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Despite these differences the constructed flat is still comparable in diversity, abundance 

 and species composition to other intertidal flats. Diversity (H') at the constructed flat was 

 well above most other North Atlantic flats (2.8-2.9), abundance was within normal ranges 

 (-30,000 animals/m"), and species composition was similar to other sites (Table 4-1; 

 Table 4-2). As previously discussed biomass and biomass composition were also within the 

 range of values measured at other New England intertidal flats (Table 4-3). 



5.0 CONCLUSIONS 



The principal conclusion from tiie monitoring effort at Sheep Island is that a 

 physically stable and biologically functional intertidal flat has been produced. A 

 commercially exploitable population of the soft-clam, Mya arenaria , has become 

 established at the constructed flat as well as a population of the bait-worm Nereis virens. 

 Within three years of construction, the infaunal community, an important source of forage 

 for both fish and shorebirds, developed to within expected values for diversity, abundance, 

 and species composition. At Beals Island, a much older constructed flat resulting from 

 intertidal disposal of dredged material, a substantial population of N. virens and a well 

 developed infaunal community were present. Neither constructed flat supported the same 

 level of total infaunal biomass found at the respective reference areas, but the measured 

 values were similar to those of other New England intertidal flats. 



Ecological Monitoring of a Constructed Intertidal Flat at Jonesport, Maine 



