visited. In 1985, a series of stations running from the center 

 of Jordan Basin to the northeast towards the Bay of Fundy were to 

 be sampled. Unfortunately, weather limited the available dive 

 time and forced diving operations inshore toward the Nova Scotian 

 coast after only three stations were sampled. 



Sediment types are also shown in Figure 1. From one to 

 seven sediment samples were collected to characterize each site 

 for surficial grain size. The analyses were done by the U.S. 

 Geological Survey. The general sediment pattern, as shown in the 

 figure, is a gradation of course to fine sediments. Georges 

 Basin is, generally, sandy along its midsection changing into a 

 gravelly area towards the swell. Jordan Basin, which is north of 

 Georges Basin, is dominated by the finer silts and clays. 



In total, 5714 color photographs (35mm slides) were 

 examined from the 29 submersible dives. Over twenty seven 

 thousand individual organisms were counted. The overall 

 taxonomic ranking is shown in Figure 2, based on percentage of 

 the total numbers observed, for the top 18 taxonomically distinct 

 groups. These 18 groups represent 96% of all the organisms 

 counted. From the figure, it is clear that there are only five 

 dominant taxa representing two phyla, the Echinodermata and the 

 Cnidaria. Ophiuroids and asteroid starfish are the dominant 

 echinoderms while mud burrowing anemones, sea pens and rock 

 anemones account for the dominant cnidarians. 



If the same data are examined on a year by year basis there 

 are, again, very few dominant groups. In addition to the 

 echinoderms and cnidarians, arthropods (pandalid shrimp) were 

 reasonably abundant in 1984 while annelid tubes occurred at the 

 stations visited in 1985 (Table 1). The year by year breakdown, 

 like the overall ranking, demonstrated a very simple picture for 

 the softer sediment macrobenthic communities in the Gulf of 

 Maine. Seven taxonomically distinct groups accounted for 97 to 

 99% of all the biota observed. 



The relation between sediment type and animal abundance is 

 shown in Figure 3. For this figure the data were summarized, on 

 a % number basis, for each substrate type. Any taxonomic group 

 that accounted for >^ 5% of all observations for any one sediment 

 type were included. As shown previously, relatively few taxa 

 dominate; only 8 groups accounted for 95% of the observations in 

 this substrate specific breakdown of the database. What is of 

 interest is the substrate specificity of the various groups. Sea 

 pens, of the genus Pennatula , occur in gravel to clayey-silt, for 

 example. They are, however, more common in clayey-silt than 

 gravel; occurring at only one gravelly station compared to ten 

 stations dominated by clayey-silt. Cerianthus , the mud burrowing 

 anemone is also not especially substrate specific. It was found 

 over the entire gradation of sandy substrates. Bolocera on the 

 other hand, is an anemone that attaches to hard, rocky, 

 substrates. Consequently, it was observed only in areas of 

 gravel and sand. 134 



