REPORT OF COMMISSIONERS OF INLAND FISHERIES. 107 



did set, they were immediately covered over so deeply by the diggers 

 that they were destroyed. 



Another case in point was observed at Greene's Island. On the 

 east shore of this island is a long flat which in 1901 was set so thickly 

 with clams that 7,910 were counted in a single shovelful. In 1902 

 and 1903 the clams from this set were abundant, and the shore was 

 dug over continually by clammers. In 1904 the clam set was good 

 on this area, though less abundant. In 1905, however, there were a 

 few large clams, but not a single clam from the set of 1904, which 

 was so abundant, as noted above, on every other shore in the Bay. 

 The cause of this is not difficult to see. The constant digging had not 

 only buried the young clams so deeply that they were destroyed, but 

 had left the upper layers of soil loose and shifting, and no clams can 

 set under these conditions. In this case, then, the constant digging 

 has practically exterminated the clams. 



So we must be careful about concluding as to the results of digging 

 over a clam bed. It will be recalled that almost every shore has a 

 good set occasionally, and then for a few years there seems to be no 

 new set. When the clams become quite scarce again, and digging 

 ceases for a while, the set appears again. 



Summing up, then, the apparent conditions caused by digging over 

 the clams, we find that continual digging may be beneficial to a 

 clam bed by thinning out a too thickly set area and thus promoting 

 more rapid growth in those that are left; but that, on the contrary, 

 continual digging is prejudicial to a new set of clams. A sort of 

 rotation of areas, then, would seem to provide the ideal condition, 

 allowing certain undisturbed shores to start a good set, while others 

 are being dug over; and then, by changing the areas, provide for a 

 new set on the exhausted territory. That the conditions maintained 

 above seem to hold throughout the Bay is shown by the facts brought 

 out in the table below : 



