Mean salinity values are lowest at 

 the mouth of the river and in East Bay 

 (Table ?, Figure 13). According to the 

 Venice system of brackish water 

 classification, the lower reaches of the 

 Apalachicola River constitute the limnetic 

 zone, with salinities reaching O.S parts 

 per thousand (ppt). During periods of 

 high river flow, the zone expands to 

 include East Bay and considerable portions 

 of Apalachicola Bay. Because of extreme 

 seasonal and annual variability, there are 

 no clear-cut zones that remain stable in 



the bay system. Rather, the salinity 

 gradients move through the bay area 

 according to upland runoff conditions. 

 East Bay, lying northeast of the river 

 head, is oliqohaline (O.'i-'i.O ppt) durinq 

 most of the year (Figure 13). 

 Apalachicola Bay, St, Vincent Sound, and 

 western portions of St. George Sound vary 

 between mesohaline (5-18' ppt) and 

 polyhaline (18-30 ppt) conditions, 

 depending on river flow and upland runoff 

 (Livingston 1983d). Areas near the passes 

 and in the eastern sections of St. George 



SALINITY (ppt) 



FWOuEW oiSTRiauriON or o»ia <K»n values im each uexei 



TURBIDITY (Jackson turbity units) 



FREOUENCY aSTSIBUTION Of OA'A OOINT VAIUES IN EACH LEVEL 



LEVEL L 



id^iiH 



Mm %. 000 300 600 iO£K> IIOQ TOOL: 

 Mo. TU 3X 60O tOOO 1500 2000 3500 



I I Hi Hi IB 1^1 



000 12 00 

 .2 00 1500 



15.00 

 700 



1900 2100 

 2100 2400 



DISSOLVED OXYGEN (ppm) COLOR (Pt-Co units) 



fHiO^itNCt r>iSt»<iBU*iON Oi L-iTi i.-:.!NT VA^UtS IN EACH Ltvtl 



-r---] 



QABil 



fRfOufWCY OtSTHISUTlON OF '.^ATa oOINt VALUES IN EACH LtVSl 

 LEVCL I 2_ 



Vr pe*r OOC 5 00 '5C 3 00 y ^C> 9 00 

 »o. p(n^ 500 75C eOO 850 900 iOOO 



:]diiiM 



■"li fSEQ 4 ? •> 



M.r ptco 000 2000 4QCX) 550C moO 9000 

 Moi III CO 2000 4000 5500 7000 9000 16000 



Figure 13. SYNMAP projections of average levels of salinity, dissolved oxygen, 

 turbidity, and color at permanent stations in the Apalachicola estuary, based on data 

 taken monthly from 1972-1980. 



16 



