LEGEND 

 00 Unllned Dffdg* Somptc 

 a Llntd Dredgt Sldlion* 

 < ) ytat Ylald Slolioni 

 PhOlarop* Sampling Ai 



2.5 12. -OS "15 ■** 7 00 0.1 



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HAMTUCK ET^ 



Figure 6.--Hard clam distribution in Nantucket Sound 



Tuckernuck Shoal -Great Point area is the 

 next most important of the three general 

 areas surveyed. It had the highest single 

 sample of the entire survey, 34.8 bushels 

 per tow. In general, hard clams were 

 spread over the entire area in relatively 

 low abundance. Most of the large catches, 

 however, were made on one rather extensive 

 bed. Of the 75 samples taken in the area, 

 87 percent contained hard clams (table 1), 

 but only 4 percent of the samples contained 

 cornmercial quantities of clams, i.e., over 

 8 bushels per tow. 



The sediments in the places of higher 

 clam concentration were principally firm 

 sand-mud mixtures. Some rocks were found 

 near the eastern tip of Tuckernuck Shoal. 

 The low concentrations of clams in the 

 center of the area were associated with soft 

 mud sediments. The shoal water near Nan- 

 tucket Island had sediments of a sand -mud 

 mixture containing some rock and shell. 



Where major population densities of 

 clams were found, the whelks, Busycon sp.. 



and moon shells, Lunatia (Polinices) heros were 

 frequently caught. In the muddy areas the 

 dredge brought up hundreds of parchment 

 \worms, Chaetopterus pergamentaceus, and their 

 tubes. 



Edgartown Area 



The Edgartown area lies in the bight 

 between Oak Bluffs and Cape Poge and is 

 the approach to Edgartown Harbor, This 

 is the least important of the three general 

 areas since the average density was 1.7 

 bushels per tow. Of the 14 samples taken 

 in this area, 86 percent contained hard 

 clams (table 1) but only 7 percent of the 

 samples contained commercial quantities 

 of clams. The major clam concentrations 

 were found north of Cape Poge in more than 

 30 feet of water. 



Clam concentrations occurred in sedi- 

 ments of sand -mud mixtures, with rocks 

 and shell in some of the samples. Whelks, 

 Busycon sp., and horseshoe crabs, Limulus 

 polyphemus, -were also found in these places. 



