LINDALL, HALL, and SALOMAN: CONDITIONS OF UPLAND CANALS 



mesh body fitted with a 0.6-cm mesh inner liner 

 in the cod end. No suitable control station for 

 trawling was established in the adjacent bayou 

 because of numerous snags and oyster beds. 

 Specimens from the trawl were killed in a 10% 

 Formalin-seawater solution and transferred to 

 50 "^r isopropyl alcohol for preservation. All spec- 

 imens Avere identified to species and enumerated. 



RESULTS 



TEMPERATURE 



Only small diflferences were recorded between 

 surface and bottom water temperature at canal 

 stations or the control station in any sampling 

 period (Table 1). With few exceptions, bottom 

 temperatures were slightly lower than surface 

 temperatures in all months except July and Au- 



gust 1971 when the situation was reversed. The 

 greatest difference observed was at Station 4 

 in February when bottom temperature was 1.8°C 

 lower than temperature at the surface. 



SALINITY 



Drought conditions prevailed throughout the 

 Tampa Bay area during most of the study period, 

 and, as a result, salinity rose almost steadily 

 from 2S.2'/i, in August 1970 to greater than 

 30.0:^, by July 1971 (Table 1). During this 

 period salinity at the control station was similar 

 to that in the canals. Heavy rains in August 

 1971 reduced salinity values considerably. This 

 was the only time during the study when strat- 

 ification occurred at all stations. Bottom sa- 

 linity at the control station was 9.0//^ higher than 



Table 1. — Monthly hydrologic measurements of surface and bottom water, August 1970-August 1971. 



157 



