dredged material but to date there has been little interest in developing 

 them. Wetlands can be established under a wide range of conditions and often 

 satisfy technical, economic, and social constraints. The value of a new wet- 

 land must always be weighed against the value of habitat replaced. Therefore, 

 the desirability of wetland establishment is quite site specific and must be 

 evaluated on a case by case basis. Some coastal areas have an abundance of 

 marshes whereas other areas, e.g., southern California, have few marshes. The 

 creation of a new marsh in certain areas may be a valuable method of dredged 

 material disposal. 



According to Smith (1578), consideration of habitat development involves 

 a preliminary assessment of potential followed by a detailed evaluation of 

 feasiblity. Factors to consider include characterization of the dredged 

 material, site selection, engineering, cost of alternatives, sociopolitical 

 implications, and environmental impact. 



The following discussion of advantages of marsh creation are adapted from 

 Smith (1978) but also includes additional comments of our own or from other 

 references. 



(a) Marsh development has considerable public appeal — other disposal 

 options, such as open water or confined disposal, are meeting with increased 

 public resistance and are often unacceptable; 



(b) Desirable biological communities can be created -- early indications 

 are that artificially created marshes function similar to, and are as produc- 

 tive as, naturally created marshes. Fine-grained dredged material is very 

 productive because of its relatively high organic and nutrient content (Barko 

 et al. 1977). In many areas, marshes have been destroyed by man and artifi- 

 cially created marshes can be used to replace a portion of those lost (Palermo 

 and Zeigler 1976). 



(c) Marsh creation can be used to minimize adverse impacts — marshes 

 and other habitat lost to dredging projects can often be replaced with artifi- 

 cially created marshes. 



(d) Marsh creation is frequently a low cost option -- if the marsh is 

 created in a shallow-water, low-energy area, costs will be only slightly above 

 that of open-water disposal. Costs could be considerably less than those asso- 

 ciated with confined disposal. 



(e) Marshes can also be created by reclaiming or developing an existing 

 disposal area -- dredged material may be used to restore a miarsh that is erod- 

 ing (Environmental Laboratory 1978). 



The following discussion of problems of marsh creation are adapted from 

 Smith (1978) but also includes cur thoughts. 



(a) Availability of appropriate sites is limited -- optimum sites are in 

 shallow water, have low energy, and are located near the dredging site. If 

 long distance transport or protective dikes are required, costs will greatly 

 increase. 



43 



