REPORT OF COMMISSIONER OF FISH AND FISHERIES. 123 



During the years 1878 aucl 1879, Lieut. Francis Winslow, U. S. Navy, 

 tlieu attached to tiie IT. S. Coast and Geodetic Survey, made a very 

 detailed study of the oyster bottom in Tangier and I'ocomoke sounds, in 

 the course of which he determined accurately the positions and outlines 

 of all the oyster beds and calculatod the number of living oysters 

 upon them to the square yard. The small ])roportion of live oysters 

 to the quantity of dead shells and other debris, which he discovered 

 to exist, occasioned much surprise, and also furnished tangible proof 

 of the gradual depletion of the beds tlirough overlishing. A few years 

 later Prof. W. K. Brooks, of Johns Hopkins University, made a second 

 but less exhaustive examination of the same ground. 



The plans for the present survey and the methods to be pursued in 

 executing them were based upon those of Lieut. Winslow, but with 

 some changes and additions. Besides the customary liydrographic 

 and physical observations, the outlines of all the natural oyster-beds 

 or ''rocks" and of the areas of scattered oysters are to be. accurately 

 determined, and also the characteristics of the entire bottom not occu- 

 pied by oysters. The following are among the principal facts to be 

 ascertained regarding the condition of the beds and of the oyster crop: 

 The number of oysters of different sizes and the relative quantity of 

 debris to the square yard, and also the composition of the latter; the 

 abundance and distribution of the set of spat with reference to the 

 physical conditions of the water; the size at which oysters begin to 

 spawn, the limits of the spawning season, and the proportion of ripe 

 spawners on the beds at any time ; the character and abundance of 

 natural enemies, and the general natural history of the grounds. The 

 inquiry differs entirely in character from that previously made in ^outh 

 Carolina, in that it has to deal with grounds which have long been drawn 

 upon, instead of with crude and undeveloped resources. The region 

 is a natural and typical producing district, and the information w^hich 

 it is exi^ected to obtain from the work now in progress will be sug- 

 gestive in regard to future surveys on any part of the coast. The States 

 directly interested in the investigation, Maryland and Virginia, are 

 chiefly concerned to know the conditions of their grounds and the 

 manner in which they may be extended and enriched, and also to 

 obtain the necessary data on which to base a standard of production 

 for defining the natural or public beds in case the present movement to 

 permit the lease of oyster bottom to private parties shall be carried out. 



Mr. John D. Battle has acted as chief assistant in connection with 

 the liydrographic work, and has also been in charge of the observations 

 upon the material obtained by dredging, while special biological sub- 

 jects have been atten<led to by j\Ir. J. Percy Moore, of the University 

 of Pennsylvania. Much delay was occasioned in the beginning from 

 the fact that nearly all of the origiiml triangulation points established 

 in this region by the Coast Survey had disa])pearcd, and the shore lines 

 had also been greatly mcKlified by the actiiui of the currents since the 



