Assemblage 1. Comprises all sandy offshore banks, most 



prominently Jeffreys Ledge, Fippennies Ledge, and Platts 

 Bank; depth on top of banks about 70 m; substratum usually a 

 coarse sand with some gravel; fauna characteristically sand 

 dwellers with an abundant interstitial component. 



Assemblage 2: Comprises the rocky offshore ledges, such as 

 Cashes Ledge, Sigsbee Ridge, and Three Dory Ridge; 

 substratum either rock ridge outcrop or very large boulders, 

 often with a covering of fine sediment; fauna predominantly 

 sponges, tunicates, bryozoans, hydroids, and other solid 

 substratum dwellers; overlying water usually cold Gulf of 

 Maine Intermediate Water. 



Assemblage 3: Probably extends all along the coast of the Gulf 



of Maine in water depths less than 60 m. ; bottom waters warm 

 in summer and cold in winter; fauna rich and diverse, 

 primarily polychaetes and crustaceans; probably consists of 

 several (sub-) assemblages due to heterogeneity of 

 substratum and water conditions near shore and at mouths of 

 bays. 



Assemblage 4: Extends over the soft bottom well within the 



depths of the cold Gulf of Maine Intermediate Water, that 

 is, from 60 to 140 m; bottom sediments primarily fine muds; 

 fauna dominated by polychaetes, shrimp, and cerianthids. 



Assemblage 5: This a mixed assemblage comprising elements from 

 the cold water fauna as well as a few deeper water species 

 with broader tolerances; overlying water often a mixture of 

 Intermediate Water and Bottom Water, but generally colder 

 than 7°C most of the year; fauna sparse, diversity low, 

 dominated by a few polychaetes, with brittle stars, sea 

 pens, shrimp, and cerianthids also present. 



Assemblage 6: Comprises the fauna of the deep basins; bottom 



sediments generally very fine muds in basins but may have a 

 gravel component in the offshore morainal regions; overlying 

 water usually 7 - 8°C, with little variation; fauna shows 

 some bathyal affinities but densities are not high, 

 dominated by brittle stars and sea pens, and sporadically by 

 a tube-making amphipod. 



Assemblage 7: This is the true upper slope fauna that extends 

 into the Northeast Channel; water temperatures are always 

 above 8°C and salinities are at least 35 o/oo; sediments may 

 be either fine muds or a mixture of mud and gravel. 



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