ECOLOGICAL OBSERVATION OF POOLS 

 IN THE SALT MARSHES OF NEW JERSEY 



by 



Edwin T. Moul 

 Rutgers University 



During the summer of 1950, studies were made of a series of 1 pools 

 on the salt marsh at Edge Cove, Tuckerton, New Jersey. The pools varied 

 in size from 3 to 30 feet in diameter and in depth from 0. 5 to 2 feet. Some of 

 the pools were covered wholly or partially with a mat of algae composed prin- 

 cipally of Cladophora expansa and a number of blue -greens; others were com- 

 pletely open. The temperature of the water of these pools remained high from 

 June 13th to August 16th. Salinity over the same period rose constantly to a 

 high of 56°/00 in one pool. (See tables 1 and Z). During this period there was 

 a record of only 4 inches of rain in the rain gauge at the New Jersey Shellfish 

 Houseboat Laboratory, moored in an adjacent creek. These pools were iso- 

 lated during this period from any tidal influx, as the tide gauge at the labora- 

 tory did not show the tidal rise of 2 feet required to flood the marshes at this 

 point, between June 13th and August 21st. 



Each pool showed a slightly different combination of species of plants 

 and animals, and many of these persisted through the period of rapid temper- 

 ature and salinity change, thus showing a wide range of tolerance to tempera- 

 ture and salinity. The general trend in dominance was from Cladophora and 

 other green algae in June to blue -greens, such as Oscillatoria, Rivularia, 



Lyngbya and Calothrix in August. The microflora showed a trend from diatom 

 doininance in number of individuals and species in June to a dominance of 

 dinoflagellate species and individuals in August. Pink sulfur bacteria were 

 present in some pools and frequently streaks of "red tide", caused by aggre- 

 gated dinoflagellates, were visible. Ciliates, rotifers and nematodes were 

 present in the plankton of these pools throughout the period of observation. 

 Egg reproduction in the rotifer population was greatest in August. Table 3 

 gives a composite list of the organisms present and their abundance in these 

 pools during the period of observation. 



This exploratory study of the organisms of the pools in the salt marsh 

 has lead to the isolation of some of the algae and the nutritional studies report- 

 ed below by Mr. Stanley Scher. 



Table 1 . 

 Pool #1 Located at Edge Cove, 100 feet from marsh front on Little Egg Harbor 

 - depth 1. 5 feet. Temperatures in degrees Centigrade; salinities in °/00. 



Date 6/13 6/21 7/19 8/16 10/6 10/15 



Temp, (mid-day) 35 29 35 31(mat) 18 14 



Salinity 30.6 34.1 43.5 dry -- 26.6 



Surface covered covered 0. 1 open mat white covered 



58 



