54 



Infaunal species composition of the Jonesport study sites was similar to other 

 Maine, Bay of Fundy and New England intertidal flats (Table 4-2). In a study of a number 

 of Maine flats Larsen and Doggett (1991) reported oligochaetes as the most abundant and 

 commonly occurring taxon. In fact, more than half the regional studies of intertidal infauna 

 list oligochaetes as one of the dominant taxa. While most of these smdies do not identify 

 which species are present, Commito (1987) has reported T\ benedini as the most abundant 

 species in a smdy at Bob's Cove, Maine (also in Washington County). Other taxa 

 commonly described as dominants in North Atlantic intertidal assemblages include the 

 amphipod Corophium volutator , the polychaetes Heteromastus filiformis . Nereis virens, 

 Polydora spp. and Streblospio benedicti , and the bivalves Macoma balthica and Mya 

 arenaria . All are among the Sheep Island dominants (Table 4-2). 



The very high infaunal abundances encountered during the first sampling (June 

 1990) suggest that community development was not yet complete. Typically infaunal 

 assemblages progress through a series of successional stages beginning with a community 

 composed of a few pioneering species present in extremely high abundances (e.g., Pearson 

 and Rosenberg, 1978; Rhoads and Boyer, 1982; Rhoads and Germano, 1982). This 

 assemblage consists primarily of small mbe-dwelling polychaetes or small bivalve molluscs 

 colonizing the surficial sediments. Over time the pioneering fauna are replaced by slightly 

 larger, longer-lived and deeper burrowing infauna. These later assemblages are more 

 diverse but less abundant and often include tubiculous ampeliscid amphipods and shallow- 

 dwelling bivalves (Santos and Simon, 1980). Finally, a highly diverse assemblage 

 dominated by large, long-lived, and deep-burrowing animals such as maldanid polychaetes 

 develops. Alternatively, there may be no predictable successional sequence, but simply a 

 rapid colonization by whatever taxa are present in nearby sediments (e.g., Diaz, 1994; 

 Zajac and Whitlach, 1982). 



There may also be an annual successional sequence as described by Trueblood, 

 Gallagher, and Gould (1994) in Boston Harbor. This sequence has three "stages": a spring 

 assemblage dominated by harpacticoid copepods, a spring-summer assemblage composed 

 of oligochaetes and the polychaetes Capitella sp., S^ benedicti , and P. elegans, and a fall- 

 winter assemblage dominated by R ligni . Whitlach (1977) has reported a slightly different 

 seasonal sequence with spring dominants being the amphipod C. insidiosum and the 

 polychaetes Marenzellaria viridis and Scoloplos sp. Summer dominants included S. 

 benedicti , H. filiformis , and Gemma gemma and fall- winter dominants included Mya 

 arenaria and Capitella sp. 



The high abundances encountered during the first sample period (June 1990) may 

 correspond to the pioneering stage described by Pearson and Rosenberg (1978) and Rhoads 

 and others (Rhoads and Boyer, 1982; Rhoads and Germano, 1982). Likewise, high 



Ecological Monitoring of a Constructed Intertidal Flat at Jonesport, Maine 



