3. Sediments 
The bottom of Tampa Bay, especially Hillsborough Bay, exerts a 
substantial influence on water quality. Biota such as clams filter 
particulates from enormous volumes of bay water and seagrasses trap 
suspended sediment, but accumulations of fine, organic sediments play an 
even greater role by acting as sources --and sinks-- of nutrients. 
According to Ross et al. (1984), the benthos stores 84% of the carbon, 
85% of the nitrogen, and 65% of the phosphorus moving through Tampa Bay’s 
ecosystem. Preliminary estimates of flux rates are shown in Figure 14. 
The central role of sediments as a nutrient problem have caused engineers 
to propose either dredging or capping of the benthos. Others counter 
that sediment release of nutrients at high rates mean that benthic 
conditions will improve if given enough time without the heavy loadings 
which have occurred for almost a century. A detailed look at sediment- 
water interactions is given by Johansson and Squires, later in this 
report. 
Figure 14. Nutrient sources and sinks, from Ross et al. 1984. 
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