for a station 15 miles above the river mouth are presented in Table 2. 
This station is about four miles upstream of the maximum penetration of 
brackish water during the dry season and represents the majority of 
inflow to the lower river and Tampa Bay from the watershed. Water 
quality at this station is similar to the upstream reaches, except for 
nitrate concentrations which are markedly greater downstream. The most 
common water quality problem in the Little Manatee River is periodic high 
counts of coliform bacteria. Low fecal coliform to fecal streptococcus 
ratios indicate non human contamination, possibly from feedlots, dairies, 
or fish farms (see Drew et al. in review). 
Although nutrient levels in this river are somewhat elevated and 
significant withdrawals are taken from the river by a local power plant, 
the Little Manatee probably best represents the natural ecological 
interactions of a river and its watershed with Tampa Bay. For that 
reason, the Little Manatee River will be the subject of investigation for 
the next two years in a study supported by NOAA’s coastal grants program 
locally administered by the Florida Department of Environmental 
Regulation. This study will examine runoff (streamflow) quantity and 
quality at several sub-basins within the watershed and compare these to 
land use, soils, vegetation and topography in each sub-basin. In the 
estuary the response of fish, zooplankton, phytoplankton, salinity, water 
chemistry and limiting nutrient conditions will be related to seasonal 
changes in freshwater inflow. It is hoped that this study will enable 
local planners and resource managers to better evaluate the impacts of 
human activities in a watershed to its receiving estuary and, therefore, 
approach the goals of estuarine management from a basin-wide perspective. 
Manatee River 
The drainage basin for the Manatee River is primarily in range 
(41%) and agricultural (38%) land uses. The lower portion of the river, 
however, is heavily urbanized as it flows between the adjacent cities of 
Palmetto and Bradenton. The river is impounded for municipal water 
supply 24 miles above its mouth. Water quality in the upper river above 
the reservoir is generally good, but periodic high levels of phosphorus, 
ammonia and coliform bacteria, however, indicate that agricultural runoff 
is a significant nutrient source. Water quality data from the Manatee 
River reservoir serves as the most downstream station above the lower 
river. Based on the limited data presented in Table 2, reservoir water 
is higher in nitrogen species and organic color than that of the upper 
river. 
Below the dam, Gamble Creek and the Braden River are the major 
tributaries to the river. Gamble Creek experiences high concentrations 
of nutrients and coliforms after heavy rains apparently due to 
pastureland runoff. The Braden River is the largest tributary to the 
Manatee, and its basin is largely in agriculture -- mainly range, 
improved pasture, and cropland. The Braden enters the Manatee 8 miles 
above its mouth, and similarly is impounded for municipal water supply. 
Downstream of the dam the Braden River is estuarine, with salinities 
40 
