492 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



A summary of the total cost of material and labor to 

 oysters follows : 



Materials : 



Two 25-foot cedar logs $30. 00 



Polyethylene tubing used for spacers ($23.75/ 



1,000 feet) 16.00 



Coiiper paint ( $7.7.5/gallon ) 15.50 



Two 50-pound nnid anchors ( $18.50/anchor) — 37. 00 



Miscellaneous (rope, peavie, .staples) 10.00 



Commercial spat (.$1..50/bushel) 30.00 



construct a 2-log raft, to prepare the strings, and to market 



Labor : ( Chatham $1..50 hourly wage) 



2 hours, cut and straighten wire $3. 00 



8 hours, cut polyethylene tubing 12. 00 



4 hours, paint and staple logs (5. 00 



36 hours, assort, put in holes, and string shells- 54. 00 



3 hours to moor raft and secure strings 4. 50 



4 hours to disassemble raft and plant oysters — 6. 00 

 16 hours to tong, cull, and pack oysters 24. 00 



Total costs for material $138. 50 



111 1959, the oystermeii at Chatham were paying 

 as miicli as $7 a bushel for Long Island oysters. 

 These oyster.s were planted in the spring to grow 

 and fatten during the summer, and were sold in 

 the fall at $11.50 a bushel, with a gross profit of 

 $4.50 a bushel. Approximately the same number 

 of bushels of oysters planted are sold because nat- 

 ural mortality balances any increase in volume re- 

 sulting from shell growth. The net profit is less 

 because the labor costs, to plant, gather, and pack 

 the oysters for market, are not known "^ and have 

 not been deducted. 



One cannot overlook the fact that the oystermen 

 at Chatham are earning $4.50 a bushel each year, 

 whereas the profit of $3.75 a bushel earned fi-om 

 raft-grown oysters require 2 yeare. Profits from 

 raft culture could be earned on a yearly basis by 

 suspending new strings of young oysters at the 

 time when the 1-year-old raft-grown oysters are 

 planted on the bottom, tlius developing a contin- 

 uous operation. 



The cost of materials in raft oyster culture may 

 be considerably reduced and the profit increased 

 if the operation were conducted on a large and 

 continuous scale. 



DISCUSSION AND RECOMMENDATIONS 



Our data show that raft -grown oysters grow 

 faster and have a higlier survival rate than those 

 kept all the time on bottom. The question arises 

 whether this faster growth and higher survival is 

 enough to warrant the extra cost for materials and 

 labor necessary for raft culture. From the find- 

 ings of these preliminary observations it appears 

 that raft-grown oyster farming may be feasible in 

 Cape Cod waters. The study should now be re- 

 peated on a larger semicommercial scale. A pilot 



« Oj-stermen working In oyster Pond River rarely employ hired 

 labor. 



Total costs for labor 109.50 



Grand total (materials and labor) $248.00 



oyster farm should be tried to ascertain the true 

 commercial practicability of raft-grown oysters in 

 Massachusetts. 



The raft used in our study was primitive and 

 could only support the weight of 32 bushels of 

 oysters. By increasing its buoyancy more oysters 

 could be attached and the yield would, therefore, 

 be greater. 



Oyster Pond River was selected as the site for 

 this study because the area was easily accessible by 

 road. Though it proved a satisfactoi-y site for 

 our experiments, this river is not suitable for raft 

 oyster culture on a commercial scale. Because 

 the river is shallow, only 5-foot strings could be 

 used. In deeper water longer strings could be 

 attached and the yield would increase considera- 

 bly. The danger of floating ice in the winter also 

 makes the river undesirable for raft culture. 



There are many salt-water ponds along the shore 

 of Cape Cod were raft culture could be established. 

 For example, Taylors Pond, West Chatham 

 (Mass.) appears suitable for this purpose. Here 

 the water is more than 9 feet in depth and there 

 is little danger of floating ice. Additional re- 

 search is necessary to locate the ponds on the Cape 

 that are suitable for raft culture, and to determine 

 their pi'oductive capacity. 



The importance of suspending an early set 

 should not be overlooked, if and when raft oyster 

 culture is conducted on a commercial scale. Our 

 observations show that marketable oysters are 

 obtained in •2'^/> years when a July set is attached 

 to the raft. On the other hand, when an August 

 set is suspended the average oyster after 21/2 years 

 is less than the 3-inch legal minimum size. It 

 would be necessary to carry these oysters for an- 

 other season. Losses inflicted by predators during 

 this time would reduce profits considerably. 



