Figure 3.— Sea floor at station 5, south of Martha's Vineyard, at water depth of 59 m. Identifiable animal: northern 

 starfish, Asterias vulgaris, 16-cm. diameter. Scale bar 10 cm. long. 



The 10-cm. scale bar at the righthand side 

 of the photographs (figs. 3 - 8) is specifically 

 for reference to objects located midway be- 

 tween the foreground and background. Because 

 of the camera's perspective view, the fore- 

 ground objects are slightly larger and the 

 background objects slightly smaller than that 

 indicated by the scale bar. 



Faunal samples were collected with a stand- 

 ard New Bedford sea scallop dredge 3.3 m. wide. 

 The dredge bag was constructed of iron rings 5 

 cm. in diameter. An odometer was attached to 

 the rear of the dredge. The record of the number 

 of odometer revolutions for each tow permitted 

 a rather accurate measure of distance the 

 dredge was towed. The number of specimens in 

 the dredge samples were counted; table 2 shows 

 the calculated number of individuals, prorated 

 to 10,000 square meters of bottom area. 



DESCRIPTIONS OF BIOTOPES 

 FROM PHOTOGRAPHS 



This section gives a description of the 

 physical environment, as deduced from photo- 

 graphs, at each of the four stations studied. 



Emphasis has been placed on the composition 

 of bottom sediments and the microrelief of the 

 sediment surface. Biological and hydro- 

 graphical causes of the observed relief are 

 discussed briefly. A summary of our observa- 

 tions and conclusions concerning movements 

 of bottom water at the four study sites is 

 given at the end of this section under the 

 heading Water Movement. 



Station 5 (off Martha's Vineyard) 



Photographs (example in fig. 3) reveal a 

 slightly uneven microrelief with somewhat 

 smooth, gently rounded irregularities. Small 

 indistinct animal tracks are superimposed on 

 low mounds, ridges, and pockets. The rounded 

 contours of nearly all irregularities indicate 

 a rather high silt-clay content of the sediment. 

 Tracks and trails of crabs, gastropods, star- 

 fish, and other motile invertebrates are 

 common. These imprints are not clearly 

 discernible and rarely extend more than 1/2 

 cm. deep into the sediment, presumably be- 

 cause of the large proportion of fine particles 

 and the soft texture of the sediment. Burrows 



