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fewer species than a terrestrial ecosystem might because only a few 
plants or animals can adapt to the extremes in temperature, salinity, 
and wetness that a marsh undergoes. 
Plants 
Macro plants.—Cord grass, marsh hay. 
Micro plants.—Blue-green algae, filamentous algae, green algae, phyto plankton. 
Bacteria. 
Animals 
Wildluife—Ducks,* heron,* egret,* osprey, rails,* sparrow, raccoon, deer, 
mouse, opossum, skunk. 
Fish.—Minnow,* menhaden,* flounder,* striped bass,* bluefish.* 
Insects.— Grasshoppers, mosquitos,* leaf hopper. 
Mud Dwellers.—Clams,* mussels,* snails,* sea anemones, blue crabs, worms, 
fiddler crabs,* protozoa, hermit crabs. 
Figure II. A partial listing of the flora and fauna of a Salt Marsh. An asterisk 
indicates species for which the marsh is an essential habitat. 
However, this implies that these relatively few species are free 
from their natural competitors and enemies; hence they are more 
abundant in the salt marsh than they otherwise would be. Using this 
brief description of a salt marsh as a starting point, I will now expand 
on some of the specific interrelationships that occur within the system 
and try to show how these relationships create a balance that is of 
acute importance to man. 
The primary production of a marsh is mainly accomplished by the 
marsh grasses, with secondary importance given to algae and phyto- 
plankton. The growth of marsh plants is like other plants and is 
affected by the supply of nutrients, availability of sunlight, water, 
and by temperature. Given the proper growing conditions, the plants, 
as plimary producers, synthesize inorganic materials into plant mate- 
rial that is usable to animals. The nutrients are available from the 
sediment deposits upon which the marsh is built, they are recycled 
from decayed organic matter, and are found in solution. Many 
nutrients are brought to the estuary via the river and, as a result of 
the currents caused by the mixing of fresh and saline waters, these 
nutrients are trapped and used rather than being swept out to sea. 
As previously mentioned, plant species that inhabit the marsh are 
found in certain areas, depending on the amount of wetness present. 
Cord grass, which grows as tall as 6 feet, covers the low marsh and 
the banks of tidal creeks where the soil is premanently moist. 
Salt hay grows in the upper marsh where the soil 1s drier and less 
saline. Both of these species are perennials and begin growing in the 
spring but are dormant in the winter. Together they account for 
two-thirds to three-fourths of the total production. The mud algae 
produces less material than the marsh grasses, but it is productive all 
year long and this fact makes it an important factor in the salt marsh 
ecosystem. In the summer, algae produces fastest at high tide and in 
the winter it produces fastest at low tides in order to take advantage of 
the limited warming of shallow water. The unicellular phytoplankton 
which grow suspended in the water are the least important contributors 
to the primary production of the marsh. This is due to the fact that 
the turbidity of the silty waters reduce their photosynthetic ability, 
to the fact that constant mixing by the tides keeps the population 
dispersed, and to the fact that the volume of the tital creeks is rela- 
tively small compared to the total volume of the marsh. 
