84 REPORT OF COMMISSIONERS OF IXLAXD FISHERIES. 



are either forced entirely out of the soil or are kept from reaching a 

 proper depth, and consequently their growth is interfered with. 



Whenever the clams are covered by the tide a renewed activity 

 occurs, and the constant moving about of some in each group in their 

 efforts to burrow disturbs the whole mass of clams. This disturb- 

 ance causes the clams to draw in their siphons frequently, and thus 

 stops their feeding. Since the growth of the clam, as of most marine 

 animals, depends almost entirely on the amount of food that is 

 obtained, this disturbance amounts to considerable in retarding the 

 growth. The clams which are crowded out of the too thinly settled 

 beds, and often die in considerable numbers, have naturally a dele- 

 terious effect upon those that remain alive. 



A well-stocked bed is distinctly beneficial to the adjacent ones if it 

 is allowed to remain undisturbed through the spawning season. The 

 undisturbed spawning sets afloat millions of seed clams which the 

 tide spreads over the neighboring shores. While the Commission 

 does not take the credit, often attributed to it, of being responsible 

 for the recent large set on account of the spawn from its reserve beds, 

 yet it is quite noticeable that n, heavier set has occurred on the shores 

 in the immediate vicinity of these beds. 



The set of 1906 was very small. Some spots, as at Greene's Island, 

 where the soil was undisturbed, received a good set, as has been men- 

 tioned before. In the accompanying table is a list of the shores 

 visited in 1906, with notes on the clam sets of the previous three 

 seasons. 



