486 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



inches apart) was placed alonji; tlie side of eacli 

 log at vi<rht anj^les to the notches. The lojj was 

 copper-painted for protection ajjainst various 

 foiilinff and wood-boring organisms. In 1956 the 

 raft consisted of two logs; two more were added 

 in 1957. After storm-damage on January 7, 1958, 

 the raft was reduced to the original two logs. 



The raft was moored in Oyster Pond River 

 from September through November 195(i, and 

 from April through November 1957 and 1958. 

 During tlie winters of 1956 and 1957, it was moved 

 and anchored in Oyster Pond to protect it from 

 being damaged and carried away by floating ice 

 whicli occurs in the river during this period. In 

 November 1958 tiie raft was dismantled.' 



ORIGIN OF OYSTERS USED IN THE 

 EXPERIMENT 



Oysters used in tiie 1956 experiment were ob- 

 tained from a setting that took place during the 

 last week of August between the outlet of Crooked 

 River and Long Beach Point, AVareham River, 

 Mass. Several bushels of cultcli were transferred 



to Oyster Pond River, strung on galvanized wire, 

 and placed on the raft by October 5. All but 

 two strings of Wareham River oystere were 

 destroyed in the storm of January 1958. The 

 two remaining strings were kept attached to the 

 raft until November 1958, wiien tliey were re- 

 moved and taken to tlie laboratory for measure- 

 ment. 



The oysters used in the 1957 experiments came 

 from Mill Creek, a tidal outlet of Taylors Pond in 

 West Chatham, Mass., which runs for about one- 

 half mile before emptying into Nantucket Sound. 

 The creek bottom is hard sand changing to soft 

 mud near the banks. Along the length of the 

 creek are several sand bars exposed at low tide. 

 Since 1955 a local oyster grower has been catching 

 oyster spat by placing chicken-wire bags each con- 

 taining one-half bushel of shells on these bars 

 (tig. 6)''. In 1957 setting occurred around July 

 15. On August 12, samples of these oysters were 

 transferred to Oyster Pond River, and l)y A\igust 

 30 all were placed on the raft. Fortunately, only 

 a few strings of oysters were lost in the 1958 



- Shortly after the enmiilethm o£ this study a Flberglas raft 

 was designed, built, and successfully tested for growing oysters 

 off the bottom. See : Shaw (lyCO). 



" Kecent studies at Mill Creek indicate that more spat are 

 caught on shells strung on wires and hung horizontally from 

 racks than on shells placed in chicken wire bags. 



Figure 6. — Spat eoUectois in Mill Creek. 



