SAMPLING PROCEDURES AND 

 LABORATORY TECHNIQUES 



The study began in January 1964 and continued 

 through January 1965. The sampling consisted 

 of monthly collections of water samples near 

 the surface and bottom at 10 stations (fig. 1). 

 Station depths ranged from 1.8 to 4.6 m. Water 

 samples at all stations were collected with a 

 modified Van Dorn sampler (Van Dorn, 1957). 

 Samples for total phosphorus and inorganic 

 phosphate-phosphorus were immediately put into 

 200-mm. culture vials capped with polyethylene- 

 lined screw-caps, and quick-frozen. Samples for 

 the determination of copper and oxygen were 

 transferred into 250-ml. glass-stoppered bottles, 

 and for salinity into 113-nil. prescription bottles. 

 Water samples for the determination of iron and 

 chlorophyll were placed in polyethylene containers 

 and sterile 500-ml. Erlenmeyer flasks. 



The following physical and chemical methods of 

 analysis were employed : 



Water temperature — mercury thermometer 

 calibrated to the nearest 0.1° C. 



Salinity— Mohr-Knudsen method (Knudsen, 



1901). 

 Inorganic phosphate-phosphorus — Robinson 



and Thompson (1948) method. 

 Total phosphorus— Harvey (1948) method. 

 Total dissolved copper — Hoste, Eeckhout, 



and Gillis (1953) method. 

 Total iron— Armstrong (1957) method. 

 Dissolved oxygen — Winkler method (Jacob- 

 sen, Robinson, and Thompson, 1950). 

 Chlorophyll "a"— Richards and Thompson 

 (1952) method. 

 Samples for copper analysis were filtered, but 

 not those for total phosphorus and iron. The iron 

 and total phosphorus values represent the re- 

 spective elements in true solution and i)articulate 

 form combined. 



DISTRIBUTION OF METEOROLOGICAL, 

 HYDROLOGICAL, AND BIOLOGICAL 

 PROPERTIES 



PRECIPITATION 



Data on precipitation are from the Annual 

 vSummary of Climatological Data, 1964, pre- 

 pared by the Environmental Science Services 

 Administration, U.S. Department of Commerce. 

 Stations used were: Tampa, Hillsborough River 

 State Park, and Plant City for the Hillsborough 



FLORIDA'S WEST COAST TRIBUTARIES 



and Alafia Rivers; St. Petersburg, Parrish, and 

 Bradenton for the Little Manatee and Manatee 

 Rivers; Sarasota, Venice, and Myakka for the 

 Myakka River; Wauchula and Punta Gorda for 

 the Peace River; and Captiva Island, Fort 

 Myers, La Belle, and Moore Haven for the 

 Caloosahatchee River (fig. 1). 



From January 1964 to January 1965 the mean 

 annual precipitation was 135.1 cm. for Tampa Bay 

 and 108.2 cm. for the Charlotte Harbor-Pine 

 Island Sound area. The period July through 

 September contributed 54 percent and February 

 10.5 percent of the total precipitation. Minmium 

 and maximum mean monthly precipitation values 

 were 6.6 cm. and 267.5 cm. in the area of the 

 Hillsborough and Alafia Rivers. 



RIVER DISCHARGE 



The office of the U.S. Geological Survey, Branch 

 of Surface Water, Ocala, Fla., supplied informa- 

 tion on river discharges at seven stations (fig. 1). 

 These stations gave a combined flow of 2,566,- 

 729,830 m.3 from all rivers from January 1964 

 through January 1965 (grand total discharged). 

 Volumes of water were lughest in the Hills- 

 borough and Peace Rivers (figs. 2, 8, and 9). 

 River flow was highest in periods of heavy rainfall 

 (figs. 2-11). 



SALINITY 



Only two stations (6 and 8) possessed limnetic 

 characteristics throughout the period of study. 

 Salinities at the remaining stations ranged from 

 0.12 p.p.t. (parts per thousand) at stations 9 and 

 1 during the rainy season to 28.93 p.p.t. at station 

 4 in May just before the onset of the rainy season. 



The true temi)oral and vertical distribution of 

 saHnity cannot be assessed from these observations 

 because the samples were collected without regard 

 to tidal stage. Nevertheless, the rainfall-river dis- 

 charges and salinity showed a close inverse rela- 

 tion (figs. 2, 4, 6, and 11). At a few stations (1, 5, 

 and 10) saUnity reached 0.12 p.p.t. during, or im- 

 mediately following, periods of heavy rainfall. 



The difference in saUnity between the surface 

 and bottom at all stations varied from to 13.11 

 p.p.t. Vertical mixing was relatively good at sta- 

 tions 4, 5, 7, 9, and 10. The most pronounced 

 vertical differences of saUnity were at stations 1, 

 2, and 3, near the mouths of the Hillsborough, 

 Alafia, and Little Manatee Rivers. 



465 



