in that 

 portion of Tampa Bay near the Alafia River. A similar spatial distribution 

 was shown by fecal coliform counts. High counts were recorded for the upper 

 portions near the Alafia River (677/100 to 12,500/100 ml) and low fecal coli- 

 form counts at the entrance to Tampa Bay around 109/100 to 116/100 ml. The 

 State standard of 200/100 ml for fecal coliform sometimes has been exceeded 

 occasionally in East Tampa Bay. Broad macroinvertebrate diversity was 

 reported, which suggests rather low levels of general pollution. Recent 

 studies indicate a general improvement in water quality in the East Tampa Bay, 

 particularly in the area of Hillsborough Bay. Trends suggest that water qual- 

 ity has improved throughout East Tampa Bay near the Alafia River. Water 

 quality generally appears to be good in the southern portion of East Tampa 

 Bay, and fair in the Hillsborough Bay area. The better water quality in West 

 Tampa Bay is somewhat higher than in East Tampa Bay. 



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