94 



NOAA Technical Report NMFS 140 



Biomass was small, averaging only 0.01 

 g/m 2 or less, in all temperature ranges 

 (Tables 23, 24; Fig. 67). 



The frequency of occurrence of nema- 

 todes in samples in the various tempera- 

 ture ranges diminished from a high of 17%, 

 where the temperature range was narrow, 

 to zero where the temperature range was 

 20°Cor more (Table 25). 



Relation to Sediment Organic Carbon 

 Nematodes occurred onlv in the four low 

 to moderate level organic carbon content 

 classes (Tables 26, 27; Fig. 68). They were 

 most abundant (3.1/m 2 ) in sediments with 

 low organic carbon levels (0.01-0.49%) and 

 least abundant (0.4/m 2 ) at moderate car- 

 bon levels (1.5-1.99%). 



Biomass was very low (<0.()1 to only 0.02 

 g/m 2 ) in all levels of sediment organic car- 

 bon in which they were found (Tables 28, 

 29; Fig. 68). 



Frequency of occurrence in samples in 

 the four carbon content classes ranged from 

 7 to 17% (Table 30). 



Annelida 



Polvchaete worms formed a major compo- 

 nent of the benthic fauna in terms of biom- 

 ass and numbers of individuals. They were 

 present throughout the study area and 

 made up 28% of the total number of indi- 

 vidual animals and nearly 10% of the total 

 biomass (Table 3). 



Taxonomically diverse as well as abun- 

 dant, this group of organisms contributed 

 over 300 species from among approximately 

 170 genera to the New England benthic 

 fauna. 



Size differential from the smallest to the 

 largest specimen was moderate compared 

 with that for other taxa. The smallest speci- 

 mens recovered were 3 to 4 mm in length; 

 the largest were over 200 mm. Although 

 the vast majority of annelids from these 

 collections are elongate and cylindrical in 

 shape (similar to the common earthworm), 

 the species that is largest in terms of weight 

 is Aphrodita hastata, the sea mouse. It is 

 ovate in shape, ventrally flattened, convex 

 dorsally, and weighs 75 g or more. The 

 average wet weight of individual annelids 

 in the region is less than 0.05 g. A wide 



