Population 
(millions) 
Improved 
Land. (%) 
Pollen 
(oak/rogweed) 
Sedimentation 
Rote 
(cm/yr) 
Metal Load 
(cadmium p.p m) 
SAVS 
Diatoms 
Waterweed. pondweed 
wild celery obudnant 
Epiphytes ond clear water forms 
"•■ftTi-J Sv r. . —- ' ——~ l . 
Waterweed. pondweed 
sporadic, celery abundant 
Wild celery, few others 
Wild celery, 
pondweed 
Decrease in all species 
Decreased epiphytes 
Increased eutrophic forms 
All SAV 
Milfoil gone 
XZX] 
Eutrophic 
& Planktonic 
forms 
dominant 
Fishery 
Landings 
(x 10 3 tbs) 
Figure 7, EPA, 1983 
TIME HISTORY OF NORTHERN CHESAPEAKE BAY, 1600 TO 1980. An important aspect of understanding how Chesapeake Bay will respond 
to pollution is to examine the Bay's past. In the northern Bay, human activity, beginning at the top of the chart with population growth, 
has been changing waler quality since the time line began (see Appendix A for further discussion). 
29 
