is connected to Long Island Sound through a single channel and is 

 flushed twice daily by the tide. Amount of freshwater entering the 

 marsh is small. The topography is simple enough that there is a 

 possibility of making detailed budgets of inputs and outputs of carbon 

 and other nutrients essential for life. This report describes the 

 marsh--its history, topography, vegetation, hydrology, and physical 

 dimensions--and outlines current research. At high tide, the area 

 of water is about 574,000 sq m; volume is about 880,000 cu m; salinity 

 averages 26 percent; mean tidal range is about 1.8 m. The tidal 

 pattern varies little over the year; the duration of ebb tide is 

 usually two hours longer than that of the flood due to a sill in the 

 entrance of the channel. Principal vegetation is Spartina alterniflora . 

 Details of the pond's structure and function are being accumulated to 

 the point where this estuarine marsh is one of the most thoroughly 

 known such sites in the world. Chemistry, sediments, vegetation, and 

 fish are described. (A. A.) 



Keywords: salt marshes, nutrients, Spartina alterni flora . Long 

 Island 



coastal pond. American Elsevier Publishing Company, 



Oyster Pond is a freshwater pond on the southern coast of Cape Cod. 

 This study investigates all aspects of the pond and its plant and 

 animal life. Beginning in April and continuing until November, areas 

 shallower than about one meter are partly covered by Ceratophyllum 

 demersum (coontail), Potamogeton crispus (pondweed), and P. foliosus 

 Cleafy pondweed). Also present are Zannichellia palustris (?) and 

 Xyris congdoni (?). These sessile plants probably comprise a large 

 part of the food supply that makes the pond attractive to birds. 

 During the summer period of greatest growth, masses of the plants 

 break away from the bottom and drift about the pond. Their remains are 

 found on the bottom, to which they contribute organic matter, although 

 probably less than is provided by phytoplankton. 



Little benthic animal life is present except along the pond shores. 

 In contrast, so many fishes live in the pond that their requirements 

 exceed their food supply at least seasonally, so that they have become 

 somewhat dwarfed. The base of the food pyramid for all animals is 

 the very abundant planktonic algae that impart a light green color 

 to the water and that have an annual primary productivity of about 

 400 gm of carbon per square meter per year. Most of this organic 

 carbon is oxidized to carbon dioxide through respiration by the 

 plants and animals that live in the pond. Somewhat less than 10 

 percent of it is carried to the ocean within the overflowing water 

 from the pond, and a bit more than 10 percent of it is buried in the 

 bottom sediment each year. Because of the high productivity and the 



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