COLLECTION OP SEED OYSTERS 53 



waterproof cardboard 15 inches long, li/o inches wide, and %5 of an 

 inch thick. A single assembled partition collector consists of 100 

 inner closed compartments surrounded by a row of 44 partially 

 inclosed spaces, giving a total collecting surface of approximately 

 1,000 square inches. 



In Great South Bay 1,000 partitions were tested out by the Blue- 

 points Co., and the Connecticut Oyster Farms Co. tested 1,000 in 

 Milford Harbor. The partitions were coated by quickly dipping 

 them into a vat containing a mixture of quicklime, sand, and cement 

 mixed with either fresh or sea water to a consistency of thick cream. 

 After being allowed to drain, they were set aside for several days 

 until thoroughly dry. The mixtures used varied from a proportion 

 of 2 parts quicklime, 2 parts cement, and 1 part fine sand to 1 part 

 hydraulic or Portland cement, 1 part quicklime and 2 to 4 parts 

 ordinary beach sand. The coating should preferably be one-thirty- 

 second of an inch or less in thickness and of sufficient hardness and 

 strength as to make the partitions rigid enough for stacking and 

 handling. For the collectors that were planted in Great South Bay 

 in 8 feet of w^ater, a coating of equal parts cement, quicklime, and 

 sand, approximately one-thirty-second of an inch thick, was found 

 very satisfactory. For the ones that were planted in Connecticut on 

 tidal flats and exposed to wave action, the coating was made slightly 

 heavier and harder by using more cement in the mixture. The most 

 uniform coating was obtained by dipping the partitions twice in a 

 more watery mixture so as to give them two very thin coats, the 

 second of which was applied after the first had set but was still moist. 



The real value of the partitions as seed collectors depends largely 

 upon obtaining a thin, shell-like coating that will either disintegrate 

 as the spat grow or that will allow their separation from the parti- 

 tions when the set is shifted to growing grounds. In Great South 

 Bay the partitions were thrown overboard into water 6 to 8 feet deep, 

 where they settled immediately over a previously planted layer of 

 oyster shells. The shells served to hold the partitions a short distance 

 above the bottom, allowing the water to circulate through them and 

 preventing the accumulation of sediment within the compartments. 

 In a few cases where the partitions fell on hard mud bottom the 

 growth and survival of spat on the lower half of the collector were 

 considerably reduced by deposition of sediment and lack of water 

 circulation. On the lower portion of these, the spat attained an 

 average size or diameter of only one-eighth of an inch in two months, 

 while those on the upper edges reached a length of over half an inch. 

 This same condition is found in spat collected on shells in this region, 

 the ones on the lower side and edges growing very little and even- 

 tually dying, while those one-half inch or more above the bottom 

 grow very rapidly. 



An examination of the partitions during the early part of July 

 showed the attachment of a fairly uniform and heavy set ranging 

 from approximately 100 to 200 spat per square inch. The growth 

 and survival of these spat were essentially the same as that given in 

 the following figure which is' based on a study of the heavy set in 

 Milford Harbor in 1925. The curves show clearly the competition 

 between the spat in growth and survival that results in a loss of over 

 99 per cent at the end of a year. The rate of mortality is unusually 



