RAFT CULTURE OF OYSTERS IN MASSACHUSETTS 



487 



storm. In November 1958, tlie Mill Creek oysters 

 were removed from the raft and planted on the 

 bottom. Here they remained until November 1959, 

 when most of them were sold. 



ASSEMBLING THE STRINGS OF OYSTERS 



To each stai)le on the log was attaclied a 5-foot, 

 #14 galvanized wire that had been previouslj' 

 strung with scallop and oyster shells'with 5 or 

 more young oysters attaclied to each. Before 

 stringing the shells, a hole was punched through 

 each one using a tack hannner with a punch bi'azed 

 to one end (tig. 7). P'acli string contained ap- 



fi-om both the Wareham River and Mill Creek 

 strings (tig. 8). Tlie oystei-s were cleaned, taking 

 care not to damage the new shell. They were then 



Figure 7. — Hammer used to punch holes in shells. 



proximately 20 pairs of shells, the pairs being 

 separated l)y a 3-inch piece of plastic tubing. A 

 total of 191 strings were suspended in 1956 and an 

 additional 19'2 were hung in 1957. After the 1958 

 storm the total number of strings was reduced to 

 182. 



DETERMINING SHELL GROWTH AND OYSTER 

 MORTALITY 



Increments of shell growth were noted at 

 monthly intervals. The shell dimensions selected 

 were the height (greatest dorso ventral distance) 

 and length (greatest anteroposterior distance) ; 

 other measurements such as total volume, total 

 weight, and weight of meat were not taken be- 

 cause the oysters could not be killed during this 

 study without destroying tlie commercial aspects 

 of the ex])erimeiit, e.g., the determination of the 

 total number of l)usliels tliat can be harvested from 

 a log raft. 



The ])roceduie of measuring oysters was as 

 follows: Approximately 100 oysters were taken 



Figure 8. — Left, 19.">T Mill Creek set Krown on log raft 

 for one year. Right, 19.">0 Wiireham Kiver set grown on 

 log raft for two years. 



measured to the nearest 1.0 mm. with vernier 

 calipers. The same oysters were selected each 

 month in order to keep the cleaning process at 

 a mininuim. Immediately after the measurements 

 were completed, tlie two experimental groups wei-e 



