WATER QUALITY TRENDS AND ISSUES, EMPHASIZING TAMPA BAY 
Ernest D. Estevez 
Mote Marine Laboratory 
Sarasota, Florida 
INTRODUCTION 
Modern reports of water quality in Tampa Bay go back 150 years, in 
the form of accounts of red tides, fish kills due to freezes, and mass 
mortalities of bay life caused by heavy rains and runoff. Even earlier 
records of water quality may be read in the shell middens created by 
prehistoric humans, by the seasonality of deposits, identity and size of 
shelled animals, or their microscopic or chemical structure. In this 
paper, I shall review a much more recent collection of facts about Tampa 
and Sarasota Bays, actually just more than one decade’s worth, to fulfill 
NOAA’s request that readers might learn (from existing information) 
something about overall water quality in the bays, and ongoing or new 
issues or management programs related thereto. 
The water quality of Tampa and Sarasota Bays is rather well-known 
but poorly understood because the underlying chemistry and biology which 
control water quality have received scant attention. Water quality 
refers to measurable comparisons to specific standards or designated 
uses, and in a more general way includes parameters associated with 
violations or loss of use, although their direct, mechanistic link to an 
impact is unclear. For example, Florida has no specific standard for 
nitrogen and excess nitrogen does not impair human contact or use, j)er 
se, but nitrogen’s known origin in effluent and runoff and role as a 
stimulant of phytoplankton blooms cause it to be monitored as an 
indicator of water quality. 
The statement that local water quality is well known is true in 
the following senses but with certain qualifications. Compared to other 
estuaries of the nation, Tampa Bay’s continuous monitoring program is 
relatively mature (16 years). The program covers the entire bay and 
tributaries, although very shallow areas are probably under-represented. 
Quality control has been above average although a change in analytical 
technique for nitrogen prevents meaningful trend analyses. There is also 
a feeling among bay area scientists and resource managers that the very 
large data base is not being utilized fully to understand processes 
controlling water quality, such as weather, runoff, circulation, and 
biological interactions. 
Nevertheless, the general water quality monitoring program in 
Tampa Bay is a facet of resource management deserving national attention. 
The program was begun in 1972 by the Hillsborough County Environmental 
Protection Commission (HCEPC) and covers all of Tampa Bay, even the 
waters of Pinellas and Manatee Counties (which have not assisted HCEPC 
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