■So X. J. Agricultural Experiment Statiox, Bulletin 348 



be emphasized. If the brackish water is withdrawn from the 

 marshes and kept off too continuously the salt grasses will die, their 

 deep penetrating roots will rot, the particles of soil will come closer 

 together and the surface of the marsh will lower to such an extent 

 that removal of water by pumping may become necessary. If the 

 gates are kept completely open from the first of November until the 

 end of the following March, especially if the circulatory system 

 above described is inaugurated, the strength of the salt-grass sod is 

 not likely to be impaired. 



D 



Fig. 45. Twelve-inch centrifugal pump, which was installed to drain an 



area of marsh slightly below sea level. (Photos by Hudson 



County Mosquito Extermination Commission). 



The enclosed, shrunken hut non-polluted salt marsh. The 

 second type of enclosed marsh (enclosed, shrunken but non- 

 polluted basins) must either be opened to the tides and thus covered 

 with tidal water and shoals of killifish or the water removed by 

 sluices and tide-gates supplemented by pumps. Numerous examples 

 of this type of enclosed marsh exist along the coast. The examples 



