of higher forms. The pathways of any food web illustrate the complex inter- 

 relationship of all organisms to the environment and the fine balance that is 

 necessary to sustain life (Figure 1), Wetlands perform a valuable function in 

 pollution filtration by oxidizing organic waste and by serving as nutrient 

 "sinks", thus reducing the pollution load entering the Sound and the resulting 

 algal blooms and eutrophication. They also act as "sediment traps" for mater- 

 ials otherwise deposited in channels » However, in erosion-prone parts of bays 

 and along channels, wetlands can work in the opposite direction; if not vege- 

 tated, they can become a source of sediment » 



Wetlands also act as heavy metal sinks » When heavy metals are 

 introduced into a salt marsh situation, chelation (combining with sulfides or 

 organic molecules) may occur, followed by precipitation of the newly-formed 

 compounds. This reduces the load in the water column, but provides the aquatic 

 plants with these substances as a substrate. Several heavy metals can have a 

 deleterious effect on organisms in the estuarine environment: silver, arsenic, 

 cadmium, chromium, copper, nickel, mercury, and zinc (Table 2), 



TABLE 2, CHARACTERISTICS OF COMMON METALS OF CONCERN IN THE ESTUARINE ENVIRON- 

 MENT 1 



^National Estuarine Pollution Study, 1970. 



2 



Alexander, J.E., J. Foehrenbach, S. Fisher, and D. Sullivan, 1973. Mercury 



in striped bass and bluefish. N.Y. Fish 6^ Game Journal. 20(2) : 147- 151. 



