32 THE OYSTER AND THE OYSTER INDUSTRY. 



ground.*^ The method of examining samples of water for numbers 

 of larvae described on page 31 was employed. It was found to be 

 possible to ascertain from day to day during the spawning season, 

 lasting, roughly, from June 5 to July 17, the number of larvae per 

 gallon of water at various representative stations in the bay. In 

 this way the points of aggregation of the greatest numbers of larvae 

 were determined and charted on the map. Beds of shells had been 

 placed at various points in the bay. The quantity of set caught on 

 the different beds substantiated predictions based on the data 

 derived from the study. The heaviest set was obtained from the 

 beds located at the points in the bay where there had been the 

 greatest accumulation of larvae. To be specific, it was found that 

 the tide caused the larvae to accumulate along the channel from 

 about Ocean Beach on Fire Island Beach to the inner United States 

 channel buoy, in the direction of Sayville, Long Island. Cultch beds 

 should be placed along this channel where the bottom is or may be 

 made suitable. 



By the use of methods such as just described the distribution of 

 oyster larv^ could be worked out for any particular region. The 

 possibilities of this procedure have been discussed above in connec- 

 tion mth the recommendation that such lines of investigation be under- 

 taken for the various oyster waters, perhaps by State authorities. 



Location ofspaioninc/ beds. — Oftentimes the catching of set depends 

 as much on the location of the spawning oysters as on the position 

 of the cultch. Both are important, and sometimes the best results 

 can be accomplished only by the providing of the proper relationship 

 between the two. Spawning beds should be placed where conditions 

 are most favorable for spawning, at the same time putting the cultch 

 at a point where the larvae from the bed will be carried back and forth 

 across it by the tides or be accumulated over it by eddies or cross 

 currents. 



For example, in Great South Bay, Long Island, which is large and 

 shallow, the oysters are placed about over the bay at various points 

 where they grow and fatten best, the catching of set from them being 

 a matter of rather secondary importance in this locality. As a 

 matter of fact one place is as favorable as another for the spawning 

 of the oysters, the bay being of fairly uniform depth and salinity. 

 As stated above, the larvae accumulate in the channel, and cultch 

 should be placed there. 



In Long Island Sound a different condition prevails. The catching 

 of set has been a large featui'e of the oyster industry there. Cultch 

 •beds were planted at greater or lesser distances offshore or in the 

 lower part of the mouths of rivers. Owing to a recent failure of the 

 set there, investigations have been made by the United States 

 Bureau of Fisheries during 1917, 1918, and 1919. It has been found 

 that in the past the bulk of the set consisted of larvae from natural 

 oyster beds in the shallow waters of bays, coves, and river mouths, 

 where the water became warm relatively early in the season and 

 the spawning occurred early enough for the larvae, carried out by 

 the currents to shell beds in deeper waters, to develop, set, and 

 acquire a fair size before the close of the short summer season 



a Churchill. E. P. Jr., and Outsell, J. S. Investigation of Oyster Larvse in Great South Bay. Forth- 

 coming report, U. S. Bureau of Fisheries. 



