326 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
It is considered most important to complete the survey in Mobile Bay first, and then to carry it 
through Mississippi Sound to such an extent as the time will permit. 
By the term oyster bed is understood an accumulation of oysters of sufficient extent and produc- 
tiveness to permit of its being' worked with more or less profit by the customary methods of oystering. 
That any collection of oysters is entitled to be so designated may be determined by the testimony of 
the oystermen of the region, one of whom will be engaged as pilot, and by the actual examination 
of specimens obtained by tonging or by other means. All deposits of oysters, however, whether of 
workable extent or not, should be taken into consideration and be appropriately described and platted 
upon the chart. Areas of bottom suited to oyster planting and growth are generally considered to be 
such as are sufficiently firm to prevent the oysters from sinking into the bottom and at the same time 
possess sufficient cohesion to resist the shifting action of the waves, all other conditions being also 
favorable. Very soft, muddy bottoms are unsuitable, but those of a somewhat firmer consistency can 
often be rendered appropriate bj r first covering them with a layer of stones and shells, and such areas 
should be noted. In fact it will bo best to so indicate upon a chart the conditions of the bottom 
throughout the bay, where the conditions are otherwise suitable, that all of its characteristics in this 
respect may be plainly brought out. 
In connection with this subject, however, it is of prime importance to determine the density or 
salinity of the water, the observations upon which may alone be sufficient to show the unsuitableness 
for oyster growth of any portion of the bay or sound. Density and temperature observations should 
therefore be made over the entire bay and sound, to the extent of ascertaining with certainty the 
conditions of their waters in this respect in all parts during the continuance of this survey; and from 
local authorities information should be sought concerning the greater influx of fresh waters during 
freshets in rivers tributary to the bay. Officers of the United States Engineer Corps now stationed 
at Mobile may be able to furnish this information. The minimum density in which oysters are 
considered to grow to advantage in Chesapeake Bay is about 1.0100 or 1.0110. 
This survey will be regarded as in the nature of a reconnoissance, and the work should be pushed 
as rapidly as seems to you expedient. It will be best, however, to make collections of oysters from 
time to time, by means of tongs or such other methods as are available, and the specimens preserved 
for transmission to Washington. Specimens of any natural enemies of the oyster which you may 
discover or which the oystermen may point out should also be preserved for future study. 
It is not considered advisable to spend more time in those parts of the bay where oysters do not 
occur or could not be made to grow than may be regarded by you as necessary to establish those facts. 
From information now at hand it seems probable that the existing beds in the bay are confined to the 
lower part of the bay, and chiefly to the eastern and western sides. It is therefore possible that your 
work will be mostly limited to those localities, so far as the bay is concerned, and that you may be 
relieved from a detailed consideration of other parts of the bay, after they have been subjected to a 
rapid examination. 
Mate James A. Smith, United States Navy, and Mr. W. F. Hill, assistant, United States Fish 
Commission, who will be members of your party, have both had considerable experience in this 
character of oyster investigations, and they will be able to advise you as to many details which 
have not been explained in these instructions. 
It is requested that the results of the investigation be presented in the form of a chart and 
descriptive report suitable for publication. The chart should show, by means of colors, the distribution 
of oysters in the bay andsound (their relative abundance being indicated by differences in intensity of 
coloring), the areas of bottom suitable for oyster-planting, and all other areas which may be considered 
as offering no opportunity or advantages for oyster growth. 
METHODS USED AND SUMMARY OF WORK. 
The areas and location of the oyster beds were determined by the ordinary 
methods in use in bydrogra-phic surveying. A chart projection of the locality to be 
examined was obtained from the Coast and Geodetic Survey before starting for the 
held. On this projection there had been platted triangulation points, shore lines, and 
other data from Coast Survey records. Upon arrival in the field some of the triangu- 
lation points were found and signals erected thereon ; and such additional intermediate 
signals as were needed were put up and located by triangulation (sextant). In the 
