used to grade the site prior to planting. In which case, the issue of heavy 

 metal release should be resolved on a case-by-case basis. However, it is also 

 advisable to consider this issue when sizable shore stabilization projects are 

 proposed for areas with highly polluted sediments. 



c. Introducing Nuisance Species . Although most coastal marsh species are 

 highly regarded as ecologically beneficial, some are not. Common reed 

 (Phvagmites aommunis) in particular has a reputation in this country as a 

 nuisance plant. More literature is available on eradicating common reed than 

 on planting it. It is purported to be of little direct value to wildlife and 

 aggressively crowds out other desirable species. It grows in dense monotypic 

 stands often to a height of more than 3 meters, which can interrupt views of 

 the water and preclude public access. 



The introduction of nonnative species may also have negative impacts. 

 Most marsh plants are aggressive colonizers. When introduced to regions where 

 they do not occur naturally, they may spread rapidly in the absence of the 

 diseases and predators which act as biological controls in their native 

 environments. However, in their new environment they may displace species 

 which have ecological or agricultural significance. For these reasons all 

 plants recommended for planting in this report are native in the region for 

 which they have been recommended. 



d. Nutrient Pollution . The possible contribution to eutrophication 

 should be considered when the addition of nutrients to any part of an estuary 

 is contemplated. Although there are no data bearing directly on this ques- 

 tion, the following are sound reasons to believe that the judicial use of 

 fertilizers in developing marshes for shoreline erosion control is unlikely to 

 contribute significantly to the pollution load of estuaries: 



(1) The amount of nitrogen applied in a planting encompassing 

 only a small part of an estuary will be insignificant in comparison 

 with the nitrogen regularly entering that estuary from other sources 

 (agricultural, municipal, and industrial). 



(2) Little phosphorus is likely to leave the planted area because 

 of the affinity of marsh sediments for this nutrient. The planting 

 will remove and immobilize phosphorus from the estuary in succeeding 

 years. 



(3) Utilization of applied nitrogen by marsh plantings can be 

 quite efficient. Apparent recovery in aboveground growth in the year 

 of application has been as high as 50 percent, comparable to that of 

 most upland crops (Woodhouse, Seneca, and Broome, 1976). 



(4) Slow-release materials will contribute even less to the 

 estuary. 



(5) Fertilization will usually be a one season, or in rare cases, 

 a two- or three-season event. The resulting marsh will be capable of 

 immobilizing much larger quantities of pollutants every year. 



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