300 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



In deeper water the clearing up of the grounds is usually done by- 

 means of the dredge, all debris being carefully removed. This work is 

 best performed by steam, the larger planters owning vessels and the 

 smaller ones hiring them for the purpose. The work with sailboats is 

 more laborious and less rapid. 



If the bottom is firm, or if there is a firm substratum an inch or two 

 below the soft surface-layer, no further preparation is needed. When 

 there is a soft mud of some depth, however, it is absolutely necessary 

 that the surface be prepared in some way which will prevent the oysters 

 from becoming completely submerged and suft'ocated in the soft deposit. 

 This is usually done by distributing over the soft places various hard 

 substances, which, resting upon the mud, give it a firm surface upon 

 which the oysters may repose in safety. 



In France, where the lack of suitable grounds frequently requires 

 the use of very soft bottoms, this difficulty is sometimes overcome by 

 the expensive means of macadamizing the bottom with gravel and 

 clay. While this, of course, forms an excellent bottom, hard and 

 smooth, it can only be used on grounds exposed at low tide. 



American planters usually provide a firm surface by strewing oyster 

 shells, clam shells, gravel, or sand over the bottom in such (juan titles 

 as to have the desired effect. When shells or gravel are used the double 

 purpose is often served of preventing the submergence of the adult 

 oyster in the mud and offering a place of attachment for the spat. In 

 certain places sandy and gravelly material resulting from dredging for 

 harbor improvements has been utilized for this purpose, and much soft 

 bottom, before valueless, has been made to yield a profitable return to 

 the i)lanter. Such material can often be obtained at a very small cost, 

 sometimes merely for the expense of transportation to the beds. 



In surfacing, care should be exercised that the firm layer be deposited 

 uniforndy, as otherwise the muddy bottom will be exposed in places 

 and the oysters falling thereon in planting will be engulfed in the mud. 

 Plenty of material should always be used, as it is poor economy to 

 spend money for work and material which is insufficient to accomplish 

 the end sought. The exact amount necessary will depend upon the 

 character of the bottom. Where it consists of a very deep, pulpy or 

 flocculent deposit it is useless in most cases to attempt to improve it, 

 as the surfacing material will sink almost as fast as it is deposited. 

 In places perhaps this might be overcome by the French system of 

 macadamizing, but as more suitable bottom is abundant on our coast 

 such an expensive procedure would be unnecessary. 



When the bottom is properly surfaced with coarse sand or gravel it 

 does not as a riTle require another coat for four or five years. When 

 there is a rapid deposit of mud it will, of course, soon become covered 

 up, but a location where this takes place with much rapidity should 

 perhaps be better left alone, as the seed oysters are liable to sufibcation 

 by the deposit of material upon them. A strong current will prevent the 

 deposit and keep the surface scoured after it has been once prepared. 



