TOTAL PHOSPHORUS 



Total phosphorus concentrations in the 

 Galveston Bay system during 1966 varied from 

 0.1 fig at/liter in East Bay to 47.5 jug at/hter in 

 Upper Galveston Bay. The lowest and highest 

 values respectively were 0.7 and 13.7 /jg at/liter 

 in 1964, and 0.3 and 17.1 ;ug at/liter in 1965. 



Comparison Between Habitats 



concentration of phosphorus in the open water 

 than in the other habitats in 1964 and 1965, 

 whereas, in 1966, phosphorus concentrations 

 were greater in the peripheral than in the 

 open-water habitat (samples were not taken in 

 the channel). Mid-Galveston Bay had a greater 

 concentration of phosphorus in the open-water 

 than in the peripheral habitat in 1966. 



Comparison Between Bay Areas 



Difference in phosphorus concentrations be- 

 tween habitats in all bay areas except East and 

 mid-Galveston Bays were not significant (Table 

 8, Figure 11). In East Bay, there was a greater 



Table 8.— Comparisons of annual mean concentrations 

 of total phosphorus between habitats within each bay 

 area in the Galveston Bay system, 1964-66. 



h 73?* 

 22, 71** 



♦ Significance level = 5%. •* Significance level = 1%. 



TniNlTT BAY 



UPPER GALVESTON BAY 



MID,GAt,VESTON BAY 

 LOITER GALVESTON BAY 



Figure 11. Mean concentrations of total phosphorus 

 by date and habitat within each bay area of the 

 Galveston Bay system, 1964-66. 



Each year concentrations of phosphorus 

 varied significantly between bay areas within 

 each habitat (Table 9). Greatest concentrations 

 were in Upper and mid-Galveston Bays and 

 lowest concentrations were in East Bay. In 

 1964 and 1965 concentrations of phosphorus 

 decreased from north to south and from west 

 to east in the bay system (Figure 12). 



Table 9.— Comparisons of annual mean concentrations 

 of total phosphorus between bay areas within each 

 habitat in the Galveston Bay system, 1964-66. 



> Sign.Ii, 

 , No dat; 



TOTAL PHOSPHORUS 

 (/iiG AT/L ) 



Figure 12. Isopleths (annual average)for total phos- 

 phorus in the Galveston Bay system. 1964-65. 



